From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains (GSA Field Guide 17)

From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains

edited by

Kevin R. Evans Department of Geography, Geology, and Planning Missouri State University 901 S. National Avenue Springfield, Missouri 65897 USA James S. Aber Earth Science Emporia State University Emporia, Kansas 66801 USA

Field Guide 17 3300 Penrose Place, P.O. Box 9140

Boulder, Colorado 80301-9140 USA

2010

Copyright © 2010, The Geological Society of America (GSA), Inc. All rights reserved. GSA grants permission to individual scientists to make unlimited photocopies of one or more items from this volume for noncommercial purposes advancing science or education, including classroom use. For permission to make photocopies of any item in this volume for other noncommercial, nonprofit purposes, contact The Geological Society of America. Written permission is required from GSA for all other forms of capture or reproduction of any item in the volume including, but not limited to, all types of electronic or digital scanning or other digital or manual transformation of articles or any portion thereof, such as abstracts, into computer-readable and/or transmittable form for personal or corporate use, either noncommercial or commercial, for-profit or otherwise. Send permission requests to GSA Copyright Permissions, 3300 Penrose Place, P.O. Box 9140, Boulder, Colorado 80301-9140, USA. GSA provides this and other forums for the presentation of diverse opinions and positions by scientists worldwide, regardless of their race, citizenship, gender, religion, or political viewpoint. Opinions presented in this publication do not reflect official positions of the Society. Copyright is not claimed on any material prepared wholly by government employees within the scope of their employment. Published by The Geological Society of America, Inc. 3300 Penrose Place, P.O. Box 9140, Boulder, Colorado 80301-9140, USA www.geosociety.org Printed in U.S.A. Library of Congress Cataloging-in-Publication Data From Precambrian rift volcanoes to the Mississippian Shelf margin : geological field excursions in the Ozark Mountains / edited by Kevin R. Evans and James S. Aber. p. cm. -- (The Geological Society of America field guide ; 17) Includes bibliographical references. ISBN 978-0-8137-0017-5 (pbk.) 1. Geology--Ozark Mountains. 2. Geology, Economic--Ozark Mountains. 3. Ozark Mountains Region--History. I. Evans, Kevin R. II. Aber, James S. QE78.7.F76 2010 557.67’1--dc22 2010007882 Cover: General locations of field trips held during the 2010 Joint Meeting of the North-Central and South-Central GSA Sections, 11–13 April 2010, Branson, Missouri. Triangles represent field trips not included in this guidebook. Inset: New road cuts at the Branson Regional Airport.

10 9 8 7 6 5 4 3 2 1

Contents Preface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v 1.

Route 66—Geology and legacy of mining in the Tri-state district of Missouri, Kansas, and Oklahoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 J.S. Aber, S.W. Aber, G. Manders, and R.W. Nairn

2.

Preliminary geology of the Proffit Mountain flood scour, Reynolds County, Missouri . . . . . . . . 23 C.M. Seeger and D.J. Wronkiewicz

3.

Geomorphology and paleontology of Riverbluff Cave, Springfield, Missouri . . . . . . . . . . . . . . . . 31 C.W. Rovey II, M. Forir, G. Balco, and D. Gaunt

4.

Civil War and cultural geology of southwestern Missouri, part 1: The geology of Wilson’s Creek Battlefield and the history of stone quarrying and stone use . . . . . . . . . . . . . . . . 39 J.T. Hannibal and K.R. Evans

5.

Civil War and cultural geology of southwestern Missouri, part 2: Geologic influences on the Battle of Forsyth, guerrilla activities, and post-war vigilantism. . . . . . . . . . . . . . . . . . . . . . . . 69 K.R. Evans

6.

Rift-related volcanism and karst geohydrology of the southern Ozark dome . . . . . . . . . . . . . . . . 99 G.R. Lowell, R.W. Harrison, D.J. Weary, R.C. Orndorff, J.E. Repetski, and H.A. Pierce

iii

Preface After more than 200 years of scientific investigations—since the expedition of Meriwether Lewis and William Clark (1804–1806), the travels of Henry R. Schoolcraft (1818–1819), and early reports of the Missouri Geological Survey (published ca. 1855) under State Geologist George C. Swallow, until today—the Ozark region still provides geologists with some enigmas. The complex interconnection among the Proterozoic basement, extensive development of Paleozoic sedimentary strata, structural overprinting, and the complexities of groundwater conditions and karst development gives ample evidence that we, as geologists, have barely scratched the surface in our understanding of this region. This field trip guidebook provides a glimpse of some of the more interesting aspects of Ozark geology and some innovative approaches for investigating the evolution of groundwater systems, landscape development, and the cultural and economic impact of geology on Ozark residents. In chapter one, Aber and others provide geological insight into the extraction of the world-class lead and zinc mineral accumulations in the Tri-state mining district of Kansas, Missouri, and Oklahoma, and they highlight the aftermath of unintended consequences and environmental concerns that continue to plague the area. Seeger and Wronkiewicz, in chapter two, document the Precambrian and Cambrian geology of Proffit Mountain exposed by the catastrophic reservoir-collapse and flood scour that occurred along the East Fork of the Black River in December 2005. In chapter three, Rovey and colleagues provide a synopsis of the history of sedimentation and paleomagnetic age dates at Riverbluff Cave, which contains a rich, well-preserved Pleistocene fauna. Hannibal and Evans give a historical account of the rock resources of southwestern Missouri in chapter four, and together with the subsequent article by Evans in chapter five, both give analyses of the impact of geology on two Civil War battlefields in southwestern Missouri. In chapter six, Lowell and others report on a comprehensive geologic mapping project centered along the Ozark Scenic National Riverways in south-central Missouri; they provide evidence of the connection between structure and lithology on surface and subsurface hydrology. While this volume is by no means a compendium of Ozark geology, it does provide a diverse array of topics that elucidate small parts of the geologic record of the Ozarks. Kevin R. Evans and James S. Aber

v

The Geological Society of America Field Guide 17 2010

Route 66—Geology and legacy of mining in the Tri-state district of Missouri, Kansas, and Oklahoma James S. Aber Susan W. Aber Earth Science, Emporia State University, Emporia, Kansas 66801, USA Gina Manders Earth Science, Emporia State University, Emporia, Kansas 66801, USA, and LEAD Agency, Vinita, Oklahoma 74301, USA Robert W. Nairn Center for Restoration of Ecosystems and Watersheds, School of Civil Engineering and Environmental Science, University of Oklahoma, Norman, Oklahoma 73019, USA

ABSTRACT Route 66 is among the most famous American highways of the middle twentieth century. A portion of the original Route 66 runs through southwestern Missouri, southeastern Kansas, and northeastern Oklahoma. This section of the road was intimately linked to the Tri-state region’s economic geology, namely mining lead and zinc as well as producing the fossil fuels—coal and natural gas—to smelt the ore. Mining began in the Tri-state district in the mid-nineteenth century and continued into the late twentieth century. An economic boom led to regional population growth and contributed to national development, but no environmental regulations existed during this period. The legacy of mining includes severe pollution, ruined communities, serious human-health issues, and devastated landscapes. Efforts now focus on protecting human health, reclamation of mined land, and remediation of water resources, led by federal and state agencies as well as universities and non-governmental organizations.

INTRODUCTION

southwestern Missouri, southeastern Kansas, and northeastern Oklahoma, which is the subject of this field guide (Fig. 1). This section of the road was intimately linked to the Tri-state region’s economic geology, namely mining lead and zinc as well as producing the fossil fuels—coal and natural gas—to smelt the ore. The story of how Route 66 came into being is connected largely with one man, Cyrus Stevens Avery, who became known as the “Father of Route 66.”

U.S. Highway 66, commonly called Route 66, is among the most famous American highways of the middle twentieth century. It has been called the “Mother Road” and the “Mainstreet of America” (Wallis, 2001). Linking Chicago to Los Angeles, it was one of the country’s first continuously paved, transcontinental highways. A portion of the original Route 66 runs through *[email protected]

Aber, J.S., Aber, S.W., Manders, G., and Nairn, R.W., 2010, Route 66—Geology and legacy of mining in the Tri-state district of Missouri, Kansas, and Oklahoma, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, p. 1–22, doi: 10.1130/2010.0017(01). For permission to copy, contact [email protected]. ©2010 The Geological Society of America. All rights reserved.

1

A

Figure 1. (A) Topographic map of the Tri-state mining district showing selected cities and rivers mentioned in this description of the region. Elevations range from less than 200 m (dark blue) to more than 400 m (red). Derived from digital elevation data of the Earth Resources Observation and Science Data Center, U.S. Geological Survey. (B) Space photograph of the Tri-state region with selected cities and water bodies annotated. Adapted from Gateway to Astronaut Photography of the Earth, image ID: ISS017E019415, taken 30 September 2008, http://earth.jsc.nasa.gov/.

Route 66 Avery was a successful businessman in Tulsa, Oklahoma, with interests in real estate, coal, and oil fields. He also was quite active in state and national organizations for highway development. When national highways were first considered in the early 1920s, Avery was appointed by the Secretary of Agriculture as a special consultant to lay out what became the original U.S. Highway System (Wallis, 2001). Strong political pressure came to bear immediately on proposed routes from Chicago to Los Angeles. Some favored the old Santa Fe Trail route, while others supported a more southerly path along the Butterfield Stage Line. Avery was able to establish a third highway in between, which just happened to run through his hometown, Tulsa. Highways running generally east-west were given even numbers, and the primary routes were multiples of ten—highways 20, 40, 50, etc. These “zero numbers” were taken quickly and guarded jealously by various factions, and so the number 66 was selected for Avery’s route. The number had a pleasing sound and was easy to remember. The U.S. Highway System, including Route 66, was approved officially in 1926. In that same year, lead-and-zinc ore production reached a peak in the Tri-state mining district at nearly 15 million tons (Park, 2005). The Kansas portion of Route 66 was completely paved by 1929. Within a few years, however, the Great Depression combined with recurring drought, and Route 66 became the Dust Bowl highway. Tens of thousands of people migrated from the Midwest and Great Plains to seek better lives in California. In the Tri-state mining district, attempts to unionize mine workers during the 1930s sparked strikes, demonstrations, riots, and bloodshed in Galena, Kansas. The National Guard was called out to restore peace, and Route 66 traffic had to be detoured at times (Wallis, 2001).

3

The westward movement grew after World War II, when the highway was jammed with traffic. Mickey Mantle, from Commerce, Oklahoma, got his start in the late 1940s on Route 66 playing for the Baxter Springs Whiz Kids in Kansas before signing with the New York Yankees. In the 1950s, it became apparent that Route 66 along with other federal highways could no longer support the increasing volume of cars and trucks. The interstate highway system was born in 1956, three decades after the original highway system had been approved, and gradually interstate highways were built to replace portions of Route 66. In the Tristate region, I-44 took on that role in the early 1960s, following a path slightly south of the original Route 66, thus bypassing Kansas altogether. The historic Route 66 is marked with signage across the Tri-state mining district and continues to attract many tourists to the region (Fig. 2). Several miles of the original “ribbon road” pavement are preserved south of Miami, where it is designated as an Oklahoma National Historic Landmark (Fig. 3).

A

B

Figure 2. Highway sign marking historic Route 66 in Baxter Springs, Kansas. Photograph by JSA, July 2009.

Figure 3. Route 66 “ribbon road” south of Miami, Oklahoma. The preexisting road was paved only nine feet wide to become part of the initial Route 66. The original concrete base pavement can be seen beneath an asphalt overlay with wide gravel shoulders (A). Several miles of this pavement are still open as a county road today for cars and trucks (B), but it is closed for motorcycles. Photographs by JSA, September 2009.

4

Aber et al.

HISTORY OF MINING IN THE TRI-STATE REGION Historic lead-zinc discoveries and mining in the central United States were primarily in southeastern Missouri and the Tristate region. The earliest record of lead-zinc mining was in 1742 in the so-called Old Lead Belt at Bonne Terre in southeastern Missouri (Environmental Protection Agency [EPA], 2007). The New Lead Belt or Viburnum trend, some 80 km to the southwest, has five mines still operating today with ore smelting at Herculaneum (Guberman, 2009a, 2009b). Tri-state lead ore discoveries opened as prospectors moved westward in the mid-nineteenth century. Both surface and underground mining took place in these regions, but all Tri-state mines and smelters are closed today. In the Tri-state district, mining of lead ore began in 1853 near Granby, Missouri, where production of lead was important for the Confederacy during the Civil War (see Hannibal and Evans, this volume). In the 1870s, organized mining activity migrated westward when ore was discovered in the vicinity of Joplin, Missouri, and Galena, Kansas. Also at this time, zinc production began (Clerk, 1883), and zinc surpassed lead production by 1880. Primary ore minerals were galena and sphalerite; other sulfide minerals found in the ore veins included chalcopyrite, bornite, and covellite. Rogers (1900) listed more than 40 minerals from the Tristate mining district, including several copper and zinc minerals: azurite, chrysocolla, cuprite, malachite, and smithsonite. The ore bodies were typically concentrated in relatively small, rich pockets interspersed within barren limestone and chert beds. The relative abundance of ore bodies increased upward through Mississippian strata and reached greatest abundance just below the overlying Pennsylvanian strata (Fig. 4). In most cases, galena

was concentrated near the top of each ore body with sphalerite toward the bottom (Fig. 5). The early mines were quite small and simple, often operated by just two people using only pick, shovel, and human power. Agricola, the sixteenth century mineralogist and mining expert who wrote De Re Metallica, would have found the Tri-state mines of the late nineteenth century astonishingly

A

B Figure 4. Diagram of lead-zinc ore distribution within Mississippian strata of the Tri-state mining district. The quantity of ore increases upward and reaches its maximum just below Pennsylvanian strata. The relative proportion of lead (L) and zinc (Z) minerals is indicated schematically. Sketch not to scale; adapted from Siebenthal (1915, fig. 10).

Figure 5. Sketches of lead-zinc ore bodies, as exposed during underground mining in the vicinity of Joplin, Missouri. (A) Vertical distribution of ore pockets within chert beds. Scale in feet. (B) Single, small ore pocket. Scale in inches. Galena is found at the top of individual ore bodies, and sphalerite is beneath. Adapted from Siebenthal (1915, figs. 12 and 13).

Route 66 primitive (Park, 2005). The shallow mines in the Joplin-Galena region were largely exhausted by the early 1900s. Smelting of lead and zinc ore took place where fuel was abundant. At first, zinc was set aside and lead smelted exclusively due to its demand for bullets and the ease of smelting lead in small furnaces. The increase in zinc production was dependent upon coal discoveries and coal-fired zinc smelters. Three to four tons of coal were necessary to process one ton of zinc ore; thus, it made sense to transport the ore to the fuel rather than the other way. Kansas coal mining commenced in the 1850s with early settlement. The scope of mining expanded dramatically in the 1870s to supply fuel for railroad steam locomotives and for lead and zinc smelting. The first zinc smelter was built in the Tri-state mining district at Weir, Kansas, in 1873 (Park, 2005), and nearby Pittsburg soon became the center of zinc smelting based on coal. In addition, electric power for smelting and mine operations was developed at Empire Lake where Shoal Creek joins the Spring River in southeastern Kansas. Natural gas was discovered at Iola, Kansas, in 1873, but the migration of smelting to Iola and other towns with gas did not happen until around 1900. The phenomenal rise in zinc ore and metal production in the late nineteenth and early twentieth centuries was driven by rapid urban, electrical, and industrial growth in the United States (Clark, 1970). Missouri and Kansas mines supplied zinc ore, and smelting was done mainly in southeastern Kansas. However, the Iola gas supply was largely exhausted by 1910; gas was piped from Oklahoma, and much zinc smelting was relocated again into Oklahoma to Bartlesville and nearby sites. In 1914 larger, deeper, and richer ore deposits were discovered at Picher, Oklahoma, and nearby Treece, Kansas. Nearly all mining took place in this vicinity after 1920, and additional major deposits were found after 1925. During the Great Depression, many small companies were consolidated into a few larger companies, and by 1950 the Eagle Picher Company controlled more than half of all production in the district (Park, 2005). After World War II, production gradually declined. Larger mines had ceased operating by 1957; the last small mines were closed in 1970. Total estimated lead and zinc production from the Tri-state mining district was nearly 12 million tons (Table 1). USES OF LEAD AND ZINC Lead has been known since ancient times and was among the first ores to be exploited in the colonial New World, TABLE 1. ESTIMATED LEAD AND ZINC PRODUCTION IN THE TRI-STATE MINING DISTRICT BY STATE AND OVERALL State Lead Zinc Missouri (1850–1957) 885 3619 Kansas (1876–1970) 691 2900 Oklahoma (1891–1970) 1307 5220 Overall 2883 11,739 Note: Values in thousands of short tons; based on Park (2005).

5

because of its myriad uses. In the twentieth century, Route 66 marked the beginning of popular cross-country travel with automobiles, and lead was at the forefront of this success. Lead was an additive to gasoline from the 1920s until the 1970s, small lead counterweights were added to vehicle wheels for tire balancing, and lead-acid batteries powered the vehicles. Although vehicles now run on lead-free gasoline and fewer wheels require counterweights, lead batteries still power most vehicles and account for 88% of the lead consumption in the United States (Guberman, 2009a). In the United States today, three times more lead is produced from secondary refining, mostly recycling lead batteries, than from primary refining of new lead (Guberman, 2009c). In the twenty-first century, lead continues to have many uses, ranging from ammunition to X-ray aprons and nuclear shields. Nonetheless, it is hazardous to human health when inhaled, ingested, or in contact with skin; lead concentrates in the body and can affect every organ and system, causing everything from increased blood pressure to impaired kidney and brain function. Many companies now report that their products are lead free (e.g., American Standard, 2009). Zinc, in contrast, is essential in the human body for disease resistance and wound healing. It has important pharmaceutical and cosmetic uses such as preventing sunburns and diaper rash. Zinc is used as a white pigment for paint, fire retardant, and preservative for wood. Yet more than half of all zinc produced is used for corrosion prevention, such as in galvanizing or protective coating for iron and steel. Zinc is an important alloy with copper to form brass; since 1982, a penny coin is copper-coated zinc, 97.5% zinc and 2.5% copper (Tolcin, 2009). GENERAL GEOLOGY OF THE TRI-STATE REGION Surficial geology of the Tri-state region consists primarily of Mississippian strata including limestone, cherty limestone, and chert in southwestern Missouri, northeastern Oklahoma, and the southeastern corner of Kansas. Prominent formations include the Warsaw, Burlington-Keokuk, and Reeds Spring–Elsey; Mississippian strata total about 300 m in aggregate thickness in southwestern Missouri (Fig. 6). These units are subject to considerable lateral facies changes, especially in regard to chert content. The region of Mississippian outcrop corresponds to the Ozark Plateau, specifically the Springfield Plateau sector (Thompson and Robertson, 1993; Aber and Aber, 2009). As the limestone has dissolved over millennia, chert and insoluble clay have accumulated at the surface to form leached, acidic, relatively infertile soils (Fig. 7). Caves, springs, and other karst features are ubiquitous. The Joplin-Galena vicinity is drained by the Spring River and its main tributary Shoal Creek, which carry clear water over chert gravel beds. Miami, Oklahoma, is situated at the confluence of Tar Creek and the Neosho River. Pleistocene terraces are found along most stream valleys flanking Holocene floodplains (Seevers, 1975).

6

Aber et al. To the north and west, middle Pennsylvanian rocks of the Cherokee Group unconformably overlie Mississippian strata. The unconformity is marked by paleokarst features including filled sinkholes. The Cherokee Group is composed of interbedded sandstone, siltstone, and shale with thin limestone and coal beds approximately 140 m in total thickness in southeastern Kansas (Fig. 8). These strata underlie the Cherokee Lowlands physiographic region (Aber and Aber, 2009). The most prominent structural features of the Tri-state region are northwest-trending lineaments in southwestern Missouri, namely the Chesapeake, Sac River, and Bolivar-Mansfield fault systems (Fig. 9). They are high-angle normal fault zones that display extensive brecciation, dolomite alteration, calcite veins, and conspicuous drag folds. These faults continue for 100s

Figure 6. Composite stratigraphic section for Mississippian Subsystem strata in southwestern Missouri. Adapted from Thompson (1995, fig. 25).

Figure 7. Typical exposure of Mississippian limestone overlain by several meters of residual chert and clay in the Ozark Plateau upland. Section revealed by recent U.S. Highway 71 construction near Pineville, McDonald County, Missouri. Photograph by JSA, March 2007.

Figure 8. Composite stratigraphic section for middle Pennsylvanian Subsystem Cherokee Group in southeastern Kansas. Adapted from Seevers (1975, table 2).

Route 66 of km along strike, extending from the Reelfoot Rift in northeastern Arkansas to the Midcontinent Rift in north-central Kansas. Other lineaments, such as the Seneca Graben, trend NE-SW and are clearly visible in the landscape of northeastern Oklahoma and southwestern Missouri (see Fig. 1). These fracture systems probably came into existence in the late Proterozoic with the breakup of Rodinia and were reactivated subsequently during episodes of late Paleozoic continental collision and early Mesozoic breakup of Pangaea (Thomas, 2006). Early ideas about the genesis of lead and zinc ore of the Tristate region focused on artesian groundwater flow westward from the Ozark uplift. Groundwater circulating through deep Ordovician and Cambrian strata was thought to mobilize and transport lead and zinc upward into Mississippian strata; where the water encountered the impermeable cap of Pennsylvanian shale, ore deposits were precipitated (Siebenthal, 1915). Modern interpretation involves building of the Ouachita Mountains in Arkansas and Oklahoma in the late Paleozoic, when hot, chemically active fluids were squeezed northward into the sedimentary rock sequence (Oliver, 1986). These epigenetic ore deposits were concentrated in Mississippian limestone and chert, particularly along regional faults and the unconformity with overlying Pennsylvanian shale. Thus, the major ore deposits are progressively deeper from east to west following the regional westward dip of strata. Tri-state lead-zinc ores are typical of the Mississippi Valley Type (MVT), which are found throughout the world. Leach et al. (1995) considered the Tri-state region to be among the most important MVT districts in North America.

7

GEOHYDROLOGY OF THE TRI-STATE REGION The Tri-state mining district enjoys ample precipitation, and several large rivers and perennial streams drain the region. In addition, subsurface solution of thick Mississippian limestone has created well-integrated underground drainage within cave systems. Surface and subsurface hydrology are connected via abundant sinkholes, disappearing streams, and springs. Shallow aquifers experience rapid recharge and discharge with the potential for contamination of groundwater from human activities at the surface. Groundwater is produced from alluvial aquifers of the river valleys as well as the Ozark Plateau aquifer system, comprising the Springfield Plateau and Ozark aquifers. This system consists mainly of limestone and dolostone of Mississippian, Ordovician, and Cambrian ages that outcrop in the Ozark Plateau. The bedrock dips westward beneath Pennsylvanian strata of the Cherokee Lowlands, where the aquifer becomes confined. In recent years, both quantity and quality of water from the Ozark Plateau aquifer have declined, however, because of increasing regional demand and surface pollution in the recharge area to the east. Because of these concerns, Kansas placed a moratorium on new appropriations from the aquifer in 2004, and an interagency investigation was undertaken on water quality and flow conditions. In general, groundwater changes from fresh to saline toward the west. In the recharge region of Missouri, water chemistry is typically calcium magnesium bicarbonate. Westward into Kansas, however, water chemistry changes to sodium calcium bicarbonate or sodium calcium chloride bicarbonate type (Pope et al., 2009). This transition takes place near the Missouri-Kansas border.

Figure 9. Major faults and lead-zinc mining districts of southwestern Missouri. Adapted from Thompson and Robertson (1993, fig. 10B).

8

Aber et al.

LEGACY OF MINING Mining lead and zinc ore generated a huge volume of waste rock—chat, which was simply dumped on the surface in big piles. The word “chat” is a miner’s term derived from chert, in which the main ore zones were located. No environmental regulations existed at the time. Leach et al. (1995) noted that abandoned mines and tailings piles pose serious environmental problems for ~1800 km2 in the Tri-state mining district. At the close of mining in the 1970s, more than 500 million tons of chat were left; more than three-fourths of this waste now has been removed, but ~100 million tons of chat remain in the Tri-state area (EPA, 2007). The chat piles, water-filled mines, and former smelting sites are today sources for highly polluted water that contains heavy metals. In addition to lead and zinc, mining byproducts include cadmium, germanium, and gallium (Park, 2005). Streams, lakes, and shallow aquifers of the Tri-state mining region are contaminated (Chambers et al., 2005; Juracek, 2006; Nairn et al., 2009). Coal mining in the Cherokee Lowlands also has contributed to significant local and downstream water pollution in the region (Arruda, 1992). Such contamination led to establishment of Environmental Protection Agency (EPA) superfund sites in Missouri, Kansas, and Oklahoma beginning in the early 1980s. Lead poisoning, especially for children, was a special concern. A study in 1993 found that at least one-third of Picher children had blood levels of lead that posed a risk for brain and nerve damage (New York Times, 14 September 2009). To a large extent, the former mining areas around Joplin and Galena have been reclaimed. Chat piles were removed and the material used for concrete and construction aggregate, pits and sinkholes were filled in, and the land covered and revegetated. In the final phase of mining, after the larger companies had abandoned mines, so-called “wildcat gougers” removed the pillars that had supported mine caverns, which led to widespread surface collapse. Such collapses and sinkholes continue to take place nowadays throughout the Tri-state mining district. The risk of subsidence was, in fact, the primary justification in the federal legislation for the voluntary buyout and relocation of Picher residents, although environmental contamination and human health risk certainly were recognized by local residents and Indian tribes as well as state and federal officials. Reclamation efforts are under way also in the Treece, Kansas, vicinity, where about 70 families still live. The level of environmental degradation is comparable to Picher, but Treece had been passed over for the buyout option given to Picher until quite recently. EPA received Recovery Act funds in 2009 for Cherokee County, Kansas, to support cleanup activities at Baxter Springs, Treece, and other sites for ongoing excavation, consolidation, capping, and revegetation (EPA, 2009). This work was in progress already, and extra funding should accelerate completion of the cleanup project (Fig. 10).

In August 2009, EPA administrator Lisa Jackson sent three of her top aides to review the situation; they recommended comprehensive blood testing of all residents in Treece. Median bloodlead level was 4.0 micrograms per deciliter of blood, which compares with 2.5 for the state norm, and at least one child exceeded 10, the threshold for lead poisoning (Lefler, 2009). Following this sad finding, the U.S. Congress approved and President Obama signed the 2010 Interior-Environment Appropriations bill, which included authorization for EPA to buy out and relocate residents of Treece. In her statement, Jackson said, “EPA determined that the people of Treece, Kansas faced a unique and urgent threat from the legacy of pollution in their community. EPA has determined that relocation is the primary option to address the concerns of Treece residents—just as it was in neighboring Picher, Okla.” The Treece buyout cost is estimated at $3.0 to $3.5 million (Lefler, 2009). DESCRIPTIONS OF FIELD SITES Grand Falls, Joplin, Missouri Grand Falls on Shoal Creek is reputed to be the highest perennial waterfall in the state of Missouri with a vertical drop of 15 ft (5 m) at normal flow and 25 ft (8 m) descent at high flow (Beveridge and Vineyard, 1990). The upper portion has a low dam that impounds water upstream for the city of Joplin, but this dam has little impact on the falls (Fig. 11). Some potholes are present, particularly on the eastern side, which is inundated during high water. This site is popular on hot summer days for swimming and picnicking. Those who jump off the falls must be quite careful to dive into the deepest plunge pool below. The falls are formed on resistant, massive, sheet chert beds up to 25 ft (8 m) thick at this location (Fig. 12), which is the stratotype for the Grand Falls Chert (Robertson, 1967; Thompson and Robertson, 1993; Thompson, 1995). The Grand Falls Chert is limited to the Joplin vicinity and ranges from 24 to 40 ft

Figure 10. Reclamation of mined land in progress at Treece, Kansas. Photograph by JSA, July 2009.

Route 66

9

Figure 11. Overview of Grand Falls on Shoal Creek, Joplin, Missouri. A lowwater dam runs across the top of the falls. Note person on far right. Photograph by JSA, July 2009.

(8–13 m) in thickness. It represents portions of the Reeds Spring and Elsey Formations as well as the Keokuk Limestone that have been replaced locally by chert. Lateral facies changes take place over short distances between these formations in the surroundings, and the Grand Falls Chert is discontinuous. At its type locality, it is highly fractured.

The site is best approached from the eastern side, where there is a natural parking area on top of the chert above the falls (Fig. 13). From exit 6 on I-44, take Glendale Road under the interstate highway and continue to a low-water bridge. Cross the bridge, turn north (right) on Riverside Drive, and continue to Grand Falls. Schermerhorn Park, Galena, Kansas

Figure 12. Massive chert beds exposed on the eastern side of Grand Falls, Joplin, Missouri. Water fills potholes near scene center. Parking area on top of the chert beds. Photograph by JSA, July 2009.

Located south of Galena along the northern margin of Shoal Creek, Schermerhorn Park is the best preserved Ozark terrain in the state of Kansas. Schermerhorn Park is located adjacent to Kansas highway 26, 2.2 miles south of its junction with state highway 66 (historic Route 66) at the center of Galena. The park contains picnic and swimming areas along with a small natural history museum; however, the cave is closed to the public. This region has one of the most beautiful landscapes in the state (Fig. 14), as well as some of the most serious pollution and geological hazards associated with old mines. This vicinity is underlain by thick, cherty limestone beds of Mississippian age, the Warsaw Limestone and Keokuk Limestone, totaling 250 ft (75 m) in thickness. Caves, springs, and other karst features are commonplace. The larger caves are found in the Keokuk Limestone at or near the level of valley bottoms (Young and Beard, 1993), as at Schermerhorn Park. Mining in the Galena area reached a peak in the 1890s, but shallow ores were soon exhausted, and mining migrated to deeper strata to the west from Baxter Springs to Treece and southward into Oklahoma. Although some of the ore was smelted near the mines, much was transported out of the region for smelting where fuel was abundant—coal at Pittsburg and natural gas at Iola. From a peak mining-boom population of more than 10,000 in 1900 (Clark, 1970), Galena has diminished to less than onethird that size today. The magnitude of mining in the Galena vicinity is illustrated on older topographic maps of the area (Fig. 15). Numerous tailings piles along with pitted, hummocky terrain and ponds resemble ice-stagnation topography, particularly immediately

Figure 13. Topographic map of the Grand Falls vicinity showing route (blue squares) from I-44 to the falls near the center of section 28. Adapted from Joplin West, Missouri-Kansas: U.S. Geological Survey, 1:24 000-scale, 7.5 minute series (topographic), 1962. Contour interval—10 ft (~3 m).

Figure 14. Aerial view of Ozark terrain at Schermerhorn Park, Cherokee County, Kansas. View eastward; oak-forested limestone upland to left; valley of Shoal Creek to right. Taken from Aber and Aber (2009, fig. 74).

Route 66 west and north of Galena. By the late twentieth century, the landscape had become a bleak display of chat piles, collapsed mines, and rusting machinery (Fig. 16). In the vicinity of Galena today, chat piles mostly have been removed for use as railroad ballast and construction aggregate all over the United States, and the terrain has been smoothed and revegetated. Nonetheless, several old mine shafts have collapsed in Galena recently, which dem-

11

onstrates the continuing legacy and risk of past mining for the city of Galena. Empire Lake, Riverton, Kansas Empire Lake is dammed at the confluence of the Spring River and Shoal Creek; it receives drainage from approximately 6500 km2 in southwestern Missouri and southeastern Kansas. It

Figure 15. Topographic map of the Galena, Kansas, vicinity showing the impact of lead-zinc mining on the landscape. Location of Schermerhorn Park indicated by asterisk (*); historic Route 66 marked (blue squares). Adapted from Baxter Springs, Kansas: U.S. Geological Survey, 1:24 000-scale, 7.5-minute series (topographic), 1959. Contour interval—10 ft (~3 m).

12

Aber et al.

was completed in 1905 and is owned by Empire District Electric Company; the lake provides cooling water for a coal-fired power plant at Riverton. The lake covers about 840 acres (~380 ha) and is relatively shallow owing to a century of sediment accumulation. Kansas state highway 66 (historic Route 66) crosses Empire Lake, 3 miles west of Galena (Fig. 17).

Water quality in Spring River and its tributaries is heavily impacted and degraded by runoff from abandoned mines, agricultural activities, and municipal wastewater discharge (Arruda, 1992; Davis and Schumacher, 1992; Dutnell et al., 1995). The lake appears to be a sink for phosphorus and some nitrogen (NH3-N) derived from upstream, but not for NO3-N (Chambers et al.,

A

B

C

Figure 16. Views of collapsed mines (A) and abandoned processing plants (B) on the northern edge of Galena, Kansas. Photographs courtesy of P. Johnston, 1977. (C) 1986 aerial photograph mosaic of Galena and the area immediately to the west showing extent of lead-zinc mining (light patches). Image processing by L. Lefebvre.

Route 66

13

Figure 17. Topographic map of the Galena–Baxter Springs vicinity showing Empire Lake at Riverton, Kansas. Historic Route 66 marked with blue squares. Adapted from Joplin, Missouri-Kansas: U.S. Geological Survey, 1:100 000-scale metric topographic map, 30 × 60 minute quadrangle, 1991. Contour interval—10 m.

2005). Bottom sediment of Empire Lake contains high levels of cadmium, lead, and zinc, which substantially exceed the guidelines for probable toxic biological effects (Juracek, 2006). Contaminated sediment from Empire Lake could be transported and redeposited downstream as far as Grand Lake O’ the Cherokees in Oklahoma. Big Brutus, West Mineral, Kansas The region between Pittsburg, Weir, and West Mineral in Cherokee and Crawford counties has been altered substantially by coal strip mining. Among several shallow coal beds in the Cherokee Group, the Weir-Pittsburg is thickest at 3–5 ft (1– 1.5 m) and was most important economically (Brady and Dutcher, 1974). All coal mining in this vicinity ceased in the late twentieth century. Big Brutus, a huge power shovel that operated in the Pittsburg and Midway mine #19 in the 1960s and 1970s near West Mineral, is an iconic symbol of the Kansas coal industry (Fig. 18). Big Brutus has been restored and is the main attraction at a mining heritage museum located one mile west and half a mile south of West Mineral (Fig. 19). To reach West Mineral, take state highway 102 west from its junction with state highway 7, and follow signs to Big Brutus. Prior to 1969, mined land was abandoned and left to overgrow with brush and trees. Those areas are marked by ridges of spoil and intervening troughs. As an experiment, trees were

planted on several thousand acres of mined land in northwestern Cherokee County in the late 1930s (Muilenburg, 1961), and these sites are now wildlife refuges known for excellent deer hunting and fishing. However, acid-water leaching from coal-mine debris, known as gob piles, has degraded surface and groundwater. In Cherry and Little Cherry creeks, immediately south of West Mineral, only the most acid-tolerant organisms have survived (Arruda, 1992). Since 1969, state law requires that mined land must be reclaimed for productive agricultural use. Picher, Oklahoma The Picher vicinity, including nearby Cardin, Oklahoma, and Treece, Kansas, experienced the most thorough mining of any region in the Tri-state district, primarily in the early and mid-twentieth century. Picher is located on U.S. Highway 69, which runs through the center of the town one mile south of the Oklahoma-Kansas border; Treece is along the border to the north, and Cardin is about one mile to the southwest (Fig. 20). Historic Route 66 passes nearby through Quapaw and Commerce, Oklahoma. Mines in this vicinity required modern methods and equipment in order to reach the deeper ore bodies below the water table. Ore was produced mainly from the Boone Formation consisting of cherty limestone and dolostone. Galena and sphalerite were the primary ore minerals along with chalcopyrite, enargite, luzonite, marcasite, pyrite, and barite (Nairn et al., 2009). The

Figure 18. Big Brutus restored at the mining heritage visitors center near West Mineral, Cherokee County, Kansas. One of the world’s two largest electric-power shovels, it stands 160 ft (50 m) tall with a working weight of 5500 tons (5000 metric tons). View looking to the northeast with West Mineral in the left background and reclaimed mined land on right side. Taken from Aber and Aber (2009, fig. 72).

Figure 19. Topographic map of the Weir– West Mineral vicinity, Cherokee County, Kansas. Location of Big Brutus indicated by asterisk (*). Reclaimed mined land shown in brown; unreclaimed mined land is dark green. Adapted from Joplin, Missouri-Kansas: U.S. Geological Survey, 1:100 000-scale metric topographic map, 30 × 60 minute quadrangle, 1991. Contour interval—10 m.

Route 66

15

Figure 20. Topographic map of the Picher-Miami, Oklahoma vicinity. Locations of Oklahoma field sites are indicated: 1—Picher chat piles, 2—passive water treatment system, 3—Tar Creek at Northeastern Oklahoma A&M College campus, 4—original Route 66 “ribbon road.” Historic Route 66 marked with blue squares. Adapted from Neosho, Missouri-Oklahoma-Kansas: U.S. Geological Survey, 1:100 000-scale metric topographic map, 30 × 60 minute quadrangle, 1986. Contour interval—20 m.

first large central mill for ore processing was constructed at Cardin in 1932. It had a capacity of 3600 tons per day, and 90% of the district’s ore was processed in such central mills by 1950 (Park, 2005). The magnitude of mining in this vicinity resulted in substantial disruption of both surface and subsurface environments (Fig. 21). Large chat piles accumulated within and around Picher and nearby mining communities (Fig. 22), and mine water was pumped at rates up to 50,000 m3 per day (Reed et al., 1955). Soon after active mining ceased, metal-laced mine water began discharging naturally in 1979 through open mine shafts, springs, and artesian wells of the vicinity. Initial minewater discharges were highly acidic; however, the water chemistry is now net alkaline with total alkalinity greater than total acidity. This discharge continues today, and dust from exposed

chat piles blows over the surrounding landscape. Among the most severely impacted streams is Tar Creek, which drains the Picher-Cardin-Treece vicinity (Fig. 23). According to the U.S. Army Corps of Engineers, “Tar Creek is highly toxic and, for all intents and purposes, dead” (USACE, 2005); however, continued stream monitoring recently has revealed the presence of some fish and macroinvertebrates. Quapaw people live in the Picher vicinity and own much of the destroyed land. Past policies of the Bureau of Indian Affairs (BIA) exacerbated the pollution problems (USACE, 2005). The situation began in the 1870s when BIA forced the Quapaws to lease their land to mining interests. Those individuals who resisted were declared incompetent, and the BIA opened the land to mining companies. Lead and zinc mining commenced in 1891 and continued until 1970. BIA policy required mining companies

Figure 21. 1938 aerial photograph mosaic of the Picher, Oklahoma–Treece, Kansas, vicinity showing extent of leadzinc mining (light patches) just prior to World War II. Image processing by L. Lefebvre.

Figure 22. Overview of chat piles at Picher, Oklahoma, as they appeared at the end of the mining era in 1977. Taken from the top of a chat pile; photograph courtesy of P. Johnston.

Figure 23. Tar Creek carries highly polluted mine runoff from the Picher-Cardin-Treece vicinity, as shown by its typical rust-orange color at low flow. View downstream just east of Commerce, Oklahoma. Photograph by JSA, July 2009.

Route 66

17

Figure 24. Panoramic aerial view over Picher, Oklahoma. Assembled from two wide-angle shots taken from a small helium blimp. Photograph by JSA and SWA, July 2009.

to leave chat piles on the land, because the chat might be of economic value, but later the Quapaw tribe was prevented from selling or removing the chat because of its hazardous nature. Thus, enormous chat piles accumulated during decades of mining, and many remain to this day (Fig. 24). EPA has designated several primarily responsible parties for the environmental debacle at Picher. Most of these are now bankrupt mining companies along with the Bureau of Indian Affairs, which illegitimately leased much of the mined land. However, the BIA refuses to take responsibility for its past actions, which creates a bureaucratic impasse between federal agencies for obtaining cleanup funding (USACE, 2005). To add further misery to this situation, an EF-4 tornado struck Picher on 10 May 2008. Six people died, and 20 city blocks were destroyed by the mile-wide twister (Fig. 25). The tornado even removed portions of some chat piles, spreading contaminated dust and debris over the area. As a result, EPA accelerated

Figure 25. Aerial view of tornado damage in Picher, Oklahoma. Note lack of trees and buildings; part of chat pile in right background was removed by the tornado. Helium-blimp photograph by SWA and JSA, July 2009.

plans to close Picher, and many people had no choice but to move out. Nearly all buildings are condemned or already removed, and few businesses or governmental services remain. From a population of some 20,000 people during its mining peak, Picher now has become a virtual ghost town. It ceased to exist officially on 1 September 2009 (New York Times, 14 September 2009), but the legacy of ruined land and human health will endure for many decades to come. Passive Treatment Facility, Commerce, Oklahoma Perennial mine-water discharge through two boreholes was first identified between Commerce and North Miami, Oklahoma, in 1983 (see Fig. 20). The site is behind a carpet warehouse, on the south side of U.S. Highway 69 on the southern edge of Commerce, approximately 0.3 mile northeast of North Miami (Fig. 26). Known as site 14, this location was selected for passive treatment of the toxic water (Nairn et al., 2009). Periodic data collection began in 1998 with monthly sampling since 2004. The targeted discharge has pH just <6, total alkalinity ~400 mg/L as CaCO3, flow rates of 400–700 L/min, and elevated levels of Fe, Zn, Pb, and Cd. Given the nature of the target discharge, a multiprocess unit conceptual design was developed. Individual process unit designs focused on specific water-quality improvement goals including Fe oxidation, solids settling, metal-sulfide formation, etc. In addition, an identical parallel treatment train approach was deemed appropriate for at least two reasons. First, the parallel trains allow for simultaneous performance of necessary maintenance and continued treatment. Second, given the research focus of this site, the parallel trains allow experimental manipulations to be conducted. The conceptual design process identified six distinct process units (Table 2). Through a competitive bidding process, a design-and-build engineering contract was awarded to CH2M Hill using funds provided by the EPA and the U.S. Geological Survey. Design and construction tasks included capture and control of the two known

18

Aber et al.

Figure 26. Northward overview of passive treatment site in the left foreground and Commerce, Oklahoma, behind. Chat piles in the Picher-Cardin vicinity are visible in the right background. Boyhood home of Mickey Mantle marked (*) on western side of Commerce. Helium-blimp aerial photograph by SWA and JSA, September 2009.

artesian mine-drainage discharges, implementation of all passive treatment process units including water conveyance structures, and provision of as-built documents. Construction began in July 2008 and was completed in late November 2008 (delay was caused by record rainfall during the summer of 2008). Diversion of storm-water flows from a ~470-ha upgradient watershed was necessary. During construction, a third mine-water discharge was discovered and incorporated into the design. The completed system (Fig. 27) includes ten distinct process units with a single initial oxidation pond (cell 1) followed by parallel surface-flow aerobic wetland-ponds (cells 2N and 2S), vertical-flow bioreactors (cells 3N and 3S), re-aeration ponds (cells 4N and 4S), horizontal-flow limestone beds (cells 5N and 5S), and a single polishing pond-wetland (cell 6). Wind and solar power provide the only necessary energy for the treatment operation (cells 4). Mine water was diverted into the passive treatment system for the first time on 2 December 2008. Monitoring began in January 2009, and preliminary results

indicate highly effective reduction or removal of metals from the treated water (Table 3). This system represents a state-ofthe-art ecological engineering research site for passive treatment of ferruginous lead-zinc mine waters. Flooding at Miami, Oklahoma Miami is located between the Neosho River and Tar Creek, and historic Route 66 runs north-south through the center of the town (see Fig. 20). The city has a population of nearly 14,000 people and is home to Northeastern Oklahoma A&M College. The field-trip stop is the college athletic field on the eastern side of campus. To reach this site from I-44, take the exit for state highway 10. At the end of the exit, turn left on Steve Owens Blvd. Drive west 0.4 mile to Elm Street, and turn north. Continue north on Elm Street for 0.75 mile; turn west on McKinley Blvd., and continue to Rockdale Blvd. Turn left on Rockdale, drive west across the Tar Creek bridge, and continue to the athletic field on left.

TABLE 2. SUMMARY OF FINAL CONCEPTUAL DESIGN PROCESS UNITS, PRIMARY TARGETED WATER-QUALITY PARAMETERS, AND DESIGN FUNCTION Process unit Targeted parameter Function Oxidation pond Fe Oxidation, hydrolysis, and setting of iron oxyhydroxide solids and trace-metal sorption. Surface-flow wetlands and ponds Fe Solids settling. Vertical-flow bioreactors Zn, Pb, and Cd Retention of trace-metal sulfides via reducing mechanisms. Re-aeration ponds Oxygen demand and odor Wind- and solar-powered re-aeration. Stripping oxygen demand and H2S. Adding O2. Horizontal-flow limestone beds Zn, Mn, and hardness Final polishing of Zn as ZnCO 3. Final polishing of Mn as MnO2. Adding hardness to offset bioavailability of any remaining trace metals. Polishing pond and wetland Residual solids Solids settling. Photosynthetic oxygenation. Ecological buffering. Note: Based on Nairn et al. (2009).

Route 66

19

Figure 27. Passive treatment facility at Commerce, Oklahoma. Vertical aerial photograph annotated with pool numbers. Inlet pool (1) with three artesian wells (*) upper left; outlet channel lower right; north toward top. Note vehicles in upper left corner for scale. Heliumblimp aerial photograph by JSA and SWA, September 2009.

Since 1986, Miami has experienced more than 20 floods, of which 14 had significant impact on the community (Manders, 2009). About one-quarter of the city is situated in federally designated floodplain. Ottawa County, which includes Miami, is considered to be the most flood-prone county in Oklahoma. Thus, flooding is a perennial problem facing the city of Miami. This situation is exacerbated by past mining activities, which have led to diminished stream capacity and give rise to toxic pollution of surface drainage and soils, particularly in the Tar Creek basin. Upstream flood-control reservoirs on the Neosho River and its tributaries in Kansas have little influence at Miami, and Grand Lake O’ the Cherokees immediately downstream creates backwater flooding at Miami. At normal pool level, Grand Lake O’ the Cherokees is operated by the Grand River Dam Authority for hydroelectric power. When lake level rises, the U.S. Army Corps of Engineers takes over operation for flood-control pur-

TABLE 3. COMPARISON OF SYSTEM INFLUENT AND EFFLUENT DATA FOR SELECTED METALS (mg/L) AND CALCULATED PERCENTAGE DIFFERENCES Metal Influent Effluent Change (%) Mean SE Mean SE As 0.062 0.0005 BDL BDL 100 Cd 0.017 0.003 BDL BDL 100 Fe 172.51 5.54 1.055 0.439 99.4 Ni 0.893 0.012 0.049 0.024 94.5 Pb 0.063 0.009 BDL BDL 100 Zn 8.093 0.092 0.232 0.062 97.1 Note: SE is standard error; BDL refers to data below detectable limits.

poses. However, the reservoir has insufficient storage capacity to avoid backwater flooding upstream along the Neosho River and Tar Creek at Miami. Under modern guidelines, at least 3500 additional acres (1590 ha) would be necessary for an adequate flood pool (Manders, 2009). The most recent severe flood at Miami took place in July 2007, when the Neosho River crested at more than 4 m above flood stage with a peak discharge of nearly 4000 m3/s. This flood

Figure 28. Aerial view looking toward southeast of flooding on the Northeastern Oklahoma A&M College campus in July 2007. Submerged football field in upper left corner. The student activity building (*) stands above the flood, but other structures on the eastern side of campus are inundated. Photograph courtesy of S. Ankenman.

20

Aber et al.

ranks as the second highest on record, exceeded only by the flood of 1951. Large portions of the city bordering the Neosho River and Tar Creek were inundated, including part of the college campus (Fig. 28), mostly due to a backwater effect from Grand Lake O’ the Cherokees. Following flooding, structures were evaluated for action. Those that would cost more than 50% of their assessed pre-flood value to repair were red flagged (Fig. 29). These structures could not be reoccupied and could be rebuilt only if the foundations were raised above flood level. Many of these structures were abandoned and have been or will be demolished. Other structures were blue flagged as repairable and habitable. Within close proximity, the difference between red and blue often depended on heights of foundations or building grades (Fig. 30). Flooding

at Miami remains a complex problem, and the city is undertaking a feasibility study to obtain federal assistance in the future. ACKNOWLEDGMENTS The authors wish to thank P. Johnston for providing ground photographs and background information related to past lead and zinc mining in the Galena-Picher area. L. Lefebvre created mosaics of historical aerial photographs for Cherokee County, Kansas, and adjacent Oklahoma. Part of the preparation for this guidebook was undertaken in connection with a project on Kansas physiographic regions sponsored by the Kansas Geological Survey. M. Everhart and another reviewer provided constructive comments for revision of the manuscript. The authors also

Figure 29. Pattern of July 2007 flood in Miami, Oklahoma, as depicted by evaluation of damaged structures. Red squares—buildings could not be reoccupied or rebuilt. Blue squares—buildings could be reoccupied and repaired. Yellow squares—status still under review. Small circles are geographic positioning system way points. Taken from Manders (2009, fig. 22).

Route 66

21

Figure 30. Aerial view of the Brookside neighborhood immediately north of the Northeastern Oklahoma A&M College campus. Structures marked in red could not be reoccupied or repaired without raising the foundations above flood level. Other structures were deemed habitable and repairable. Tar Creek is the brown stripe across top of view. Helium-blimp aerial photograph by SWA, JSA, and GM, April 2008.

thank their home institutions for continuing support of research involving the Tri-state mining district. REFERENCES CITED Aber, J.S., and Aber, S.W., 2009, Kansas physiographic provinces: Bird’s-eye views: Kansas Geological Survey, Educational Series 17, 76 p. American Standard, 2009, Lead-free in 2009: American Standard online, http://www.americanstandard-us.com/assets/documents/amstd/leadfree/ LeadFree.pdf (accessed September 2009). Arruda, J.A., 1992, Water in southeast Kansas: Kansas Academy of Science, Guidebook 5, p. 81–91 and Kansas Geological Survey, Open-File Report 92-22. Beveridge, T.R., and Vineyard, J.D., 1990, Geologic wonders and curiosities of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Educational Series 4, 391 p. Brady, L.L., and Dutcher, L.F., 1974, Kansas coal: A future energy resource: Kansas Geological Survey Journal, 28 p. Chambers, D.K., Arruda, J.A., and Jaywardhana, A.A., 2005, A synoptic water quality survey of the Spring River and its tributaries: Kansas Academy of Science, Transactions, v. 108, p. 47–56. Clark, J.G., 1970, Towns and minerals in southeastern Kansas: A study in regional industrialization 1890–1930: Kansas Geological Survey, Special Distribution Publication 52, 147 p. Clerk, F.L., 1883, The lead and zinc region of Missouri and Kansas: The Kansas City Review of Science and Industry, v. 6, no. 6, p. 330–335. Davis, J.V., and Schumacher, J.G., 1992, Water quality characterization of the Spring River basin, southwestern Missouri and southeast Kansas: U.S. Geological Survey Water Resources Investigations Report, v. 90, p. 4176. Dutnell, R.C., Storm, D.E., Waits, D., Umbach, D., and Woodruff, S., 1995, Grand Lake basin management plan. Phase 1: Identification of critical areas: Oklahoma Conservation Commission, Oklahoma City.

Environmental Protection Agency, 2007, Tri-State mining district—Chat mining waste: EPA530-F-07-016B, Environmental Protection Agency online, http://www.epa.gov/osw/nonhaz/industrial/special/mining/chat/fsr67 -607.pdf (accessed September 2009). Environmental Protection Agency, 2009, Superfund Program Implements the Recovery Act: Cherokee County/Badger, Lawton, Baxter Springs, and Treece Subsites, Cherokee County, Kansas: Environmental Protection Agency online, http://www.epa.gov/superfund/eparecovery/cherokee .html, (accessed November 2009). Guberman, D.E., 2009a, Mineral commodity summaries: Lead: U.S. Geological Survey online, http://minerals.usgs.gov/minerals/pubs/commodity/ lead/mcs-2009-lead.pdf (accessed September 2009). Guberman, D.E., 2009b, 2007 Minerals Yearbook: Lead (updated online 2/2009): U.S. Geological Survey online, http://minerals.usgs.gov/ minerals/pubs/commodity/lead/myb1-2007-lead.pdf (accessed September 2009). Guberman, D.E., 2009c, Mineral industry survey (updated 8/2009): U.S. Geological Survey online, http://minerals.usgs.gov/minerals/pubs/ commodity/lead/mis-200905-lead.pdf (accessed September 2009). Hannibal, J.T., and Evans, K.R., 2010, this volume, Civil War and cultural geology of southwestern Missouri, part 1: The geology of Wilson’s Creek Battlefield and the history of stone quarrying and stone use, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, doi: 10.1130/2010.0017(04). Juracek, K.E., 2006, Sedimentation and occurrence and trends of selected chemical constituents in bottom sediment, Empire Lake, Cherokee County, Kansas, 1905–2005: U.S. Geological Survey Scientific Investigations Report 2006-5307, 79 p., http://pubs.usgs.gov/sir/2006/5307/ (accessed July 2009). Leach, D.L., Viets, J.B., Foley-Ayuso, N., and Klein, D.P., 1995, Mississippi valley–type Pb-Zn deposits, in du Bray, E.A., ed., Preliminary compilation of descriptive geoenvironmental mineral deposit models: U.S. Geological Survey Open-File Report 95-831, http://pubs.usgs.gov/of/1995/ ofr-95-0831/CHAP30.pdf (accessed September 2009).

22

Aber et al.

Lefler, D., 2009, Congress approves buyouts for Treece: Wichita Eagle, posted online 30 October 2009, http://www kansas.com/news/state/ story/1033610.html (accessed November 2009). Manders, G., 2009, Mapping of the July 2007 Miami, Oklahoma Flood: Unpub. graduate research report, Earth Science Department, Emporia State University, 28 p. Muilenburg, G., ed., 1961, Stories of resource-full Kansas: Featuring the Kansas landscape: State Geological Survey, University of Kansas, Pamphlet 1, 42 p. Nairn, R.W., Beisel, T., Thomas, R.C., LaBar, J.A., Strevett, K.A., Fuller, D., Strosnider, W.H., Andrews, W.J., Bays, J., and Knox, R.C., 2009, Challenges in design and construction of a large multi-cell passive treatment system for ferruginous lead-zinc mine waters, in Barnhisel, R.I., ed., Revitalizing the Environment: Proven Solutions and Innovative Approaches: Billings, Montana, Joint Conference of the 26th Annual Meetings of the American Society of Mining and Reclamation and 11th Billings Land Reclamation Symposium, 30 May–5 June 2009, p. 871–892. Oliver, J., 1986, Fluids expelled tectonically from orogenic belts: Their roles in hydrocarbon migration and other geologic phenomena: Geology, v. 14, p. 99–102, doi: 10.1130/0091-7613(1986)14<99:FETFOB>2.0.CO;2. Park, J.R., 2005, Missouri Mining Heritage Guide: South Miami, Florida, Stonehouse Publishing Company, 279 p. Pope, L.M., Mehl, H.E., and Coiner, R.L., 2009, Quality characteristics of ground water in the Ozark Aquifer of northwestern Arkansas, southeastern Kansas, southwestern Missouri, and northeastern Oklahoma, 2006–2007: U.S. Geological Survey Scientific Investigations Report 2009-5093, 60 p., http://pubs.usgs.gov/sir/2009/5093/ (accessed July 2009). Reed, E.W., Schoff, S.L., and Branson, C.C., 1955, Ground-water resources of Ottawa County, Oklahoma: Oklahoma Geological Survey Bulletin 72, 203 p. Robertson, C.E., 1967, The Elsey Formation and its relationship to the Grand Falls Chert: Missouri Geological Survey and Water Resources Report of Investigations 38, 62 p.

Rogers, A.F., 1900, Annotated list of the minerals occurring in the Joplin lead and zinc district: The Kansas University Quarterly, v. 9, no. 2, p. 161–165. Seevers, W.J., 1975, Description of the surficial rocks in Cherokee County, southeastern Kansas: Kansas Geological Survey, Geology Series 1, 7 p. Siebenthal, C.E., 1915, Origin of the zinc and lead deposits of the Joplin region, Missouri, Kansas, and Oklahoma: U.S. Geological Survey Bulletin 606, 283 p. Thomas, W.A., 2006, Tectonic inheritance at a continental margin: GSA Today, v. 16, no. 2, p. 4–11, doi: 10.1130/1052-5173(2006)016[4:TIAACM] 2.0.CO;2. Thompson, T.L., 1995, The stratigraphic succession in Missouri: Missouri Department of Natural Resources, v. 40 (2nd series) Revised, 190 p. Thompson, T.L., and Robertson, C.E., 1993, Guidebook to the geology along Interstate Highway 44 (I-44) in Missouri: Missouri Department of Natural Resources Report of Investigations 71, Guidebook 23, 185 p. Tolcin, A.C., 2009, 2007 Minerals Yearbook: Zinc (updated online June 2009): U.S. Geological Survey online, http://minerals.usgs.gov/minerals/pubs/ commodity/zinc/myb1-2007-zinc.pdf (accessed September 2009). U.S. Army Corps of Engineers (USACE), 2005, The results of mining at Tar Creek: Environmental case study by NRE 492 Group 5: Miami Public Library online, http://www.supportlibrary.com/nl/users/1miami/mweb/ path1-5.html (accessed July 2009). Wallis, M., 2001, Route 66: The Mother Road, 75th Anniversary Edition: New York, St. Martin’s Griffin, 276 p. Young, J., and Beard, J., 1993, Caves in Kansas: Kansas Geological Survey Educational Series 9, 48 p.

MANUSCRIPT ACCEPTED BY THE SOCIETY 30 NOVEMBER 2009

Printed in the USA

The Geological Society of America Field Guide 17 2010

Preliminary geology of the Proffit Mountain flood scour, Reynolds County, Missouri Cheryl M. Seeger* Missouri Department of Natural Resources, Division of Geology and Land Survey, P.O. Box 250, Rolla, Missouri 65402, USA David J. Wronkiewicz Geology & Geophysics Program, 159 McNutt Hall, 1870 Miner Circle, Missouri University of Science and Technology, Rolla, Missouri 65409, USA

ABSTRACT The 2.4-km-long Proffit Mountain flood scour formed when the upper reservoir of the Taum Sauk Power Plant, a reversible pumped electric storage facility, failed on 14 December 2005. Approximately 1.3 billion gallons of water drained from the reservoir in roughly 12 minutes, scouring a small tributary on the west flank of Proffit Mountain to bedrock and depositing debris in the valley floor and in the valley of the East Fork of the Black River. The stratigraphic succession exposed includes Mesoproterozoic Taum Sauk Rhyolite and Munger Granite, Cambrian conglomerate and dolomite and flood deposits. The site provides a unique opportunity to study a landscape-scale outcrop.

flood exposed bedrock ranging from Mesoproterozoic rhyolites and granites to Cambrian conglomerates and dolomites. Flood deposits are unique examples of deposition under extreme flash flood conditions. The site provides an extraordinary opportunity to see a landscape-scale outcrop with bedrock relationships clearly exposed and traceable for hundreds of feet.

INTRODUCTION The Proffit Mountain flood scour is located in Reynolds County, Missouri, ~90 miles south-southwest of St. Louis (Fig. 1). The scour is located in the S ½ S ½ Sec. 9, the NE ¼ Sec. 16 and the Center W ½ Sec. 15, T. 33 N., R. 2 E., Johnson Shutins 7.5′ quadrangle. The scour is in the heart of the St. Francois Mountains, a region characterized by exposures of Mesoproterozoic igneous rocks. The scour begins on land owned by AmerenUE and extends onto and ends in Johnson’s Shut-ins State Park. The 2.4 km (1.5 mi) scour formed when the upper reservoir of the Ameren-UE Taum Sauk power plant, a reversible pumped electric storage facility, overflowed and failed. The resulting

PHYSIOGRAPHIC SETTING Proffit Mountain is located in the St. Francois Mountains, an expression of the broad, asymmetrical Ozark uplift. The St. Francois Mountains are, in part, composed of Mesoproterozoic igneous rocks of the St. Francois terrane. The terrane is deeply

*[email protected] Seeger, C.M., and Wronkiewicz, D.J., 2010, Preliminary geology of the Proffit Mountain flood scour, Reynolds County, Missouri, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, p. 23–29, doi: 10.1130/2010.0017(02). For permission to copy, contact [email protected]. ©2010 The Geological Society of America. All rights reserved.

23

24

Seeger and Wronkiewicz (Fig. 3). The grade decreases to 19% on the westernmost portion of the conglomerate exposure, with the edge of the conglomerate outcrop marking a hydraulic jump. The slope west of the hydraulic jump is marked by a gentle grade (2% slope).

Columbia Kansas City

GEOLOGIC SETTING

St. Louis

Scour Springfield Reynolds County

Figure 1. Location of the Proffit Mountain flood scour in southeast Missouri.

eroded and dissected, resulting in rugged topography, unroofed granite plutons, and exposures of subvolcanic granites. The igneous rocks are overlain by Middle and Upper Cambrian alluvial conglomerates and fluvial and marine sediments. Mesoproterozoic outcrops that comprise the St. Francois Mountains represent structural and topographic highs. Exposed granites are commonly erosional lows surrounded by more resistant volcanic rock topographic highs. The flood scour is located on the western side of Proffit Mountain (Fig. 2) and has an elevation drop of 207 m (680 ft). The slope is 26% grade where bedrock is rhyolite and granite

The Mesoproterozoic St. Francois terrane underlies Paleozoic sedimentary rocks in southeast Missouri and is exposed in the St. Francois Mountains. Granite is the dominant lithology in the subsurface; the remainder of the terrane is primarily rhyolite, rhyolitic-composition rocks, and intermediate-alkalic rocks. Minor mafic to intermediate rocks are present. Kisvarsanyi (1980, 1981) recognized three types of granite bodies in the St. Francois terrane: subvolcanic massifs, ring complexes, and central plutons. Ring complexes, such as the Munger Granite in the scour exposure is the deeply eroded root of a more extensive volcanic terrane and was emplaced in ring fractures related to caldera collapse and subsidence. Silicic volcanic rocks in the St. Francois terrane are dominantly rhyolite ash-flow tuffs, similar to the Taum Sauk Rhyolite exposed at the site, and typically contain alkali feldspar phenocrysts and iron-rich mafic minerals. Rhyolite lava flows, shallow intrusives, bedded tuffs, and pyroclastic breccias are also present in the terrane. The volcanic rocks commonly display variable and random attitudes within short distances, possibly the result of megabrecciation (Kisvarsanyi, 1981). Proffit Mountain is located inside the western margin of the Taum Sauk caldera. The caldera has undergone deep erosion; preserved rhyolites are those that flowed into the central low

Highway N Highway

House H ous se ffoundation ou o u n d at i o n

Flood scour Ca pg Ca

und und

n

Eas E as Blac Blac c

of tthe he r

Figure 2. Aerial photograph of the Proffit Mountain flood scour. Black line outlines areas affected by the flood event.

Preliminary geology of the Proffit Mountain flood scour portion of the caldera. Rhyolites from at least six eruptions are visible on nearby Taum Sauk Mountain and surrounding knobs. RESERVOIR FAILURE EVENT The Taum Sauk upper reservoir failure occurred on the morning of 14 December 2005, at ~5:00 a.m., when the northwest corner of the upper reservoir breached, cutting a gap nearly 700 feet wide in the side of the reservoir (Fig. 2). Approximately 1.3 billion gallons of water drained from the reservoir in ~12 min, scouring a small tributary on the west flank of Proffit Mountain down to bedrock and depositing reservoir wall debris and eroded materials on the valley floor and in the channel and floodplain of the East Fork of the Black River (Fig. 2). The flood also scoured a large pool at the intersection of the scour valley and the East Fork. The water and debris traveled south down the valley of the East Fork, destroying and damaging the park campground and structures within the park. A portion of the water briefly ran north, destroyed the park superintendent’s home, and washed across Highway N before running south. Fortunately, there were no fatalities associated with the event. However, the environmental repercussions will be noticeable for decades from the result of surficial material and bedrock stripping, redeposition of reservoir wall and stripped material, removal of vegetation and wildlife habitat, and degradation of a high-quality forested fen located on the edge of the East Fork’s floodplain. In addition, mobilization of kaolinite clays continues to cause water quality issues in the East Fork of the Black River and in the Black River downstream of its confluence with the East Fork.

25

STRATIGRAPHY The stratigraphic succession exposed in the Proffit Mountain flood scour comprises Mesoproterozoic Taum Sauk Rhyolite and Munger Granite, Cambrian basal conglomerate (possible Lamotte Sandstone equivalent), and Cambrian dolomites (Fig. 3). Residuum is exposed on the sides and in the banks of the flood scour. The flood deposits represent the youngest geologic features within the scour. The units are described below in the order they are encountered as one travels from the intersection of the scour with the East Fork of the Black River east up the flank of Proffit Mountain. Cambrian Dolomite Dolomite exposed in the lower portion of the valley is likely Upper Cambrian, but is currently unidentified as to formation. The dolomite is medium-bedded, medium-crystalline whiterock and is suggestive of a planar stromatolitic origin. No other fossils were noted, although some beds are highly burrowed. Exposures contain beds with moderate glauconite content. Scattered rounded to subrounded igneous clasts and thin, sand-rich layers suggest continued shedding of material from surrounding knobs during carbonate deposition. A gentle dip away from Proffit Mountain is presumed to be depositional dip. Strong jointing, visible on aerial photography, trends approximately N45°E. Open karst and soil- or residuum-filled joints follow this trend. The dolomite is marked by numerous solution and karstrelated features (Fig. 4), including one small, short cave. Dissolution commonly follows joint trends with highly variable fissure

Legend Cambrian Dolomite and flood deposits Cambrian basal conglomerate Munger Granite

aplite a plite o tcrop ou op outcrop

Saprolite Taum Sauk Rhyolite

Figure 3. Aerial photograph of the Proffit Mountain flood scour with formations and area with deposition of flood deposits within the scour marked. The location of the Proterozoic aplite outcrop is indicated.

26

Seeger and Wronkiewicz

size and depth. There is also marked variability in the degree of dissolution of different beds in the dolomite sequence. Aplite Outcrop An exposure of Proterozoic aplite is present in the lower part of the scour valley (Fig. 3). The exposure appears to be a paleooutcrop (Fig. 5), surrounded by possible boulders of aplite with dark-gray alteration or weathering rims. Portions of the aplite were intruded by mafic dikes; these areas have dark-gray alteration rims. Some boulders are cemented by sandy dolomite.

Cambrian Basal Conglomerate (Lamotte Sandstone) The Cambrian basal conglomerate (Fig. 6), generally included in the Lamotte Sandstone, onlaps the western portion of the Munger Granite exposure. The conglomerate is cemented by variably iron- and glauconite-rich sandstone. Clasts are granite and rhyolite with minor mafic rocks, are rounded to subangular and are commonly boulder to pebble sized. Some clasts are extensively weathered. The conglomerate is interlayered with arkosic sandstone, arkosic dolomite, and silty dolomite, representing shoreline and near-shore facies or possibly the margin of an alluvial fan. Ripple marks are visible in exposures of interlayered siltstone; mud cracks are also present in the formation. The matrix sandstone exhibits draping over individual boulders (Fig. 6). The conglomerate exhibits minimal high-angle fracturing; parting is common along bedding planes, and forms small ledges running roughly north-south (Fig. 6). Exposed sandstone and siltstone layers with low clast content display linear scratches from transported flood material. Munger Granite The contact between the Taum Sauk Rhyolite and the Munger Granite strikes approximately north-south and appears to dip near vertical; it is characterized by the saprolite zone discussed below. The granite is red to red-gray in color; weathered surfaces are lighter in color and often exhibit iron-oxide staining. The granite has a strong joint trend of approximately N45°E in the upper portion of the exposure that is visible on aerial photography.

Figure 4. Karst features in Cambrian dolomite in the western portion of the flood scar.

Figure 5. Outcrop of Proterozoic aplite near the western extent of the flood scar.

Figure 6. Cambrian basal conglomerate. The conglomerate contains interbedded sandstone and siltstone layers; clasts are pebble to boulder sized. Note draping of matrix sandstone over boulders near center of photograph.

Preliminary geology of the Proffit Mountain flood scour The Munger Granite exhibits signs of deep weathering. Pinnacles of granite are exposed where surrounding weathered material was removed during the flood event. Some pinnacles exhibit impact fracturing related to movement of flood material (Fig. 7). Horizontal and low-angle exposures of the granite display scratching and gouging by flood-transported material. The lower portion of the exposure of Munger Granite is marked by extensive post-flood weathering. Immediately after exposure the bedrock exhibited near horizontal fractures or partings with iron-oxide stains on the surfaces. The original appearance and subsequent extensive weathering of the exposure suggest that this portion of the outcrop is a grus.

27

with weathering and alteration to clay-sized material while in situ (Fig. 9). The material is five meters or greater in thickness where it is exposed in a scour pit. In places, this material is capped by remnant granite boulders. Locations of joints that bounded the original blocks are marked by stockworks of manganese oxide veins. Concentric bands of iron-stained, clay-sized material mark the former blocks. Some have whitish cores or bands of kaolinite. The clay-sized material was later fractured, and leaching of silica and iron resulted in the formation of whitish kaolinite along the fractures. The granite saprolite is characterized by a lighter orange color than the diabase saprolite. The material, similar to the other saprolites, is soft and easily eroded, and contains quartz grains

Saprolite Contact Zone The contact zone between the granite and rhyolite is marked by extreme weathering of Taum Sauk Rhyolite, Munger Granite, and a possible later diabase intrusive body. The rhyolite saprolite is characterized by a purplish color, is extremely soft and easily eroded, and contains remnant boulders of rhyolite. Some portions retain relict fractures, defined by the fracture cement. The rhyolite saprolite is in sharp contact (Fig. 8) with a darkorange saprolite, determined to be a diabase saprolite. The saprolite contains rare remnant core stones of diabase and has no remnant quartz. Rounded core stones of diabase are found scattered in flood deposits located downstream. The position of the diabase saprolite between the saprolitic rhyolite and granite suggests that the diabase intruded at the granite-rhyolite contact. There are also other intrusions of intermediate to mafic igneous rocks in the scour, including in the aplite outcrop discussed above. A wide area of possible diabase saprolite on the northern edge of the flood scour exhibits spherical textures consistent

Figure 7. Pinnacle of Munger Granite with surrounding soft weathered material removed. Outer part of pinnacle exhibits lightened color due to weathering on boulder surface. Top of pinnacle has been fractured due to impact by flood transported material.

Figure 8. Contact between Taum Sauk Rhyolite and rhyolite saprolite (upper half of photograph) and the diabase saprolite (lower half of photograph).

Figure 9. Possible diabase saprolite, exhibiting in situ circular weathering features.

28

Seeger and Wronkiewicz

and relict blocks of Munger Granite. The saprolite exhibits later fracturing, with fractures healed with calcite and possible kaolinite. These later fractures crosscut the former blocks. Taum Sauk Rhyolite The upper portion of the flood scour exposes the Taum Sauk Rhyolite. The rhyolite is porphyritic (Fig. 10), with alkali feldspar and quartz phenocrysts, and is dark red to purplish in color. Phenocryst concentrations vary from a few percent to ~30%. Exposures exhibit near-vertical flow banding and possible pumice fragments, suggesting potential post-lithification megabrecciation and rotation. The rhyolite contains xenoliths or dikes of felsic igneous rocks and occasional concentrations of hematite. Portions of the rhyolite exhibit manganese-oxide enrichment. The rhyolite is highly jointed, with two major joint sets that trend N30°W and N45°E. The joints frequently exhibit selvages of up to one centimeter of highly weathered kaolinized rhyolite (Fig. 10). Joint surfaces also exhibit iron-oxide staining. Weathered, rounded surfaces typify individual joint blocks that were near the former ground surface; more angular surfaces are also present. The extensive jointing results in an irregular hummocky topography on the surface of the exposed rhyolite. Several faults that trend nearly east-west are in the exposed rhyolite and are generally expressed as linear depressions related to associated intense shearing (Fig. 11). The attitude and sense of movement on the faults could not be determined. A small part of the rhyolite outcrop is composed of an aphanitic purple igneous rock with minor phenocrysts of unidentified composition. Cursory examination suggested that this rock may be a mylonite. The rock is faulted into position against more typical Taum Sauk Rhyolite.

Figure 10. Taum Sauk Rhyolite. Phenocrysts are alkali feldspar. Note kaolinite-filled fracture cutting rhyolite.

Sedimentology of Flood Deposits Although scattered flood debris is present on the lower portions of the conglomerate exposure, deposition is minimal until the hydraulic jump at the break in slope on the west side of Proffit Mountain. On the downstream side of the slope break, flood-transported material was deposited in a large mound that is steep on the upflow side and nearly horizontal on the downflow side (Fig. 12). The material deposited throughout the valley varies from poorly sorted to well sorted. The sorting may be representative

Figure 11. Fault marked by a depression in the Taum Sauk Rhyolite. The fault line is characterized by extreme fracturing and shearing of the rhyolite within the fault plane.

Figure 12. Scour at hydraulic jump at the westernmost extent of the Cambrian conglomerate outcrop. Deposition of boulders and cobbles resulted in a large mound that is steep on the upflow side and nearly horizontal on the downflow side.

Preliminary geology of the Proffit Mountain flood scour of different stages in the flood or may be the result of sediment sieving. Potentially earlier sediments contain a greater percentage of fines, while possible later overlying sediments are coarser with minimal to no fines (Fig. 13). Sediments deposited early in the flood are cut by channels formed later in the event. Flooddeposited material near the western end of the flood scour is generally poorly sorted, with greater mixing of coarse and fine material. Overall, the material coarsens upward from fines and cobble-sized material to boulders.

29

Several channel margin deposits are strongly suggestive of point bar sequences. Natural levees developed during flood deposition. A crevasse splay, developed through a break in a natural levee, is present at the easternmost end of the flood sediment depositional area, and is visible on aerial photography. SUMMARY The Proffit Mountain flood scour was the result of overtopping and failure of the upper reservoir of the Taum Sauk power plant. The flood event caused extensive damage to a tributary valley of the East Fork of the Black River and destruction of structures, the campground, and sensitive ecological systems in Johnson’s Shut-ins State Park. The environmental repercussions of this event will be evident within the park for decades. The flood scour does, however, give geologists a unique opportunity to see features and lithologic and stratigraphic relationships normally not visible in the St. Francois Mountains area of southeast Missouri. Study of the scour will lead to greater understanding of the geologic history of this region and of what is often unseen under our feet. REFERENCES CITED

Figure 13. Material deposited by flood event. Deposits exhibit a greater percentage of fines near the base, overlain by coarser material with few fines.

Kisvarsanyi, E.B., 1980, Granitic ring complexes and hotspot activity in the St. Francois terrane, midcontinent region, United States: Geology, v. 8, p. 43–47, doi: 10.1130/0091-7613(1980)8<43:GRCAPH>2.0.CO;2. Kisvarsanyi, E.B., 1981, Geology of the Precambrian St. Francois terrane southeastern Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigations 64, 58 p. MANUSCRIPT ACCEPTED BY THE SOCIETY 23 NOVEMBER 2009

Printed in the USA

The Geological Society of America Field Guide 17 2010

Geomorphology and paleontology of Riverbluff Cave, Springfield, Missouri Charles W. Rovey II Department of Geography, Geology, and Planning, Missouri State University, 901 S. National, Springfield, Missouri 65897, USA Matt Forir Missouri Institute of Natural Science, 2327 W. Farm Road 190, Springfield, Missouri 65810, USA Greg Balco Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, California 94709, USA David Gaunt Missouri Geological Survey, 111 Fairgrounds Road, Rolla, Missouri 65401, USA

ABSTRACT Riverbluff Cave developed near the southern margin of the Springfield Plateau as a single passage between James River and its tributary, Ward Branch. Portions of the cave preserve a general fining-upward sediment sequence, but with highly fossiliferous gravel beds near the middle. These gravel beds include fragments of various vertebrates, including mammoth and horse. Trackways and claw marks are also preserved atop the sediment in numerous locations. Cosmogenic isotope data provide burial dates for some of the sediment layers and fossil remains. The earliest sediment (reverse magnetic polarity) entered the cave at ~1.1 Ma, while the fossiliferous gravel bed is dated at ~0.74 Ma. The overlying laminated silts and clays have normal polarity with a burial date of ~0.65 Ma at the base. Thus, the sediment sequence spans the Matuyama/Brunhes paleomagnetic datum, and records at least 450 ka of sedimentation within the cave.

INTRODUCTION AND HISTORY

and they had planned to place more for a large blast, but after the attacks the government ordered a halt to construction blasting. The in-place charges presented a problem, however, because they could not be removed safely; therefore, these three charges were detonated. The small explosion did not bring down the entire bluff section as planned, but was powerful enough to open a small entrance into a previously sealed cave. The construction

Riverbluff Cave was discovered on 11 September 2001 (http://www.riverbluffcave.com/). Construction workers were grading a road bed into the James River Valley, and the limestone pinnacles along the bluff required blasting. Workers had wired three explosive charges before the terrorist attacks on that day,

Rovey, C.W., II, Forir, M., Balco, G., and Gaunt, D., 2010, Geomorphology and paleontology of Riverbluff Cave, Springfield, Missouri, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, p. 31–38, doi: 10.1130/2010.0017(03). For permission to copy, contact [email protected]. ©2010 The Geological Society of America. All rights reserved.

31

32

Rovey et al.

workers fortuitously had blasted into and preserved the highly decorated main room of Riverbluff Cave (Fig. 1). Members of the Missouri Speleological Survey soon began exploring the cave and found numerous trackways and claw marks (Fig. 2). Shortly thereafter a gravel bed with a concentration of vertebrate remains was located along the cave’s main passage (Fig. 3). In light of these discoveries, Greene County officials purchased the site and established a museum to display the cave’s specimens. GEOMORPHIC RELATIONSHIPS Riverbluff Cave is near the southern margin of the Springfield Plateau (Fig. 4). The Springfield Plateau is capped by the Burlington-Keokuk Formation (see Fig. 7 in the Road Log). This formation is a pervasively cemented crinoidal grainstone with thick-to-massive bedding and widely spaced joints. Thus, the Burlington-Keokuk Formation is ideally suited for channeling of recharging water along discrete discontinuities, leading to the formation of karst and caves. Riverbluff Cave is just one of hundreds of caves in Greene County, Missouri, but it is unique in that all of the natural entrances had been sealed by various geologic processes before its discovery. The sealed entrances account for the remarkable preservation of its trackways and claw marks, but how long had the cave been sealed? The cave is an ~800 m passage between the James River Valley and its tributary Ward Branch (Fig. 5). Thus, the cave functioned for a time as a spillway or piracy between a swallow hole along Ward Branch and the James River. The upstream paleoentrance along Ward Branch is ~13 m above the current (Ward Branch) channel, but it is below the elevation of a prominent bedrock/strath terrace of the James River. This entrance was sealed by a combination of breakdown within the cave and colluvial mass wasting along the ground surface above the entrance. A sidebranch (East Passage) is sealed from the main passage by

A

B Figure 2. (A) Peccary tracks in the upper layer of cave sediment. (B) Claw marks on cave wall. These marks are believed to be from a short-faced bear. Figure 1. View into the main room of Riverbluff Cave.

Riverbluff Cave, Springfield, Missouri

A

33

breakdown materials. Its presence, however, indicates that additional upstream (Ward Branch) point sources may have drained into the cave before this passage collapsed. The downstream paleoentrance along the James River Valley is ~9 m above the active floodplain at an elevation corresponding closely to a high alluvial terrace. This paleoentrance may have been sealed partially by alluvial deposition, although colluvial processes again appear to be a major factor. Thus, cave formation followed incision of the James River and tributaries, and the cave’s history reflects the geomorphic development of James River and the surrounding watershed. SEDIMENT FILL

B Figure 3. (A) Mammoth tibia recovered from the Gravel Beds. (B) Juvenile mammoth tooth recovered from the Gravel Beds.

Springfield Plateau

A stratified sediment sequence is exposed along portions of the cave’s main passage (Fig. 6). These sediments are divided into 10 “layers” based on lithology and grain size (Table 1). The oldest sediments above the cave floor (Layers 9 and 10, Table 1) are thin (10–20 cm) beds of gravely coarse sand. These sands are overlain locally by a gray laminated silt ~50–100 cm thick (the Gray Silt, Layer 8), which contains plant debris and organic-rich laminae. The Gray Silt is overlain by coarse cross-bedded gravel of variable thickness (the Gravel Beds, Layers 6 and 7). This gravel contains concentrations of vertebrate fragments, including mammoth, horse, fox, and bird bones (Fig. 3). The gravel beds are overlain by a fining-upward sequence of laminated red clay, which thickens toward the James River paleoentrance. The Red Clay is visually homogenous except for bioturbation within the upper 0.6 m. The layer divisions (1–5) within the Red Clay (Table 1) reflect uniform (30.5 cm) divisions established by the Missouri Speleological Survey during mapping and surveying.

Riverbluff Cave Branson 0

100 km

Figure 4. Location map of the Springfield Plateau and Riverbluff Cave.

Figure 5. Riverbluff Cave. The cave map is superimposed on an aerial photo. The dots are survey points, mostly within the cave. Cox Road is oriented approximately north-south, and the cave’s main passage is ~760 m long.

34

Rovey et al. We interpret the laminated fine-grained sediment as suspension deposits (slackwater facies). The Gray Silt (Layer 8) appears to be a localized accumulation above low spots of the cave floor, and thus, may be a sump deposit where water was ponded intermittently between high-discharge events. The laminated Red Clay (Layers 1–5) also could not have been deposited from flowing water, and instead must represent deposition of suspended sediments which entered the cave as backflow from the James River during floods. Thus, the general sedimentation pattern within the cave is a fining upward sequence corresponding to the transition from upstream (Ward Branch) bedload deposits to downstream (James River) suspension sediments. The concentration of vertebrate fragments within the gravel beds is unique for this area. Mammoth remains have been recovered in Missouri, but these are rarely found in a datable geologic context. The remains here, within a stratified sediment sequence, provide an unparalleled opportunity for dating these fossils. DATING TECHNIQUES

Figure 6. Sediment sequence within the main passage of Riverbluff Cave.

We interpret the coarse sandy and gravely sediment as bedload or channel facies deposits of a flowing current (i.e., Bosch and White, 2004; White, 2007). Given the slope of the cave from the (upstream) Ward Branch paleoentrance to the (downstream) James River paleoentrance, the coarse sediment must have entered the cave from the Ward Branch entrance(s). The Gravel Beds (Layers 6 and 7) thicken toward the north up to the Ward Branch paleoentrance, confirming that this was the entry point for these sediments.

Radiocarbon analyses of peccary remains atop Layer 1 (Red Clay) give open dates; thus, the sediment sequence was deposited prior to ~55,000 14C yr B.P. Given that mammoth fossils in North America indicate an age ≤1.5 Ma (Kurtén and Anderson, 1980; Graham, 1998; Lister and Bahn, 2007), Layers 1–7 must be between 55 ka and 1.5 Ma in age. The last reversal of the earth’s magnetic field occurred at 0.78 Ma (Cande and Kent, 1995) during the Matuyama/Brunhes reversal. Therefore, any type of reversed polarity within the cave sediments would prove a depositional age >0.78 Ma. A normal depositional or detrital remanence would give a presumed age of <0.78 Ma, with just a small chance of an older age corresponding to the short Jarimillo Normal Polarity Subchron (0.99–1.07 Ma). More precise ages of cave sediment can be obtained from ratios of the cosmogenic isotopes 26Al and 10Be (Granger, 2006). These isotopes are produced within quartz at a fixed ratio whenever quartz grains are very close to the ground surface. If the quartz grains are then transported into an environment (e.g., buried within a cave) where they are shielded from cosmic radiation, production of these isotopes stops, and

TABLE 1. STRATIGRAPHIC SEQUENCE WITHIN RIVERBLUFF CAVE Gene ral lithology Layer Polarity Comments 1 Bioturbated, numerous rodent bones 2 Bioturbated, clay rich 3 Normal Laminated, silty Red Clay 4 Normal Laminated, silty 5 Normal Laminated, sandy Gravel Beds Gray Silt Gravely Sands

6

Fossiliferous; numerous vertebrate fragments

7 8 9 10

Reverse

Laminated, wood and plant debris

Riverbluff Cave, Springfield, Missouri differential decay changes their ratio in proportion to burial time. Thus, burial dating has been widely used to date quartzbearing cave sediment (Granger et al., 1997, 2001; Stock et al. 2004, 2005, 2006). Rovey et al. (2010) discuss the dating process for Riverbluff Cave sediments, including procedures, assumptions, and standards. RESULTS Paleomagnetic Measurements The paleomagnetic and cosmogenic isotope results are summarized in Table 2. Paleomagnetic samples from the Red Clay preserved a strong, stable, and consistent normal remanence. Stepwise alternating-field demagnetization of these samples revealed no reversed components of magnetization, and isothermal remanent magnetization (IRM) measurements indicate that this magnetization is carried by magnetite. Therefore, the normal magnetic remanence within the Red Clay is a primary or depositional remanence. Given that the age of the underlying Gravel Beds (with mammoth fossils) is ≤1.5 Ma, the normal remanence indicates that the Red Clay is probably younger than the Matuyama/Brunhes polarity transition at 0.78 Ma. The Gray Silt below the Red Clay preserves a weak, hard, reversed remanence, or a mixed remanence with reversed components. These samples did not demagnetize under alternatingfield treatment, meaning that magnetite is virtually absent. Instead, thermal demagnetization and IRM measurements confirm that the reversed remanence is carried primarily by hematite. Because hematite may form as a secondary mineral within buried sediment, this magnetization may be a secondary chemical remanent magnetization. Nevertheless, the reversed polarity proves that the Gray Silt was subjected to a reversed magnetic field at some point during or after its deposition. Therefore, the Gray Silt and subjacent layers must be >0.78 Ma in age. By inference, the Matuyama/Brunhes transition must have occurred between deposition of the Gray Silt and the Red Clay, possibly within the stratigraphic interval occupied by the Gravel Beds.

35

Cosmogenic Isotope Measurements: Burial Ages Burial ages for the Riverbluff Cave sediments (Table 2) range from 1.08 Ma at the base (Layer 10) to 0.65 Ma at the bottom of the Red Clay (Layer 5). The upper portion of the Red Clay could not be dated because it does not contain enough sand-sized quartz grains. Notably, each age determination is in the correct stratigraphic sequence (i.e., the ages decrease upward) and the ages are consistent with the placement of the Matuyama/Brunhes paleomagnetic datum between the Gray Silt and the Red Clay. The sample from the intervening Gravel Beds was a composite spanning the boundary between Layers 6 and 7, and the resulting age (0.735 ± 0.073 Ma) is within error limits of the Matuyama/ Brunhes reversal at 0.78 Ma. These burial ages establish that by ~1.1 Ma coarse sediments were entering the cave from the general Ward Branch direction, and at ~0.74 Ma fossiliferous gravel was entering from the Ward Branch paleoentrance. Cosmogenic Isotope Measurements: Erosion and Incision Rates Cosmogenic isotopes can also be used to quantify rates of various geomorphic processes. The absolute concentrations of 10 Be and 26Al depend on both burial ages and the quartz grains’ effective exposure time. Thus, the isotope measurements also provide a measure of the landscape’s average surficial erosion rate that prevailed as the grains were exhumed. Isotope measurements of the cave sediments indicate that the landscape within the James River watershed generally experienced erosion rates of ~1 m/Ma (Table 2). The Gray Silt, with an erosion rate of 2.2 m/Ma, seems anomalous by comparison, possibly indicating an episode of increased landscape instability. Notably, the age of the Gray Silt (~0.90 Ma) coincides with the onset of the Mid-Pleistocene climate transition (Raymo et al., 1997; Lisiecke and Raymo, 2005) and the change from 41-ka to 100-ka climate cycles. Although the general landscape was fairly stable over this time interval, the James River and its tributaries were actively

TABLE 2. BURIAL AGES, SURFICIAL EROSION RATES, AND MAGNETIC POLARITY FOR RIVERBLUFF CAVE SEDIMENT Layer Burial age Surface erosion rate before burial Magnetic polarity (Ma) (m/Ma) 5 0.648 ± 0.079 0.963 ± 0.11 No r m a l 6/7 0.735 ± 0.073 1.306 ± 0.15 Matuyama/Brunhes datum (0.78 Ma) 8 0.899 ± 0.072 2.16 ± 0.26 Reverse 9 0.963 ± 0.068 1.187 ± 0.13 10 1.078 ± 0.073 0.883 ± 0.10 Note: Error limits are at the 1-σ level and include both analytical uncertainty and external uncertainty, which includes uncertainty in nuclide production rates and decay constants. Rovey et al. (2010) provide a detailed analysis of the burial dating process for these sediments. The sample from Layer 6/7 is a composite, taken from near the boundary between layers. The paleomagnetism of Layers 6 and 7 could not be measured due to coarse grain size. The Matuyama/Brunhes datum is inferred within these layers based on the paleomagnetic sequence within the adjacent layers.

Rovey et al.

ROAD LOG

Sys.

Ser.

PENN. Meramec. Desm.

Sub.

Channel sandstone Warsaw Formation

MISSISSIPPIAN Osagean

Short Creek Oölite Mbr.

Burlington-Keokuk limestones (undivided)

Elsey Formation Pierson Limestone Kind.

incising. At ~0.74 Ma the Ward Branch paleoentrance was an active swallow hole directing sediment into the cave. Shortly thereafter, however, this entrance was abandoned as Ward Branch eroded below that level. This entrance is ~13 m above the adjacent floodplain of Ward Branch, giving a long-term incision rate of ~0.018 mm/yr (18 m/Ma), which is ~8–20 times greater than the average erosion rates throughout the same watershed. Much of the relief along the margins of the Springfield Plateau and the James River apparently has developed since the Early Pleistocene. The James River paleoentrance is ~9 m above the active floodplain. The history here is more speculative, but the finingupward sequence of red clay above the Gravel Beds (~0.74 Ma) seems to represent downcutting of the James River below that level, with progressively finer suspended sediment being backflushed into the cave until floods could no longer reach that entrance. Thus, the long-term incision rate of the James River is ~0.12 mm/yr (12 m/Ma). Extrapolating this rate backward, a locally preserved strath terrace ~15 m above the active floodplain would have been occupied last at ~1.2 Ma. Evidence for an even older river level is preserved nearly directly above the cave’s main passage. Here, rounded river gravels are preserved at an elevation ~30 m above the current floodplain. Again extrapolating the 12m/Ma rate backward, this level would have been last occupied at ~2.5 Ma. Interestingly, these dates of 2.5, 1.2, and 0.74 Ma are very close to major expansions of the early Laurentide Ice Sheet into northern Missouri (Balco and Rovey, 2008). The correlation between terrace levels (or their incision) and glaciation requires much extrapolation and is obviously speculative. Nevertheless, testing of this possible correlation could stimulate additional research into the geomorphic development of the southern Springfield Plateau and the James River Basin.

Northview Formation Compton Limestone Bachelor Formation “Swan Creek Sandstone” Mbr.

O R D OV I C I A N Ibexian

36

Cotter Dolomite

Leave Convention Center. Turn right onto Sycamore Street, and then turn right again onto Main Street. Follow Main Street for one block to Branson Landing Boulevard. Mileage begins at this intersection. Mileage (cumulative and interval) 0.0

0.0

0.4

0.4

1.0

0.6

1.2

0.6

2.1

0.5

Intersection of Main St. and Branson Landing Blvd. Turn left onto Branson Landing Blvd. Go through roundabout, and stay on Branson Landing Blvd. Intersection with Hwy. 65. Turn right (north) onto Hwy. 65. Road cuts to the left are in the Cotter Dolomite (see Fig. 7). More Cotter Dolomite. All of the road cuts for the next 11 miles are in the Cotter. The Cotter is a peritidal deposit. Fresh cuts show color banding corresponding to cyclic alternation between subtidal, intertidal, and supratidal subfacies.

Rockaway Conglomerate Mbr.

Jefferson City Dolomite base not reached sandstone

cherty limestone

siltstone and shale

dolomite

limestone

cherty dolomite

oölitic limestone

breccia

Figure 7. Stratigraphic column, southwest Missouri (after Thomson, 1986).

Riverbluff Cave, Springfield, Missouri 4.5

2.4

4.6

0.1

7.0

2.4

7.5

0.5

9.2

1.7

10.2

1.0

10.3

0.1

11.7

1.4

12.4 13.1

0.7 0.7

14.8

15.8 16.1

1.7

1.0 0.3

Intersection with Ozark Mountain Highroad. Continue north on Hwy. 65. The hilltops provide good views of the Salem Plateau Physiographic Subprovince— relatively flat ridges are dissected by deep valleys. The round hilltops are capped by Lower Mississippian strata, or residuum of these strata above Cotter Dolomite. These hills are called “knobs” by locals; knobs without trees are “baldknobs.” A local vigilante group began meeting atop these hills in the late 1800s and, hence, became known as “Baldknobbers.” One of Branson’s popular music groups takes their name from these earlier residents. Spectacular view of knobs to the left. Note the resemblance to glacial kames. Another good view of knobs, this time off to the right. For the next half mile road cuts expose clayfilled “cutters” within the Cotter. Shallow cutters are common within the upper Cotter, but sinkholes and caves are not. Dolomitization and ubiquitous shale laminae account for its resistance to karstification. The red cherty residuum on both sides of the highway is typical of that developed from the Mississippian formations, although no Mississippian bedrock remains here. Intersection with Hwy. 176E. Continue north on Hwy. 65. From this ridge the Burlington Escarpment (edge of the Springfield Plateau) is faintly visible ahead. Look for a cluster of radio towers. Small thrust fault in Cotter on the right side. Entrance to Saddlebrook Village. The road cut directly ahead exposes Mississippian strata (Bachelor through Elsey Formations) in the upper portion. North of this point ridges are capped by Mississippian outliers. Vegetation band (cedars) along the slopes marks the approximate position of the Swan Creek member (sandstone) within the Cotter. Elsewhere, vegetation differences commonly mark the Ordovician-Mississippian unconformity with cedars within the Cotter and hardwoods rooted above within the more clay-rich Mississippian residuum. Entrance to Busiek State Forest. Exposure of Compton through Reeds Spring Formations on the right. The Northview is the thin green shale layer. We are near the southern limit of the Northview Formation,

16.7

0.6

18.3

1.6

18.9

0.6

21.3

2.4

25.2

3.9

25.9

0.7

26.5

0.6

26.7

0.2

31.0 31.8

4.3 0.8

33.2

1.4

33.4

0.2

36.6

3.2

37 which pinches out just south of Branson. Here the Northview is about two feet thick, but north of Springfield it reaches nearly 90 feet in thickness. Exposures of the Elsey Formation. We are also near the northern limit of the Reeds Spring Formation, which thins and grades into Elsey lithology. The road cut on the left is cut by the Highlandville Fault. The Northview is a good marker bed; it shows ~20 feet of uplift on the south side. From here we have a long grade up to the Springfield Plateau. For the next few miles the road follows a narrow southward trending ridge of the Burlington-Keokuk Formation. This ridge is bordered on either side by streams entrenched into the Cotter Dolomite and eroding headward into the Springfield Plateau. We’re now on top of the Springfield Plateau, which is capped by the Burlington-Keokuk Formation. Note the much flatter topography. The Burlington-Keokuk is very hard and resistant to physical weathering, but it is highly susceptible to chemical weathering and karstification. The stream density is low due to internal drainage; much of the local relief is due to sinkhole formation. Road cuts of Burlington-Keokuk Formation on the left. We’re now passing through the city of Ozark. Descending into the valley of the Finley River. More exposures of the BurlingtonKeokuk Formation. Exposures of cherty Elsey Formation along the Finley River. Intersection with Hwy. 14. Exit from Hwy. 65 and turn left (west) onto Hwy. 14 and proceed toward Nixa. Entering Nixa. Intersection with Hwy. 13/160. Continue west on Hwy. 14. Intersection with Nichols/Cox Road. Turn right (north) onto Nichols/Cox Road. We are now crossing part of the Nixa Sinkhole Plain, one of the most intensely karstified areas of the Ozarks. Most of the stock ponds are plugged sinkholes. Most of the sinkholes are of the gradual subsiding type, but occasionally a rapid cover-collapse sink will also open. In 2006, a rapid sinkhole collapse ~3 miles to the east swallowed a garage and part of the attached house. Descending into the James River Valley.

38

Rovey et al.

36.8

0.2

37.4

0.6

37.7

0.3

Crossing a high bedrock terrace of the ancestral James River. Cross the James River. Intersection with Rivercut Road. On the left (west) note the elevation of the active floodplain. To the right (east) is a low alluvial terrace. A small remnant of a higher alluvial terrace is preserved just above and to the left of the Rivercut Golf Course sign. The James River paleoentrance to Riverbluff Cave is at the top of this upper terrace. Turn left (west) onto Rivercut Road. Turn right into the driveway of the Missouri Institute of Science, and Riverbluff Cave.

REFERENCES CITED Balco, G., and Rovey, C.W., II, 2008, An isochron method for cosmogenicnuclide dating of buried soils and sediments: American Journal of Science, v. 308, no. 10, p. 1083–1114, doi: 10.2475/10.2008.02. Bosch, R.F., and White, W.B., 2004, Lithofacies and transport of clastic sediments in karstic aquifers, in Sasowsky, I.D., and Mylroie, J., eds., Studies of Cave Sediments: Physical and chemical records of paleoclimate: New York, Kluwer Academic/Plenum Publishers, p. 1–22. Cande, S.C., and Kent, D.V., 1995, Revised calibration of the geomagnetic polarity timescale for the Late Cretaceous and Cenozoic: Journal of Geophysical Research, v. 100, no. B4, p. 6093–6095. Graham, R.W., 1998, The Pleistocene terrestrial mammal fauna of North America, in Janis, C.M., Scott, K.M., and Jacobs, L.K., eds., Evolution of Tertiary Mammals of North America, Volume 1: Terrestrial Carnivores, Ungulates, and Ungulatelike Mammals: Cambridge University Press, p. 66–71. Granger, D.E., 2006, A review of burial dating methods using 26Al and 10Be, in Siame, L.L., Bourlès, D.L, and Brown, E.T., eds., In situ-produced cosmogenic nuclides and quantification of geological processes: Geological Society of America Special Paper 415, p. 1–16. Granger, D.E., Kirchner, J.W., and Finkel, R.C., 1997, Quaternary downcutting rate of the New River, Virginia, measured from differential decay

of cosmogenic 26Al and 10Be in cave-deposited alluvium: Geology, v. 25, p. 107–110, doi: 10.1130/0091-7613(1997)025<0107:QDROTN> 2.3.CO;2. Granger, D.E., Fabel, D., and Palmer, A.N., 2001, Pliocene-Pleistocene incision of the Green River, Kentucky, determined from radioactive decay of cosmogenic 26Al and 10Be in Mammoth Cave sediments: Geological Society of America Bulletin, v. 113, p. 825–836, doi: 10.1130/0016-7606(2001)113<0825:PPIOTG>2.0.CO;2. Kurtén, B., and Anderson, E., 1980, Pleistocene mammals of North America: New York, Columbia University Press, 442 p. Lisiecke, L.E., and Raymo, M.E., 2005, A Pliocene-Pleistocene stack of 57 globally distributed benthic δ18O records: Paleoceanography, v. 20, PA 1003, doi: 10.1029/2004PA001071. Lister, A., and Bahn, P., 2007, Mammoths: Giants of the Ice Age: Berkeley, University of California Press, 192 p. Raymo, M.E., Oppo, D.W., and Curry, W., 1997, The mid-Pleistocene climate transition: A deep sea carbon isotopic perspective: Paleoceanography, v. 12, no. 4, p. 546–559, doi: 10.1029/97PA01019. Rovey, C.W., II, Balco, G., Forir, M., Gaunt, D., and Kean, W.F., 2010, Stratigraphy, paleomagnetism and cosmogenic-isotope burial dates of fossilbearing strata within Riverbluff Cave, Greene County, Missouri: Journal of Caves and Karst Studies (in press). Stock, G.M., Anderson, R.S., and Finkel, R.C., 2004, Pace of landscape evolution in the Sierra Nevada, California, revealed by cosmogenic dating of cave sediments: Geology, v. 32, p. 193–196, doi: 10.1130/G20197.1. Stock, G.M., Granger, D.E., Sasowsky, I.D., Anderson, R.S., and Finkel, R.C., 2005, Comparison of U-Th, paleomagnetism, and cosmogenic burial methods for dating caves: Implications for landscape evolution studies: Earth and Planetary Science Letters, v. 236, p. 388–403, doi: 10.1016/ j.epsl.2005.04.024. Stock, G.M., Riihimaki, C.A., and Anderson, R.S., 2006, Age constraints on cave development and landscape evolution in the Bighorn Basin of Wyoming, USA: Journal of Caves and Karst Studies, v. 68, no. 2, p. 76–84. Thomson, K.C., 1986, Geologic Map of Greene County: Watershed Management Coordinating Committee, Springfield, Missouri, 1 sheet [now distributed by the Watershed Committee of the Ozarks]. White, W.B., 2007, Cave sediments and paleoclimate: Journal of Caves and Karst Studies, v. 69, no. 1, p. 76–93.

MANUSCRIPT ACCEPTED BY THE SOCIETY 22 JANUARY 2010

Printed in the USA

The Geological Society of America Field Guide 17 2010

Civil War and cultural geology of southwestern Missouri, part 1: The geology of Wilson’s Creek Battlefield and the history of stone quarrying and stone use Joseph T. Hannibal* Cleveland Museum of Natural History, 1 Wade Oval Drive, Cleveland, Ohio 44106, USA Kevin R. Evans* Department of Geography, Geology, and Planning, Missouri State University, 901 S. National Avenue, Springfield, Missouri 65897, USA

ABSTRACT This field trip provides an overview of geological features in southwestern Missouri that are related to the American Civil War and to human culture. This includes the geology and history of the Wilson’s Creek National Battlefield (where the second important battle of the American Civil War was fought on 10 August 1861), Zágonyi’s Charge (25 October 1861), the Battle of Springfield (8 January 1863), and the gravestones and monuments of the National Cemetery in Springfield in which many of those who fought at Wilson’s Creek and other Civil War conflicts are buried. Other stops include the Springfield Underground and the quarries and facilities at what was once the town of Phenix (which, along with Carthage, Missouri, was the home of some of the largest dimension-stone quarries west of the Mississippi River); and a reconstructed mill site in Point Lookout, just south of Branson. Most of the field trip involves outcrops, quarries, and bedrock composed of the Mississippian BurlingtonKeokuk limestones (undivided), providing numerous chances to examine outcrops and products made of limestone and chert.

INTRODUCTION

tle of the war. Both Union and Confederate troops desired control of the region in part due to nearby natural resources. And the karst deposits of the region provided springs whose waters were desired by armies on both sides of the war. The 10 August 1861 Battle of Wilson’s Creek occurred where it did in part because of the availability of spring and stream water. And one of the central points of the conflict was a bald-topped limestone prominence

This field trip focuses on the geological aspects of historical events, particularly during the Civil War, in southwestern Missouri and explores the use of local stone over the past 200 years in that part of the state. A number of battles occurred in this region, including the Battle of Wilson’s Creek, the second important bat-

*[email protected]; [email protected]. Hannibal, J.T., and Evans, K.R., 2010, Civil War and cultural geology of southwestern Missouri, part 1: The geology of Wilson’s Creek Battlefield and the history of stone quarrying and stone use, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, p. 39–68, doi: 10.1130/2010.0017(04). For permission to copy, contact editing@ geosociety.org. ©2010 The Geological Society of America. All rights reserved.

39

Hannibal and Evans Springfield plateaus. The geology of the upper White River valley is featured in a companion article (Evans, this volume). A large portion of southwestern Missouri is underlain by lower and middle Mississippian carbonates (Fig. 1), including, in reverse stratigraphic order, the Meramecian Warsaw Formation and the Osagean Burlington-Keokuk limestones and Elsey Sys.

Ser.

PENN. Meramec. Desm.

Sub.

Channel sandstone Warsaw Formation Carthage Stone

MISSISSIPPIAN Osagean

Short Creek Oölite Mbr.

Phenix Stone Burlington-Keokuk limestones (undivided) Springfield Underground Elsey Formation Pierson Limestone

Kind.

known afterwards as “Bloody Hill.” A famous sinkhole on the battleground was the original burial site for many of the men killed during this battle. The history of stone use in southwestern Missouri extends back to that of the Native Americans and has continued until the present day. Local limestone was utilized for buildings and lime, beginning in the nineteenth century. In the mid-twentieth century, this region once boasted that it had the largest dimension-stone quarries west of the Mississippi River. These are the quarries of the Carthage area in east-central Jasper County and the Phenix quarry in northwest Greene County. These areas historically have stood out as producers of building stone and “marble” (polished limestone) slabs. Mississippian limestones were utilized in both: Phenix quarried the Osagean Burlington-Keokuk limestones (undivided), and Carthage Marble quarried the younger Meramecian Warsaw Formation. Burlington-Keokuk limestones were also quarried outside of the small town of Wilson Creek, located within the boundaries of the Battlefield. This field trip provides an overview of geological features in southwestern Missouri that are related to the American Civil War and to human culture. In the following sections, we discuss: the physiographic and geologic setting of southwestern Missouri; the cultural geology of the area, including quarrying of Carthage and Phenix “marble”; and the Civil War in southwestern Missouri, especially aspects of the war tied into geology and geological resources. We then describe six stops: Springfield Underground; the Phenix “marble” quarries; Wilson’s Creek Battlefield; Zagonyi Park, Springfield (site of Zágonyi’s Charge on 25 October 1861), and the site of Civil War Fort No. 4 in Springfield; Springfield National Cemetery; and Edwards Mill, a reconstructed mill in Edwards Point, just south of Branson, Missouri. Please note some variation in spelling in this guidebook chapter: Wilsons Creek is the Creek (we use U.S. Geological Survey usage here), versus the Battle of Wilson’s Creek (the most accepted usage for the battle); also Zágonyi is the correct spelling of the Hungarian general but the name of the park named for the general lacks the accent mark.

Northview Formation Compton Limestone Bachelor Formation “Swan Creek Sandstone” Mbr.

O R D OV I C I A N Ibexian

40

Cotter Dolomite

PHYSIOGRAPHIC AND GEOLOGIC SETTING Rockaway Conglomerate Mbr.

In the classic work on the physiographic provinces of eastern North America (Fenneman, 1938), the Ozark Plateaus Province was divided into four sub-provinces: the St. Francois Mountains, Salem Plateau, Springfield Plateau, and Boston Mountains. The geology of each sub-province controls the physiographic expression of the landscape. The St. Francois Mountains are cored by Precambrian igneous rocks. The Salem Plateau is underlain by Middle Cambrian through Lower Ordovician dolomite and sandstone (Sauk Sequence). Mississippian carbonates dominantly comprise the Springfield Plateau, and Pennsylvanian sandstones and shale crop out extensively in the Boston Mountains. The upper White River drainage basin is etched deeply into the southern part of the Ozark Plateaus, and probably should comprise a fifth subprovince that is characterized by deep incision of the Salem and

Jefferson City Dolomite base not reached sandstone

cherty limestone

siltstone and shale

dolomite

limestone

cherty dolomite

oölitic limestone

breccia

Figure 1. Geologic column showing rock units exposed in southwestern Missouri (after Thomson, 1986). Black bars indicate units exposed at Carthage and Phenix Stone quarries and at the Springfield Underground.

Civil War and cultural geology of southwestern Missouri, part 1 Formation. These Mississippian rocks are underlain by lower Ordovician carbonates. Clay and chert-rich residuum of the Springfield Plateau in the vicinity of Springfield is underlain by the Burlington-Keokuk limestones (undivided). A thin limestone unit assigned to the Warsaw Formation (Meramecian Series) crops out locally on the western part of the Springfield Plateau. The Short Creek Oölite, the uppermost member of the Keokuk, is the marker unit that makes it possible to distinguish these units in the field and in core. Lower Mississippian strata mostly crop out around the periphery of the plateau or in valley exposures where streams are deeply incised. Lower Mississippian strata (Kinderhookian Series) include the Bachelor Formation, Compton Limestone, and Northview Formation. Around the Springfield Plateau, Kinderhookian strata unconformably overlie lower Ordovician strata assigned to the Ibexian Series. Stratigraphic units above the Kinderhookian and below the Burlington-Keokuk limestones, in stratigraphic order, include the Pierson Limestone and Reeds Spring and Elsey formations of Osagean age. The latter units are limestones with up to 50% chert. The combined Burlington-Keokuk limestones are ~160 ft (~50 m) thick. Both the Burlington and Keokuk limestones are crinoid-rich, ranging from wackestone to grainstone textures; both were deposited in a relatively high-energy carbonate banktop setting. Because of the high-magnesium calcite content of crinoids, the Burlington-Keokuk is particularly prone to dissolution and karstification. The sizes of grains present in these limestones may also help in developing adequate pathways for water to infiltrate the stone and in creating the needed porosity and permeability to remove saturated waters (George H. Davis, 2010, personal commun.). Whatever the exact mechanism, numerous caves, sinkholes, and springs are found in the karst terrain underlain by the Burlington-Keokuk limestones. Despite being situated in the Ozark Mountains, Springfield is located on a relatively flat and nearly featureless plain. This relatively flat area around Springfield, however, is pock-marked with sinkholes. A few of the small streams that drain the Springfield area have formed solution valleys of relatively low relief. Springfield-Greene County Parks oversees three parks that feature caves and springs, including Doling and Sequiota parks (Fig. 2) and Valley Water Mill. There are a plethora of springs in this region. There were more than 300 springs recorded in Greene County, Missouri, in 2001 (Bullard et al. 2001).

41

Missouri was that of the Native Americans, who used the chert found in this sequence for various types of tools, and sandstones of the region for implements used in milling grain (Chapman, 1975, p. 7; National Park Service, 2004, v. 1). This light-colored chert, derived from the Burlington-Keokuk, is typically referred to as Burlington chert in the reports of archaeologists (National Park Service, 2004, v. 1, p. 3-111–3-112). Limestones of the area were used in local construction by European-Americans as they settled in this area, especially as foundation stone. Larger-scale quarrying in southwestern Missouri began with the need for good dimension stone as cities such as Carthage and Springfield grew. Sandstones were used by Native Americans for grinding tools and by European-Americans for foundations. Limestone in Missouri also was used for lime in agriculture and for mortar in the early nineteenth century. The easiest way to produce lime at this time was to calcine (heat to high temperature to drive off carbon dioxide) limestone in a rudimentary kiln. The calcining would result in the breaking up of the stone so that it could be used as agricultural lime, and as a key ingredient of mortar. Larger, more elaborate kilns were eventually constructed in areas with suitable limestone bedrock. Carthage and Phenix Quarries Two quarry regions of southwestern Missouri have historically stood out as producers of lime, building stone, and, especially, polished limestone (“white marble”) slabs. These are the Carthage area quarries (Figs. 3 and 4) in east-central Jasper County and the Phenix area quarries in northwest Greene County. These quarry areas have been discussed in Buckley and Buehler’s classic 1904 work on Missouri quarries and Hinchey’s later report on Missouri “marble” (Hinchey, 1946). The Carthage area became the center of Missouri’s limestone industry just after 1900 (Buckley and Buehler, 1904, p. 121), stimulated, at least in part, by the need for building materials in response to the

CULTURAL GEOLOGY The geology and hydrology of the region have been important for the cultural development of the Ozarks. The carbonates that underlie this region have yielded lime, building stone, aggregate, water, and, after underground quarrying, extensive, secure underground storage space. These carbonates contain varying amounts of chert, which were utilized by Native Americans for tools, and which affect the usability of these carbonates for building stone and aggregate. The chert also is a noticeable component of the “flinty” soils of the area. The earliest use of stone in southwestern

Figure 2. Sequiota Spring, emanating from a cave, in southern Springfield (2009 photo).

42

Hannibal and Evans

regional growth due to the lead and zinc mining in the area (Carthage Marble Corporation, ca. 1956, p. 19). The Carthage Marble Company was created in 1927 by the consolidation of six small companies, included the Carthage Marble and White Lime Co. (Fig. 3), and the F.W. Steadley Co. By the 1950s, the Carthage Marble Company had what were claimed to be the largest gray marble quarries in the world and the largest quarrying and finishing complex for marble west of the Mississippi River (Carthage Marble Corporation, ca. 1956, p. 19–20). The stones from the Carthage and Phenix areas have been used for signature buildings of southwestern Missouri (e.g., Fig. 5). There were certain advantages to quarrying in southwestern Missouri. Chief was the availability of suitable stone. The relatively warm climate of southwestern Missouri (with relatively few days of below-freezing temperatures) allowed quarrying operations to continue for most of the year, giving the region an advantage over quarries in colder climes. Both the Carthage and Phenix quarries utilized Mississippian limestones. Phenix quarried the Osagean BurlingtonKeokuk limestones (undivided) and the Carthage companies quarried the younger Meramecian Warsaw Formation (Fig. 1).

Figure 3. Carthage Marble and White Lime Co., 1890s illustration from the Carthage Press (1889), courtesy of the Powers Museum, Carthage, Missouri.

Figure 4. The quarries at Carthage in the 1950s. (Carthage Marble Corporation, ca. 1956, cover illustration.)

Both stones were used for decorative stone and lime. Stone from the two quarry areas are quite similar in appearance; both come in shades of gray and contain generally similar fossils (pelmatozoan columnals, brachiopods, etc.) and both may or may not be stylolitic. When Carthage and Phenix stone was originally cut into slabs by means of gang saws in the early 1900s, the cuts were made parallel to bedding. Later, both stones were also cut perpendicular to bedding. For interior use, Phenix stone was typically set perpendicular to bedding (Carthage Marble, 1961, no. 5); an example of this is seen in the second and third floor interior walls of the rotunda of the Missouri State Capitol building in Jefferson City. The stylolitic surfaces in both formations are typically parallel to bedding in outcrop, but the thickness and amount of organic and insoluble residue in the sutures is quite variable (see, for instance Buckley and Buehler, 1904, p. 163). Quarry workers typically called stylolites crow-feet or suture lines. They have also been called veins in the stone industry. Whatever they are called, these stylolitic surfaces add to the character of both stones. Both were cut in thin slabs both parallel and perpendicular to bedding giving stylolites different expressions: perpendicular cuts, resulting in what were known as “veined” stone, show the stylolites in cross section as jagged lines; parallel cuts, resulting in what is known in the stone trade as fleuri, show the stylolites as a dark, diffuse, undulatory pattern. Carthage Marble (and before that its predecessor, F.W. Steadley) produced these cuts under the names Ozark Gray Veined and Ozark Fleuri. If the stylolites are tightly knit (that is, without any open spaces), slabs will retain their integrity when used as decorative stone. Stylolitic stone, however, is problematical when the stone is used outdoors, especially when stylolitic surfaces are exposed in a vertical position (Fig. 6) In his classic monograph, Geology of Missouri, E.B. Branson warned against such vertical use, and also recommended that stone with stylolites that were greater than ¼ inch from tip-to-tip not be used for walls (1944, p. 389).

Figure 5. Entranceway of the Jasper County Courthouse, Carthage, Missouri. This 1895 building features elegant Romanesque stone arches. The stone was quarried by the Carthage Stone Company.

Civil War and cultural geology of southwestern Missouri, part 1 Distinguishing the Stones from Phenix and Carthage Buckley and Buehler (1904, p. 122) characterized the stone in the Carthage quarry that they examined as having “a slightly bluish gray tint, the upper beds being whiter than those deep in the quarry” and the dressed stone as being white, and Hinchey (1946, p. 29) noted it as gray and bluish gray. The stone from Phenix was noted as being somewhat darker than Carthage (Buckley and Buehler, 1904, p. 164). The Phenix stone is also somewhat browner than Carthage stone. When commercial polished slabs of the two stones are compared, Phenix stone (Napoleon Gray) tends to be close to a pale yellowish brown (Munsell 10YR 6/2) whereas Carthage stone (Ozark Gray) varies from a medium light gray (N7) to a light olive gray (5Y 6/1). The color plates published in Marble of the Month also show the Phenix stone (Napoleon Gray; Carthage Marble, 1961, no. 5), as being brown compared to that of Carthage (Ozark veined and Ozark fleuri, also known as Ozark Gray veined and Ozark Gray veinless; Carthage Marble, 1962, nos. 2 and 9). Roughly cut (thus lighter colored) pieces of both stones also differ in color in a similar way, but the color differences are more difficult to distinguish. Phenix marble had the reputation of having more prominent stylolites. Still, these differences can be subtle, so it is difficult to distinguish the two stones when used on the outside or even in the inside of a building. Both Ozark Gray and Napoleon Gray have been classified as class-A marbles using the Marble Institute of America clas-

Figure 6. Limestone block in the entranceway of the Jasper County Courthouse, Carthage, Missouri. Stylolitic surfaces have preferentially weathered. Scale is in cm.

43

sification. This classification is based on the practical workability of the stone. Class A marbles are uniform with few flaws or void spaces. They may, however, have veining, but typically this is muted as with Botticino “marble” from Italy. The veining of the Missouri stones is more prominent than Botticino, however. History of Carthage and Phenix Stone Use The history of the use of Carthage marble, also known as Carthage limestone or Carthage stone, has been chronicled in a number of publications (e.g., Anonymous, ca. 1956, p. 28–29). Carthage stone was originally used for exterior construction, with the first use just after the Civil War for paving material and trim. Stone in the Carthage area was subsequently calcined in lime kilns in the 1880s in response to the need for lime after a large fire in Carthage. The first building stone quarry was opened in the 1880s. According to Wharton et al. (1969, p. 115) polished slabs were being fabricated by 1910, but their production probably began somewhat earlier (Michele Hansford, January 2010, personal commun.). Phenix stone was primarily an interior stone, but was also used for some exterior construction including larger buildings such as the Greene County courthouse, statuary and mausoleums. It was also used for stone facing for houses in Springfield, Missouri. Both Carthage and Phenix stone were extensively used for shower stalls, including prefabricated compartments (e.g., Carthage Marble, 1961, no. 5). These stones were used from coast-to-coast. In the 1920s, one of the Carthage quarriers, F.W. Steadley, was boasting that it was one of the largest marble quarriers in the west. By the 1950s, the Carthage Marble Company, the successor to Steadley and other firms after the consolidation of 1927, employed ~350 people. The Carthage Marble Corporation purchased the operation at Phenix in 1953 (see Stop 2). Carthage Marble continues to operate in St. Louis, but it no longer owns an interest in the Carthage, Missouri, or Phenix operations. The Carthage Marble Corporation was once noted for the production of its Marble of the Month. These were 3-by-5–inch samples of a wide variety of stone accompanied by illustrated descriptive sheets. The accompanying sheets began as two-color single-sided paper sheets and evolved into two-sided cardboard sheets including a large color illustration of the featured stone. The company issued binders to keep the sheets together. Among the various stones promoted, of course, were the products of the Carthage-owned quarries. The Marble of the Month materials were sent primarily to architects and stone dealers. The series was produced in the 1960s and 1970s. These samples and the accompanying sheets remain invaluable in identifying building and decorative stones. The structures built using Carthage stone (Warsaw Formation) include the beautiful Jasper County Courthouse (Fig. 5; Buckley and Buehler, 1904, pl. 19), the Nelson-Adkins Museum of Art in Kansas City, Missouri, and a number of buildings on the Springfield Campus of Missouri State University, including Carrington Hall (completed in 1908). Most of the stone has held up quite well over time, except in a few cases such as when the stone

44

Hannibal and Evans

has been turned on its side and preferentially weathered along stylolitic surfaces (Fig. 6). Carthage stone (with the trade name Ozark Gray marble) was also used for the exterior of the Missouri Capitol building, but only after a law requiring Missouri stone to be used was passed, and the lower bid using Indiana Limestone was therefore eliminated (Anonymous, 1913, 1917). And, as the label on the paperweight made of this stone, given out at the 28th International Geological Convention (1989), states, “it was used in many buildings and monuments in Washington, D.C.” Stone from these quarries that was not suitable for dimension stone was crushed and used for a number of purposes including aglime, terrazzo, and aggregate (Fellows, 1967). “Marble” blocks are no longer being actively cut from these quarries today, but previously cut blocks from both quarries are still being utilized to this day. The chief use of southwestern Missouri carbonates in the twenty-first century, however, is for aggregate. More information on the history of the stone quarrying in southwestern Missouri can be found in the references cited in this paper as well as those included on the web sites of Powers Museum et al. (2010) and Phillips (2010). Underground Storage Missouri is notable for its utilization of underground spaces. In fact, the state of Missouri probably has more underground storage space developed than any other state in the United States, and may have more per-capita underground resource space than anywhere on the planet (George H. Davis, 2009, personal commun.). Most of these are former mines (underground quarries) now used as storage facilities (Whitfield, 1981) and for manufacturing, but others are used for underground parking, education facilities (e.g., Park University), and other purposes. These facilities are advantageous as they offer a more controlled climate and greater security than above-ground facilities, as well as protection from storms and tornadoes. Notable facilities in southwestern Missouri include the Americold facility in Carthage (Fig. 7) and the Springfield Underground in Springfield (Stop 1). The former is developed in the Warsaw Formation; the latter in the Burlington-Keokuk limestones (undivided) (Fig. 1). The Carthage facility was a planned development, with sequential underground quarrying of stone and utilization of underground space. The facilities here have an average temperature of 56.7 °F. The Americold facilities in Carthage are quite large and are noted for their underground tennis court (Whitfield, 1981, fig. 6). The Springfield Underground began with subsurface mining in the 1950s.

In Missouri and other border states, the public was deeply divided in its sympathies. This division led to early conflict within the state. Missouri had strategic importance as it bordered the Mississippi River, its population was a source of military recruits and materiel, and the state had access to key minerals. A number of events leading up to the war occurred in Missouri (and adjacent Kansas). Indeed, John Brown raided Missouri as part of the prewar conflicts in Kansas and Missouri, and the war began early in Missouri. From beginning to end, the State of Missouri was the scene of many battles and guerrilla activity throughout the War Between the States. And some of this conflict spilled over into the post-war era continuing long after the war has ended (Evans, this volume). Twenty-nine major Civil War engagements are recognized in Missouri by the National Park Service American Battlefield Protection Program (National Park Service, http://www.nps.gov/ history/hps/abpp/battles/bystate.htm#mo, accessed 17 October 2009). If all actions were included, such as ambushes and skirmishes, the number of events would be in excess of 900 according to the Missouri Commandery of the Military Order of the Loyal Legion of the United States (2009). Edom (1963, p. 146–155) lists 716 battles, skirmishes, and events in the Missouri Sketch Book. Southwestern Missouri was a focus of much of this conflict. Union forces considered Springfield, located on the watershed divide between the Osage and Arkansas rivers, as the “key to the whole southwestern part of Missouri, commanding an area of nearly 60,000 square miles” (U.S. War Department, 1881, p. 551). And so it was fortified with several earthen forts (see Stop 4b for more on these), causing Col. Joseph Shelby (1888, p. 204) of the Confederate Calvary to call it the Union “Gibraltar of the Southwest.” This phrase, however, has been dismissed as being hyperbolic (Britton, 1899, p. 447). Several Civil War battles unfolded in and around Springfield, a major town in southwestern Missouri with a population of ~1,500 according to the 1860 census. Just south of Springfield, in the hills along Wilsons Creek, the Union Army and the Confederate Army clashed on 10 August

THE CIVIL WAR IN SOUTHWESTERN MISSOURI The Civil War in Missouri and the Importance of Springfield During the Civil War, Missouri was known as a border state, that is, a slave-holding state that shared a border with a free state.

Figure 7. Underground storage entranceways to the Americold facilities, the old Carthage Marble quarries.

Civil War and cultural geology of southwestern Missouri, part 1 1861, in what has been considered the second major battle of the Civil War, and the first major battle west of the Mississippi River. To convey the significance of this battle, after the First Battle of Bull Run (21 July 1861), the Battle of Wilson’s Creek, with more than 16,000 troops involved, was the second largest battle ever fought by Americans up to that time (Knapp, 1993, p. 18–19). Subsequently Springfield became the location of two minor engagements of note: Zágonyi’s Charge, also known as the Battle of Springfield I (25 October 1861), and the Battle of Springfield II, or simply the Battle of Springfield (8 January 1863). Between these clashes, Fulbright Spring, just west of Springfield, was the location of Price’s winter quarters from 25 December 1861 until 12 February 1862 (Anderson, 1868, p. 134–141). After the Missouri State Guard vacated and Gen. Curtis arrived, five earthen and timbered forts, known only by their assigned number, were constructed for the defense of Springfield in 1862. Citizens of the city were marshaled in to work on the fortifications which were completed by early January of 1863. Strategic Minerals Even prior to the Civil War, Missouri was known to have a great wealth of minerals, notably galena (the chief ore of lead), zinc, iron ore, and coal, which had direct military importance. Southwestern Missouri was one of the leading pre-war producers of lead and zinc ore. Lead ore had been discovered in Granby, Missouri, in 1850 and was under intense production in southwestern Missouri by the beginning of the war. These ores were mined from Mississippian carbonates of what was to be known as the Tri-State District zinc-lead ore deposits. The lead ore galena is the state mineral of Missouri. There had been some exploration for lead in the Wilson’s Creek Battlefield area after the war (National Park Service, 2004, v. 1, p. 21). A number of small mines were located west of Springfield near the present-day town of Bois D’arc. Lead was one of the chief strategic military supplies produced in Missouri during the war (see Aber et al., this volume) Both sides used lead mined and smelted in Missouri, with Union troops capturing lead ingots (pigs) from smelters that had provided lead to secessionists in the St. Louis area in May of 1861, a little more than a month after the start of the war (Cole, 1881). The lead ore deposits at Granby were purported by some to be the largest in the country, the continent, and possibly even the world (Blow and Kennett, 1862; Rosecrans, 1864). This lead was mined by both sides, but not at the same time (Winslow, 1894a, p. 291; Buckley and Buehler, 1906, p. 1–2; see Stop 3a for additional information). Both sides (e.g., White, 1881) made their own bullets at times in Missouri. The presence of iron ore in Missouri had been known since the explorations of Father Marquette, but large-scale production of iron from Missouri ores did not occur until the 1840s, with production peaking in the 1860s (Crane, 1912, p. 4). This source of iron was used and shipped via rail at the beginning of the Civil War; iron was needed for hardware, artillery ordinance (Caporaso et al., 2008), artillery (field guns were made of iron or bronze),

45

railroad rails, horseshoes (White, 1881), ironclad boats, and other materiel (Fig. 8). Coal, of course, had many uses, especially for steam engines. The caves of Missouri (and northern Arkansas) also were a source of saltpeter (nitrate minerals) used in making gunpowder. These were utilized by Confederate troops. See Evans (this volume) for more on strategic natural resources and the war in Missouri. Geologic Influences on Battles in the Springfield Area There are geological aspects to just about every battle on land, including those of the American Civil War (Higgins, 2002). The battle of Gettysburg (Cuffey et al., 2006) is the exemplar in the effect of geology on the battle, particularly with the opposing armies arrayed upon two intrusive bodies within a sedimentary basin. The loess deposits at Vicksburg were crucial elements of the defense of that key Mississippi River outpost. According to Zen and Walker (2000), inadequate Union defenses at Thoroughfare Gap, a water gap through a resistant quartzite ridge, played a crucial role in the Confederate victory at the Second Bull Run. Lithological differences, including differences in underlying carbonates, played a key role in the terrain upon which the Chickamauga campaign played out (Henderson, 2004). Topographic expression of the geologic setting and strategic water supplies supplied by springs were key elements of the Battle of Perryville in Kentucky (Andrews, 2005, p. 3). Pittman (2002, p. 99) has argued that terrain has played a central role in all Civil War battlefields, and others have echoed this view. And a number of participants in the war were knowledgeable about geology and terrain (Pittman, 2000). Mapping, including topographic mapping was used during the war, and Civil-War era maps of some of the battlefields in Missouri, including Wilson’s Creek, have been preserved (National Archives, 1986, p. 92–93). Maps showing topography remain essential for a good understanding of Civil War battles, whether the maps utilize hachures (Knapp, 1993), contours as in standard topographic maps (Kennedy, 1990), or other means of depicting topography.

Figure 8. Cannon near visitor center at Wilson’s Creek National Battlefield.

46

Hannibal and Evans

The caves and springs of the Springfield-Greene County Parks such as Doling and Sequiota parks and Valley Water Mill, outside of the city limits during the Civil War, likely played a role in the position of troops and movement prior to the battles. A natural well, a karst window with a shallow pool of water below, was one of the principal reasons Springfield was founded in its location on the southern bank of what later became known as Jordan Creek (Bullard, 2008, p. 2). Jordan and Fassnight creeks are located in central and southern Springfield respectively and would have provided ~50 ft (~15 m) of relief at most. Confederate defensive positions on high ground above Jordan Creek seemed to have played a minor role in the outcome of Zágonyi’s Charge. In contrast, the location of Fort No. 4 on the highest point south of the square could have offered some command over the field of battle to the south. The geology of the Wilson’s Creek Battlefield and the environs of Springfield also played a role in the battles that took place at these locales. Karst features developed in the Mississippian limestones at Wilson’s Creek affected the development and aftermath of the battle. Springs that emanated from the carbonate bedrock were key features in the positioning of armies and fortifications in the area. The terrain, since it was developed on karst, was also uneven in places in what was at the time a fairly open area. Glades developed on surficial or shallow bedrock affected the battle, most critically at the knob that would become known as Bloody Hill. The shallow depth to bedrock would also have an effect on the ability to dig entrenchments and gave an advantage to artillery. And, sadly, sinkholes were used for convenient burial of corpses. Probably the most important role that geology played was the actual location of the city. Springfield was founded in the early 1830s on the uplands of the Springfield Plateau. The original land was parceled from the Campbell homestead, approximately two blocks northeast of the square, where a small spring flowed into Jordan Creek. Just north of Jordan Creek is the divide between the Sac-Osage-Missouri and James-White rivers drainage basins. Springfield is situated on the backbone of the Ozark Mountains, and it quickly became a transportation hub. Native American trails predated development of European-American roads. During the Civil War, Springfield was the northern terminus of the Old Wire Road, which ran to Fayetteville, Arkansas. Numerous other regional roads radiated toward the north and south. As a consequence, Springfield was strategically important for controlling southwestern Missouri during the Civil War. Springfield is on an ecological boundary between prairies and woodlands. The Kickapoo Prairie was an expansive grassland south of Springfield. Just a few miles west of Springfield, the Great Prairie, a sea of tall grasses stretched across the landscape, extended intermittently into eastern Kansas. Gen. Lyon’s approach to Wilsons Creek came through these fields, where it is said that grasses grew tall enough for a horse and rider to easily travel in cover. There is a major precipitational gradient that runs more or less along the Missouri-Kansas border. Springfield

averages 40 inches (101.6 cm) of rain per year, whereas parts of eastern Kansas, which are mostly prairies, receive closer to 25 inches (63.5 cm). Following the Civil War, the rival city of North Springfield developed as a railroad hub and later a repair and paint shop for the St. Louis and San Francisco (Frisco) Railroad, which currently is BNSF Railroad. North Springfield and Springfield were merged in the 1920s. Today, Springfield remains a transportation hub, as well as a regional center for health care and education. The city of Springfield currently is home to more than 150,000 people with ~250,000 in the metropolitan area. Two small claims

Walnut Grove 2

Fair Grove

Willard

16 0

65 13

Ash Grove 44

Strafford 1 4b

4a 44

Springfield

5 3

Republic

60

Wilson’s C Creek eek National Battlefield

Ozark

Nixa

60

Sparta Billings

16 0

Highlandville Crane 65

Galena

Forsyth

Branson West

Branson 13

16 0

Hollister 6

N 5 mi (8 km)

MI SSOURI ARKANSAS

Figure 9. Sketch map showing location of field-trip stops, southwestern Missouri. (1) Springfield Underground; (2) Phenix “marble” quarries; (3) Wilson’s Creek Battlefield; (4A), Zagonyi Park; (4B) site of Fort No. 4; (5) Springfield National Cemetery; and (6) Edwards Mill.

Civil War and cultural geology of southwestern Missouri, part 1 to fame (or infamy) for Springfield are that it was the location of the first western gunfight, which took place on the square in 1865 between Wild Bill Hickok and Dave Tutt, and that it became a transportation hub on Route 66 (and later I-44; see Aber et al., this volume). FIELD TRIP STOPS Stops (Fig. 9) are arranged so that they can be visited in the course of a day, but a detailed visit to these sites could take several days. The stops can be visited in any order. Locations of all sites are noted. Some sites, however, require special permission (this is noted where relevant). Wilson’s Creek National Battlefield is accessible to the public during specific hours. Some others, on private property, require permission from the owners. Stop 1. Springfield Underground Springfield Underground is an active mining operation located in northeast Springfield southeast of the intersection of U.S. 65 and Route 744 (Kearney Street, Historic Route 66). The underground mining and storage space extends between Route 744 in the north to Division Street in the south, and from U.S. Route 65 east beyond Le Compte Road. Because most underground facilities are secure installations, advance permission is needed to visit this and other commercial underground storage facilities in Missouri.

The operation at this location has had several name changes over the years, and was the General Warehouse Corporation underground storage facility noted in Whitfield’s (1981) report, “Underground Space Resources in Missouri.” Quarrying at this site began at least by the 1940s, with agricultural lime being the chief product, then aggregate. The quarry’s prime location along Route 66 facilitated transport of material from the quarry. The mined (quarried) area in the Springfield Underground is ~60–100 ft below the surface in the lower portion of the Burlington-Keokuk (Fig. 10). This lower section of the unit was preferentially quarried as it contained less chert than the upper more cherty beds of the unit (Whitfield, 1981, fig. 4). Aggregate from this facility has been used to pave most of I-44 to Rolla; the carbonate here is reputed to be among the most pure (lacking quartz or clay minerals) in the United States. The Elsey Formation, which underlies the Burlington-Keokuk, is extremely cherty, so was not quarried extensively. The underground facility acts as a warehouse (as reflected by the original name of the facility) as well as a distribution center and location for manufacture of various products. Companies include Graybar Electric Company, Dairy Farmers of America, and a number of other well-known companies. This and other similar underground facilities are supported by large rock pillars remaining after room-and-pillar mining. Thus features of the mined rock can be seen in some of the pillars that have not been covered with shotcrete. The ceiling height varies from 25 to 45 ft. Pillars typically are 25 to 30 ft in diameter. The excavated areas between pillars are ~50 ft across. More than

CHARACTERISTICS soil cover

150’ – 200’

Limestone, light gray to almost white, crystalline, fossiliferous, medium to massive bedded, contains numerous chert nodules except for lower portion

Underground Quarry

20’ – 25’

60’ – 80’

40’ – 50’

30’

Pierson Limestone

Elsey Limestone

Burlington-Keokuk limestones (undivided)

STRATIGRAPHIC UNITS

47

Limestone, light gray, thin to medium bedded, very cherty

Limestone – dolomite, brown to buff colored

Figure 10. Diagrammatic cross section of the underground quarry at Springfield, now the Springfield Underground (adapted from Whitfield, 1981, fig. 4).

48

Hannibal and Evans

a square mile of rock has been quarried from this facility. A new facility on the west side of Springfield is in the planning stages. Stop 2. Phenix “Marble” Quarries The Phenix Quarry is centered in the northernmost part of Section 35 of T. 31 N, R. 24 W Greene County, Missouri (Fig. 11; southernmost Walnut Grove, Missouri, Quadrangle and northernmost Ash Grove Quadrangle U.S. Geological Survey 7.5 min quadrangle maps). It is located between the towns of Walnut Grove and Ash Grove, a few miles northeast of the Nathan Boone Homestead State Park. The street address for the quarry is 9455 North Farm Road 45, Ash Grove. The quarry is actually comprised of a number of smaller quarrying opera-

tions. These quarries are within the Greene County Phenix Quarry Historical District of Phenix. Permission is needed to visit the quarries. The stone at this stop is the Burlington-Keokuk limestones (undivided) (Hinchey, 1946, p. 23; Missouri Geological Survey open-file map). There does not appear to be any easily seen sharp faunal change in the sequence here. The classic work on the conodonts of the Keokuk is that of Branson and Mehl (1941). The Phenix Stone and Lime Company first opened a quarry in Phenix, Greene County, in 1888, and continued in operation until 1943 (Hinchey, 1946, p. 22). Initially it produced both stone and lime. In the early 1900s with change in ownership and emphasis, the name was changed to Phenix Marble. A small company town replete with company housing, a library, and a

Phenix Quarry

Nathan Boone Homestead State Park

1 mile

1 kilometer

Figure 11. Geologic map showing the Phenix Quarry as well as the Nathan Boone Homestead State Park. Geologic map modified from Kenneth C. Thomson (1982, 1983) of U.S. Geological Survey Ash Grove and Walnut Grove 7.5′ quadrangles, Greene and Polk counties, Missouri. Rock units are the Mississippian Osagean BurlingtonKeokuk (Mobk), the Mississippian Meramecian Warsaw Formation (Mmw), Pennsylvanian channel sandstones ( ) of uncertain stratigraphic position, and Quaternary alluvium (Qal).

Civil War and cultural geology of southwestern Missouri, part 1 church, grew up next to the quarry. The Vermont Marble Company bought Phenix Marble in 1945 and expanded the operation by adding a quarry to the east of the original quarry. By the late 1940s, however, activity diminished. In 1953, the Carthage Marble Corporation purchased the quarry and operations at Phenix, adding wire saws and other equipment, increasing production to over one million dollars of the Phenix product in the next two decades (Carthage Marble Corporation, 1959, sheet 2). Carthage Marble promoted Phenix along with Carthage stone, as well as stone from other domestic and foreign sources. Production of dimension stone eventually diminished during the last decades of the twentieth century, however. The little town of Phenix almost disappeared (Wilson, 1979), and today only a few structures remain. Carthage Marble no longer operates the quarry. Only a few remnant stone buildings remain of what is now a quarry ghost town, now part of the Greene County Phenix Quarry Historic District. Quarrying (now known as mining in the industry) continues for aggregate and dimension stone by Phenix Rock Quarry, Inc., however, and dimension stone from the old quarries continues to be used for various purposes. The primary dimension-stone product of the Phenix quarries was a type of limestone known as Napoleon Gray marble or, by its alternative spelling, Napoleon Grey Marble. Napoleon Gray is one of a number of “marbles” quarried in the United States and France under variants of the name Napoleon (McClymont, 1990). The classic Napoleon marble was a pale buff-brown stone quarried at Hydrequent, Pas de Calais, France (Grant, 1955, p. 65). There are several versions of the story of the naming of the Missouri Napoleon Gray, all hinging on someone (sometimes that someone is a geologist) noting the similarities of the Missouri and French stones. Napoleon Gray has been primarily used as an interior stone but has sometimes been used as exterior stone. The stone was sawn perpendicular to bedding and is typically marked by stylolites seen in cross section. This stone has had numerous uses in Missouri and elsewhere, including use as wainscoting and as bathroom and shower partitions. It has been used at or for the Missouri State Capitol, the Los Angeles City Hall, the historic 1929 Russ Building in San Francisco; the lobby of the Renaissance Cleveland Hotel in Cleveland, Ohio (Phenix Marble Company, 1922), the John Hay statue at Cleveland’s Lake View Cemetery (Hannibal, 2007, p. 85), and elsewhere. World War I provided a boost to the Missouri product as supplies from France diminished (Phenix Marble Co., ca. 1926, p. 54). The stone became popular for various usages. Advertisements for this stone in the 1920s claimed, hyperbolically, that it was an “exceptionally sound marble” that “weathers well…rain only serves to heighten its pleasing appearance” (Phenix Marble Company, 1927). Carthage Marble promoted Phenix stone in its Marble of the Month and continued to produce stone slabs from the Phenix quarries into the 1970s (Wilson, 1979). Previously quarried stone from the quarry, however, continues to be used. Freddie Flores, a sculptor and stone fabricator, operates saws and other equipment to produce ornate table tops,

49

artistic bowls, and other objects. He has also worked on restoration and remodeling projects, notably the remodeling of the Missouri Capitol. Stop 2a. Lime Kilns The two partly ruined lime kilns (Fig. 12) remain at the Phenix site near the old railway line (see Figure 3 for an analogous situation at the Carthage site). At one time there were three (Wilson, 1979). These were continuous kilns; that is, kilns in which material was fed from an upper level and removed, after heating, from a lower level. The type of kilns seen here were also known as vertical kilns, distinguishing them from the now-dominant horizontal kilns which utilize a rotating metal cylinder. The kilns here utilized stone from the south part of the original quarry as well as quarry waste and weathered (“bouldery”) surficial rock to produce white lime by heating (known as burning or calcining) (Buckley and Buehler, 1904, p. 164). The kilns are made of the local limestone, but with linings of sandstone and fire brick. Limestone kilns had to be lined with other materials as the heat of the kiln could otherwise calcine the kiln itself. Stop 2b. Power House This 1922 power house, made of the local limestone, provided electricity for the quarry, the company town of Phenix, and nearby Walnut Grove (Wilson, 1979). Photographs of the power house and other facilities here have been published in various works (including Phenix Marble Company, ca. 1926). Coal was burned to produce the electricity. The power house no longer produces power, but instead houses stone-cutting saws and finishing tools. Various types of equipment used for cutting, including a wire saw (Fig. 13) used to cut large blocks of stone into thin slabs for use as table tops and other uses, can be seen near the power house.

Figure 12. One of a pair of old kilns along old railway at Phenix Marble.

50

Hannibal and Evans

Stop 2c. Quarry The vertical quarry walls (Fig. 14) in the Phenix quarries provide excellent exposures of the Burlington-Keokuk. Since the stone was quarried over a long period of time, there are differences in weathering; older exposures are generally darker. A number of features stand out in the quarry, including joint sets, sinkholes and other karst features (Figs. 15 and 16), stylolites, and bands of light-colored nodular chert. The chert nodules vary in shape; some are flattened and others are globular. The quarry walls show evidence of various types of quarrying techniques used over time. These techniques are also documented in a number of sources (Brewster, 1914; Hinchey, 1946). The fabled ability of this stone to take a polish is still evident in the sheen seen on decades-old quarry cuts.

of Highways M and ZZ. The park is open seven days a week except for major holidays; see its Web site for hours and the current admissions charge (http://www.nps.gov/wicr/contacts.htm). The park consists of the battlefield which can be traversed via a 4.9-mi-long Tour Road. There are parking areas at key points along the Tour Road. Walking trails also lead from the Tour Road at points. The battlefield as seen today is much like it was at the

Stop 3. Wilson’s Creek Battlefield Wilson’s Creek Battlefield (Figs. 17 and 18) is located southwest of Springfield, Missouri, just west of the small town of Battlefield, and three miles east of Republic. The main park entrance is located off of Farm Road 182 just to the east of the intersection of Highway ZZ, 1.5 mi. south of the intersection

Figure 15. Cross section of sinkhole at Phenix quarry. Scale is 1.5 m tall.

Figure 13. Wire saw apparatus used to cut table-top sized slabs from limestone block at Phenix Marble.

Figure 14. Quarry Walls at Phenix Marble (2009 photo).

Figure 16. Dissolution along joints and planes with water stains, old Phenix Marble quarry.

B T AT LE FI E LD

FA U LT

3a 3b

3f

3d

3c

Wilson’s Creek National Battlefield 3e

1 mile

1 kilometer

Figure 17. Geologic map showing the region of the Wilson’s Creek National Battlefield. Stop locations (Stops 3a–3e) are shown. See caption for Figure 11 for explanation of rock units, except for the Mississippian Osagean Elsey Formation (Moe). Geologic map modified from Kenneth C. Thomson’s (1981a, 1981b) maps of U.S. Geological Survey Brookline and Republic 7.5′ quadrangles, Greene and Christian counties, Missouri.

Highway ZZ

Farm Road 182

Visitor Center

Wilson’s Creek National Battlefield

W ils

on

Edgar

sC

re e

k

Museum

3a oute Tour R

Short oats

3b

Gibson Gibson’s Mill corn

ad

DU BOIS

Bald Knob

PLUMMER

The Sinkhole

Tour Route

TOTTEN

GREER

orchard

McINTOSH

ire

W

Ray

3c

3f Bloody Hill LYON

PULASKI

3d

Guinn

PRICE

McCULLOCH WOODRUFF

Edwards

BLEDSOE

PEARCE

REID

McCULLOCH

Wilson Creek

Manley

ad

Highway ZZ

3e SIGEL (final) BACKOFF Sharp

W

ire

Ro

corn

SIGEL (2nd) stubble

Lit

tle

Gwinn

Yo r

kR

oa

d

W ils

ad ire Ro

W

Wilson’s Creek National Battlefield

SIGEL (1st) on

sC

re e

k

Dixon

MILES

N

0

0.25

0.5

Ro

corn

Figure 18. Digital elevation model (DEM) of the Wilson’s Creek Battlefield showing geographic features, stop locations (Stops 3a–3e), buildings present at the time of the battle (small black squares), the Wire Road (Telegraph Road), the position and movement of Union (blue) and Confederate (red) forces, and the one-way modern tour route. Stop 3a is at the battlefield parking lot; Stops 3b–3e can be reached via paths or trails from parking spots along the tour route (see text for details). DEM data from U.S. Geological Survey; locations of houses and fields, from Knapp (1993); and troop locations and movements from Eicher (2001) and other sources.

Civil War and cultural geology of southwestern Missouri, part 1 time of the battle, except for a generally greater amount of native and introduced vegetation, and some landscape change due to quarrying activity subsequent to the war. The Battle of Wilson’s Creek, 10 August 1861, pitted Union forces of Brigadier General Nathaniel Lyon against Confederates under the command of Ben McCullough and the Missouri State Guard under the command of Sterling Price. The battle has also been known by other names, especially by its Confederate name, the Battle of Oak Hills (U.S. War Department, 1881) or Oak Hill (Emerson, 1911, p. 64) or, less frequently, the Battle of Springfield (Piston and Hatcher, 2000, p. 319), not to be confused with other battles given that name. Union names for important battles typically took the name of rivers and streams, whereas Confederate names took the names of towns or other places. Thus the names for this battle are unusual in that both sides name it for geographical features. At the Battle of Wilson’s Creek, the pro-Southern Missouri State Guard fought side-by-side with Confederate troops, but Missouri guardsmen swore allegiance to the State of Missouri rather than the Confederacy. It was not until later that a proSouthern government in absentia convened in the southwestern Missouri town of Neosho and adopted the articles of secession, paving the way for acceptance into the Confederacy. Following this, Gen. Price and parts of the Missouri State Guard were sworn in as soldiers of the Confederacy. Some Missouri troops, however, would not enter Confederate units. Other, pro-Northern militias were formed in Missouri under sanction of the federal government, such as the Missouri Home Guard, Missouri State Militia and Enrolled Missouri Militia. The Battle of Wilson’s Creek pitted a Union force of 5,400 against a force of Missouri State Guards and other Confederate forces totaling more than 12,000. Despite the Union forces being outnumbered, Lyon split his forces, sending Union Col. Franz Sigel, a German immigrant (and veteran of the 1848 revolutions in central Europe), on a broad flanking movement that would attack the Confederate forces from the south while the main force moved in from the northwest. Both Lyon and Price had some ties with geology, or at least rocks. Lyon, according to Monagham (1955, p. 169) once said, “I was born among the rocks.” Sterling Price was governor of Missouri (1853–1857) when the Geologic Survey of Missouri was founded (Swallow, 1855). Geology and Terrain of the Wilson’s Creek Battlefield Area The Battle of Wilson’s Creek took place on karst terrain dissected by Wilsons Creek and its tributaries (Figs. 17 and 18). The battle played out as troops and artillery dueled along low hills and knobs, the most famous of which has become known as Bloody Hill. This prominence and a nearby sinkhole (Fig. 18) are canonical karst-related features of the battlefield. The Battlefield Fault, also known as the Sac River or Republic Fault (Thompson and Robertson, 1993, p. 40) is the largest structural feature associated with the Wilson’s Creek National Battlefield (Fig. 17). This NW-SE–trending fault is located along

53

the northeast corner of the battlefield. Along I-44, it is fractured and dolomitized with vug and vein-filling calcite crystals. An extension of the Sac River Fault cuts Pennsylvanian strata in northeastern Lawrence County, northwest of I-44 (Middendorf, 2003). Faults likely are an expression of transpressional adjustment of the Ozarks in the hinterland of the Ouachita orogen during the Pennsylvanian. Many of the faults in southwestern Missouri are oriented NW-SE, including the Chesapeake and Bolivar-Mansfield fault zones. Segments of these faults can be traced from the Arkansas to Kansas state lines. The Highlandville Fault system, a similarly oriented fault swarm approximately ten miles (16 km) south of the Battlefield Fault has kinematic indicators that suggest a component of strike-slip movement, where a series of faults displace strata vertically up to 250 ft (76 m) in a graben (Vierrether, 1998), indicating transtensional strain. The Ten O’Clock Run Fault near Branson, which links up with the Chesapeake Fault, is similarly oriented and shows transpressional folding at a broad bend in the fault. Elsewhere, the north and south sides are variously upthrown and downthrown along the length of it (see Evans, this volume). Most bedrock directly underlying the battlefield is the Burlington-Keokuk (undivided). The Mississippian Elsey crops out along the creek sides, thickening southward at lower elevations. Both the Burlington-Keokuk and the Elsey are composed predominantly of limestone and contain chert. They are predominantly flat-lying. The stream bottoms are floored with Quaternary alluvial sediments. Some of the soils developed on the bedrock are in places high in chert, forming cherty savannas. The chert can also be seen in outcrops of the Burlington-Keokuk within the national battlefield (Fig. 19). Karst Features in the Battlefield Karst features in the battlefield area include springs, sinkholes, glades, small caves, and an estavelle (a feature that alternates from being a sinkhole to a spring, depending on the

Figure 19. Detail of chert-rich outcrop of Burlington-Keokuk within the National Battlefield. Scale is marked in dm.

54

Hannibal and Evans

groundwater-table level). The Burlington-Keokuk is particularly noted for springs (Vandike, 2001, p. 53). In the setting around Wilson’s Creek Battlefield, chert beds or thin shale beds likely provided semi-permeable confining layers at the base of an unconfined aquifer. Springs played an important role in this and other Civil War battles and movements in southwestern Missouri (Bullard, 2001, p. 11–12). There were several springs on the battlefield site. Their presence, as well as the presence of stream water for horses, and the availability of food, was the reason that the Missouri Guard camped at this location (Hess et al., 2006, p. 23) along with the fact that the site was along Telegraph Road (also known as the Wire Road and later the Old Wire Road). Clean water, such as that supplied by springs, was especially valued during the Civil War, and soldiers’ memoirs note the presence, and absence, of springs (Anderson, 1868, p. 37, 90, 203; Sorrel, 1905; Piston and Hatcher, 2000, p. 118). Campsites and fortifications were located near springs in a number of cases in Missouri and other states. Andrews (2005, p. 16), for instance, has noted the key role of springs in the 1862 Battle of Perryville, which occurred in the karst Bluegrass region of Kentucky. At Perrysburg, as at Wilson’s Creek, Confederate armies camped near springs. Soldiers, however, would utilize almost any source of water, dependent upon the situation (Schroeder-Lein, 2008, p. 91). Springs were also the sites of field hospitals, that of the Union forces north of Bloody Hill and the two field hospitals of the Missouri Guard on the west side of the Manley House and southeast of the stream ford (1883 Souvenir Program of the battle cited in Bearss, 1978, p. 91). Additionally, the first stop for retreating Union troops after the battle was a spring. The battlefield here is notable for limestone glades (Fig. 20; National Park Service, 2004, p. 2-9, 2-13). In local usage a glade is a more or less open area developed on shallow limestone bedrock, including cherty bedrock, due to stresses (e.g., desiccation). Depth to bedrock is very shallow in places, for instance in the limestone glades where it approaches zero. Such

Figure 20. Glade along trail within park. Bedrock here is at or very near the surface, resulting in a xeric flora that includes prickly pear cactus. Kevin Evans for scale.

shallow depth provides little opportunity for cover by infantry. It also would serve as a hard surface where enemy fire, rifle and cannon, would have greater effect. Several barren areas were located in the battlefield: the most notable is that of Bald Knob– Bloody Hill. Glades here are especially stressed in the summer and characterized by plants, such as prickly pear cactus, that can withstand drought. Acoustic shadows, presumably caused by topography and weather patterns, and the lack of them, seem to have played a role in the battle as well as in some other battles of the Civil War. They presumably helped to mask the Union forces’ advance (Piston and Hatcher, 2000, p. 213). The first engagement at Wilson’s Creek Battlefield began as a detachment of Union troops swept southward on the east side of Wilsons Creek, attacking the Confederate right. Meanwhile, Lyon moved his forces from the north toward the prominence now referred to as Bloody Hill to attack the front of the Confederate forces. Col. Sigel was able to hear well enough to know that the battle was developing to his north. The battle unfolded with Sigel moving behind the eastern ridge of Wilsons Creek in an attempt to flank the Confederate Army under McCullough and Price. The object was to throw the Confederate Army into complete disarray. The two-pronged attack was initially successful, as it had the advantage of surprise. Topography also played a role in the placement of artillery (Fig. 18). Totten’s battery (Union) was located on the high ground to the rear of Union lines on Bloody Hill. An artillery duel developed as shells were lobbed at Woodruff’s Battery (Confederate) on a small prominence next to Telegraph Road. Reid’s Battery, a little to the south of Woodruff opened fire to the southwest where Sigel had taken up a position on the south along Telegraph Road. Telegraph Road was most effectively used by southern forces who quickly positioned troops where they were needed. Contrary to expectations, southern forces did not run but rapidly formed up a line of battle on the southern slope of Bloody Hill and to the west. Despite the advantage of surprise and occupation of the high ground, the north lost the initiative. Infantry movements were controlled by the erosional features carved out of the landscape by the creek and intermittent tributaries. These features helped to mask the movement of troops during various phases of the battle, including the movement of Lyon’s forces early on in the battle. The valleys between the branches of Wilsons Creek also served as effective blocks to communication between the divided parts of Lyon’s forces, however. This enabled the interior lines of the Confederate forces to respond to and defeat in turn each of the uncoordinated attacks by Sigel and Lyon, resulting in an eventual Confederate victory. On a smaller scale, the uneven ground of the battlefield caused parts of the Confederate counterattacks to stall (Hess et al., 2006, p. 58). Much of battle would focus on Bloody Hill (Fig. 18), and it was here that Gen. Lyon was fatally wounded. The battle would eventually turn out to be a Confederate victory. Further details of the battle are given below, but there are a number of resources

Civil War and cultural geology of southwestern Missouri, part 1 available for those who wish more information on the battle. Two books are especially recommended: Piston and Hatcher’s (2000) Wilson’s Creek: The Second Battle of the Civil War and the Men Who Fought It, the most comprehensive and accurate narrative work on the battle, and Hess et al.’s (2006) Wilson’s Creek, Pea Ridge, and Prairie Grove: A Battlefield Guide with a Section on Wire Road, a guidebook that includes information on the effect of terrain on the battle and which has excellent maps with topography indicated by contour lines. Knapp’s (1993) guide to the battlefield provides a military perspective. The published official records of the battle (U.S. War Department, 1881) provide vivid contemporary perspectives of both Union and Confederate sides on the events surrounding the battle. A guided audio-tour of the battlefield by Jeff Patrick is also available from the park bookstore. Subsequent Utilization of Stone at the Battlefield Site The limestone deposits in and around the battlefield were exploited for building stone and lime over time. Bedrock was used for the base of the mill on the property before the war and a lime kiln was constructed by the Rodgers White Lime Company in the short lived town of Wilson Creek (Fig. 18) in the battlefield area in the early 1900s (National Park Service, 2004, p. 75). The kiln, in operation between 1908 and 1913, utilized the Burlington-Keokuk for lime production. Archaeologists have also reported a European-American sandstone quarry just southwest of the Manley Cemetery (National Park Service, 2004, v. 1, p. 3-111), which is located on the eastern edge of the battlefield. This sandstone body, and perhaps other small bodies of Pennsylvanian channel sandstones, has not been mapped on the geologic map of the region (Fig. 17). Sandstone from these and other deposits of the general region was used for foundations and steps of several structures in the park. Stop 3a. Visitor Center and Civil War Museum The park visitor center, located off of Farm Road 182 just east of Highway ZZ, provides an introduction and overview of the Battle of Wilson’s Creek. This includes a short film and a fiber-optics map display that shows troop movements during the battle. A nearby Civil War museum in a separate building contains a variety of artifacts related to the western theater of the war. One item of particular geological interest is a lead ingot (pig) made at the Blow-Kennett (Blow and Kennett) Co.’s Granby furnace. Granby, in what is now known as the Tri-State Lead and Zinc District, was a source of lead for both Union and Confederate forces, depending on who controlled the area at the time. The importance of these mines is shown by both Union and Confederate correspondence. These include a pair of October 1861 letters (p. 717–718 in U.S. War Department, 1881) between members of the Confederacy. One, from Gen. B. McCullough to J.P. Benjamin, Confederate Secretary of War, states that 200,000 pounds of lead could be transported per month from these mines. Another, from G.W. Clark to Benjamin states that Clark had

55

shipped 32,000 pounds of lead from Granby and that he thought that these mines could supply all of the lead needed by the Confederate Army. At least some of the lead was transported overland to Van Buren, Arkansas, and shipped up the Mississippi River to the Tennessee ordnance factory at Memphis. Confederate control of the mines concerned Blow and Kennett, as Henry Taylor Blow, one of the principals of Blow and Kennett, was an ardent Missouri Republican (Anonymous, 1901). A 1 December 1862 letter in the Library of Congress from Blow and Kennett (1862) to Abraham Lincoln requested that he protect Granby from the Confederates so that the mines could be reopened. The letter also claimed that these mines could supply all the lead needed for the Union cause, or even for a conflict with England (early on in the war it was feared that England may recognize the Confederacy). Consequently, Granby became the object of both Union and Confederate movements, continuing into the late stages of the war as a fall 1864 letter from Union General Rosecrans to Abraham Lincoln indicates (Rosecrans, 1864). The ingot on exhibit was discovered in the 1980s at a campground of the Missouri State Guard in Springfield (see Buckley and Buehler, 1904, pl. 4 for an illustration of an 1860 pig). Such ingots were used to manufacture bullets of various types. The Missouri State Guard troops had a variety of weapons, necessitating such local production of ammunition, sometimes in a simple manner utilizing iron skillets to melt lead from Granby (Piston and Hatcher, 2000, p. 117). Arkansas troops were molding bullets at Wilsons Creek the day before the battle (Piston and Hatcher, 2000, p. 162). Various balls and bullets made of lead, as well as a bullet mold, are also on exhibit. After the war, because of lead and zinc discoveries not far to the north in the Brookline area (Winslow, 1894b, p. 630, map after p. 542), there was some exploration for lead along Wilsons Creek (National Park Service, 2004, v. 1, p. 21). The Civil War cannons displayed outside the visitor center (Fig. 8) and elsewhere in the park are not left from the battle. Such artillery were obtained sometime after the war as surplus cannons were distributed by the federal government. At least some were produced by foundries in the Mississippi watershed. A 4.9 mi one-way loop road, known as the tour road, is accessible from the visitor center parking lot. The following stops begin at various parking areas along the loop. There are a number of other worthwhile stops along the tour road for those who have more time to explore the park. There is also a Civil War Museum located along Highway ZZ a short distance from its intersection with Farm Road 182. Stop 3b. Mill Trail, Site of Gibson’s Mill The Mill Trail leads from the park tour road (the parking area at the head of this tail is stop 1 of the official park tour route) to the site of Gibson’s Mill, which is no longer standing. Confederate James Rains had his headquarters at the mill before the battle (Piston and Hatcher, 2000, p. 156–157), and Union troops forded Wilsons Creek at this location.

56

Hannibal and Evans

The bedrock at the upper part of the mill site seen at exposures here is a crinoidal grainstone with rugose corals belonging to the Burlington-Keokuk. The mill was powered by a millrace (headrace) which drained water from a dam ~0.7 mi. upstream of the mill This provided a 16-ft drop (16 ft of hydraulic head) to power the mill. Based on the length of the millrace (3862 ft) and the amount of fall the mill was probably powered initially by an overshot water wheel (National Park Service, 2004, p. 3-103). The headrace was necessitated by the lack of a natural waterfall in this area, which is due to the amount of alluvial sediments in the valley of Wilsons Creek (Fig. 17). This wheel was eventually replaced by a turbine. The mill is noted in a mill-turbine handbook (Leffel, James & Co., 1872) as having a 23-inch Leffelturbine water wheel. A large number of chert millstones and millstone fragments were recovered as part of a survey of the area, which reported the stones to be composed of locally quarried brecciated and cellular chert (Bray, 1967; National Park Service, 2004, p. 3–103). The use of local versus other cherts in southwestern Missouri, however, is poorly documented. Although previously identified as local Mississippian or lower Paleozoic cherts (William Hayes and Edwin Kurtz in Bray, 1967, p. 51), at least some of these stones may be from other parts of the country or even France (see Stop 6, Edwards Mill, for more on millstones). A 1966 report in files of the library at Wilson’s Creek National Battlefield notes that a millstone from this mill was once located behind the Silverleaf Shopping Center. The dam has been removed (an early case dam removal) and only parts of the foundation of the mill remains at this site (see Stop 6, Edwards Mill, for a discussion of a reconstructed mill in this region). During the Civil War, mills were key elements of the agricultural infrastructure. Wheat crops and the threshing and grinding of grain provided provisions for the field armies of both sides in Missouri (Anderson, 1868, p. 90; Piston and Hatcher, 2000, p. 115, 119). A rain-delay in threshing wheat and lack of bread rations were of special concern to Union officers in southwestern Missouri just prior to the Battle of Wilson’s Creek (Schofield, 1881, p. 58). Mills also served as headquarter buildings for various armies. Generals Price and McCullough corresponded over the destruction of mills in this theater of war during November of 1861 (U.S. War Department, 1881, p. 736–738). McCullough (1861) was adamant about destroying them, writing that, “If the enemy advance into Arkansas, I shall destroy all the mills and grain that I have to leave in my rear, having already done so on the roads towards Springfield….” Later in the war, during Marmaduke’s expedition into Missouri (see Stop 4b) Confederate troops captured and operated a mill in Hartville, Wright County, Missouri (Porter, 1888, p. 206). Confederate troops also burned Lawrence’s Mill, in Douglas County, southeast of Springfield on Beaver Creek (Crabb, 1888, p. 183–84). Wilsons Creek now is in a flood zone, but flows in the past have supposedly been more stable (National Park Service, 2004, p. 2-10). The surface water of much of Wilsons Creek is used in the Springfield southwest (sewage) treatment plant. It also collects much of the storm run-off from the city of Springfield, so

there episodically are concerns about water quality at Wilson’s Creek National Battlefield, particularly since karst allows a direct connection between surface and subsurface fresh-water resources (Richards and Johnson, 2002, p. 4, 6). Stop 3c. Ray House and Springhouse The Ray House and the accompanying springhouse are accessible from paths leading from the tour road (the parking area is stop 2, Ray House and Cornfield, of the official park tour route). These two structures are the last remaining structures that were present at the time of the Battle of Wilson’s Creek. In the aftermath of the battle, the Ray House served as a hospital for Confederate troops. The troops also brought the body of Nathaniel Lyon to this site for a time. Due to its advantageous location along the Wire Road, the Ray House was also a post office during the late 1800s. Springhouses are another common feature of the Ozarks, and are of course, tied to the karst terrain provided by carbonates. The springhouse, as well as the foundation for the Ray House is made of local stone. The spring that cooled the springhouse for cool storage was also used for drinking water for the family as well as for the temporary hospital. The initial flanking movement of the Union (under Plummer) was in the Ray cornfield, across the road to the north and northwest. As superior Confederate forces gathered to repulse the attack, Union troops withdrew under fire across Wilsons Creek. The older buildings in the park, including the Ray House, the springhouse, and the Price Cabin, utilize Paleozoic carbonates and sandstones from this area, or perhaps even from northwest Arkansas. Stop 3d. Wire Road The Wire Road is easily accessible from the parking lot of the Ray House and Cornfield (stop 2 of the official park tour route). The Wire Road passes right by the Ray House. The path from the Wire Road passes limestone quarries en route to Pulaski’s Battery. The Wire Road was constructed in 1838. A telegraph line was placed beside it in 1860 resulting in it being called the Wire Road. Both the Burlington-Keokuk and the Elsey (lighter colored lower unit) are exposed here at the quarries. The main quarry wall is ~25 ft high and includes a number of vertical drillmarks ~5 cm in diameter. Stop 3e. Sigel’s Last Position This stop is stop 5 of the park battlefield tour. It is located along Telegraph Road just to the southwest of a parking area along the tour road. Franz Sigel had successfully attacked and scattered the Confederate forces in the early part of the battle. He then waited with his troops arrayed across Telegraph Road (Wire Road) here in

Civil War and cultural geology of southwestern Missouri, part 1 the southern part of the battlefield, eventually to be attacked from the north by McCullough, who was able to marshal his forces in a “dead zone” protected from cannon fire by topography (Hess et al., 2006, p. 48). Sigel’s response to the Confederate attack was delayed, as Sigel thought that the approaching Confederates were part of Lyon’s army, and he was overwhelmed. Sigel and his troops were routed, and they fled south along the Wire Road. In retreat Sigel split his command, half taking the Little York Road to Springfield safely. Leading the other group, Sigel encountered Confederate troops that cut off his escape and nearly captured him near Delaware Town on the James River (Neal Lopinot, Missouri State University Center for Archaeological Research, 2010, personal commun.). Stop 3f. Bloody Hill and the Sinkhole Bloody Hill (Fig. 21) was the site of the decisive engagement of the battle. It was originally a Confederate position that was taken over early on in the battle by Union troops. Union Capt. James Totten then placed his artillery on this hill which was subsequently attacked by Price’s Missouri infantry. Lyon formed two lines along the southeast and southern end of the ridge and extending westward along a small gulley. Other forces were held in reserve to the north. Bloody Hill is a dissected hill. It has simply been called “the crest of a ridge” in an 1881 battle report (Schofield, 1881, p. 60) as well as in some subsequent reports. At the time of the battle it was a fairly open area, with one account noting that it was “almost bald” (quoted in National Park Service, 2004, p. 23–37). In his memoirs published not long after the war Anderson (1868, p. 42) described this prominence as “a hill whose summit was bare and imbedded with rock and gravel, known as ‘the bald or bloody hill.’” This is also the Oak Hill, named for the scrub oaks that grew in the thin soil. And Oak Hill (or Oak Hills) is the battle as named in Confederate reports. There are a number of maps that show the location of Bloody Hill, some labeling the high area on the north

Figure 21. View of Bloody Hill taken near the Edwards cabin along Wilsons Creek.

57

side of Bloody Hill as Bald Knob (e.g., map 3 in Knapp,1993). But, according to other sources, Bald Knob is a synonym for Bloody Hill, adopted after the War (Eicher, 2001, p. 104). Price and McCulloch, with numerically superior Confederate forces (although most of the Missouri State Guard were poorly equipped and some were unarmed), made repeated attacks on the hill (Fig. 18). While the hill and its slopes were fairly open, the surrounding terrain, from which Price’s forces attacked, was more difficult to advance through in a uniform manner. Trees and underbrush of this lower terrain also served to screen Confederate troops and artillery, obscuring the Union’s field of fire (Totten,1881). Union soldier Bennett eloquently explained this situation: “The small ravines entering the valley of the stream and the woody slopes of the hillsides were admirably adapted for concealing the approach of the enemy, while our forces were exposed on the tops of the hills where the trees were few and the land open” (Bennett, 1966, p. 15). Southern cavalry and infantry attempted to flank the Union right, but intense fire from a detachment of Totten’s and DuBois’ batteries, two companies of Missouri Home Guards, and two companies of the Second Kansas Regiment thwarted the attempt. After roughly five hours of fighting and with the loss of Gen. Lyon, Union troops withdrew during a lull in the shooting. Gen. Sturgis took command and withdrew to Springfield and then on to Rolla. Confederate forces, equally stunned by the number of casualties declined to follow the Federals. In all nearly one out of four Union soldiers in the fight was killed, wounded, or missing, totaling ~1,300. The number of Confederates killed and wounded was ~1,200. The well-known sinkhole noted on many maps of the battlefield is located along the trail between the position of Totten’s Battery and the Lyon Marker. A path leads from the Park Road eastward to these sites. The sinkhole was in the midst of some of the heaviest fighting during the battle. It was also a place of burial just after the battle. This sinkhole was measured as being 25 by 15 ft by 37 in deep previous to one of its more recent excavations (National Park Service, 2004, v. 1, p. 3-103). The sinkhole (not always noted by that term, however) has been a stop for many visitors to this battlefield, even during the Civil War. In his diary entry for 23 February 1862, Union soldier Lyman O. Bennett (1966, p. 15) noted that he “found graves thickly scattered along the bank of the creek for a mile or more and in some places, was told scores were buried in one common trench or grave. A sort of cave upon the hill was filled with the bodies of the dead and lightly covered with logs and dirt.” In his memoir, Ephraim Anderson (1868, p. 143), who had been a Confederate soldier, told of visiting the sinkhole during the war. He noted that “We visited the sinkhole…said to contain several hundred bodies; the earth thrown on top being partially washed away, the clothing and bones protruded in some places.” Bray’s (1967) archaeological investigation of the sinkhole found more than 200 human body parts, mostly arm and leg bones, in the sinkhole. One might surmise that such bones were the remains of amputated limbs, but no evidence has been found

58

Hannibal and Evans

to date of Federal troops performing amputations on the field at this battle. All evidence indicates that those requiring amputation were taken back to Springfield for surgery. Therefore, the smaller bones found by the archaeologists may have been parts that the previous retrieval parties missed during their excavations (Jeffrey Patrick, 2010, personal commun.). Union burial places also included an additional sinkhole and a well, and Confederate bodies were buried alongside the creek (National Park Service, 2004, v. 1, p. 1-21, 2-38). These have not been relocated. Stop 4. Zagonyi Park and the Site of Fort No. 4, Springfield Zágonyi’s Charge and Battle of Springfield: Historical Perspective Springfield, as noted above, was perceived to be the key city to the control of southwestern Missouri. Following the Battle of Wilson’s Creek, however, Union forces withdrew from southwestern Missouri to Rolla. Confederate forces under Gen. McCulloch returned to Arkansas, having successfully defended Arkansas from the Federal threat. A contingent of pro-Southern troops occupied Springfield, while the main force of the Missouri State Guard under Gen. Price proceeded northwestward to attack pro-Union militias on the Kansas border (Battle of Dry Wood Creek), then northward to re-take Lexington, Missouri. Union troops under the command of Maj. Gen. John C. Frémont continued to hold St. Louis and Rolla, and by October, his forces, 38,000 strong, advanced slowly on Springfield. By late October, his army reached Bolivar. By the end of October 1861, Price had withdrawn to McDonald County, Missouri. Zágonyi’s Charge (also known as the Battle of Springfield or the Action at Springfield) took place in October of 1861. It was the first Union victory since the earliest days of the war. After driving out secessionist troops, Zágonyi quickly retreated to Frémont’s main body. Frémont marched into Springfield and, in a political move, was summarily replaced by Gen. David Hunter. Hunter ordered his troops to pull back from Springfield to Kansas, Sedalia, and Rolla. Springfield again fell into Confederate hands. Springfield was recaptured by Union forces in the early spring of 1862. The city did not fall under pro-Southern control for the remainder of the war. Springfield became headquarters for counter-insurgency operations and was a judicial center for martial law under the Federal Provost Marshall’s command. Union dominion, however, did not go unchallenged. In the early winter of 1862–1863, a large Confederate force was advancing from Arkansas. Led by Brigadier General John S. Marmaduke, this expedition was divided into three columns. The main force, led by Marmaduke, drove north through Forsyth and Ozark. Col. Emmet McDonald led the second force up Beaver Creek in Taney County, and Col. Joseph Porter attacked Union forces in Hartville. Marmaduke’s goals were to secure provisions, recruit soldiers, and disrupt Union military actions, such as drawing troops into the Trans-Mississippi theater. As reports filtered in about the attack on the garrison at Ozark, the Enrolled

Missouri Militia (Union) troops of Springfield, under the command of Gen. Egbert B. Brown, began to prepare for the impending attack. The resultant battle came to be known as the Battle of Springfield (or, alternatively, the second Battle of Springfield). This field trip will stop at two key sites (Figs. 22–24) related to battles at Springfield: the site of the October 1861 Zágonyi’s Charge (Stop 4a) and at the former location of Fort No. 4 (Stop 4b) in downtown Springfield (corner of Elm Street and South Avenue), the focal point of the January 1863 Battle of Springfield. Those with more time are encouraged to visit the History Museum of Springfield-Greene County in downtown Springfield (which contains exhibits related to the Civil War) as well as other Civil-War related sites in Springfield. The History Museum is located on the third floor of the Old City Hall in Springfield which is located at 830 Bonneville Avenue. “Battle of Springfield: A Guide to the Historical Marker Route,” a handout or brochure showing the location of Civil War markers in Springfield is available at the Wilson’s Creek Battlefield as well as the History Museum. Geology of Zágonyi Park and Central Springfield Most of Springfield rests upon the Burlington-Keokuk limestones (Osagean Series) (Fig. 23). The Burlington is typically a lime wackestone or packstone to fine grainstone in the Springfield area; the Keokuk interval is more coarsely crinoidal with cross-bedding that indicates deposition above normal wave base. Because the Springfield Plateau dips gently (<1°) to the northwest, a few of the higher locations on the west side of Springfield are overlain by the Warsaw Formation (Meramecian Series). The Warsaw is a limestone nearly identical to the Burlington-Keokuk; in the type area of these units in southeastern Iowa and western Illinois, however, they are distinctive. The Warsaw in southwestern Missouri is a coarse crinoidal grainstone to packstone with abundant macrofauna in addition to crinoids. These include brachiopods, bivalves, and notably Archimedes bryozoans, which seem to be rare in the Burlington-Keokuk (Thompson, 1986). The Short Creek Oölite, the uppermost member of the Keokuk, is a key marker bed that makes it possible to map these stratigraphic units. The Short Creek is an oöid grainstone ~6–8 ft thick. Oöids typically are 1 mm or smaller in diameter. The cortices of these oöids are commonly quartz grains, some with authigenic overgrowths that show double terminations. The type area of the Short Creek is in southeastern Kansas, and the unit is widespread across Missouri (Thompson, 1986). The most accessible exposures of Short Creek Oölite in Springfield are in road cuts at the intersections of Kansas Expressway and Bennett Street and also, Kansas Expressway and Catalpa Street, about ½ mile south of the battlefield. It also is exposed along Highway 160 on the road to Willard. Although both the Burlington-Keokuk and Warsaw are interpreted as relatively shallow-water limestones, the Short Creek Oölite is interpreted as a very shallow marine unit that records a brief lowering of sea level. The succeeding flooding event occurred during the Meramecian.

3 4 5 6

7

S. Hampton Ave.

E. Cherry St.

Gen. Frémont dispatches personal bodyguard under command of Maj. Zágonyi and Prairie Scouts under command of Maj. White (handing over command to Zágonyi for combined force of 300 cavalry) to probe Confederate forces at Springfield. Pickets north of Springfield spot Union force. Zágonyi moves west to regain element of surprise, encountering main encampment of Missouri State Guard (~1,200 infantry and cavalry) under Col. Frazier on Mt. Vernon Road. Southern forces concentrate in field east of encampment. Zágonyi with two leading companies veers from Mt. Vernon Rd. along lane to south and east, running “the gauntlet.” Prairie Scouts company under Capt. Foley attempts flanking movement. Zágonyi regroups cavalry under shelter of embankment along Jordan Creek. Zágonyi charges up hill and attacks superior force. Seccessionist forces take flight. Foley’s company resumes action, mopping up area. Zágonyi’s men chase Secessionists into Springfield ~1.5 miles to east, securing the town for Union.

13

Mary Campbell house (Confederate field hospital)

E. Monroe St. E. Madison St. S. Kings Ave.

S. Holland Ave.

S. Kimbrough Ave.

E. Harrison St.

John Q. Hammons Parkway

2

S. Thomas Ave. S. Roanoake Ave.

Fort No. 3(?)

1

S. Robberson Ave. S. Jefferson Ave.

6

5 S. Campbell Ave.

W. Monroe Terr. College and stockade (prison)

S. Market Ave.

“Dutchtown”

Missouri State University E. Grand St.

S. National Ave.

4

14

S. Florence Ave.

S. 7th Ave. West

S. 8th Ave. West

S. 9th Ave. S. New Ave.

S. Newton Ave.

S. Nettleton Ave.

ssw ay

E. Elm St.

12

Events at Zágonyi’s Charge

2

E. Walnut St.

Fort No. 4 Toney house

11

W. Madison St.

W. Lombard St.

Battle of Springfield (Jan. 8, 1863)

Methodist Ch. (Arsenal)

9

W. State St.

W. Grand St.

1

7

Fort No. 5 E. St. Louis St.

3

E. McDaniel St.

W. McDaniel St.

8

W. Central St.

S. Grant Ave.

4

7

W. Elm Arc.

S. Broadway Ave.

2

Ka nsa s

S. Park Ave.

3

Exp re

“the gauntlet”

S. Kansas Ave.

n C reek

S. Wabash Ave.

Jord a

“the lane”

5

S. Fort Ave.

W. Elm St.

W. Mt. Vernon St.

6

W. Olive St 10

W. Walnut St.

S. Lafoun- W. Lincoln St. tain Ave.

. way Exp

E. Traffic

E. Olive St. Park Central Square

Fort No. 2

S. Douglas Ave.

W College St

r St.

te W. Wa

Fulbright Spring

S. Missouri Ave.

W. Olive St.

S. Patton Ave. South Ave.

Highway 13

N. Marion Ave

N. Warren Ave.

W. Water St.

Zágonyi’s Charge (Oct. 25, 1861)

1

E. Phelps St. W. Mill St.

N. Sherman Pkwy.

W. Wall St.

BNSF Railroad

S. Clay Ave.

W. Wall St.

N. Main St

W. Tampa St.

Fort No. 1

W. Phelps St.

Events at Battle of Springfield 1 2 3 4

5

6 7

8

9

10 11 12

13 14

General Brown orders burning of houses to open field of battle. General Marmaduke in position south of Springfield. Confederate cavalry skirmish at Union left flank is repulsed. Confederate cannonfire concentrated on Fort No. 4. Union troops return fire. Marmaduke moves in force into “Dutchtown,” concentrating fire on Fort No. 4 and capturing a field piece in exposed Union position. Gen. Brown rallies troops on “exposed” ride. Under cover of small ravine, Confederates capture Union prison (old college) and stockade to serve as stronghold against Union fire. Confederate troops drive Union right back, until Union right halts Confederate advance. House-to-house urban combat pits Confederate veterans against Union regulars, furloughed soldiers, Enrolled Missouri Militia, and the sick, and wounded “quinine brigade.” Union reinforcements from Fort No. 1 arrive and help to push Confederates back. Hand-to-hand combat ensues with little ground gained on either side. Col. Shelby leads frontal cavalry assault on Fort No. 4 and is repulsed. Confederates withdraw from field to camp at Phelps farm (Phelps Grove Park). Confederates withdraw next morning along St. Louis Road.

Figure 22. Present-day street map of Springfield, Missouri, with events related to Zágonyi’s Charge (25 October 1861; Stop 4a) and The Battle of Springfield (8 January 1863; Stop 4b) superimposed. Location of Stop 4a is indicated by asterisk (left side of figure).

60

Hannibal and Evans

Stop 4a. Zagonyi Park The site of the October 1861 Zágonyi’s Charge is the park at 1724 Mt. Vernon Street in Springfield (Fig. 22). The battle was set into motion when Gen. Frémont dispatched a cavalry detachment (three companies of his bodyguard) under the command of Maj. Charles Zágonyi to Springfield to reconnoiter and harass rebel forces in anticipation of retaking Springfield. Zágonyi, who had been a Hungarian officer in the defeated Hungarian Revolution of 1848 (Vasvary, 1939, p. 86), was in command of the Frémont’s cavalry bodyguard. On 25 October 1861, Zágonyi, with ~320 troops, made a daring cavalry raid into the heart of Springfield. Most of the action took place west of Springfield, at this park which is now part of west-central Springfield. Zágonyi attacked the Confederates, leading his men through withering fire to find protection behind a small rise next to Jordan Creek. Frémont’s Guards (~160 men in his two companies) from the Missouri State Guard (commanded by Col. Julian Frazier) were positioned on the hill (est. ~1,200 men). Zágonyi was southeast of the Missouri State Guard ~400 yards. White’s Prairie Scouts (Union) did not follow Zágonyi but mounted a flank attack on the west side of the Missouri State Guards. In an epic moment Zágonyi ordered his men to charge uphill into the Missouri State Guard’s position. His charge, with the help of the flank attack, succeeded in routing the secessionist force. Union forces suffered 85 casualties and the pro-Southern forces 133 killed and wounded (casualties of this battle are difficult to assess, however, as reports vary on this and other aspects of the battle). Many of the latter casualties were due to sword wounds (swords were effective cavalry weapons when horsemen were

pitted against forces armed with single-shot muskets). From this point, Frémont’s Guards putting the enemy to flight began mopping up actions as they continued the charge into Springfield, 1.25 mile to the east. A lesson in historical revisionism, common in Civil War literature, is provided in the account of Ephraim Anderson (1868, p. 133). He puts a different spin on the battle, noting that, “Our command marched out about a mile, and went into camp at Fullbright’s [sic] Spring, near where Fremont’s body guard had been defeated: the trees around bore marks of a pretty severe skirmish.” (For more contrary discussion of these events see the reports in U.S. War Department (1881) or do a Web search on Zágonyi’s Charge.) More information on this battle can be found in the caption for Figure 22, the original reports published in the War of the Rebellion (U.S. War Department, 1881) and on the Web site “Community in Conflict: The impact of the Civil War in the Ozarks” (Springfield-Greene County Library District, 2010). Stop 4b. The Site of Fort No. 4, Springfield, Site of the January 1863 Battle of Springfield In 1862, Union forces supervised construction of a series of forts (Fig. 24) intended to protect Springfield from Confederate attack. The number of forts was controversial especially in regard to the manpower needed to defend them, and one of the forts, No. 3, was never completed. The locations for the forts were determined by location in respect to the town, to topography, and in part by the location of springs (Bullard, 2001, p. 12). Fort No. 5 was located a few hundred yards to the south of Berry

* Fort No. 1 Mobk

Mobk

* Park Central Square* Fort No. 5 * Fort No. 2 Battle of Springfield * Fort No. 4

Zágonyi’s Charge Mobk

* College (Conf. stronghold)

Qal

Mmw Qtd

0.5 miles

* Fort No. 3 (?) 0.5 kilometers

N

Figure 23. Geology of the Springfield, Missouri, area, showing the locations of Zágonyi’s Charge and The Battle of Springfield. Geologic map modified from Kenneth C. Thomson’s (1981c) map of U.S. Geological Survey Springfield 7.5′ quadrangle, Greene Counties, Missouri. Rock units are the Mississippian Osagean Burlington-Keokuk (Mobk), the Mississippian Meramecian Warsaw Formation (Mmw), Quaternary alluvium (Qal), and Quaternary and Tertiary deposits (Qtd).

Civil War and cultural geology of southwestern Missouri, part 1 Spring during the war. This spring flowed into a sinkhole as seen in period maps as well as in a contemporary bird’s-eye view illustration (Bullard, 2008, p. 6). This spring, also known by its post-war name of the Jones Spring, was diverted in the 1950s and so is no longer apparent on the surface. A rifle pit and covered path was constructed to connect Fort No. 2 with Fulbright Spring. Fort 2 was at the top of a hill and the spring is in the lowland ~100 ft lower elevation.

61

Fort No. 4, the most centrally located of the forts, however, was the focus of the 1863 Battle of Springfield. The site of Fort No. 4 is in downtown Springfield at the corner of Elm Street and South Avenue (Fig. 23). The site is indicated by one of the twelve markers placed at or near sites in Springfield related to the January 1863 Battle of Springfield. A brief account of the battle is given in the official records and is summarized by Ingenthron (1980).

Jef fer

son

Cit yR

d

Ebenezer Rd

d an ille ds. ev on la R Bo sceo O

Convalescent Hospital Berry Spg. si sinkhole? ol

Fort No. 1

Greenfield Rd.

Fort No. 3

.

Rd

Roc

kbr

idg

eR

d.

[Jefferson Ave ]

k ree

nC

da Jor

lla

Ro

Fort No. N 4

Militaryy Prison so and Stockade tock d

[South Ave ]

* Site of Zágonyi’s Charge

Robinson Mill Rd

Mt. Vernon Rd.

[Fort Ave ]

natural natura well el Fulbright Spg. Fort No. 5 QM Depot Depo Court House QM Stor Storess [St. Louis St.] Covered Pathway H pital Hospital [Walnut St.] and Rifle Pit Arsenal Fort No. 2 Ch HQ Ch. Rifle Pit

Marionville Rd. ark Oz

ght C

reek

.

Fassn i

Rd

on Wils reek C

Ca

ssv

ill

eR

d

N 0 0

1 mile 1 kilometer

Figure 24. Redrafted copy of Map of the Picket-Roads, Springfield Missouri, 1862, “lettered” by Private George W. Ernst, Co. H, 26th Indiana Volunteers; (original is in the National Archives) Map shows the locations of forts No. 1, 2, 4, and 5, the site of uncompleted Fort No. 3, roads, and creeks. Only buildings noted on the original map are shown (Ch. = church, which was shelled in the battle of Springfield by Confederate artillery; none of the structures is still standing).

62

Hannibal and Evans

Fort No. 4 (Figs. 22–24) was a small, almost-square earthen fort ~190 ft on each side, with two projecting gun emplacements (Bradbury, 1984). In January of 1863, it held two Union 12-pound howitzers, mounted on wagon carriages, and one 6-pound cannon, approximately six blocks south of the square On the morning of 8 January 1863, Gen. Marmaduke’s troops entered Springfield from the south, near the intersection of present-day South Street and Grand Avenue, at the edge of the city, ~12 blocks south of the square. By mid-morning, after minor cavalry skirmishes, the Confederates dismounted and cannon fire was focused on Federal Fort No. 4. Although the 6-pound cannon was captured when it was brought outside the fort, the Union battery proved fairly effective, even though manned mostly by untrained volunteers. Gen. Brown had ordered the destruction of several houses south of Fort No. 4 to open the field of battle. Confederate forces attacked and after several attacks on the fort were repulsed, Marmaduke’s left flank maneuvered in to the west. There, Southern forces pushed back Union troops from a two-story brick and colonnaded structure that was being used as a prison, and house-tohouse combat continued for several hours with minor advances alternately made by both sides. After hours of fighting, the Union front southwest of the square collapsed but only briefly as the Enrolled Missouri Militia troops rallied, and the Confederates eventually were pushed back in intense hand-to-hand combat. By late afternoon, failing to take Fort No. 4 and after making little progress in capturing anything other than exposed field artillery, Marmaduke’s troops withdrew to the Phelps’ farm south of Springfield (near present-day Phelps Grove Park). The next morning, they retreated eastward along the St. Louis Road to rejoin the other columns. Marmaduke’s expedition was thwarted and he returned to Arkansas. Gen. Brown’s militia of “mostly green” troops and citizens, compared with Marmaduke’s seasoned veterans, held the field and were commended for their valiant defense of the city. Gen. Brown was severely wounded during the battle. Springfield was a strong pro-Union city, flanked by pro-Southern rural areas to the north, west, and south for the remainder of the conflict.

tle and were reinterred at the National Cemetery over the years, some only within the past 10 years. Gravestones (Figs. 25 and 26) in the cemetery are predominantly upright white-marble military-style tablets. Those of U.S. veterans have rounded tops (Fig. 25), while those of Confederates have pointed tops (Fig. 26). This is a national pattern used to distinguish the graves of the veterans of the two sides. It has been claimed that the Confederates chose to have pointed-top gravestones so that union veterans would not sit on their gravestones. This is a fascinating functional explanation, but various types of

Figure 25. Union gravestone at Springfield National Cemetery made of a fine-grained marble.

Stop 5. Springfield National Cemetery The Springfield National Cemetery is located at 1702 East Seminole Street in Springfield, Missouri. This cemetery, run by the U.S. Department of Veterans Affairs, contains the remains of veterans of the Civil War, as well as veterans of other wars, including Buffalo Soldiers, and the spouses of veterans. The cemetery was founded in 1867 and was originally reserved for veterans of the U.S. armed forces. A Confederate cemetery was built alongside. These two areas were originally separated by a fence. Both cemeteries are now encompassed within the National Cemetery. Many veterans of the Battle of Wilson’s Creek are buried here. These include a number of the soldiers who had died at the battlefield and who were originally buried at the site of the bat-

Figure 26. Confederate gravestone with pointed top, Springfield National Cemetery.

Civil War and cultural geology of southwestern Missouri, part 1 pointed-topped gravestones were used contemporaneously with rounded-top styles in the 1800s (Bauer et al. 2002) and were used by pacifists such as Shakers. Wood rounded-top Confederate markers made during the war are known (e.g., specimen 42.985 in the collection of the Western Reserve Historical Society, Cleveland, Ohio). Thus it is likely that the style was simply used to distinguish Confederate gravestones from Union gravestones. Marble became the preferred stone for use in national cemeteries by the 1870s, replacing original markers made of wood (U.S. Department of Veterans Affairs, 2009). During the nineteenth century, marble gravestones replaced wooden markers in other cemeteries as well (Emerson, 1911, p. 305). The marble tablets installed in the nineteenth and early twentieth century are made of a fine-grained marble, almost certainly quarried in the Vermont marble belt. In the nineteenth century the federal government supplied stone from contractors in West Rutland and Proctor, Vermont, as well as from Lee and Stockbridge, Massachusetts, for veterans’ gravestones (Office of the Quartermaster General, 1967). These marbles are Ordovician in age, resulting from metamorphism during the Taconic Orogeny. Marble is greatly affected by acid rain, however, which results in reduced surface features. The surfaces of the older marble gravestones have “sugared,” that is the surficial marble grains have weathered to the extent that they feel and look like sugar. A good number of the original marble gravestones in this cemetery have been replaced by the U.S. Department of Veterans Affairs. Such replacement of historic stone is not encouraged by historic preservationists, but it is typically less expensive to replace a historic stone than to repair it or make any corrections to carvings in situ. This controversy over replacement is best exemplified by the Yule marble block used for the Tomb of the Unknowns in Arlington Cemetery. There have been moves to replace it, but these have been stopped for now because of opposition (Anonymous, 2009). At least in recent years, most stone in the Springfield National Cemetery has been replaced instead of being repaired. In recent decades replacement marble for upright marble gravestones has come from Georgia. The replacement marble is the Murphy Marble, a coarse-grained marble quarried in the Tate area of northern Georgia. The Murphy Marble used for gravestones can be distinguished by its larger grain size from the typically fine-grained marbles from the Vermont marble belt (and from Carrara, Italy, another important source of finegrained white marble used for gravestones in the past; see Bauer et al., 2002). The Murphy Marble was formed from metamorphism in the Late Cambrian or early Ordovician, as part of the Taconic Orogeny. Three tall monuments stand out in the cemetery: the Union (Bailey) Monument, the Lyon Monument, and the Price Monument. The 25-ft-high Union Monument (Fig. 27), also known as the Bailey Monument, honors the Union soldiers that were wounded and died defending the garrison at Springfield on 8 January 1863. (Some of the wording on the carved dedication, however, is in a carved rectangular depression, which may signify a change in the original wording.) This monument was unveiled on

63

Decoration Day (30 May) of 1873 (Holcomb, 1883, p. 541). The will of Thomas Bailey, who had been a pro-union slaveholder, provided funds and land for his former slaves as well as $5,000 for this monument (Greene County, Missouri, probate file no. 449 of Dr. Thomas J. Bailey). The monument is composed of several types of limestone and marble. The base is made of one of the gray, stylolitic, southwestern Missouri stones, possibly from the Phenix quarries. This base of local material is surmounted by a series of stones from elsewhere. These include a gray-veined marble, “blue Vermont,” a white Vermont marble, and a red-andgray mottled limestone, possibly “red Tennessee” (Anonymous, 1872). The latter is weathered differentially as well as along stylolitic surfaces. The statue of the soldier atop the monument is a white marble. Most of the marble used for the monument is from the Vermont marble belt, while it is likely, but not certain, that the statue on top is made of Carrara marble, quarried in the Apuan Alps of Italy. “Thompson and Kenna” is inscribed on the base of the monument. The Thomson and Kenna marble works were once located at the intersection of South and Walnut streets in Springfield (R.P. Studley Company, 1873, p. 149).

Figure 27. Union Monument (also known as the Bailey Monument) at Springfield National Cemetery. Note red, white, and blue stones near base.

64

Hannibal and Evans

Numerous Civil War monuments, especially statuary, both in the South (see, for example, Emerson, 1911) and in the North, utilize Carrara marble, which was renowned for its beauty and sculptural properties, especially, but not only, in the nineteenth century. Carrara and Vermont marble and other carbonate rocks, however, can be problematical when used as part of outdoor sculptural elements due to weathering. The marble of the monuments, and most of the older marble gravestones in the cemetery, has been so weathered, evidenced by the “sugaring” of the stone. The ~13-ft-tall Lyon Monument (Fig. 28) is a cenotaph (Lyon is buried in Connecticut) which honors Gen. Nathanial Lyon, killed at the Battle of Wilson’s Creek. Lyon was the first Union general to die in the Civil War and so has been memorialized in a number of ways. In addition to this monument, counties in Kansas, Iowa, and Minnesota have been named for him. According to newspaper reports (e.g., Springfield News Leader, 1959) and other sources, the Lyon Monument was first unveiled in 1883 in the Springfield public square and set up in the cemetery in 1884. The monument is composed of a concrete base and a low block of pink (?)Missouri granite surmounted by a multi-

part marble structure. The upper part of the structure is composed of a large marble facies (an ancient Roman symbol of unity used in a number of U.S. Civil War monuments and memorials as well as in the Lincoln Memorial in Washington, D.C.) topped with a helmet and other symbols. The marble used for this monument is a fine-grained white marble. The Price Monument, which was erected in 1901 when this part of the present cemetery was still the separate Confederate Cemetery, honors Confederate Gen. Sterling Price. This monument features a bronze soldier and bronze bas-reliefs by Gaetano Trentanove mounted on a large, 16-ft-high base composed of Barre Granite (Emerson, 1911, p. 231). Barre Granite (technically a biotite granodorite) is a famed monumental and gravestone granite quarried in Barre, Vermont. The use of Vermont stone in Confederate monuments is not unusual; it was used for a number of such monuments (Emerson, 1911). Leaching from the bronze has caused some staining, probably cosmetic, of the stone. The change in use of stones for these three monuments exemplifies changing trends in usage over time. The earliest of the three monuments, the Union Monument, uses local limestone plus marble. The Lyon Monument utilizes granite as well as marble, and the Price Monument, the last to be erected, is made of bronze and granite. This change in materials may at least in part be due to the recognition of the susceptibility of limestone and, especially, marble to weathering. This susceptibility was becoming known in the scientific community before the turn of the century (see references in Dale, 1912, p. 37–39 and references therein). Newly available materials and tools such as Carborundum and pneumatic drills that facilitated the carving and polishing of granite had also been put into use in the last decades of the nineteenth century (Bauer et al., 2002, p. 95–96). This change in usage, however, is in contrast with the continued use of marble for individual gravestones. Stop 6. Edwards Mill, Point Lookout, Missouri

Figure 28. Lyon Monument, Springfield National Cemetery.

Edwards Mill is a reconstructed mill on the grounds of the College of the Ozarks in Point Lookout, Missouri. The College is ~4 mi from the center of Branson. The mill may be reached from Branson by taking U.S. Route 65 south the College of the Ozarks exit, passing through the college gate onto Opportunity Avenue, then turning left (northwest) on Opportunity Avenue and proceeding until Opportunity intersects Vocational Way. Turning right (east) on Vocational Way, the mill will be on the left. This working mill is a twentieth-century recreation of a nineteenthcentury mill utilizing an overshot waterwheel (Fig. 29) not unlike that hypothesized for Gibson’s Mill (Stop 3b). The Edwards Mill utilizes millstones to produce stone-ground flour. Mills were a key component of the nineteenth-century cultural landscape of the Ozarks as the dissected terrain of the region made transportation difficult. Thus many mills were constructed to grind grain for nearby farmers. Most of these mills in southwestern Missouri, as elsewhere in the United States,

Civil War and cultural geology of southwestern Missouri, part 1

65

were abandoned in the nineteenth and twentieth centuries. The Edwards Mill was one of the first to be recreated or reconstructed in this region as interest in the history of mills and milling has increased in the past few decades. Mills are interesting geologically for a number of reasons ranging from their hydrogeologic setting to the types of stone used for their construction and for grinding grain. The Edwards Mill is especially notable for the geologically diverse collection of millstones (>17 millstones or parts of millstones) on exhibit, including both domestic and imported stone, most from old mills in Missouri, including southwestern Missouri. The stones are finished and unfinished, monolithic and composite. There are also metates built into a low stone wall. The most eye-catching and exotic millstones in the collection are a pair of large (48 in diameter) millstones made of French buhr (Fig. 30). These are composite millstones with cut pieces of

chert fitted together and held in place with iron bands. The upper stone of the pair, known as the runner in millstone terminology, also has an added top made of plaster. The lower stone, known as the bedstone, has a flatter top and bottom. The sign by these millstones states that they came from the Pyrenees via St. Louis from which oxen were used in 1847 to transport them to the Joseph Lyons Mill near Ava, Missouri, which is located ~40 miles northeast of Branson. The stone for French buhr was typically quarried from Cenozoic deposits near Paris (Ward, 1993), however, not the Pyrenees. French buhrstones were manufactured (from pieces of stone imported from France) at St. Louis since at least 1839 (Ball and Hockensmith, 2007, p. 92). French buhr was notable for its “cellular” nature stemming from the presence of visible void spaces in the stone. The edges of the void spaces were thought to provide sharp cutting edges, thus enhancing the effectiveness of these stones in milling. There are several other chert millstones made in one piece (monolithic millstones). Some of these may have been fashioned from chert derived from the Mississippian or other carbonate sequences of Missouri or Arkansas. Chert from various counties in central and southern Missouri, as well as northern Arkansas, was known to be used for such purposes in Missouri. Hockensmith (2004) has summarized accounts of such usages of local chert (using the archaeological term “flint”) as well as potential usages of the chert, culled from the geological and other literature. For more information on chert, granite, and sandstone millstones of Missouri see Hockensmith (2004, 2009). The Kissee millstone, once owned by the last owner of the Kissee Mill (which was located ~11 mi east of Branson) is the most unusual, as it is made of dolomite, an uncommon material for millstones.

Figure 29. Overshot water wheel providing power to Edwards Mill in Point Lookout, Missouri.

SUMMARY

Figure 30. Pair of French buhr millstones at Edwards Mill. Stone to the left is the runner stone and has plaster on its top (side facing to the right). Stone to the right is the bedstone. The millstones are composite, made of polygonal pieces of French buhr.

This field trip provides an overview of the connections between southwestern Missouri culture and geology. The geologic setting and rich cultural heritage are intertwined in the saga of the Civil War and post-war eras. This karstic landscape was the stage and backdrop for historical events; geology is the underpinning of geomorphic characteristics that affected military actions (high ground, slope, terrain, and mobility). Each factor played a role in the conduct of war at the Battle of Wilson’s Creek, Zágonyi’s Charge, and the Battle of Springfield. Springs, creeks, agricultural products, and forage dictated locations of encampments and troop movements. These also were the principal factors in the development of transportation networks. Local millstones, dimensional building stone, lead and zinc, agricultural lime, cement, and limestone aggregate are the products of an industrious people. French buhr millstones, Vermont marble gravestones, and Italian marble statuary were employed only where imported products were perceived to be superior to local material. Understanding the connections between geology and culture provides for place-based learning and deeper awareness of the fundamental role of geoscience education.

66

Hannibal and Evans

ACKNOWLEDMENTS Jeffrey Patrick, librarian of the Wilson’s Creek National Battleground, and Robert Neumann, Greene County Archives and Records Center, Springfield, Missouri, answered numerous queries and provided key sources of information used in this study. Patrick also made a number of corrections to the manuscript. Chris Wood, Cleveland Public Library; Wendy Wasman, Cleveland Museum of Natural History Librarian; Michele Hansford, Powers Museum, Carthage, Missouri; Sally McAlear, Springfield, Missouri; and Renee Glass, the Library Center, Springfield, Missouri, provided additional information and materials. Many of the stone samples studied are from the Wellington Collection of the Mineralogy Department of the Cleveland Museum of Natural History. Kathleen Farago, Cleveland Heights/University Heights Library, and Douglas Dunn and Evan Scott, Cleveland Museum of Natural History, proofread versions of the manuscript. George Davis, Missouri Department of Transportation, also commented on the manuscript. Freddie Flores provided information on the Phenix quarries. Dave Richter at Phenix Quarry made it possible to visit the working area. Cecil Ward provided information on dimension stone at the Carthage Marble quarry. The staff at a museum in Carthage found and kindly returned Hannibal’s lost field notebook. The Americold Realty underground storage facility in Carthage allowed access to their facilities. John Greismer provided access for the field trip to Springfield Underground. Photographs in this article were taken by J. Hannibal in May 2009; other illustrations, including maps, were drafted by K. Evans. The National Association of Geoscience Teachers provided sponsorship for this trip. Shermon Lundy, Cedar Falls, Iowa, and Michele Hansford provided formal reviews of the paper. REFERENCES CITED Aber, J.S., Aber, S.W., Manders, G., and Nairn, R.W., 2010, this volume, Route 66—Geology and legacy of mining in the Tri-state district of Missouri, Kansas, and Oklahoma, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, doi: 10.1130/2010.0017(01). Anderson, E.M., 1868, Memoirs: historical and personal including the campaigns of the first Missouri Confederate brigade: Times Printing Company, St. Louis, Missouri, 436 p. Andrews, W.M., Jr., 2005, Geology and the Civil War in central Kentucky: Camp Nelson: Field trip guidebook for the 42nd Annual Meeting of the American Institute of Professional Geologists, 25 p., http://www.uky.edu/ KGS/geoky/fieldtrip/2005%20AIPG%20Guidebooks/CampNelson.pdf. Anonymous, 1872, A soldier’s monument: Missouri Weekly Patriot, 12 December, p. 3. Anonymous, 1901, Blow, Henry Taylor, in Conrad, J.L, ed , Encyclopedia of the history of Missouri: New York, Southern History Company, v. 1, p. 305–306. Anonymous, 1913, Stone bid for the Missouri Capitol: Stone, v. 34, p. 636. Anonymous, 1917, The Missouri State Capitol: Stone, v. 38, p. 301–303. Anonymous, 1956, Missouri marble is world known: Missouri News Magazine, October, p. 26–27. Anonymous, 2009, Repairs planned for cracks in Tomb of the Unknowns: New York Times, November 1, p. A30. Ball, D.B., and Hockensmith, C.D., 2007, Preliminary directory of millstone makers in the eastern United States, in Ball, D.B., and Hockensmith,

C.D., Millstone Studies: Papers on their Manufacture, Evolution, and Maintenance: Special Studies no 1, Symposium on Ohio Valley Urban and Historic Archaeology, Murray, Kentucky, and Society for the Preservation of Old Mills, East Meredith, New York, p. 1–9. Bauer, A., Hannibal, J.T., Hanson, C.B., and Elmore, J.V., 2002, Distribution in time, provenance, and weathering of gravestones in three northeastern Ohio cemeteries: The Ohio Journal of Science, v. 102, p. 82–96. Bearss, E.C., 1978, Historical base and ground cover map Wilson’s Creek National Battlefield, Greene and Christian Counties, Missouri: unpublished report in the files of the library of the Wilson’s Creek National Battlefield, 125 p. Bennett, L.O., 1966, A soldier’s diary: White River Valley Historical Quarterly, v. 2, no. 9, p. 7–11. Blow & Kennett, 1862, Letter to Abraham Lincoln, Monday, December 01, 1862: Abraham Lincoln Papers at the Library of Congress, Series I, General correspondence: http://memory.loc.gov/cgi-bin/query/P?mal:1./ temp/~ammem_2yxU (accessed January 2010). Bradbury, J.F., Jr., 1984, Fort No. 5: A Civil War field fortification in Springfield, Greene County, Missouri: unpublished report in the files of the library of the Wilson’s Creek National Battlefield. Branson, E.B., 1944, The geology of Missouri: University of Missouri Studies, v. 19, no. 3, 535 p. Branson, E.B., and Mehl, M.G., 1941, Conodonts from the Keokuk Formation: Journal of Scientific Laboratories of Denison University, v. 35, p. 179–188. Bray, R.T., 1967, An archeological survey and excavations at Wilson’s Creek Battlefield National Park, Missouri, 168 p. Brewster, B.B., 1914, Quarrying marble at Phenix, Missouri: Mine and Quarry, v. 8, p. 791–796. Britton, W., 1899, The Civil War on the border: New York, Putnam’s Sons, 473 p. Buckley, E.R., and Buehler, H.A., 1904, The quarrying industry of Missouri: Missouri Bureau of Geology and Mines, v. 2, series 2, 371 p. Buckley, E.R., and Buehler, H.A., 1906, The geology of the Granby area: Missouri Bureau of Geology and Mines, v. 24, series 2, 120 p. Bullard, L., 2001, Springs in the Civil War, in Bullard, L., Thomson, K.C., and Vandike, J.E., eds., The Springs of Greene County, Missouri: Missouri Department of Natural Resources Geological Survey and Resource Division, Water Resources Report no. 68, p. 11–12. Bullard, L., Thomson, K.C., and Vandike, J.E., 2001, The Springs of Greene County, Missouri: Missouri Department of Natural Resources Geological Survey and Resource Division, Water Resources Report no. 68, 120 p. Bullard, L., 2008, Jordan creek, story of an urban stream: Watershed Committee of the Ozarks, Springfield, Missouri, 21 p. Caporaso, A.L., Carlson-Drexler, C.G., and Masters, J., 2008, Metallurgical analysis of shell and case shot artillery from the Civil War battles of Pea Ridge and Wilson’s Creek: Technical Briefs in Historical Archaeology, v. 3, p. 15–24. Carthage Marble Corporation, ca. 1956, Carthage Marble: Carthage, Missouri, Carthage Marble Corporation, AIA File 22-A-2, 44 p. Carthage Marble Corporation, 1959–1970, Marble of the Month: Carthage, Missouri, Carthage Marble Corporation, [individual issues]. Carthage Press, 1889, [illustration of Carthage Marble & White Lime Co.]: Carthage Press, Special fair Issue, Sept 12, 1889, p. 3. Also available at http://cdm.sos.mo.gov/u?/riches,319. Chapman, C.H., 1975, The archaeology of Missouri, I: Columbia, University of Missouri Press, 288 p. Cole, N., 1881, Report of Capt. Nelson Cole, Fifth Missouri Infantry…May 16, 1861, U.S. War Department, 1881, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 3 Washington, D.C., Government Printing Office, p. 10–11. Crabb, B., 1888, Report of Col. Benjamin Crabb, Nineteenth Iowa Infantry, of engagement at Springfield, Mo. in U.S. War Department, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 22, part 1, Washington, D.C., Government Printing Office, p. 183–187. Crane, G.W., 1912, The iron ores of Missouri: Missouri Bureau of Geology and Mines, v. 10, series 2, 434 p. Cuffey, R.J., Inners, J.D., Fleeger, G.M., Smith, R.C., II, Neubaum, J.C., Keen, R.C., Butts, L., Delano, H.L., Neubaum, V.A., and Howe, R.H., 2006, Geology of the Gettysburg battlefield: How Mesozoic events and processes impacted American history, in Pazzaglia, F.J., ed., Excursions in Geology and History: Field Trips in the Middle Atlantic States,

Civil War and cultural geology of southwestern Missouri, part 1 Geological Society of America Field Guide 8, p. 1–16, doi:10.1130/2006 .fld008(01). Dale, T.N., 1912, The commercial marbles of western Vermont: U.S. Geological Survey Bulletin 521, 170 p. Edom, C.C., 1963, Missouri sketch book, a collection of words and pictures of the Civil War: Lucas Brothers, Columbia, Missouri, 163 p. Eicher, D.J., 2001, The Longest night: a military history of the Civil War: New York, Simon & Schuster, 990 p. Emerson, B.A.C., 1911, Historic southern monuments: representative memorials of the heroic dead of the southern Confederacy: New York, Neale Publishing Company, 466 p. Evans, K.R., 2010, this volume, Civil War and cultural geology of southwestern Missouri, part 2: Geologic influences on the Battle of Forsyth, guerilla activities, and post-war vigilantism, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, doi: 10.1130/2010.0017(05). Fellows, L.D., 1967, Marble, in Mineral and Water Resources of Missouri, v. 43, p. 147–149. Fenneman, N.M., 1938, Physiography of the eastern United States: New York, McGraw-Hill Book Company, 714 p. Grant, M.H., 1955, The marbles and granites of the world: London, J. B. Shears & Sons, 158 p. Hannibal, J.T., 2007, Teaching with tombstones: Geology at the cemetery, in Shaffer, N.R., and DeChurch, D.A., eds., Proceedings of the 40th Forum on the Geology of Industrial Minerals, 2–7 May 2004, Bloomington, Indiana: Indiana Geological Survey Occasional Paper 67, p. 82–88. Henderson, S.W., 2004, The geology of the Chickamauga Campaign, American Civil War, in Caldwell, D.R., Ehlen, J., and Harmon, R.S., eds., Studies in Military Geography and Geology: Dordrecht, The Netherlands, Kluwer Academic Publishers, p. 173–184. Hess, E.J., Hatcher, R.W., III, Piston, W.G., and Shea, W.L., 2006, Wilson’s Creek, Pea Ridge, and Prairie Grove: A battlefield guide with a section on Wire Road: Lincoln, University of Nebraska Press, 282 p. Higgins, B., 2002, Viewing the Civil War through a geological window: CRM, no. 4, p. 21–25. Hinchey, N.S., 1946, Missouri marble: Missouri Geological and Water Resources Report of Investigations no. 3, 47 p. Hockensmith, C.D., 2004, The millstone industry of Missouri: The Millstone, v. 3, no. 2, p. 29–34. Hockensmith, C.D., 2009, The millstone industry: A summary of research on quarries and producers in the United States, Europe, and elsewhere: Jefferson, North Carolina, McFarland & Co., 269 p. Holcomb, R.I., 1883, History of Greene County, Missouri: St. Louis, Western Historical Company, 919 p. Ingenthron, E., 1980, Borderland rebellion, a history of the Civil War on the Missouri-Arkansas border: The Ozark Mountaineer, Branson, Missouri, 373 p. Kennedy, F.H., 1990, The Civil War battlefield guide: Boston, Houghton Mifflin, 317 p. Knapp, G.E., 1993, The Wilson’s Creek staff ride and battlefield tour: Fort Leavenworth, Kansas, Combat Studies Institute, U.S. Army Command and General Staff College, 93 p. Leffel, James & Co., 1872, Illustrated book of Leffel’s improved double turbine water wheel: Springfield, Ohio, Leffel News Print, 152 p. McClymont, J.J , compiler, 1990, A list of the world’s marbles: Farmington, Michigan, Marble Institute of America, [various paginations, about 280 p.] McCullough, B., 1861, [Letter to Sterling Price, Nov. 10], in U.S. War Department, 1881, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 3 Washington, D.C., Government Printing Office, p. 736–737. Middendorf, M.A., ed., 2003, Geologic map of Missouri 1:500,000: Missouri Department of Natural Resources, Division of Geology and Land Survey. Missouri Commandery of the Military Order of the Loyal Legion of the United States (MOLLUS), 2009, http://home.usmo.com/~momollus/BATTLES .HTM (accessed September 2009). Monagham, J., 1955, Civil War on the western border: Boston, Little Brown, 454 p. National Archives, 1986, A Guide to Civil War maps in the National Archives: Washington, D.C., National Archives and Records Administration, 139 p. National Park Service, U.S. Department of the Interior, 2004, Wilson’s Creek National Battlefield, Republic, Missouri: Cultural Landscape Report, 2 v.

67

Office of the Quartermaster General, 1967, Records of the Office of the Quartermaster General, Record Group 92, Series 628, Card Record of Headstone Contracts and U.S. Soldiers’ Burials, in Preliminary Inventory of the Records of the Office of the Quartermaster General, Part I: Washington, D.C., National Archives. Phenix Marble Company, 1922, Napoleon Gray Marble: Stone, v. 43, no. 3, p. 123. Phenix Marble Company, ca. 1926, Napoleon Gray: An adaptable marble: New York, Tomkins-Kiel Marble Company, 61 p. Phenix Marble Company, 1927, Napoleon Gray, universally adaptable [advertisement]: Through the Ages, v. 4, no. 11, p. 43. Phillips, B., 2010, Early stone cutters in Missouri: Butler, Missouri, Poplar Heights Farm, http://www.stone.poplarheightsfarm.org/index.htm (accessed January 2010). Piston, W.G., and Hatcher, R.W., III, 2000, Wilson’s Creek: The second battle of the Civil War and the Men who fought it: Chapel Hill, University of North Carolina Press, 408 p. Pittman, W.E., 2000, Geologists and the American Civil War, in Rose, P.F., and Nathanail, C.P., eds., Geology and Warfare: Examples of the Influence of Terrain and Geologists on Military Operations: London, The Geological Society, p. 84–103. Pittman, W.E., 2002, Tullahoma: Terrain and tactics in the American Civil War, in Doyle, P., and Bennett, M.R., eds., Fields of Battle: Dordrecht, Kluwer Academic Publishers, p. 99–115. Porter, J.C., 1888, Report of Col. J. C. Porter, Missouri Cavalry (Confederate), commanding brigade, in U.S. War Department, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 22, part 1, Washington, D.C., Government Printing Office, p. 205–207. Powers Museum, Joplin Museum Complex; Missouri Southern State University, Spiva Library Archives and Special Collections; Western Historical Manuscript Collection-Rolla at Missouri University of Science and Technology, 2010, Riches From the Earth, http://www.sos.mo.gov/archives/ mdh_splash/default.asp?coll=riches (downloaded January 2010). Richards, J.M., and Johnson, T., 2002, Water quality, selected chemical characteristics, and toxicity of base flow and urban stormwater in the Pearson Creek and Wilsons Creek basins, Greene County, Missouri, August 1999 to August 2000: U.S. Geological Survey Water-Resource Investigations Report 02-4124, 38 p. Rosecrans, W.S., 1864, Letter to Abraham Lincoln, September 15: Abraham Lincoln Papers at the Library of Congress, Series I, General Correspondence, 1833–1916. Schofield, J.M., 1881, Report of Maj. John M. Schofield, First Missouri Infantry, and Acting Adjutant-General Army of the West, of operations August 1–14, in U.S. War Department, 1881, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 3 Washington, D.C., Government Printing Office, p. 57–64. Schroeder-Lein, G.R., 2008, The encyclopedia of Civil War medicine: Armonk, New York, M.E. Sharpe, 421 p. Shelby, J.O., 1888, Report of Col. Joseph O. Shelby, Missouri Cavalry (Confederate), commanding brigade, in U.S. War Department, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 22, part 1, Washington, D.C., Government Printing Office, p. 199–205. Sorrel, G.M., 1905, Recollections of a Confederate: New York, Neale Publishing, 315 p. Springfield News Leader, 1959, Lyon monument moved from Public Square to National Cemetery May 1884: News Leader, 31 May. Springfield-Greene County Library District, 2010, Community in Conflict: the impact of the Civil War in the Ozarks: http://www.ozarkscivilwar.org/ (downloaded January 2010). R.P. Studley Company, 1873, Directory of Springfield, Missouri for 1873–74: St. Louis, R.P. Studley Company, 180 p. Swallow, G.C., 1855, The first and second annual reports of the Geological Survey of Missouri, 207 p., 239 p. Thompson, T.L., 1986, Paleozoic succession in Missouri: part 4, Mississippian system: Missouri Department of Natural Resources Division of Geology and Land Survey, Report of Investigations 70, no. 4, 189 p. Thompson, T.L., and Robertson, C.E., 1993, Guidebook to the geology along interstate highway 44 (I-44), in Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigation, no. 71, guidebook 23, 185 p.

68

Hannibal and Evans

Thomson, K.C., 1981a, Geologic map of the Republic 7.5′ quadrangle, Greene and Christian counties, Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey, unpublished map SP8115, 1 sheet, http://www.dnr.mo.gov/geology/statemap/springfield/ SP8115.htm. Thomson, K.C., 1981b, Geologic map of the Brookline 7.5′ quadrangle, Greene County, Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey, unpublished map SP8127, 1 sheet, http:// www.dnr.mo.gov/geology/statemap/springfield/SP8127.htm. Thomson, K.C., 1981c, Geologic map of the Springfield 7.5′ quadrangle, Greene County, Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey, unpublished map SP8142, 1 sheet, http://www.dnr.mo.gov/geology/statemap/springfield/SP8142.htm. Thomson, K.C., 1982, Geologic map of the Ash Grove 7.5′ quadrangle, Greene County, Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey, unpublished map SP8250, 1 sheet, http:// www.dnr.mo.gov/geology/statemap/springfield/SP8250.htm. Thomson, K.C., 1983, Geologic map of the Walnut Grove 7.5′ quadrangle, Greene and Polk counties, Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey, unpublished map SP8378, 1 sheet, http://www.dnr.mo.gov/geology/statemap/springfield/ SP8378.htm. Thomson, K.C., 1986, Geologic Map of Greene County: Watershed Management Coordinating Committee, Springfield, Missouri, 1 sheet [now distributed by the Watershed Committee of the Ozarks]. Totten, J., 1881, Report of Capt. James Totten, Second U. S. Artillery, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 3 Washington D.C., Government Printing Office p. 73–75. U.S. Department of Veterans Affairs, 2009, History of government furnished headstones and markers, http://www.cem.va.gov/hist/hmhist.asp (accessed August 2009). U.S. War Department, 1881, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 3 Washington, D.C., Government Printing Office, 815 p. Vandike, J.E., 2001, Geologic characteristics of Greene County springs, in Bullard, L., Thomson, K.C., and Vandike, J.E., eds., The Springs of Greene

County, Missouri: Missouri Department of Natural Resources Geological Survey and Resource Division, Water Resources Report no. 68, p. 49–64. Vasvary, E., 1939, Lincoln’s Hungarian heroes: the participation of Hungarians in the Civil War, 1861–1865: Washington, D.C., Hungarian Reformed Federation of America, 171 p. Vierrether, C.B., 1998, Bedrock geology of the Highlandville 7 1/2′ quadrangle, Christian and Stone counties, Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Open-File Report OFM-98-327-GS. Ward, O., 1993, French millstones: notes on the millstone industry at La FertéSous-Jouarre: Reading, England, International Molinological Society, 75 p. Wharton, H.M., Martin, J.A., Rueff, A.W., Robertson, C.E., Wells, J.S., and Kisvarsanyi, E.B., 1969, Missouri Minerals—Resources, production, and forecasts: Missouri Geological Survey and Water Resources Special Publication No. 1, 314 p. Whitfield, J.W., 1981, Underground space resources in Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey, Report of Investigations 65, 65 p. White, F.J., 1881, Report of Major Frank J. White, A.D.C., commanding First Squadron Prairie Scouts, U.S. War Department, 1881, The War of the rebellion: a compilation of the official records of the Union and Confederate armies: series 1, vol. 3 Washington, D.C., Government Printing Office p. 246–247. Wilson, L., 1979, Phenix, a town that is no more: self published by the author, 1 v. (unpaged) [available from Public Libraries of Springfield and Greene County]. Winslow, A., assisted by Robertson, J.D., 1894a, Lead and zinc deposits, Section 1: Missouri Geological Survey, v. 6, 387 p. Winslow, A., assisted by Robertson, J.D., 1894b, Lead and zinc deposits, Section 2: Missouri Geological Survey, v. 7, 763 p. Zen, E-an, and Walker, A., 2000, Rocks and war, geology and the Civil War campaign of second Manassas: Shippensburg, Pennsylvania, White Mane Books, 102 p.

MANUSCRIPT ACCEPTED BY THE SOCIETY 5 FEBRUARY 2010

Printed in the USA

The Geological Society of America Field Guide 17 2010

Civil War and cultural geology of southwestern Missouri, part 2: Geologic influences on the Battle of Forsyth, guerrilla activities, and post-war vigilantism Kevin R. Evans* Department of Geography, Geology, and Planning, Missouri State University, 901 S. National Avenue, Springfield, Missouri 65897, USA

ABSTRACT Climate and terrain, especially stream drainage basins and topography, greatly influenced European-American settlement patterns, agricultural practices, transportation networks, and the cultural and economic development of the southern Missouri Ozarks from the early 1800s to the American Civil War (1861–1865). These also were key factors, together with land cover and natural resources, that predicated the course of military operations and tactics during the war. The same factors affected widespread partisan conflicts during the war and vigilantism during the Bald Knobber era, a mid-1880s cultural extension of the Civil War in Taney, Christian, Douglas, and Stone counties. This field trip will examine the geology of selected areas in and around Branson in southwestern Taney County and integrate historical events and anecdotes, which illustrate the influence of geologic factors.

historical context? Ostensibly, the greatest influence may have been the way geology has shaped the landscape of conflicts and battlefields, because the outcomes of these events have molded the political world. Military geology—the study of geological influences on warfare and defense—constitutes a large part of cultural geology. Geology played an important role in the American Civil War because strategic resources, such as coal, iron, lead, and nitrates (saltpeter), were required for waging war, and the landscape was the stage where tactical movements and actions took place (e.g., Kiersch and Underwood, 1998; Zen and Walker, 2000). This field trip guidebook article provides background on the influence of geology during the Civil War and afterward, in and around Branson, Missouri.

INTRODUCTION The study of geologic hazards, commodities, and processes from a historical perspective largely has been relegated to cultural geographers, archaeologists, and historians, but the geological underpinnings of history perhaps can be examined and analyzed most adeptly by geologists. In the developing multidisciplinary field of cultural geology, geologists ask questions such as, what resources made land suitable for settlement? What made soils and landscapes suitable for various types of agricultural production? What fresh-water resources were available? How did the landscape affect transportation systems? What energy and mineral resources could be utilized? What building materials were available? And, how were geological concepts applied within a *[email protected]

Evans, K.R., 2010, Civil War and cultural geology of southwestern Missouri, part 2: Geologic influences on the Battle of Forsyth, guerrilla activities, and post-war vigilantism, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, p. 69–98, doi: 10.1130/2010.0017(05). For permission to copy, contact [email protected]. ©2010 The Geological Society of America. All rights reserved.

69

70

Evans

Branson is located in southwestern Taney County ~10 miles (16 km) north of the Arkansas border (Fig. 1). Founded in the 1880s as a railroad town, Branson is a relatively young city (McCall, 1961), but Forsyth, the county seat, was established in 1838, and much of the history of this area is connected with it and the nearby community of Kirbyville (Ingenthron, 1974). The rugged terrain and frontier setting of Taney County may have precluded it from becoming a major battleground during the Civil War, but the strategic significance of the upper White River basin and perceived control of land bordering the Confederacy made it an important objective for both North and South. A brief synopsis of the historical context of the Civil War in Missouri, including economic, political, and military aspects, is given below, along with a post-war account of these conditions in Taney County. The synopsis is followed by a discussion of resources and hazards from historical and geologic perspective. The road log features nine stops that highlight the geology and history of the Branson area. Key elements include faulting; preferential karstification and erosion of Mississippian carbonate uplands; structural control on preservation of pinnacle-like karstfill sandstone features; and development of entrenched meanders in the upper White River Basin. Each had an impact on historical events that transpired across this landscape. HISTORICAL OVERVIEW Missouri in the Civil War The Civil War was arguably the most influential time in the cultural history of the Missouri Ozarks. Missouri has a southern cultural heritage (most settlers came from Kentucky and Tennessee), but geographers and historians regard Missouri as a “border state” (Rafferty, 1980). The term “border state” is descriptive of a “slave state” that bordered by one or more “free states” (Phelps and Watson, 1862). Kentucky, West Virginia, Maryland, and Delaware were also border states. Although commonly couched in terms of states’ rights versus Federalist thought, the war was inextricably linked with slavery. The 1860 U.S. Census records show that Missouri had a large population of slaves, ranking eleventh in the United States, which was a larger slave population than Arkansas or Florida. Missouri also was the sixth most populous state in the Union so the relative proportion of slaves (9.7%) was comparatively low. The largest slave-holding areas in Missouri were in the central part of the state along the Missouri River and in the southeast (Phelps and Watson, 1862), areas that roughly are coincident with the central lowlands province of Fenneman (1938) and the location of prairies, wide floodplains, and loess deposits that were suitable for large-scale agricultural operations (Fig. 2A–2C). This pattern also is coincident with the early settlement patterns, mostly along the Missouri River and west of the northern extent of the Ozarks. The Ozarks, in contrast, had a relatively small population of slaves, partly because the land was not suitable for large-scale agriculture and because it was populated by hill folk

from Tennessee and Kentucky who generally held the concept of slavery in low regard (Ingenthron, 1974; Rafferty, 1980). Politically, Missouri was a land divided; even though the vast majority were neither slaveholders nor avid supporters of Union or Confederate causes, they sought to maintain the status quo. They were conditional Unionists. Even pro-southern leaders like Sterling Price preferred armed neutrality for Missouri prior to the onset of conflict. Castel (1968) placed the events into a geopolitical context in his biography of Price; a summary is given below. Missouri, despite its southern cultural leanings, effectively remained in the Union throughout the war, largely because Federal troops marched on the state capital, Jefferson City. Having driven out the pro-southern government, pro-Union legislators declared the government offices vacant and installed a provisional governor, Hamilton Gamble. Considering this to be an illegal act, the elected but pro-secession Governor Claiborne Jackson appointed Sterling Price, a Mexican War hero, as head of the Missouri State Guard. This faction had broad support over much of rural Missouri, and they viewed the Federal takeover of state government as a foreign invasion and occupation. The ranks of many Union military units were filled with newly immigrated Germans, who spoke little or no English. Missourians with southern leanings referred to them as “Dutch.” The immigrant Germans had settled in the St. Louis area and along the lower (eastern) Missouri and Mississippi rivers, areas that still have large populations with German ancestry, particularly between Jefferson City and St. Louis. Jackson and Price recruited troops across Missouri and trained them during the summer of 1861 at Cowskin Prairie in McDonald County in extreme southwestern Missouri. Following southern victories at the Battle of Wilson’s Creek (Oak Hills), 10 August 1861 (see Hannibal and Evans, this volume), and the Siege of Lexington, 13–20 September 1861, the pro-southern government convened in Neosho, Missouri, and declared the secession of Missouri from the United States on 31 October 1861, which the Confederate Congress promptly recognized. Historians and legal scholars still debate the legitimacy of Missouri’s act of secession, and as a consequence of this confusion, Missouri is sometimes portrayed as a Union, Confederate, or a border state (implying mixed loyalties) on post–Civil War maps. The Soldiers’ Database in the Missouri Archives (http:// www.sos.mo.gov/archives/soldiers/abstract.asp) contains 308,000 records listing ~139,000 Missourians, Union and Confederate, who served in the Civil War. Many loyalists to the Union enlisted into the U.S. Army (Regulars), Missouri State Militia, or later, the Enrolled Missouri Militia. Missouri was placed under martial law with a district and local-level system of provost marshals, which provided a framework for justice. Missouri State Guard parolees and citizens whose allegiance to the Union was questioned were required to swear oaths and post loyalty bonds. Aiding or abetting rebel activities were grounds for fines, banishment, imprisonment, or summary execution. Rather than submit to this, many pro-southern families became refugees moving to southern-held territory. Many men with southern political views enlisted in the

176

S T O N E T A N EY

Mors

Oc

248

Oc

Bull

Mors

Mk

Dickens Oc

Oc

F

Oc

Cre ek

Qal

65

Mk

Rockaway Beach

om

o

k

c ey

160

an eT ak

L

Mop

Forsyth

7

Gretna

Y Oc 248

Mop

Dewey Bald

U

Roark Creek

376

Qal

Oc

65 Hilton/BCC Oc Co

ge Table Rock St. Pk. Oc

Table Rock Mt. Mop

D

ll

Branson Hills Parkway

Mop

U

Mk

M

ke

Oc

J Mincy

Oc cy

in

Mk

ee Cr

Oc

k

Mop

ak e

Mors Mop Mk

Mop

3

Oc Mk

Fox Mt.

Mk D Oc Mk U

Qal

KK

Ojc

Oc

R on

Mors

Mk

Oc

Ojc

Mors nis

Mobk

5A5B d. G un

Mop Mk

Bear Mt.

Oc

Mors

Oc

Bear M

Mors

t R

Big Cedar LodgeMop

Oc

d

.

C O.

La

Oc

4

D

Oc

Oc ls

JJ

Mk

ck L

Sh

oa

Oc

M

Mors Ro

Oc

Bu

Melva (abandoned)

265

Oc

U

Mk Mop

K

Oc

Qal

FA ULT

Mk

le

Ojc

BB J

Mop

Baird Mt.

Qal Oc

ek

165

2

Mildred MM

76

Turk ey C re

Table Rock Dam

Ojc

VV

ld

k

Rid

Oc

Oc

Kirbyville

Point Lookout 65 O’CL OC KR UN

Ojc

s

Qal

T EN

Qal

76

Hollister

e re

ton

lC

l Fa

mp

65

College of the Ozarks

Mors

165

Ta b

on Cre ek

BUS

Ojc

O

Powersite

Ba

Co

Oc M. Graham Clark– Taney County AirportOc

265

160

Powersite Dam

pp

76 Mop

8

6

BUS

Branson

Mk

Oc Oc

Sna

1

ver Ojc Creek

Qal

Ozark Beach

T

Bea

Kissee Mills

Oc

Mk

D

76

160

Shadow Rock Ojc Park

9 Qal

Oc Oc

76

Ojc

Forsyth 176

Mors

ee Cr

Ojc

T

Oc

Oc

Oc

176

EE

176

Qal

465

Ojc

Walnut Merriam Bull Creek Shade Woods

465

FF

76

160

Qal Mk

Taneyville

Mop

Oc Mop

Oc

H

Mk

160

Mk

Mk

Mors

Oc

Sw an

C O C

36° 45' 00" N

Mop

65 Mors

Pine Mt.

ng e Cr

Mobk Mors

A

36° 30' 00" N 36° 29' 50" N

Bu

ll S

Bee

Mobk

Oc

Mobk

Ridgedale

Mk

Mobk

Oc

Mors

JJ Mobk

Mop

m

Mors

Mk

Holocene and Pleistocene

Oc

C H R I S T I A N

0

Quaternary System

Unconformity

0.5

T A N EY

1

0

1

C O. D O U G L A S

C O.

C O U N TY

2 S T O N E C O U N TY

KILOMETERS

N

ake

Ojc MISSOURI ARKANSAS

MILES

Qal

Ojc

Oc

EXPLANATION

Municipalities (overlay)

hoa

ls L

Cre

ek

Mop

Oc Mop Mk

Qal U D

93° 00' 00" W

Mk

Branson Regional Airport

Mobk

Mobk Mors Mop

Lo

93° 18' 55" 55 WA N E Y

86

2

3

M A P A R E A

O Z A R K C O U N TY

Mobk Mors

Osagean Series

Unconformity

A R K A N S A S U

Mississippian Subsystem

Mop

Carboniferous System

D

Fault; U up-thrown side; D down-thrown side; dashed where inferred, dotted where buried

Unconformity

Mk

Kinderhookian Series

Unconformity

Oc Ojc

Ibexian Series

Ordovician System

Figure 1. Geologic map and shaded relief map of southwestern Taney County, Missouri. Field trip stops, numbered 1–9, are indicated in filled black circles. The Branson Convention Center is indicated by white star in filled black circle. Geology and original geologic map modified from Thomson (1982b).

72

Evans

Confederate Army (Regulars) or Missouri State Guard. Others took up arms in the partisan conflict, or they tried to weather the consequences of war, tending their land and attempting to protect their families from the ravages of war. The Civil War devolved rapidly in southern Missouri and northern Arkansas from large-scale conflicts to widespread parti-

san fighting (Nichols, 2004, 2006). Early in March 1862, a Union victory at the Battle of Pea Ridge, Arkansas, bolstered Union control of Missouri (Fig. 3). Many of the pro-southern Missouri State Guard were sworn into the Confederate Army. Sterling Price was commissioned a Major General in the Confederate Army, and Missouri Confederates were ordered from the Trans-Mississippi

A

B

* Worth County was not differentiated from Gentry County on the 1861 United States Census Office map.

*

0-1% > 1-5% > 5-10% Prairie areas

> 10-15% > 15-20% > 20-25% > 25-30% > 30-35% > 35-40%

C

D Dissected s c Till Plains

Till plains Loess Fluvial sand and gravel

limit of glaciation

Osage Plains

Salem Plateau P t

St. Francois Mountains

Springfield n e Plateau Thickness of Surficial Sediments > 200 ft

M Mississippi ss pp p Embayment Em mbay a m nt n

50-200 ft < 50 ft

Figure 2. (A) Percentage of slaves per county in Missouri from 1860 U.S. Census data. (B) Pre-settlement prairie areas of Missouri from Schroeder (1981). (C) Surficial sediment derived from fluvial and glacial sources in Missouri from Missouri Division of Geology and Land Survey map (Anonymous, 2002b). White area covered by clay and chert residuum and colluvium. Inset shows general thickness of surficial sediment. (D) Major physiographic provinces and sub-provinces of Missouri from Missouri Division of Geology and Land Survey map (Anonymous, 2002a). The Missouri part of the Ozark Plateaus province includes the Springfield Plateau, the Salem Plateau, and St. Francois Mountains. The Central Lowlands province of Fenneman (1938) includes the Osage Plains and Dissected Till Plains. The Boston Mountains, the fourth subprovince of the Ozark Plateaus province, are located in northern Arkansas.

Civil War and cultural geology of southwestern Missouri, part 2 theater to the western theater in Mississippi and Tennessee (Castel, 1968, p. 82). This resulted in de facto Union control of Missouri for the next two years. In 1862, the last major conflict in the TransMississippi was the Battle of Prairie Grove in northwestern Arkansas (Fig. 3), another Union victory. It was not until 1864, during Price’s Second Expedition, that any consequential effort was made by Confederate forces to take Missouri. Between the withdrawal of Confederate forces in Missouri in early 1862 until the end of the war, Missouri experienced one of the most notorious guerrilla conflicts to take place on American soil (Nichols, 2004, 2006).

73

The area with the most strongly pro-southern populations was centered between Boonville, in central Missouri along the Missouri River, and Kansas City, where the majority of slave owners lived and a pre-Civil guerrilla war with Kansan abolitionists alternately had raged and smoldered since the mid-1850s. Southern guerrilla leaders included William Clarke Quantrill and William T. “Bloody Bill” Anderson. Quantrill led the infamous raid on Lawrence, Kansas, on 21 August 1863. Anderson perpetrated the Centralia massacre on 27 September 1864. After the Civil War, former guerrillas like the James and Younger brothers

1861

1862 Kirksville

State Capital Population Centers

St. Joseph

Hannibal Liberty

Major Battles

St. Joseph

Hannibal

Roan's Tan Yard

Lexington

Kansas City

Kansas City

Mt. Zion Ch. Boonville Calloway

Independence Lone Jack St. Louis

Jefferson City

Calloway St. Louis

Jefferson City Osceola

Osceola Osceola* Dry Wood Creek Fredericktown Springfield Carthage Springfield Wilson's Creek Price’s First Campaign (Aug.-Sept.) Cowskin Prairie (encampment)

Fayetteville

Springfield

Poplar Bluff

Belmont

Old Ft. Wayne

Harrisonville

Clark's Mill

Newtonia Pea Ridge Fayetteville Prairie Grove Cane Hill

Batesville

Poplar Bluff New Madrid

Harrisonville

Batesville

1863 St. Joseph

Kansas City Lawrence

St. Joseph

Hannibal

Marshall

1864

Kansas City Westport Byram's Ford

Hunter’s Column Calloway

Hannibal

Lexington Little Blue Independence

Calloway

St. Louis

Jefferson City Shelby’s Column

Glasgow

Jefferson City

St. Louis

Marais des Cygnes Mine Creek Osceola

Osceola Shelby’s Raid (Sept.-Oct.)

Marmiton River Fort Davidson

Baxter Springs

Springfield

Cape Girardeau

Springfield

Hartville

Marmaduke’s 2nd Expedition (April-May) Marmaduke’s 1st Expedition Poplar Bluff (Jan.-Feb.)

Springfield

Newtonia

Price’s Expedition (Sept.-Oct.) Poplar Bluff

Chalk Bluff

Cabin Creek Fayetteville

Harrisonville

Pochahontas Batesville

Fayetteville

Harrisonville

Batesville

Ft. Pillow

Figure 3. Major Civil War battlefields in Missouri and adjacent areas, 1861–1864, recognized by the National Park Service American Battlefield Protection Program. Battles indicated by crossed swords. Missouri State Guard and Confederate campaigns are shown in light gray.

74

Evans

achieved mythic hero status among west-central Missourians (Petersen, 2003; Stiles, 2002). A variety of names have been applied to the pro-southern guerrillas who operated in Missouri, including partisan rangers or bushwhackers. The image of guerrillas as strictly proConfederate, however, is inaccurate. Kansas “jayhawkers” and “red legs” led by Jim Lane and Charles “Doc” Jennison, respectively, were equally notorious. Lane looted and burned Osceola on 23 September 1861, killing several civilians and robbing the bank and personal effects from homes. The depredations and hardships that faced the citizens of Missouri during the war, loyalist and secessionist, were many (Nichols, 2004, 2006). Prosouthern guerrillas such as Sam Hildebrand (Hildebrand et al., 1870) targeted the “Dutch” and former neighbors, who killed two of his brothers and an uncle, drove his mother from the family home and burned it, and drove his wife and family into exile in Arkansas. Hildebrand described his motives as simply revenge rather than political. He operated from Green County in northeastern Arkansas and made excursions into southeastern Missouri, especially in the Bootheel and throughout the St. Francois Mountains. In his memoirs, he claimed to have killed more than 100 men. No part of Missouri escaped partisan conflict, but the southern and western borders were particularly dangerous (Nichols 2004, 2006). In 1863, my great-great-grandfather (aged ~60) and great-grandfather (aged 13) and other family members were among the refugees who left Washington County, Missouri for western Illinois. The horrific raids on Osceola and Lawrence and the massacre at Centralia were not isolated events. Atrocities were committed on both sides, and they date back to the Border War between Kansas and Missouri. The Marais de Cygnes massacre at Trading Post, Kansas, on 19 May 1858 involved the cold-blooded killing of five abolitionists (six others survived). Geologically, the site of the Marais de Cygnes massacre is on a butte-like outlier of Pennsylvanian limestone of the Kansas City Group perched on a slope-forming shale succession (Seevers, 1969); it was within a stone’s throw of the Missouri border. The impact of this event probably was pivotal in igniting the Civil War. John Brown built a fort at that site following the atrocity. The following year he led the raid on Harper’s Ferry. The borderland in northern Arkansas held a large force of pro-southern guerrillas. A letter from Capt. John Worthington, 1st Arkansas Cavalry (Union), reported depredations committed by refugees (secessionists) from Missouri (United States War Department, 1888, p. 780–781). The sanction of draconian countermeasures by Col. William Weer, the Union commander at Carrollton, Arkansas, dated 4 April 1863: …the forage trains of this command are repeatedly fired into on Osage Fork of Kings River by lawless men, who secret themselves in the bushes and are encouraged and entertained by the inhabitants in that vicinity, you are therefore instructed to proceed to said neighborhood with the wagons placed in your charge, destroy every house and farm etc. owned by secessionist, together with their property that cannot be made available to the army; kill every bushwhacker you find; bring

away the women and children to this place, with provision enough to support them, and report to these headquarters upon your return. (United States War Department et al., 1888, p. 197–198)

Guerrilla activities in this area continued throughout the war. On 16 April 1864, Col. John E. Phelps, Union commander of the 2nd Arkansas Cavalry and former slave owner who lived in Springfield, Missouri, wrote of the killing and mutilation of six African-American teamsters, ambushed on the Kings River as they were transporting forage for the Union (United States War Department, 1888, p. 889–890). By the end of the Civil War, southern Missouri largely was depopulated. Aftermath of the Civil War After the war, the population rebounded quickly as refugees returned (Table 1). Many of the former southern sympathizers had either lost their land or were squatters on open range that extended across the upland hills. Union veterans and their families came to settle in Taney County after the war, buying land under the Homestead Act of 1862 (Kalen and Morrow, 1993). From the late 1860s to the 1880s, “radical” Republicans controlled Missouri politics (Parrish, 1973), but Taney County was populated mostly by Democrats. The Democrats were predominantly Confederate veterans, whose families descended from the original European-American settlers. Union veterans, with a few notable exceptions, generally were Republicans and “newcomers.” Differing political views, a perceived “land grab” by Union veterans, fencing of open range, and the economic downturn of 1873 were all events that rekindled Civil War animosities in Taney County (Kalen and Morrow, 1993). TABLE 1. U.S. CENSUS DATA FOR TANEY COUNTY, MISSOURI FOR 1840–2008 Year Population 2008 47,023 (estimated) 2000 39,703 1990 25,561 1980 20,467 1970 13,023 1960 10,238 1950 9,863 1940 10,323 1930 8,867 1920 8,178 1910 9,134 1900 10,127 1890 7,973 1880 5,599 1870 4,407 1860 3,576 ** † 1850 4,373 * 1840 3,264 † Free population indicated as 4,272. *Land formerly belonging to Taney County incorporated into Ozark County in 1841. **Land formerly belonging to Taney County incorporated into Stone County in 1851, Douglas County in 1857, and Christian County in 1859.

Civil War and cultural geology of southwestern Missouri, part 2 Spencer (2004) has argued that a culture of violence permeated post-War southern Missouri. In Taney County, between 1865 and 1884, there were 30–40 murders, numerous other crimes, and only one conviction (Hartman and Ingenthron, 1988). To place the crimes in perspective, using U.S. Census data for the population of Taney County (Table 1) and recent Federal Bureau of Investigation Uniform Crime Reports (2008), Taney County had roughly the same per capita murder rate as the city of Baltimore (36 in 100,000), which ranked third in the United States behind St. Louis (47) and New Orleans (64). During the mid-1880s, Taney County was a tough neighborhood. Juries selected from kinfolk, neighbors, and political affiliates were reluctant to find guilt. From this environment, a vigilantism movement took hold. A greatly condensed summary of events concerning the Bald Knobber era is given below; these have been gathered from a variety of sources (Upton, 1939; Castleman, 1944; Mahnkey, 1975; Burrows, 1976; Hartman and Ingenthron, 1988). Nat Kinney, a Union veteran and former saloon owner from Springfield, moved to Taney County to farm in 1882. He was a reputed former prizefighter, and his physical stature, standing over 6 ft, gave him an air of authority. In 1885, Kinney organized a group of twelve men that called themselves the Anti-Horse Thief Association. The ranks of this group quickly swelled, and they proceeded to mete out justice across Taney County as they saw fit. This association was a secret society that had a military-like command structure. They met under cover of darkness on remote hilltops (Snapp Balds) around Kirbyville (Stop 6) but built large bonfires, which clearly signaled their meetings. They wore masks made from flour sacks with cork horns sewn in and further disguised their identity by wearing socks over boots and turning coats inside out. Although one might compare their notorious activities to the Ku Klux Klan, the comparison falls short in that this organization showed no noted racial bias, perhaps owing to the fact that there were few African Americans living in Taney County, and also, their political affiliations generally were Republican. Ironically, Kinney was a Democrat, along with a few of the group who were former Confederate veterans (Hartman and Ingenthron, 1988). At the hilltop meetings, criminal charges and even reputed lapses of moral rectitude were presented and discussed in mock trials for defendants in absentia. Although the group initially was formed to inculcate law and order, it transformed into oppressive extralegal mob justice. Over time, trials for horse thievery and livestock rustling gave way to lesser offenses such as cohabitation of men and women without the sanction of marriage. Lynching or “slicking” (whipping with hickory saplings stripped of bark) of supposed wrongdoers became commonplace. Nightriders drove some families from their land with verbal warnings or by tossing bundles of sticks that would indicate that next time their homes would be burned. It is difficult to assess if all of the acts were actually perpetrated by vigilantes, but in one year, the organization grew to more than 1,000 members (Hartman and Ingenthron, 1988). Most of the old settlers of Taney County resented the usurpation of authority by the Anti-Horse Thief Association, regardless

75

of how powerless the County government seemed to be. Some of the old settlers began referring to members of that group as “Bald Knobbers,” and their acts as moral police were “Bald Knobberisms.” Bald Knobberism spread to neighboring Christian, Douglas, and Stone counties. Kalen and Morrow (1993) have argued that many Bald Knobbers also used their power for economic gain. Most of the upland settlers were squatters on unpatented land. Bald Knobbers, in contrast, were mostly tax-paying landowners, and they effectively stopped the practice of open range by driving out those that opposed them. In response, some outraged citizens organized their own group of “Anti-Bald Knobbers,” whose sole purpose was to stand in opposition to the Bald Knobbers. In the 1886 elections, Republicans took control of the county offices. Taney County was a powder keg (Hartman and Ingenthron, 1988). Traveling to Jefferson City, a delegation of Anti-Bald Knobbers requested intervention from Governor Marmaduke, the former Confederate general and cavalry commander who came to power in 1884 when the Radical Republicans were swept from state offices. Governor Marmaduke dispatched his adjutant general, James Jamison, who met with Kinney and other leaders of the Bald Knobbers. The Bald Knobbers and Anti-Bald Knobbers were ordered to disband immediately or Taney County would be placed under martial law. The groups complied verbally, but the troubles of Taney County continued for a few more years as the struggle devolved into factional feuding, including several gunfights. In 1888, Kinney was assassinated. His assailant was acquitted (Hartman and Ingenthron, 1988). The “rough and tumble” frontier aspect of Taney County recorded in historic accounts of the European-American settlement, Civil War, and Bald Knobber eras in part may be attributed to the remoteness and rugged “hill and hollow” landscape of the southern Missouri Ozarks; this landscape also attracted the self-reliant hill people of the southern Appalachians (see Rafferty, 1980). GEOLOGIC OVERVIEW Physiography and Bedrock Geology The Ozarks physiographic province is an upland area that includes much of southern Missouri, extreme southeast Kansas, northeastern Oklahoma, and northern Arkansas. Physiographic sub-provinces include the St. Francois Mountains, the Salem Plateau, the Springfield Plateau, and the Boston Mountains (Fenneman, 1938). Each can be related to bedrock geology (Fig. 2D). The St. Francois Mountains sub-province of southeastern Missouri is composed predominantly of igneous rocks with surrounding basins of siliciclastic and carbonate Middle and Upper Cambrian rocks. Igneous knobs of granite and rhyolite form the highest peaks in the Missouri Ozarks; these are the erosional remnants of at least four caldera complexes that date to ca. 1.4 Ga (Kisvarsanyi, 1976). The Salem Plateau is composed of lower Ordovician dolomite and sandstone units; the Salem Plateau

76

Evans

forms the middle part of the Ozarks. Middle Ordovician through Devonian rocks are largely missing from this area but are found on the eastern periphery of the St. Francois Mountains and in the southwestern Ozarks of Oklahoma and Missouri. In western Missouri, the sub-Mississippian unconformity truncates lower Ordovician strata. Lower and middle Mississippian strata comprise the Springfield Plateau. These are predominantly limestones with lesser amounts of siliciclastics and nodular to bedded chert. The terrain of the Springfield Plateau and Salem Plateau differ significantly. It is difficult to imagine one is in the “Ozark Mountains” in Springfield because it is so flat, and it is difficult to envision the Salem Plateau as a former flat plateau because long-term erosion has dissected the landscape into steep hills and narrow hollows. The only relatively broad, flat area of the Salem Plateau is found around the town of Salem. Besides topography and bedrock, the plateaus differ in other significant ways. Land use on the Springfield Plateau is mostly small-scale farming with prairie hay production and grazing being the main activities. The Salem Plateau is more heavily forested so cattle and hay production are more limited, and forestry is a major component of the rural economy. Hardwoods are the primary timber harvested. American Stave Company near Lebanon, Missouri is a major supplier of oak barrels for whiskey and wine producers. Other wood products include oak flooring. Pennsylvanian strata of Morrowan and Atokan age form the high hills of the Boston Mountains in northern Arkansas on the southern edge of the Ozarks. A few Pennsylvanian channel sands have been mapped on the Springfield Plateau (Anderson, 2003). Most of these overlie the middle Mississippian strata although a few paleo-valleys are incised into the carbonates. Most are oriented in a north-south direction. Bretz (1965) considered that arrangement of the plateaus was weathering away due to successive stages of peneplanation, a view that is not widely accepted with regard to current thought on landscape evolution. The ages of uplifts or flexures related to tectonism remains poorly constrained. Tectonism and Uplift of the Ozark Dome The main episode of uplift in the Ozarks is thought to have been Pennsylvanian in age, but a substantial part of it could have occurred earlier. The St. Francois Mountains have been a positive element since the development of Precambrian caldera complexes. Cambrian sandstones and carbonate lap out against the resistant igneous knobs. The earliest phases of flexure and uplift in the western Ozarks probably occurred during latest Devonian or earliest Mississippian time (Cruz and Evans, 2007). The Upper Devonian Chattanooga Shale is beveled and truncated with angular discordance below the sub-Mississippian unconformity in extreme southwestern Missouri. New road cuts along Highway 71 in McDonald County show this angular discordance. Lower Ordovician Cotter and Jefferson City dolomites are progressively truncated below this unconformity from McDonald to St. Clair County, Missouri, near Osceola. In the eastern Ozarks of northern Arkansas, the Silurian Brassfield Formation crops out below this

surface; elsewhere in Arkansas, the St. Peter Sandstone, Everton Formation, and Powell Dolomite are preserved. Assuming the cumulative thickness of units below the unconformity is correlated with the total thickness of strata cut out, the missing section would amount to ~1400 ft. (425 m)(Cruz and Evans, 2007). During the middle Mississippian, at least portions of the Ozarks were at or near sea level (sea level at that time). Depositional facies of the equivalent of the Burlington-Keokuk reflect that the St. Francois Mountains region was a positive element that affected sedimentation. Articulate brachiopod specimens referable to Orthotetes keokuk have been recovered from sandstone blocks in float within the Crooked Creek structure in southern Crawford County, about ten miles south of Steeleville (Mulvany, 2004). These indicate shallow marine deposition of siliciclastic rather than carbonate strata, which are found over much of eastern, central, and southwestern Missouri. If one argues that the elevation of the sub-Mississippian unconformity places some constraint on subsequent uplift of the Ozark Dome, along the Buffalo River in the Ponca 7.5 min quadrangle, the elevation of the unconformity is ~335 m above sea level (Hudson and Murray, 2003). At Dewey Bald (near Stop 1) the elevation is 370 m. Constrained by water-well drill cutting logs at the Springfield Southwest Power Plant, the surface is at 285 m. Approximately ten miles to the north near the Springfield sanitary landfill, it is 315 m. At Osceola, in the type area of the Osagean Series, the elevation is around 215 m. PostMississippian faults, including the Ten O’Clock Run (Stop 1) have offset the surface of the unconformity in the Branson area and elsewhere, but the general trend is for regional dip less than 1° to the northwest from around the Arkansas-Missouri state line. The range of values for the elevation of the sub-Mississippian unconformity suggests that the movement of isolated blocks was little more than 100 m in magnitude, a small amount for such an expansive area. The uppermost Mississippian strata are mostly missing in southwestern Missouri. A few isolated exposures of Meramecian Series strata are found around Eldorado Springs in Cedar County, and a relatively thick succession is preserved near Joplin and Carthage. Chesterian Series rocks, however, are known only from near the Arkansas state line, near the town of Burlington, Arkansas, and in isolated sink-fills in Osagean strata (Thompson, 1986). In contrast, the type area of the Chesterian is relatively thick on the eastern margin of the Ozarks. Above the sub-Pennsylvanian unconformity, seas transgressed portions of southwestern Missouri, mostly northwest of the Springfield Plateau on the southern margin of the Forest City Basin. The Riverton Shale (Atokan Series) is at least partly marine black shale that was deposited in incised paleo-valleys, prior to widespread fluvial sedimentation during the Desmoinesian Series. In Arkansas, thick Atokan siliciclastics filled the Arkoma Basin. Today, these crop out along the crest of the Boston Mountains, some of which are higher than 2500 ft. Docking of the Ouachita allochthon and development of the Arkoma Basin are

Civil War and cultural geology of southwestern Missouri, part 2 thought to have initiated the generation of basinal brines that led to lead-zinc mineralization in the Tri-State District and Northern Arkansas Belt (Bradley and Leach, 2003). Many of the faults were active during the Pennsylvanian (Cox, 2009). The Ozark Dome likely has been uplifted since the Pennsylvanian. Mixed marine and non-marine Cretaceous through Paleocene strata were deposited along the margins of the Mississippi Embayment in the Bootheel of Missouri, but it is unknown whether the sea-level highstand during development of the Cretaceous Western Interior Seaway partly covered the Ozarks; there is no known record of it, other than one isolated site near Glen Allen, Missouri, that has yielded a marginal marine Cretaceous vertebrate fauna found in a karst or structural setting (Parris, 2006; Stinchcomb, 2006). At less than 600 ft elevation, Glen Allen is in the lower foothills of the southeastern Ozarks. Late Cenozoic epeirogenic uplift has long been the prevailing paradigm because of a supposed pre-erosional deposition of the Lafayette gravel (Potter, 1955). The cause of epeirogenic uplift and rejuvenation of the Ozark’s landscape is enigmatic. Despite being underlain by Mesoproterozoic basement, igneous activity has been long-lived in the midcontinent. If igneous activity is an indicator of lower crustal instability, dynamic topography may be related to the influence of mantle upwelling (cf. Conrad and Husson, 2009). Cambrian volcanism is recorded at the Dent Branch and Furnace creek near Belgrade, Missouri; strata-bound igneous flows are interbedded with the Bonneterre Dolomite (Wagner and Kisvarsanyi, 1969). The Avon diatremes and dikes are post-Devonian in age but have not been dated accurately using isotopic geochronology. In southern Illinois, an ultramafic igneous dike near Hick’s Dome, a laccolith along the Wabash Fault zone, has been dated to the Permian (Reynolds et al., 1997). Cretaceous igneous activity in the mid-continent region included emplacement of ultramafic plutons in isolated intraplate settings and along the former margin of Laurentia. Silver City and Rose Dome in eastern Kansas are lamproites. Both intruded Pennsylvanian clastics and carbonates, and ultramafic rocks are exposed at the northern edge of the Silver City Dome (Merriam, 1999; McCauley et al., 2003). Cretaceous intrusives along the suture zone include Magnetic Cove, Arkansas (Eby and Vasconcelos, 2009). The likelihood that igneous intrusives alone were responsible for uplift is remote; most intrusives tend to be localized. Also, it is difficult to argue that igneous activity is an accurate indicator of mantle upwelling. As an alternative hypothesis, a climatic driving mechanism for this episode of uplift is perhaps even more remote. The relative “fixedness” of the interregional unconformities suggests that the Ozarks behaved moreor-less as a widespread, rigid platform. Terrain and Hazards Historical Accounts The hills and hollows of the southern Missouri Ozarks are relatively steep, making travel difficult. Local relief generally is not much greater than 200 m, and most hills are generally ≤100 m

77

in relief. Roads that traversed the upper White River valley either followed the sinuous ridge tops before descending into valleys or followed the narrow valleys of tributaries from the headwaters. Stream crossings, which frequently were under flash-flood conditions, made travel perilous. The influence of terrain perhaps is best illustrated from personal accounts. The diary entries of James C. Bates, from Texas, reflected on the rugged terrain in northern Arkansas en route from Van Buren, Arkansas, to Forsyth, Missouri. He noted near Jasper, Arkansas, “The country for the last two days I thought was as poor & rough & rugged as could be but our road today was over a country the poorest, roughest I have ever seen” (Lowe, ed., 2005, p. 92). Priv. Eugene F. Ware of the 1st Iowa Infantry, in his memoirs (Ware, 1907), recalled his march from Springfield to Forsyth prior to the Battle of Forsyth (see Stop 7). The expedition from 20 to 25 July 1861 began during a stifling heat wave that was punctuated by a severe thunderstorm. It rained heavily all the next day. The Union marched along the Ozark Mail Trace (see Fig. 8) to the edge of the Springfield Plateau, where they camped the second evening before descending onto the rugged Salem Plateau the next day. Ware’s notes on the nature of the geology were precise despite the inaccuracy of his speculative stratigraphic correlation with rocks in Kansas: [22 July 1861] We then started southerly over the chert hills. Missouri, in that part, must have been at one time covered with a heavy limestone ledge full of flint nodules. There are places in Kansas on high lands where this vast limestone ledge yet remains, and in the valleys the flints are packed in the bottom of the watercourses. This great ledge had been dissolved in the portion of Missouri of which I am speaking, and the hills were covered with the flint, which is there called “chert.” (Ware, 1907, p. 235–236)

Ware’s comments on the return journey wrote also of the clean fresh water of Ozark streams: [24 July 1861] The country through which we marched, while rough and flinty, was nevertheless a most beautiful country; the hills and groves were captivating, but above all, the springs and streams: they had a crystalline flash and beauty that enchanted us. It had stopped raining, the roads were no longer muddy, and the streams were no longer discolored. They were running with water as pellucid as air and sunlight. …The march of July 24th, although the weather was warm, was the most enchanting and enjoyable of any in the campaign, in spite of the situation and dangers, we often referred to it in our conversations afterwards. (Ware, 1907, p. 245–246)

Franc B. Wilkie, newspaper correspondent from Dubuque, Iowa, was among the entourage on the Forsyth expedition, and he wrote, “The road lay down the mountains—now winding along a stupendous edge, now skirting a ravine of dizzy depths, running up almost perpendicular ascents for miles, or crossing mountain torrents, or running between vast heights and along the rocky channels of the dried-up streams” (Banasik, ed., 2001, p. 121). Flash floods were a major hazard during the Civil War. Lyman G. Bennett, Union contract surveyor, wrote details of the

78

Evans

landscape and nature of streams in Stone and Taney counties on the trek of Gen. Samuel Curtis’ army from Galena to Forsyth following the Battle of Pea Ridge. In Bennett’s account a teamster perished crossing the James River on 9 April 1862 (in Ingenthron, 1980, p. 174). Bennett also noted, “Bear Creek is of considerable size and after meandering six miles among the hills, empties into Bull Creek. We were obliged to ford it several times and the teams were frequently stalled.” (in Ingenthron, 1980, p. 175). The valley of Bear Creek was along the Springfield-Harrison Road. Difficulties in steam crossings along the road prompted later construction of the Boston Ridge Road (Ingenthron, 1961). Crossing the White River could be treacherous. In dry weather, the river locally was fordable and only a few feet deep but it was nearly a quarter of a mile across; swimming was not among the activities that most residents participated in (it commonly was held that too much bathing could lead to illness). A number of ferries operated on the White River at various times, but these generally ceased during the Civil War. In flood stage, the White River was dangerous because of the current, floating debris, and submerged snags. During high water, crossings at Forsyth were generally made by dugout canoe or by horse. The Turnbo Manuscripts provide anecdotal insight into the dangers of crossing the river under fire during the Civil War. Turnbo relates the following story of John May and two colleagues. “We tied the guns to the pummels of our saddles with the barrels hanging down and fixing the bridles and stirrups so that the horses’ feet would not get tangled up, we were ready to enter into the cold, swift running stream. …When May reached the edge of the water, he stopped and got behind his horse and took hold of his tail and urged him forward into the water, and he and the horse was soon in the embrace of the muddy stream…” (Turnbo, unpublished manuscript, Springfield-Greene County Library, accessed 10 January 2010, http://thelibrary.org/lochist/turnbo/ V1/ST003.html). Geologic and Hydrologic Hazards Geologic hazards are clearly present in the Ozarks. Seismicity of the New Madrid fault zone is the principal threat to the region, although a few rare and small earthquakes have also been recorded elsewhere in the state. Epicenters of the large earthquakes of 1811–1812 that caused extensive damage to the few existing structures of that time were located near New Madrid. U.S. Geological Survey risk maps of the Ozarks region indicate that most damage and severe shaking from a large event on the New Madrid fault would be focused along the Mississippi River valley between Memphis and Cape Girardeau, and to a lesser extent northward to St. Louis (Petersen et al., 2008). Other hazards include mass wasting and catastrophic karst collapse. Rockfall is an ever-present danger along steep bluffs. Freeze-thaw cycles and attendant frost wedging help to loosen blocks. Beveridge and Vineyard (1990) documented the collapse of a large bluff along the Gasconade River in Pulaski County near Waynesville. The collapse occurred in November 1971, and debris partially blocked the river. In the early 1980s, a 3-ft-

thick, 4 by 10 ft block of dolomite rolled end-over-end on a 250 ft journey from the top of a bluff next to Powersite Dam into Lake Taneycomo; it narrowly missed the author by 25 ft. Numerous large blocks along the White River and elsewhere attest to the danger. Catastrophic karst-cover collapse is a more subtle danger. These can pose a risk to property and they are relatively common, but the risks they pose to people are marginal. During the Civil War there were no major events, seismic or otherwise that were widely reported. The principal natural hazard of Missouri is flooding. In 2008, 12 fatalities were reported in Missouri, the most in the nation (National Oceanic and Atmospheric Administration, Office of Services, 2009). On the Springfield Plateau, heavy rains tend to gather in relatively low-relief valleys or to pond in sinkholes. In contrast, the generally abundant precipitation mixed with hilly terrain on the highly dissected landscape of the Salem Plateau provides for rapid rises of stream levels, large flow volumes, and relatively rapid returns to normal flow conditions. Many rural stream crossings are low-water bridges, which are essentially culverts with ramp-like cement approaches. It is common for drivers to misjudge the force of flowing water. According to the National Weather Service “Turn Around, Don’t Drown” program, three factors contribute to flood-related vehicle mishaps: (1) buoyancy counteracts the weight of a vehicle, (2) the lateral pressure of water (weight of 62.4 pounds/ft3) increases with the square of the velocity, and (3) loose substrates of sand and gravel reduce traction. It is sometimes difficult to judge water depth and assess the condition of the substrate in floodwaters. As a consequence, most vehicles can be swept from the lower-water crossings in 2 ft of water (National Weather Service, http://www.floodsafety.noaa. gov/tadd.shtml, accessed 9 February 2010). Although it is not a geologic or hydrologic risk, tornadoes are a seasonal concern for the citizens of Taney County. A massive tornado struck the town of Melva, a lead-zinc mining town three miles south of Hollister along Turkey Creek, on the morning of 11 March 1920. The storm killed several people and leveled the town. It was never rebuilt. We will pass near the town site when we drive south along Highway 65 to Stop 3. Strategic Resources Prehistoric and Historic Context The oldest known geological resource and probable trade commodity in Missouri was chert (Ray, 2007). Native Americans made extensive use of chert nodules and beds that cropped out in many parts of the Ozarks, particularly on the Springfield Plateau, where high-quality Mississippian cherts, such as the Burlington, were used for manufacture of stone tools. Artifacts made of Burlington chert have been found in archaeological sites surrounding the Ozark region. Historically, chert also was used for the manufacture of gunflints, but many imported European gunflints also were used (Ray, 2007). Other resources of the southern Missouri Ozarks were strategically important during the Civil War (Table 2). These include

Civil War and cultural geology of southwestern Missouri, part 2 galena, iron, and potassium nitrate (saltpeter). The main lead mining and smelting operation in southwestern Missouri was at Granby in Newton County. This area was securely in Confederate control early in the war. An estimated 75,000 pounds of pig lead was transported overland to Van Buren, Arkansas, where it was then shipped to Memphis for the manufacture of ordnance (Myers, 2009). Eventually, the mines at Granby fell into Union hands. The area around Granby was hotly contested; at least six skirmishes and one pitched battle were fought at Newtonia, east of Neosho, the county seat (Ingenthron, 1980). The Old Lead Belt in southeastern Missouri was mostly in Union control during the war. Other lead mines were located on the Springfield Plateau west of Springfield near the present-day community of Bois D’Arc and east of Springfield along Pearson Creek near presentday Turners Station, type area of the Pierson Limestone. A small mining area in upper Swan Creek in Christian County provided another local source of galena. With smaller mining areas, it was common practice to smelt the small quantities of ore in stumps (Ingenthron, 1974). Iron ore (magnetite) was mined at the Pilot Knob Mine in Iron County, Missouri. Other mining operations were mostly for bog ore (hematite in sinkholes), such as the old iron works at Meramec Spring near St. James, Missouri. Mines were the prin-

79

cipal reason for the railroad spur lines to Rolla and Pilot Knob. Iron mines generally were held by Union forces, until the Battle of Fort Davidson at Pilot Knob in 1864. After a nominal victory over a smaller Union force that escaped, these resources were never used effectively by the Confederacy. Bat guano was mined from several caves in southern Missouri. Potassium nitrate crystals (75% by volume), extracted from guano, were combined with charcoal (15%) and sulfur (10%) to make gunpowder (Schultz, 1937, p. 129–130). Understory trees, such as dogwood and alder, were used for charcoal because of their low content of volatiles. Sulfur was a byproduct of the smelting galena. Saltpeter was such an important commodity during the war that a small skirmish was fought at Saltpeter Cave near Talbot’s Ferry in northern Arkansas. Saltpeter was being shipped down the White River then up the Mississippi River to Memphis for processing, but following the Battle of Pea Ridge, General Curtis dispatched a detachment of the 14th Missouri State Militia from Forsyth (Stop 7) to destroy the works (Ingenthron, 1980; Keefe and Morrow, 1994). Agricultural productivity was important during the Civil War. The welfare of man and beast depended on forage and the mobility of supply trains (wagon trains). Reports on forage are commonly included in the Official Records. For example, in his report on the Forsyth Expedition in July 1861, Brig. Gen.

TABLE 2. STRATEGIC AND TACTICAL RESOURCES OF MISSOURI DURING THE CIVIL WAR Resources, uses, productivity, and locations Agricultural resources Cotton, fiber (export and domestic textiles)—limited production in Missouri. Forage, sustenance (fruit, garden vegetables, grains, nut crops, hay, pastures, and livestock)—variable productivity; mostly in valleys, flat highlands, and isolated prairies. Forests, building materials and energy resources (cedar, pine, and oak and other hardwoods)—productivity seemingly limitless; pines preferred for building; hardwoods used for framing, flooring, wagon wheels, furniture, etc.; oak used for cooperage; cedar fence posts and shake shingles; charcoal used for gunpowder manufacture; all woods useful for fuels; pine forests limited to southernmost part of Missouri and St. Francois Mountains. Hemp, rope manufacture and fiber—limited to areas along western part of Missouri River; the Battle of Lexington was known as the Battle of the Hemp Bales because of the improvised use of wet bales for sapping. Tobacco, smoking and chewing—largest production along western part of Missouri River; produced on local farms across Missouri. Energy and mineral resources* Coal, fuel and coke for steel manufacture—mines in Pennsylvanian strata in central Missouri from Osceola to Kansas and northward to Missouri River. Iron, (hematite and magnetite) nails, hardware, guns, and wagon tires—St. James and Pilot Knob; other isolated sinkhole/bog ores across southern Missouri. Lead and zinc, (galena and sphalerite) bullet manufacture and galvanization—high productivity in Old Mines, north of St. Francois Mountains and Granby in southwestern Missouri; limited production at Pierson Creek. Copper and gold, (native elements and chalcopyrite) common and precious minerals—found in trace amounts in glacial drift in northeastern Missouri as early as 1860; copper mining in Jefferson City Dolomite in Ste. Genevieve County. Silver, (ore)—not discovered at Silver Mines area until 1870s; found in traces (along with cobalt, nickel, and tungsten) in Old Lead Belt. Sodium nitrate, (saltpeter) bat guano and limited hay/urine manufacture for gun powder—mostly in south-central Missouri. Stone and brick, building materials—limited use during war; bricks manufactured locally from clay-rich floodplain sediments, clay pits (sinkhole fills), and shale exposures; limestone and sandstone quarried across southern Missouri. Transportation networks Railroads—trunk lines to Ironton, Rolla, Sedalia (via Jefferson City), and St. Joseph. Roads—networks across the state; most following older Native American trail systems. Rivers—full length of Mississippi and Missouri rivers; rarely to Osceola but commonly to Warsaw on the Osage River; to Forsyth on the White River. *From Branson (1944).

80

Evans

Sweeney noted the poor forage available in the White River basin (United States War Department, Series 1, v. 3, p.44–45). Later in the war, many of the major troop movements occurred during the autumn when crops were due to be harvested. Obviously, gathering forage depended in part on having an extant agricultural base and partly on weather conditions during the growing season. Because areas on the border between Missouri and Arkansas were depopulated, agricultural production was reduced, making forage difficult. Modern Mineral and Material Resources The historic lead and zinc mining areas of southwestern Missouri are no longer in operation. The world famous Tri-State Mining District ceased operations, and many of the former mine tailing sites are now considered environmentally hazardous. Other than surface and underground quarrying operations, the only active lead-zinc mines in Missouri are sub-surface operations on the western perimeter of the St. Francois Mountains along the Viburnum Trend. These continue to be profitable because of the vast richness of the deposits. A growing industry in surficial mining of fluvial chert gravel is reshaping the streams of the Salem Plateau. Front-loaders and dump trucks haul gravel from the exposed bars for washing, grading, and packaging for landscaping uses. Some concerns have been raised concerning the effect of such mining operations on the aquatic and riparian habitats (Thom, 1998). FIELD TRIP OVERVIEW All of the stops on this field trip will be in the Springfield and Salem plateaus sub-provinces (see Fig. 1). Discussion of regional structures is given at Stop 1, below. Stop 2 provides background on the history of land use in the upper White River valley. Aspects of the regional stratigraphy are discussed at Stop 3. Stops 4 and 5 highlight the historic significance of geological anomalies, such as Murder Rocks and Bear Cave on the history of the Missouri border. A brief view of Snapp Balds, prominences that played a role in the post-war vigilantism, will be given at Stop 6. Stop 7 provides an overview of the Battle of Forsyth and historical aspects of the old town site of Forsyth. Powersite Dam, the first hydroelectric dam in Missouri, is visited at Stop 8. Stop 9 is another overlook on the saddle of an entrenched meander in the White River; this location will provide an opportunity for discussing the overall tectonic history of the Ozarks region. FIELD TRIP ROAD LOG The route for this field trip begins at the Branson Convention Center at Branson Landing. Follow Main Street west through downtown Branson, where it joins Highway 76 west. Continue on Highway 76 for ~4.5 miles (7 km), and turn left (south) on Highway 376. Drive ~1 mile to the approach to the bridge across Fall Creek. Park in the pullout lane on the right side.

Stop 1. Ten O’Clock Run Fault The Ten O’Clock Run Fault is a major structural feature in southwestern Missouri. Thomson (1982a, 1982b, 1984) mapped the trace of the fault across southwestern Taney County and into Stone County (Fig. 1). As the name implies, it generally runs in a northwest-southeast direction. It can be traced for ~25 miles (40 km). To the northwest, it passes into the Marvel Cave Fault, which forms the southern boundary of a graben that crosses Indian Ridge near the Silver Dollar City theme park. On the northern side of the graben, the main segment of the fault forms the Ten O’Clock Run Monocline and continues on a more northerly direction to Spokane. More than 100 miles northwest of Spokane, the Chesapeake Fault Zone continues beyond the MissouriKansas border to the Bourbon Arch in eastern Kansas (Fig. 4). South of the White River, near Kirbyville, the Hollister Anticline, a broad open fold, runs parallel to the fault, and the fault zone is recognizable only in isolated segments (Thomson, 1982a). A little farther southeast, it runs along Bee Creek to where it is no longer detectable (Thomson, 1984). However, the trend of the fault continues well into Arkansas, where it was the focus of lead mining activity. Newspaper articles promoted the prospects along the trend of the fault in southwestern Taney County (Anonymous, St. Louis Globe-Democrat, 18–19 September 1899). Drawing a line between Joplin, Missouri, and Buffalo City, the newspaper noted that it passed through the lead mining districts at Granby and Aurora in Missouri and Lead Hill in Arkansas. Melva, near Stop 3, and Bee Creek, just a little south of Stops 5A and 5B in Taney County saw limited mining activity during the early 1900s. Segments along this fault system commonly show little vertical offset, but variously have a transpressional or transtensional expression, suggesting that there was a significant component of oblique slip. Hudson (2000) has shown that a series of complex strike-slip and oblique structures in northern Arkansas were related to the development of a foreland basin on the southern margin of the Ozark Dome with docking of Ouachita allochthon. Fault systems and broad flexure on the southern margin of the Ozarks in southwestern Missouri would comprise the hinterland of this foreland basin. Cox (2009) has argued that structural deformation in this area likely resulted in the transmission of paleo-stress from this oblique collision. He interpreted most of the SE-NW–trending faults as resulting from right-lateral oblique slip. Strata of this area are explored in detail at Stop 3, but this site provides an opportunity to see the lower Ordovician (Ibexian Series) Cotter Dolomite. Exposures along Highway 376 and virtually every other road cut in this area show the cyclic nature of the lower Ordovician. Depositional settings represented range from shallow subtidal to supratidal evaporitic salinas. Overstreet et al. (2003) have argued that meter-scale successions of these facies show the influence of precessional forcing on deposition. Plymate et al. (2003) show that the dominant cycles recorded in the gamma-ray signatures of these strata is nearer the 14-ft

K

FZ

Z

K

OZ

S

A

N

S

O

U

R

I

P L AT E A U S K AR

S

A

S

FZ

HS

Z

Z

1000 km

L

PA S AR CO C LA H

Z

SGF

I

I

E 100°W

T

L

I

N

E

E

N

CGFZ

O

Map Area

N

K

N

ILL INOIS B A S IN

Appalachian-Ouachita Front

GF

FZ

SM

EF

A

DQFZ

CG

S

T

S

FZ

S

U

WV

E

C

Figure 4. Major fault systems of northern Arkansas and southern Missouri (after Cox, 2009). Ozark Plateaus physiographic province shown in gray.

100 mi (162 km)

R

OUACHITA OROGEN

ARKOMA BASIN

A

I

Branson

M

FZ

O

TEN O’CLOCK RUN FAULT R T

Z

S

FZ

FF

FZ

FZ

BM

DC

K

faults

MJ

BA

CH

SF

anticlinal folds

RA

M IS S IS EM SI BA PPI Y R M EN IVE R T

CFZ

N

E

K

40°N

Y

RCFZ

I

82

Evans

(4.3 m) spectrum, which could possibly be an obliquity signal where there is a 4:1 bundling of cycles. Lower and middle Mississippian (Kinderhookian and Osagean series) strata unconformably overlie the Cotter Dolomite. Based on the elevation of the sub-Mississippian unconformity north and south of the Ten O’Clock Run Fault, as much as 130 ft (40 m) of vertical displacement (down to the south) is demonstrable locally. The fault trace is not seen at this locality, but dipping strata on the limb of a drag fold on the up-thrown block are exposed in the road cut on Highway 376. To the southwest, the sub-Mississippian unconformity is exposed in the high wall of a quarry (see Fig. 7). This surface can be seen from the bridge. The light gray-green beds of the Northview Formation and reddish beds of the Pierson Limestone are distinctive markers for identifying Mississippian strata from a distance in fresh cuts. The sub-Mississippian unconformity can be identified just below the ~15-feet-thick Compton Limestone, which is exposed below the Northview and Pierson formations. Looking to the north, the base of the Mississippian is visible where cedar glades are replace by hardwood forests on Dewey Bald, easternmost of the high knobs to the north. Ken Thomson (1940–2004), Missouri State University, mapped more than 160 geologic quadrangles in southwestern Missouri; he noted that the thin soils over dolomite bedrock generally support cedar glades, whereas more heavily karsted Mississippian limestones support hardwood (oak-hickory) forests (Thomson, personal commun., 1986). In many areas of southwestern Missouri, the contact between dolomites and limestone is also a sharp contact in vegetation zones that are easily recognized on air photos. On the south side of the White River, south of Kirbyville, highlands along the Ten O’Clock Run Fault preserve Lower Mississippian strata on what is mapped as the downthrown side of the fault in the Mincy 7.5 min quadrangle (Fig. 1; Thomson, 1984). A notable result is that pine and hardwood forests are preserved in this area. Place names such Pine Top School and Pine Mountain reflect the influence of geology as well as biological provincialism as these mark the northern extent of southern pine forests into southwestern Missouri. The field trip route continues southwest on Highway 376, ~0.5 miles, to Highway 265. Turn left on Highway 265 and follow it to the intersection with Highway 165, ~4 miles. Turn right on combined Highways 165/265. The route crosses Table Rock Dam, then winds around Baird Mountain, which is the high hill on the left. Baird Mountain is the type area for the Baird Mountain Member of the Northview Formation (Thompson, 1986); we will see this thin reddish unit at Stop 3. Just east of Baird Mountain Highway 265 splits off to the right. Continue on Highway 165, straight ahead at that intersection. In less than a mile, turn off into overlook parking on left. Stop 2. Table Rock Mountain Overlook This overlook showcases some of the natural beauty of the southern Missouri Ozarks. Other aspects of this view are patently

attributable to human activities, so it is a convenient spot to summarize the natural and human history of this area. The White River is a southern river (Fig. 5); it shares more commonalities, physically and culturally, with Arkansas than most of Missouri. Three forks of the White River flow northward and westward from the Boston Mountains of west-central Arkansas before they merge and turn northeastward, nipping into the southern border of Missouri where the river sinuously threads eastward through Barry, Stone, and Taney counties, before adopting a southeasterly course to the Mississippi River (Fig. 5). The White River debouches into the Mississippi River just a few miles north of the Arkansas River, and its mean discharge rivals that of the Arkansas, which has a considerably longer but semiarid drainage area. The old-growth pre-Columbian wilderness that covered the upper White River Valley was homeland of the Osage, a Native American tribe that now resides in central Oklahoma. The White River was a natural transportation corridor for French trappers and fur traders, who worked closely with the local Osage tribe. Later, displaced eastern tribes, such as the Cherokee, Delaware, Shawnee, and Kickapoo were followed by settlers mostly from Tennessee and Kentucky. The southern immigrants used keelboats and flatboats or traveled overland via the Falenash Military Road in northern Arkansas or Green’s Ferry Road into the upper White River valley. By 1851 steamships plied the waters of the

KS

MISSOURI 11 12

Springfield

7 Ozark 5 th Forsyth Branson on

10

OK

KY

9

4

8

Harrison r so

3 2

IL

14

6

1

13

TN

15

ARKANSAS

16

17

MS

TX LA

Figure 5. White River drainage basin shown in dark gray. Branches and tributaries include these streams: 1—East Fork; 2—Middle Fork; 3—West Fork; 4—Kings River; 5—James River; 6—Buffalo River; 7—North Fork; 8—Strawberry River; 9—Spring River; 10—Eleven Point River; 11—Current River; 12—Black River; 13—Little Red River; 14—Cache River; 15—Bayou De View; 16—Big Cypress Creek; 17—LaGrue Bayou.

Civil War and cultural geology of southwestern Missouri, part 2 White River as far north as Forsyth. By the 1880s, smaller steamboats were able to travel as far as Branson (Ingenthron, 1974). The Ozarks are a land of heavily forested hills and hollows, but these are second-growth forests. From this vantage point, areas to the east were partly suitable for agriculture; to the west was largely wilderness. Because of the expansive forests, railroad ties became a principal commodity following the Civil War. Tie hacking was one of the main livelihoods. Tie rafts up to 300 yards (275 m) long were floated to market down the White River. During the 1880s when railroads finally traversed the hills, tie rafts diminished in importance. Branson and Chadwick, along a railroad line and spur respectively, became important tie-cutting collection centers. By the 1920s the hills were largely deforested and smallscale agricultural operations were the principal land use through the Great Depression, when some forests were reestablished. Today, the Lake Taneycomo headwaters are perhaps the most natural part of the upper White River in Missouri (Fig. 6). Powersite Dam near Forsyth impounds Lake Taneycomo; it was constructed in 1912–1913 as the first hydroelectric dam in Missouri (Stop 8). Lake Taneycomo first became the focus for establishing a tourism economy in southern Missouri. The earliest resort community was Hollister, later it was followed by Rockaway Beach, which by the early 1950s had become a popular destination for college students on Spring Break. The headwaters of Lake Taneycomo, which are directly below the overlook, are drawn from the bottom water of Table Rock Lake. The temperature of the lake water averages around 58 °F, which allowed for introduction of a cold-water, non-native fishery of rainbow trout and German browns. Fishing and hunting add significantly to Missouri’s economy. Table Rock Dam was completed in 1958. Its construction brought the next significant impact, turning this land to an even more popular destination. The number of reservoirs in this area was influential in the founding of the sporting goods retail business Bass Pro Shops. The headquarters store in Springfield is recognized as the number one tourist attraction in Missouri. Silver Dollar City, a theme park that promotes Ozark hill country of the 1880s was established by the Herschend family around Marvel Cave (known formerly as Marble Cave; see Bretz, 1965, p. 157– 165), and it was promoted in the 1960s by some early episodes of the television show “The Beverly Hillbillies.” In the late 1970s, the producers of the television show donated acreage for the Paul and Ruth Henning State Forest in and around Dewey Bald. In the 1980s and 1990s, country and western music shows on the Highway 76 “Strip” became a complementary focus for the burgeoning tourism and entertainment-based economy. A 1991 broadcast of the CBS television news program “60 Minutes,” featuring Branson country music star Mel Tillis, caught the attention of other performers who have since opened musical theaters in the Ozarks. Branson has since become a popular vacation spot for bass and trout fishing, golf, and water recreation, and an influx of retirees further has helped to spur the local economy. As a consequence, the population of Branson has increased rapidly. Land development and construction have transformed the land-

83

scape again. One might speculate that sustainability issues may become the next key economic issue in this area. The field trip continues east on Highway 165 to the intersection at the main gate of the College of the Ozarks, where we turn right. The route continues on southbound Highway 65. Turn left into to the Branson Regional Airport. This street becomes Branson Hills Parkway. Follow the road to the airport and return to road cuts just north of the facility. Stop 3. Branson Hills Parkway Road Cuts New road cuts along Branson Hills Parkway near the Branson Regional Airport show some of the complexities associated with stratigraphy in southwestern Missouri (Fig. 7). Lower Ordovician stratigraphic units include the Jefferson City and Cotter dolomites (Ibexian Series). Mississippian units include the Bachelor Formation, Compton Limestone, Northview Formation, Pierson Limestone, and Reeds Spring Formation, the highest unit of the Mississippian succession exposed in these road cuts. Overlying Mississippian units, the Burlington-Keokuk limestones (undivided), including the Short Creek Oölite Member of the Keokuk Limestone, Warsaw, Hindsville, and Batesville formations are exposed farther south along Highway 65. We will pass some of these units in exposures but we will not have time to examine them in detail. As seen in Stop 1, the lower Ordovician Cotter Dolomite (Ibexian Series) is composed of a succession of meter-scale cycles of peritidal dolomites with thin shale beds. The Cotter Dolomite is nearly indistinguishable from the underlying Jefferson City Dolomite. The uppermost member of the Jefferson City Dolomite, the Rockaway Conglomerate, separates these two formations. At this location, identification of the Jefferson City Dolomite is questionable, but dolomitic breccia is found in the lowermost exposures. Facies of the overlying Cotter Dolomite include (1) light tan fine-grained laminated dolomitic grainstone that has sparse sandstone ripples and laminae, (2) light to medium brown structureless dolomitic mudstone, (3) faintly laminated dolomitic mudstone, (4) dolomitized stromatolites and thrombolites, (5) rare burrowed dolomitic mudstone, (6) rare thin beds of dolomitic rip-up conglomerate, (7) medium to thick beds of dolomitic breccia with irregular discontinuous thin sand bodies, (8) thin beds of cross-bedded quartz sandstone, and (9) thin beds of green-gray shale. Overstreet and colleagues (2003) did not visit this location (it had yet to be cut), but it compares favorably with other exposures of the Cotter Dolomite. These rocks were deposited in shallow water ranging from subtidal to supratidal settings. The Lower Paleozoic succession represented here is cut below the sub-Mississippian unconformity. Cruz and Evans (2007) noted that perhaps up to 1400 feet (425 m) of intervening strata preserved across northern Arkansas are represented by hiatus in southwestern Missouri. Flexure and tectonic subsidence on this southern margin of Laurentia may be partly responsible for the upwarping and truncation of lower Ordovician strata. Cruz and Evans (2007) have argued that this likely is an early phase of

Forsyth

Branson

MI SSOURI ARKANSAS

MILES 0

5

N

Figure 6. Digital elevation model of the greater Branson area including twelve 7.5 min quadrangles. In four rows, from left to right, these include (1) Spokane, Day, Garrison; (2) Garber, Branson, Forsyth; (3) Table Rock, Hollister, and Mincy in Missouri; and (4) Denver, Omaha, and Omaha NE in northernmost Arkansas. Map area is 21 miles east-west by 30 miles north-south. Overall relief is ~700 ft between the high hills in Arkansas and the Bull Shoal Lake.

Civil War and cultural geology of southwestern Missouri, part 2 Sys.

Ser.

Chert residuum

Meramec. Chester.

Sub.

Batesville Sandstone Hindsville Fm. Warsaw Formation

MISSISSIPPIAN Osagean

Short Creek Oölite Mbr.

Burlington-Keokuk limestones (undivided)

Reeds Spring-Elsey formations (undivided) Pierson Limestone

Kind

Northview Formation Compton Limestone Bachelor Formation

O R D OV I C I A N Ibexian

“Swan Creek Sandstone” Mbr.

Cotter Dolomite

5 m (scale approximate)

Rockaway Conglomerate Mbr.

Jefferson City Dolomite (base not exposed)

sandstone

cherty limestone

siltstone and shale

dolomite

limestone

cherty dolomite

oölitic limestone

breccia

Figure 7. Stratigraphic succession near Branson Regional Airport and in new road cuts south along Highway 65 toward Burlington, Arkansas (modified from Thomson, 1982b).

85

tectonism associated with the Ouachita orogeny that culminated during Pennsylvanian. The sub-Mississippian unconformity can show some angular discordance with local development of karst features and breccia fills. Lower Mississippian (Kinderhookian Series) stratigraphic units include the Bachelor Formation, a thin quartz sandstone and green shale couplet, 1–5 ft (0.3–1.5 m) thick; the Compton Limestone, a carbonate wackestone to mixed clay-rich lime mudstone, 10–15 ft (3.0–4.5 m) thick; and the Northview Formation, a green and red siltstone with minor carbonate cement. The red-weathering Baird Mountain Member constitutes the upper part of the Northview Formation and it is traceable for 10s of km to the west. Middle Mississippian (Osagean Series) stratigraphic units include the Pierson Limestone, a lime mudstone to wackestone locally with red chert, ~75 ft (22.5 m) thick. Only the Cotter Dolomite through Pierson Limestone are exposed at the airport road cuts. Thompson (1986) provides the most up-to-date treatment of Mississippian stratigraphic units and biostratigraphy in southwestern Missouri. Jeremiah Jackson currently is working on the sequence stratigraphy of the lower and middle Mississippian. Jackson first recognized the complexly interbedded carbonate and shaly carbonate facies of the Compton Formation in exposures at the Branson Regional Airport (J. Jackson, 2009, personal commun.). Shale-rich and carbonate-rich bundles of strata lap out onto local topographic highs and partly fill swaley areas in between. Comparable examples have been described as lateral accretion packages or lateral accretion deposits in relatively deep-water settings (Abreu et al., 2003). Jeremiah Jackson (2009, personal commun.) also has identified at least two hardground surfaces in the upper part of the Northview Formation, near the green to red transition in the upper part of the Northview Formation, which can be correlated at least tens of miles. The Kinderhookian Series in southwestern Missouri constitutes one depositional sequence: the Bachelor Formation and lower part of the Compton Limestone were transgressive systems tracts deposits. The upper part of the Compton is the highstand carbonate. The overlying Northview Formation comprises the late highstand to lowstand systems tracts. Thompson and Fellows (1970) and Thompson (1986) noted the reddish gray color of the lower portion of the Pierson Limestone. Exposures near the Branson Airport show this distinctive coloration. Jackson and Evans (2009) have noted that the top of the Pierson Limestone is truncated below the base of the Reeds Spring Formation in McDonald County, which they have interpreted as a sequence boundary. Consequently, the Pierson also constitutes a depositional sequence, but the distinguishable systems tracts have not been recognized in this area. At least one, and possibly two depositional sequences are represented in the Reeds Spring and Elsey formations. J. Jackson (2009, personal commun.) has found evidence of an isolated chert breccia succession in the Elsey Formation. It is likely that at least the upper part of the Elsey through Keokuk are related temporally as facies with broadly diachronous lithostratigraphic contacts. The Burlington and Keokuk limestones are not divided in

86

Evans

southern Missouri. The distinction between these cross-bedded crinoidal grainstone units is difficult. The Burlington Limestone where it is present generally overlies the Elsey Formation (Thompson and Fellows, 1970). In contrast to the BurlingtonKeokuk below, the Short Creek Oölite Member of the Keokuk Limestone is a shallow-water carbonate that is interpreted as the upper sequence boundary zone in this succession. It marks the top of the Keokuk and the Osagean Series (Thompson, 1986). A little farther south near Burlington, Arkansas, a series of new road cuts have exposed the Warsaw Formation (Meramecian Series), Hindsville Formation, and Batesville Sandstone (both of the Chesterian Series). The base of each formation is a sequence boundary. Tectonism as well as sea-level fluctuations may have influenced their development. One of the most significant novelties of the succession at Branson Regional Airport is in the differentiation between the Springfield and Salem plateaus; they constitute distinctive landforms in the upper White River valley. The Springfield Plateau, underpinned by the Mississippian succession, was more heavily karsted. Sinkholes and linear solution-enhanced fracture zones, now filled with chert residuum and red clay, are obvious in road cuts. The limestones however are not as fractured as the underlying dolomites of the Salem Plateau, and as a consequence, the siliciclastics of the Northview Formation do not form an effective confining layer south of the Ten O’Clock Run Fault, and the water table is relatively low. Historical accounts indicate that freight wagons along the Springfield-Harrison Road south of Kirbyville had to water their teams in the valleys surrounding Pine Mountain (Fig. 8; Prather, 1994). In contrast, the Salem Plateau had abundant but relatively small springs. It is notable that the Rockaway Conglomerate Member of the Jefferson City Dolomite roughly coincides with a gentle change in slope that can be traced around southwestern Taney County (Fig. 8). Many satellite towns and mill sites such as Walnut Grove, Star (Ameera), Swan, and Garrison grew around these springs. The field trip retraces the route along Branson Hills Parkway to Highway 65. Turn left (south) on Highway 65 and drive ~7 miles to Ridgedale, Missouri, where the highway crosses the Missouri-Arkansas state line. Of historical note, Ridgedale was the border town where the notorious robber and murderer Jake Fleagle hid out for several months, masquerading as a chicken farmer (Van Buskirk, 1979; Betz, 2005). In 1928, Jake and his gang, including his brother Ralph Fleagle, Howard Royston, and George Abshier, had robbed a bank in Lamar, Colorado, killing two and kidnapping two. One hostage was released during their getaway. They killed the second hostage. Later, near their hideout in Garden City, Kansas, they killed a doctor who treated a wounded gang member. The gang had attempted to destroy evidence by staging a fiery accident pushing the getaway car off into a ravine. A bloody thumbprint belonging to Jake Fleagle was discovered on a window of the car. The gang split up but robberies continued. Within a few months, three of the gang were captured, tried, and hanged. Postal inspectors and handwriting experts noted

that letters from Jake Fleagle were being posted along the Missouri Pacific line. They finally tracked him to Ridgedale, where he had lived with an accomplice for eight months under the assumed name, Walter Cook. On 14 October 1930, a group of five policemen and three postal inspectors cornered Fleagle on a southbound train at the Branson depot (across the tracks from the present-day convention center). In the ensuing scuffle, he was shot and mortally wounded. Scientifically, the Fleagle investigation is significant in that it was the first time that a single fingerprint had been used to build a criminal case (Betz, 2005). Geographically, the lesson here seems, criminals on the lam tend to prefer border areas where jurisdictional issues and communications provide obstacles to their apprehension and capture. We will expand on this theme and include a geological perspective at Stop 4. From Ridgedale, the route continues into Arkansas. After ~1.2 miles, turn left onto Arkansas Highway 14, which goes through the small town of Crest, Arkansas. After ~1.2 miles, turn left (north) on Old Springfield Road. This road becomes Highway JJ as we re-cross the state line into Missouri. Highway JJ is a paved road that generally follows the track of the SpringfieldHarrison Road (Fig. 8). After ~8 miles (13 km), the right-of-way on the right side of the road widens and a low road cut of Cotter Dolomite is present on the right side. To the left, a group of sandstone monoliths are located ~50 ft from the road; these are known as Murder Rocks. Stop 4. Murder Rocks Murder Rocks is a cluster of resistant quartz-arenite knobs up to 12 ft (~4 m) in relief (Figs. 9 and 10). They are also known as Alf Bolin Rocks. Alf Bolin (also recorded as Bolan and Bolen) was a notorious bushwhacker and reputed southern sympathizer during the Civil War; his activities and those of his gang largely revolved around robbery, murder, and assassination of citizens that presumably supported the Union cause. The gang mostly ranged from Harrison, Arkansas, to the White River valley. Before his death in 1863, he claimed to have killed up to 30 (Hartman and Ingenthron, 1988) or 40 people (Fellman, 1989). At least two Union soldiers were ambushed and killed at this site by Alf Bolin. Hooper (1983) and Mahnkey (1975) provide anecdotal

Figure 8. Major transportation corridors of the mid-to-late nineteenth century across Taney, Stone, and Christian counties superimposed on a base map of the 1908 edition of the Forsyth 30 min topographic quadrangle. The relatively flat Springfield Plateau is indicated in white. The most highly dissected part of the Salem Plateau is indicated by the light-gray overlay. The medium gray indicates rolling hills and relatively flat areas of the plateau. The rugged parts of the Salem Plateau in the upper White River valley impeded transportation and communication, slowing the settlement and development of this area. As a consequence most of the early roads were oriented north-south between the more populated areas of southwestern Missouri and northern Arkansas (modified on Ingenthron, 1974). The old town site of Forsyth is located near the northernmost extremity of the trunk stream. The first steamships arrived there in 1851. Railroad lines came last in the 1870s.

SpringfieldHarrison Road

SPRINGFIELD

St. Louis and San Francisco Railroad

PLATEAU Highlandville

Chadwick

Ozark Mail Trace ChadwickYellville Road Spokane

Garrison Reno Galena

C H R I S T I A N

St. Louis-Iron Mountain and Southern Railroad

T A N E Y

C O U N T Y

C O U N T Y

Swan

SpringfieldHarrison Road

SALEM

Day

Star (Ameera)

C O U N T Y S T O N E

Reeds Spring

Wilderness Road

PLATEAU

Taney City Walnut Shade

The Narrows

Garber

Boston Ridge Road

Dickens

Alternate Routes

Pedrow Hensley’s Ferry

Kissee Mills

Steamboat Forsyth (1838) Landing

Gretna Branson (1882)

Boston’s Ferry Hollister

Mabry Ferry

Kirbyville The Narrows Bald Knob

W

HI

IV

E

R

SpringfieldHarrison Road TE

0

Mincy

Forsyth-Lead Hill Road

Cedar Valley

N 0

R

miles kilometers

Bee Creek

3

Pinetop 8

Blue Eye

88

Evans

accounts of Alf Bolin. He was born near Jamesville, Missouri, and was raised by an adoptive family from the age of 13 along the Wilderness Road near Spokane, Missouri (Fig. 8). He formed a gang after the outbreak of war and proceeded to rob his family, who were Union sympathizers. During the robbery, he shot and mortally wounded his adoptive father. Among his other victims were an unarmed 12-year-old boy, an unarmed 14-year-old boy, an unarmed 16-year-old, the sheriff of Taney County, and an unarmed 80-year-old man, who was crossing the White River with his team of oxen and a load of corn (Hooper, 1983). The old man’s body was left to float downstream. For these and numerous other depredations, including robbery of the U.S. mail, a reward was placed on his head by Union authorities in Ozark, Missouri. The wife of an imprisoned Confederate sympathizer agreed to allow a Union soldier into her house with the expressed purpose of capturing or killing Bolin in exchange for her husband’s freedom. Her home was near Pinetop, along the SpringfieldHarrison Road, not far from Murder Rocks; Alf Bolin was known to frequent the farm. On 2 February 1863, Zack Thomas, a Union soldier from Iowa masqueraded as a Confederate on furlough.

Within a day or two, Bolin visited the cabin, making enquiries of the stranger. After dinner that evening, when Bolin knelt by the fireplace to light his pipe, Thomas struck him over the head with a plow coulter. His corpse was taken to Forsyth, where it was beheaded, and his body was buried along the road near Swan Creek. His head was taken to Ozark, Missouri, where it was placed on a pike for public viewing. Murder Rocks are on the up-thrown side of the Ten O’Clock Run Fault and on the flanks of the Hollister Anticline (see Fig. 1). These knobs have been interpreted as sinkhole fills that now are preserved as inverted topography (Beveridge and Vineyard, 1990). At Murder Rocks, the knobs crop out near exposures of the Cotter Dolomite. Several other sandstone knobs crop out along Bear Mountain to the southeast. The age or ages of these features remains unresolved. They may be correlative with the Middle Ordovician St. Peter Sandstone, which would have been removed subsequently, or they may correlate with the Bachelor Formation or possibly Lower Pennsylvanian sandstones. The most parsimonious explanation, based on proximity to the subMississippian unconformity, is that these are Mississippian sink fills correlated with the Bachelor Sandstone. In terms of military geology, Murder Rocks is a choke point. The surrounding hills and valleys are relatively steep, and the Springfield-Harrison Road ran up the nose of the ridge and continued southward along the crest of this ridge into Arkansas. According to Brian Thomas (2009, personal commun.), a local resident and U.S. Fish and Wildlife Service biologist, the Springfield-Harrison Road ran on the west side of the sandstone knobs; the present-day road is on the east side, uphill from the knobs. Alf Bolin reputedly would hide his horse in between the rocks and attack downhill, toward the south and west. Murder Rocks would have provided ample cover for such an ambush. A cluster of sandstone outcrops comparable to Murder Rocks are exposed on Bear Mountain ~2.5 miles (4 km) to the southeast as the crow flies. To reach these, continue north on Highway JJ for ~1.8 miles to the intersection of Highway J. Turn right on Highway J. Follow Highway J to the town of Mincy, ~2.7 miles. Turn right (south) on Gunnison Road. After ~1.4 miles, make a hard right onto Bear Mountain Road, a gravel road that angles northwest and up a steep hill. Follow Bear Mountain Road for ~0.8 miles. To the left, just beyond the fork in the road are a group of isolated sandstone knobs. Stop 5A. Bear Mountain Sandstone Outcrops

Figure 9. Murder Rocks was a choke point along the SpringfieldHarrison Road. It was the location of the murder of two furloughed Union soldiers by the bushwhacker Alf Bolin. The hoodoo at left is ~12 ft (4 m) high. Photo by author.

The rocks exposed at this location are comparable to Murder Rocks and other exposures along the trend of the Ten O’Clock Run Fault. Low-lying outcrops with sandstone composition are found along the ridge between Stops 5A and 5B. As at Murder Rocks, the age or ages of this sandstone remain unknown. Jim Miller, Missouri State University, has processed friable sands from this location but was unable to find conodont elements in heavy liquid residues (J. Miller, 2009, personal commun.). A few key observations are that the sandstone masses have discontinuous

Civil War and cultural geology of southwestern Missouri, part 2 quasi-linear deformational zones that are more resistant than the majority of the outcrop. These may be zones that were fractured and cemented with siliceous cement. One possible scenario for the formation of these isolated knobs would require early and likely recurrent movement along the Ten O’Clock Run fault zone during the late Devonian or earliest Mississippian. Flexure, followed by subaerial exposure could have aided in the formation of sinkholes that subsequently filled with the Bachelor Sandstone as sea level rose in the Mississippian. This is consistent with the features developing in the uppermost part of the Cotter Dolomite. Recurrent movement could

A

have introduced secondary deformational features and facilitated karstification in the surrounding dolomite. An alternative explanation that calls upon filling with St. Peter Sandstone would require early karstification during early to middle Ordovician time. This seems unlikely since marine strata of the Everton (middle Ordovician) through Brassfield formations (Silurian) are preserved in northern Arkansas. The alternative hypothesis that correlates these features with Pennsylvanian fluvial sandstones would have vexing problems relating the apparent location of these features near the sub-Mississippian unconformity; it would require cutting out most or all of the Mississippian along this ridge.

B

Low Exposures

r ea

89

d

oa

t. R

Oak Trees

M

B

~4m

~4m

Oak Tree

15° Slope

~6m

5m

Hoodoo

C C A Shelter Cave

B

Bear Cave

Low Outcrop

5m

3 km

Figure 10. (A) Sketch map of sandstone pinnacles at Stop 4, Murder Rocks or Alf Bolin Rocks. Narrow highway shoulders and limited access on private property will not allow us to stop at this location. (B) Sketch map of sandstone exposures at Stop 5A near Bear Mountain Road. (C) Inset shows locations of outcrops in relation to structural elements and stratigraphic contact between the Lower Ordovician and Lower Mississippian.

90

Evans

From a historical perspective, the location of the rocks at Stop 5A and the cave at Stop 5B, a little farther to the east, suggests that this location likely was frequented by Alf Bolin, in which case any of these could have served as campsites or hideouts. Stop 5B. Bear Cave Bear Cave is located at the base of a small sinkhole in lowermost Mississippian strata ~0.5 miles southeast of Stop 5A. It is ~100 m off of Bear Mountain Road along a trail that runs southeast. The cave was a reputed hideout of Alf Bolin and his gang and location of the supposed Alf Bolin treasure (Fig. 11; Mahnkey, 1975). The rim of the sinkhole is near the sub-Mississippian unconformity. Crinoidal limestones are found along the trail, sandstone (presumably Bachelor Formation) crops out around the mouth

of the cave, and dolomitic mudstone beds are found below the sandstone. The cave is reputed to “go-a-ways,” but the narrow entrance suggests that it is small compared to some other caves that are found along the Ten O’Clock Run Fault. Marvel Cave at Silver Dollar City has an enormous six-story-high, bell-shaped entrance room. At the level of the sub-Mississippian unconformity, Marvel Cave also is restricted. The dolomite strata of the Salem Plateau are more heavily fractured than the more massive Mississippian carbonates. As a consequence, caves in Mississippian strata tend to form larger passages. Notice that the elevation of Bear Cave is a little lower than the sandstone knobs along Bear Mountain Road. There likely is a fault that has placed strata around the cave on a down-dropped block. It is notoriously difficult to do field mapping in Missouri because vegetative cover and lack of exposures do not permit one to trace formational contacts out laterally. The use of air photos is useful but somewhat limited in mapping structures at such a fine scale. Retrace the route to the intersection of highways J and JJ, and continue for ~3 miles to the intersection of Highway 76, making a short excursion into Kirbyville, ~0.5 miles to the east. Stop 6. Snapp Balds and the Bald Knobbers

Figure 11. Stop 5B, Bear Cave, is a small sinkhole cave ~0.5 miles east of the sandstone blocks on Bear Mountain and ~150 m south of the road along a path. The entrance of Bear Cave is at the subMississippian unconformity. Crinoidal limestone is found adjacent to the mouth of the cave. Sandstone and dolomite crop out next to the entrance. Bear Cave is the reputed hiding place for Alf Bolin’s hidden treasure. Hammer (40.6 cm) for scale. Photo by author.

The U.S. Geological Survey Branson 7.5 min quadrangle has misnamed the low prominences around Kirbyville Snap Balds rather than Snapp Balds after a prominent family in the area. The Snapps trace their heritage back to the early settlement of Taney County. The knobs rise only 70–100 ft above the surrounding land. During the Bald Knobber era in the mid-1880s, these features as well as much of the countryside were nearly treeless. The hilltops served as meeting ground for the vigilantes because they were close to the Springfield-Harrison Road but they were not easily approachable with being detected. Ironically, members of the Snapp family were anti–Bald Knobbers. Wash Middleton, a close associate of Nat Kinney, the leader of the Taney County Bald Knobbers, was convicted of the second-degree murder of Sam Snapp (Hartman and Ingenthron, 1988). Cotter Dolomite crops out on the slopes of the Snapp Balds. The cyclic nature of this unit, seen at Stops 1 and 3, is expressed in the stair-step-like appearance of the hills in aerial photography (Fig. 12). The dolomitic slopes tend to form thin soils, and the southern slopes particularly are drought prone. Glades tend to have sedges, grasses, wildflowers, and prickly pear cactus cover. Cedar trees tend to grow along bedding planes. Prior to European-American settlement, the glades, with dry grasses and cedars rich in volatiles, would burn regularly and perpetuate the semi-arid setting. Owing to the harsh conditions and relative isolation, glades are home to rare and sometimes endemic flora. Control of burning over the last several decades has resulted in establishment of blackjack oaks, and the “bald” nature of these hills no longer applies. Two unrelated crimes in 1884 and 1885 led to the formation of the Bald Knobbers: (1) the public killing of a Forsyth

Civil War and cultural geology of southwestern Missouri, part 2 storekeeper followed by the acquittal of the perpetrator, and (2) the killing of Amus Ring by his consort’s grown son (Hartman and Ingenthron, 1988). The Bald Knobbers held their first open-air meeting on 5 April 1885. The following evening, ~100 horsemen gathered at the Taney County jail and threatened to lynch the suspect in the Ring murder; a noose was left on the door of the jail as a warning. The following day, the suspect was transferred to Springfield. For Frank and Tubal Taylor, the timing of their crimes was unfortunate. Tubal was wanted in Taney County for cattle mutilation; he was accused of cutting out the tongues of several cows that belonged to neighbors (Hartman and Ingenthron, 1988). On 10 April 1885, Frank Taylor, together with Tubal and Elijah Sublette, an associate, robbed and shot a storekeeper and his wife at Eglinton, near Taney City, a few miles northeast of Forsyth (Hartman and Ingenthron, 1988). The storekeeper, John T. Dickenson, was an Englishman and was a member of the Eglinton Colony of the Noble and Holy Order of the

Figure 12. Snapp Balds near Kirbyville, Missouri, were meeting sites for a group of vigilantes known as the Bald Knobbers. Beveridge and Vineyard (1990) and Hartman and Ingenthron (1988) indicated the historic location was at the northern knob (upper image). Local citizens indicate the knob at right in the lower image was a meeting site as well. The entire landscape was nearly treeless in the 1880s, and bonfires lit on these hills were visible for tens of miles. They signaled members to meet and were warning to those who opposed them. The knobs are resistant beds in the Lower Ordovician Cotter Dolomite. Aerial photography from National Agricultural Imagery Program (2009).

91

Knights of Labor. Dickenson had refused to extend credit to one of the Taylor brothers on an earlier occasion. He also had joined the Bald Knobbers a few days earlier. After the shooting, Sublette left Taney County. The Taylor brothers were indicted, and a reward was posted for their apprehension. They hid out in a cave on Long Creek in what today is known as Hercules Glades Wilderness Area (Hartman and Ingenthron, 1988). Some accounts say they conspired with their friends to hand them over to the authorities, in an effort to collect and split the reward. The Taylor brothers were incarcerated shortly thereafter at the Forsyth jail, a log structure northeast of the courthouse. On the evening of 15 April 1885, the Bald Knobbers gathered at the square and broke into the jail. Despite pleas for mercy, the brothers were hanged near the scenic overlook above Cedar Ridge, ~2 miles northwest of Forsyth along Highway 76. The Dickensons recovered from their wounds. An untold number of events attributed to the Bald Knobbers transpired in Taney County after this lynching, and most of the planning and meetings took place on the Snapp Balds. The Christian County Bald Knobbers were equally notorious (Hartman and Ingenthron, 1988). Inspired by the Taney County Bald Knobbers, they formed to drive out bootleggers, gamblers, and prostitutes from Chadwick, a tie-hacking center and terminus of the Springfield and Southern Railroad. The Christian County Bald Knobbers were equally intent on stamping out opposition to their movement. Lacking bald knobs for seclusion, this group typically met in caves and isolated hollows. Two caves are referred to as Bald Knobber Cave in Christian County. One is on the Taney County line (T25N, R20W, SW¼ SE¼ Sec. 7, Garrison 7.5 min quadrangle). The second was the most common meeting site for the group; it is located in the upper reaches of the Bull Creek drainage (T26N, R19W, SE¼ SE¼ Sec. 7, Chadwick 7.5 min quadrangle). Sometimes the Christian County Bald Knobbers met at the old lead mines and log smelter near the mouth of Browns Branch on upper Swan Creek. On 11 March 1887, leaving the smelter, a small group of Bald Knobbers led by Dave Walker, rode by the Edens-Green house, a small one-room cabin near Oldfield that was occupied by the extended family. Edens had publicly opposed the activities of the Bald Knobbers and had a long-running feud with Walker and his son. Armed men broke into the house, killing Edens and Green and severely wounded some of the women and children. The trial was reported in the Philadelphia Inquirer (Anonymous, 11 May 1889, p. 6). Eventually, four Bald Knobbers were found guilty of the murders. One escaped jail and fled to Oklahoma. The others were hanged on the square in Ozark. The Bald Knobber era might have passed away quietly, except for the work of Harold Bell Wright. Wright (1907) wrote the best-selling novel, Shepherd of the Hills, which featured Bald Knobbers. It later was made into a movie, starring John Wayne. During tourist season, a play based on the book is performed at Shepherd of the Hills Theater. Silver Dollar City also features 1880s Bald-Knobber-era ambience, including “Fire in the Hole,” a Bald Knobber–themed rollercoaster ride.

92

Evans

Stop 7. Shadow Rock Park and Battle of Forsyth Prior to the Battle of Wilson’s Creek, on 20 July 1861, ~1,200 Federal troops under the command of Brig. Gen. Thomas W. Sweeney, were dispatched from Springfield to Forsyth, to drive out pro-southern militia forces that reportedly held the town (Fig. 13; Ingenthron, 1980). On 22 July, the Battle of Forsyth took place, one day after the First Battle of Bull Run. The entire battle lasted ~45 minutes; reports vary on the number killed. The official report of Gen. Sweeney indicates 8–10 Confederate soldiers were killed and many more wounded. Union casualties included four horses killed and two men wounded (United States War Department, 1888, p. 44–45). Information on the military units and order of events comes from a variety of sources (Ware, 1907; Ingenthron, 1974, 1980; Kemp, 1973; Banasik, ed., 2001). Sweeney was appointed commander Missouri Home Guard. Federal troops assigned to the expeditionary force included the 2nd U.S. Infantry (Regulars);

to Taney City to Ozark and Springfield

to Pedrow and Walnut Shade Field Forest k Swa n C re e

Shadow Rock

Forsyth

Taney County Courthouse

N 300 m

W

e hit

River

Steamboat Landing

to Lead Hill and Yellville

to Harrison

Figure 13. Map of Forsyth and vicinity, April 1862, by Lyman O. Bennett, redrafted for clarity and publication by John Arnold in Ingenthron (1980), and further modified herein. Bennett was cartographer for Maj. Gen. Samuel R. Curtis. Union troops were encamped at Forsyth for a short period of time before marching to Batesville, Arkansas. Union troops were camped throughout the town and ~3.5 miles north of Forsyth at the junction of Blue Creek and Swan Creek. Some of the fences and houses in Forsyth were dismantled for construction of defensive barricades. The town was burned prior to the departure of the Union Army. Only one house remained.

the 2nd U.S. Artillery (Capt. James Totten’s Battery) with a 12-pound howitzer and 6-pound cannon under the command of Lt. George Oscar Sokalski; and the 1st U.S. Dragoons (designated 1st U.S. Cavalry in August 1861) Co. C and Co. D led by Capt. David S. Stanley and Lt.. M.J. Kelly. Other units included the 2nd Kansas Volunteer Infantry, commanded by Col. Robert B. Mitchell; the 2nd Kansas Mounted Infantry Volunteers (Kansas Rangers) Co. I, under Capt. Samuel N. Wood; and the 1st Iowa Volunteer Infantry led by Lt. Col. William H. Merritt. Merritt’s force included the Governor’s Grays, under Capt. Francis J. Herron, and Davenport Rifles, under Capt. Augustus Wentz. A small contingent of Christian and Taney county Home Guards led by Capt. Charles Galloway and Lt. F.M. Gideon, Sr., joined the column near Ozark. Confederate forces at Forsyth consisted of recruits from nearby areas in Missouri and Arkansas. According scouting reports, the total troop strength was estimated to be around 1,500 prior to the battle. The actual number of troops in the field during the battle was around 150. There is sparse information regarding the withdrawal of Confederate troops from Forsyth prior to the engagement. Ingenthron (1980) has noted that Maj. James Franklin commanded these forces. Other officers included Capt. (John?) Price, Capt. (James?) Wyatt, and Capt. Jackson, who was killed in the skirmishing. Forsyth would have provided for excellent defensive positions. The White River on the south and rain-swollen Swan Creek on the north were natural barriers to troop movements. The bluffs east and west formed a natural funnel for movement down Swan Creek, and overlooking the main approach, they provided for enfilade fire that eventually was employed by a few Confederate skirmishers. Union troops encountered Confederate pickets about three miles north on Swan Creek. Two were captured, and a third escaped to warn of the impending attack. The primary references on the order of events at the Battle of Forsyth are Gen. Sweeney’s reports in the Official Records (United States War Department, 1888, p. 44–45), Ware’s memoirs (Ware, 1907), newspaper reports of Franc B. Wilkie, a war correspondent from Iowa (Banasik, ed., 2001), and the notes of Vincent B. Osbourne, a private in the 2nd Kansas (in Kemp, 1973). Kemp (1973) and Ingenthron (1980) provide analyses of the military actions. On the afternoon of 22 July 1861, having already marched more than twenty miles, Union troops encountered Confederate pickets on Swan Creek about three miles north of Forsyth. Two were captured, and a third escaped to warn of the impending attack. Capt. Stanley, 1st U.S. Dragoons, Co. C, and Lt. Kelly, 1st U.S. Dragoons, Co. D, and Capt. Wood, 2nd Kansas mounted infantry, were ordered to attack Forsyth as Gen. Sweeney’s infantry and artillery marched double time to meet the enemy. The 1st U.S. Dragoons were formed in 1833 during the Seminole War in Florida and were seasoned veterans of the so-called Indian wars (Herr and Wallace, 1953). With 500 cavalry, Stanley’s force galloped to within sight of Forsyth on the Mail Trace. The Mail Trace crossed Swan

Civil War and cultural geology of southwestern Missouri, part 2 Creek several times and less than a mile away from town, Stanley crossed the stream once more and veered to the right, off the road and through a tall cornfield. The troops went undetected below Confederate soldiers on the bluff east of Forsyth that overlooked the approach. Companies C and D crossed Swan Creek once more just northwest of Forsyth (Fig. 14). Capt. Wood’s force made a flanking maneuver a little farther to the west. Stanley’s troops remounted and formed a line on the south bank of Swan Creek and came under intense fire from the Confederate defenders. The troops charged into town toward the courthouse (Fig. 14). The small Confederate force of ~150 men that held Forsyth were centered around the courthouse, and on the bluff east of town. After a brief exchange, most of the Confederates crossed the White River to safety. During the skirmishing, Gen. Sweeney brought up infantry and artillery to bear on the battlefield from across Swan Creek after Stanley’s charge had mostly cleared the town of rebel forces. Federal troops in town and across Swan Creek were still under fire from the bluff and hill to the east from ~75 Confederates. Three shells from Totten’s Battery mistakenly were fired on the courthouse driving out a bevy of Kansas Ranger looters from Confederate stores held there. The two Union soldiers were wounded by friendly fire from these errant shots. Totten’s Battery repositioned and opened fire on the bluff to suppress the sniping. The Confederates on the bluff were put to flight after Capt. Kelley’s cavalry charged uphill to the east. The only southern account of the battle is related in The Turnbo Manuscripts: …It was not a big fight but it was hot enough to be remembered by those interested enough to talk of past events. …[Ben] Price knowing that he and his men would soon be hard pressed and would probably be surrounded and all of them be either killed or captured vacated the summit of the bluff in a hurry and went across the river where he and his men joined the other southern forces. (Turnbo, unpublished manuscript, Springfield-Greene County Library, accessed 10 January 2010, http://thelibrary.org/lochist/turnbo/V2/ST046.html)

The Battle of Forsyth was ineffectual in maintaining Union control of the Missouri-Arkansas border, but a large store of Confederate supplies was confiscated. Most of the Union troops on the Forsyth expedition fought in the Battle of Wilson’s Creek (see Hannibal and Evans, this volume). Within three weeks, Forsyth again would be occupied by Confederate troops. Ingenthron (1980) notes that Capt. David S. Stanley in his memoirs recounted little of the Battle of Forsyth other than the sad loss of his horse, which was shot through the lungs. Stanley was ultimately promoted to the rank of major general and commander of the IV Corps. He also was recipient of the Congressional Medal of Honor for actions at the Battle of Franklin (Tennessee). Three other significant military actions occurred at Forsyth and in the surrounding vicinity. In April 1862, following the Battle of Pea Ridge, Gen. Samuel R. Curtis’ army arrived at Forsyth en route to Batesville, Arkansas. The southern troops had evacuated prior to their arrival. Curtis noted the unique natural setting of Forsyth and its potential for defense:

93

High water detained me so I have only arrived today at 2 p.m. Skirmishing with a rear guard of enemy’s cavalry, and some prisoners taken. My cavalry is scouring the country down in Arkansas. No force of consequence near. Main force was cavalry, and left some days since. The country is very rough. Roads pass down deep valleys or run on narrow divides. My main force must remove back to more open ground, perhaps near Ozark, for forage and convenience of movement east or west. One division, with cavalry, could hold this point against the world, and keep the enemy pressed down. I shall try to alarm the enemy in front, but cannot extend far enough to do much. The taking of Island No. 10 may soon give you the mouth of the river, which is the key to Arkansas. I am arranging a rope-ferry for convenience. White River is not fordable, and rebels come and fire across. Will soon stop that. I will try to get into telegraphic communication as soon as I complete arrangements here. This is a dilapidated town. It is only important when steamboats are running and commerce is safe on the White River. The surrounding country is not cultivated. (United States War Department, Series 1, v. 8, p. 679)

At Forsyth, Curtis’ troops mostly camped west and north of town along Swan Creek. Many of the log cabins in town were dismantled to form defensive barricades. From Forsyth, Curtis sent a column to destroy the saltpeter works near Yellville. The following day, 22 April 1862, Federal troops left and an order was given to burn the town. The Turnbo Manuscripts give a brief account of the events. …I was given a brief account of the destruction of Forsyth in Taney County by Peter Keesee who said that he saw the town set afire but did not see it burn down, “It was burned while the place was being evacuated by the federal soldiers. The commander of the main force on leaving the town left a detail of men behind to destroy the town by fire and they set every house on fire except the court house which was built of brick. Every house burned down that was set afire except a small house that belonged to Jim Berry. After the men touched this dwelling with fire it died out and the house was saved from destruction. After the detail of men did as they were told to do they left the burning village and followed on after the main body of troops. (Turnbo, unpublished manuscript, Springfield-Greene County Library, accessed 10 January 2010, http://thelibrary.org/lochist/turnbo/V2/ST047.html)

On 3 August 1862, following a Confederate raid on Ozark, a company of Union cavalry from Ozark tracked the Confederates to their camp at the village of Snapp, about two miles southeast of Forsyth. The Union attacked the unsuspecting Confederate force at dawn. Four Confederates were killed but most escaped into the brush to fight another day (Ingenthron, 1980). The last major large movement was in early 1863, when 2,000 Confederates under the command of Brig. Gen. John S. Marmaduke passed through Forsyth en route to Springfield (see Battle of Springfield, Hannibal and Evans, this volume). Geologic Setting of Forsyth The upper part of the Jefferson City Dolomite and lower part of the Cotter Dolomite are exposed in the bluffs surrounding Forsyth. The Rockaway Conglomerate, the uppermost member of the Jefferson City Dolomite, is exposed near the level of the steel bridge. The location of the road cut on the bridge western approach precludes a closer look at the contact. The distinction

1

2

Wood 3

Sweeney 5 6 Kelly 4

Figure 14. Troop movements and positions during the Battle of Forsyth, 22 July 1861, superimposed on Forsyth 30′ topographic quadrangle from 1908. Union troops (black rectangles) and movements (arrows) show advance and attack from the north. The events during the Battle of Forsyth are shown in numbered sequence. (1) Two southern guards on picket duty were captured and a third escaped. (2) Despite his lead in galloping 500 cavalry troopers within view of Forsyth, Stanley’s approach through a tall cornfield west of the road was not detected by southern militia men positioned on the bluff. Stanley crossed the rain-swollen Swan Creek and came under fire when he assembled two companies on the south bank. (3) Capt. Wood’s company of Kansas Rangers and Missouri Home Guards from Taney and Christian counties crossed Swan Creek and in a flanking movement rode into Forsyth from the west. (4) The small contingent of Confederates provide a “warm welcome” for the Union cavalry but quickly were driven from Forsyth eastward on the Yellville Road, or they fled across the White River to take up sniping positions. (5) Sweeney sent his infantry ahead but most of the fighting was over. He also placed his artillery on the north bank of Swan Creek and mistakenly fired on the courthouse, scattering undisciplined troops looting the Confederate stores. (6) Capt. Kelley’s cavalry charge uphill dispersed the Confederate snipers overlooking the Union positions north of Swan Creek.

Civil War and cultural geology of southwestern Missouri, part 2 between these units is difficult to pick. Both stratigraphic units are lower Ordovician (Ibexian Series) in age (Thompson, 1991). The Rockaway Conglomerate, as best can be determined from the type locality at Rockaway Beach, is a solution-collapse breccia, but it is difficult to characterize the breccia from its type locality due to inaccessibility (on the inside curve of a highway with narrow shoulders) and limited exposure. A breccia unit, comparable to the Rockaway Conglomerate and at the appropriate stratigraphic level, is exposed in new road cuts on the Ozark Mountain High Road northeast of Branson (Plymate et al., 2003). That section would make an appropriate standard reference section for this enigmatic unit (base at 36° 42′ 53.83″ N 93° 17′ 48.95″W). The Rockaway Conglomerate exposed on Shadow Rock is more highly weathered and is less accessible. The name of the unit should probably be redefined for the lithology of the rock, which is breccia; according to the provisions of the Stratigraphic Code (North American Commission on Stratigraphic Nomenclature, 2005), Article 18a, a unit can be redefined based on a change in the lithic designation. For convenience herein, I use the informal name “Rockaway Breccia,” until a formal redefinition can be established. At the Ozark Mountain High Road, the breccia is ~15 ft (4.5 m) thick. The upper and lower contacts are sharp bedding planes. The basal part is a dolomitic mudstone that grades upward into a chaotic collection of angular dolomitic mudstone clasts. Clasts range upward of 10 cm in maximum dimension. Extant angular interclastic pores up to 2 cm across locally form seeps. Irregular lenses of white quartz arenite sandstone are present discontinuously across the road cut. The upper part of the unit is brecciated and grades into laminated dolomitic mudstone at the top of this massive bed. An arid, equatorial peritidal setting characterizes deposition of strata belonging to the Jefferson City Dolomite. Water depth typically ranged from shallow subtidal burrowed dolomitic mudstone facies (probably less than 3 m deep) to intertidal and sabhka facies. These depositional settings would have been consistent with development of a restricted salina, where evaporite deposits could have accumulated. Solution-collapse breccias form when evaporites go into solution and interbedded strata collapse into available spaces. Comparable breccias have been characterized as solution-collapse breccias in the Ellenburger Dolomite (lower Ordovician) in West Texas (Lucia, 2007), which is roughly equivalent stratigraphically. At Shadow Rock Park, the “Rockaway Breccia” forms a resistant ledge above more recessive beds. This change of slope can be traced up Swan Creek and around other tributaries of the upper White River in the vicinity of Forsyth, where the change in slope is correlated with wider floodplains and establishment of small settlements. The Rockaway is likely the source of several small springs in the area. The historical record of Taney County has been turbulent; Taney County has had six courthouses (Ingenthron, 1974). In the 1830s, there were two log courthouses in the county, one near the mouth of Bull Creek and one on Swan Creek at Forsyth. After

95

Forsyth was selected as county seat, a brick courthouse was constructed. It was the structure shelled in the Battle of Forsyth and burned in 1862. After the Civil War, a rock courthouse was built within the foundations of the brick courthouse. It burned in 1885 during the Bald Knobber era. A replacement was built in 1891. In 1950s, construction of Bull Shoals Reservoir on the White River required the removal of all buildings in the projected upper pool level. The courthouse was rebuilt again, this time atop the hill west of Shadow Rock Park. Part of “Old Forsyth” is still on the slopes of the hill to the east. Shadow Rock Park and the Taney County Fairground were established on the former town site of Forsyth. The field trip will follow Shadow Rock Park road to the Taney County Fairgrounds, where it turns right on the low concrete bridge across Swan Creek, which is Highway Y. Follow Highway Y for ~2 miles to outskirts of the resort town of Ozark Beach. Stop 8. Powersite Dam Powersite Dam was built in 1910–1913; it was the first hydroelectric dam in Missouri (Van Buskirk, 1984). The U.S. Congress authorized its construction under the Empire District Electric Company. The dam was built by Ambursen Hydraulic Construction Company of Boston, Massachusetts. Materials for the dam arrived by rail in Branson and were floated ten miles to the construction site in 30-ft wooden barges. Heavy rains upstream immediately after the closure caused the dam to fill and overflow in just two days, where it had been estimated that it would take two weeks. The overflow of water looked like a “wide sheet of yellow velvet suspended from the top of the dam” (F.F. Bailey in Anonymous, 1963, p. 10). It is noteworthy that sediment color gives an indication of the underlying bedrock geology. The yellow sediment produced by dolomitic soils of the Salem Plateau stands in contrast to the more red soils produced by Mississippian carbonates. The flow over Powersite Dam was reported to be six feet deep and 600 feet across. The force of water from this initial flooding scoured the area downstream of the spillway down to bedrock. Since then, a number of floods have overtopped the dam; as a means of keeping the pool at a slightly higher level, a series of batter boards have been placed across the top. The field trip route continues on Highway Y through Ozark Beach and uphill. This steep drive offers views of Powersite Dam on the left and Lake Taneycomo to the right. After approximately two miles, turn left into the overlook park. Stop 9. Entrenched Meander and White River Valley Overlook The narrow saddle that the overlooks is situated on is visible in the 2009 National Agriculture Image Project aerial photo (Fig. 15). The entrenched meander that comprises the White River valley is obvious in the image but the timing of stream entrenchment is poorly constrained. Classical thought on the development of entrenched meanders indicates either a lowering of base level or uplift was responsible for downcutting. The

96

Evans

most notable entrenched meanders in the Ozarks are found in the White, Osage, and Gasconade river basins, which bisect or carve the periphery of the Ozarks, respectively. Each has a preserved relief of ~100 m. Each cuts into lower Ordovician dolomites that are relatively resistant to weathering and erosion. Downcutting clearly post-dated the Pennsylvanian, the main phase of uplift on the Ozark Dome. The field trip returns to Branson Convention Center via Highway 160 east. At the intersection with Highway F, turn left and follow that route to Highway 65 south. CONCLUSIONS Re-analyzing historical events from different viewpoints can help to highlight the relevancy of history to present-day events. There were a few major battles in Missouri, but most of the history was played out between small groups of combatants. Irregular military activities during the Border War (1856–1861) and Civil War (1861–1865) were at times comparable to terrorism in which civilians suffered most. However, history is relative to one’s personal perspective. Acts of terrorism to one may be viewed as retaliatory acts or efforts to remove foreign aggressors. Bushwhackers on both sides considered themselves freedom fighters. How can these views be reconciled? One can only hope to achieve understanding. A few soldiers fought for ideals,

Figure 15. Entrenched meander in the White River valley near Forsyth. Powersite Dam is located in the south-central part of the image. Aerial photography from National Agriculture Imaging Project flown in 2009.

but most fought for kinship, friendship, and community. Even in the twenty-first century, in many parts of Missouri, the passions of the Civil War live on among the descendants. Organized vigilantes after the Civil War in Taney County could be compared with gang activities, despite the ostensible pursuit of justice for which the group originally was founded. In reality, the Bald Knobbers were mostly Union veterans and their children. Anti–Bald Knobbers were Confederates and their descendants. Conflict during the Bald Knobber era was a cultural extension of the Civil War on the borderlands of Missouri. There were economic and political as well as cultural motivations for the struggle. From an educational perspective, identifying and analyzing geologic influences on historical events and cultural connections to the Civil War and history in general provides an opportunity for integrative learning and better understanding of the connections between place and time. Geology is the backdrop on which historical events have played out. Then, just as today, resources and hazards were important in the events that shaped the making of America. ACKNOWLEDGMENTS Joe Hannibal, Cleveland Museum of Natural History, suggested a cultural and Civil War geology symposium with field trips for the 2010 Joint Meeting of the GSA North-Central and SouthCentral Sections at Branson, Missouri. His enthusiasm and insight into the topics of cultural geology provided the stimulus for this paper. I also thank him for his review of this paper. Jeremiah Jackson, Missouri State University graduate student, worked on the stratigraphy of the Lower Mississippian at the Branson Regional Airport road cuts as part of this thesis; he first recognized some of the nuances discussed at Stop 3. Jim Miller, emeritus professor of geology at Missouri State University, helped put the road log together and collected and processed conodont samples from Bear Mountain sandstone exposures at Stop 5A. Nancy Williams, Missouri State University, was helpful in reading and reviewing an early draft of this manuscript. I thank Jack Ray for his thoughtful review of this manuscript and others at the Missouri State University Center for Archaeological Research for discussions. Jim Aber, co-editor of this volume, made many helpful suggestions. I greatly appreciate Dimitri Ioannides and Evangelia Petridou for their friendship and discussions on topics; they made it possible for me to work on this project while visiting Mittuniversitetet in Östersund, Sweden. I thank Bo Svenson and the folks of eTour at Mittuniversitetet for their hospitality and the facilities and space to work on this and other manuscripts. I also appreciate the support of Missouri State University, the College of Natural and Applied Sciences, and my department for the sabbatical that made it possible to explore this avenue of historical research and for the time to accomplish this and other tasks. All maps and photographs were created or taken by myself unless otherwise noted.

Civil War and cultural geology of southwestern Missouri, part 2 REFERENCES CITED Abreu, V., Sullivan, M., Pirmez, C., and Mohrig, D., 2003, Lateral accretion packages (LAPs): an important reservoir element in deep-water sinuous channels: Marine and Petroleum Geology, v. 20, no. 6–8, p. 631–648. Anderson, K.H., ed., 2003, Geologic map of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, 1 sheet. Anonymous, 1889, History of the Bald Knobbers. An Organization That Originated in a Desire to Suppress Crime: Philadelphia Inquirer, 11 May 1889, p. 6, col. 5. Anonymous, 1899, “Ten O’Clock Run in its peculiar relation to recent zinc discoveries,” and “Mineral discoveries inspire a run on Uncle Sam’s land office”: St. Louis Globe Democrat, 18 September 1899, in Stevens, Walter B., ed., 1990, The Ozark Uplift: St. Louis and San Francisco Railroad, St. Louis, 71 p. Anonymous, 2002a, Physiographic regions of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Fact Sheet FS-02, 1 p. Anonymous, 2002b, Surficial materials map of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Fact Sheet FS-16, 1 p. Bailey, F.F., in Anonymous, 1963, Lake Taneycomo and Powersite dam fiftieth anniversary: White River Valley Historical Quarterly, v. 1, no. 7, p. 2–10. Banasik, M.E., ed., 2001, Missouri in 1861: the Civil War Letters of Franc B. Wilkie, Newspaper Correspondent: Unwritten Chapters of the Civil War West of the River, Camp Pope Publishing, Iowa City, Iowa, v. IV, 424 p. Betz, N.T., 2005, The Fleagle gang, betrayed by a fingerprint: Author House, Bloomington, Indiana, 448 p. Beveridge, T.R., and Vineyard, J.D., 1990, Geologic wonders and curiosities of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Educational Series, no. 4, 391 p. Bradley, D.C., and Leach, D.L., 2003, Tectonic controls on Mississippi Valleytype lead-zinc mineralization in orogenic forelands: Mineralium Deposita, v. 38, no. 6, p. 652–667. Branson, E.B., 1944, The geology of Missouri: University of Missouri Studies, v. 19, no. 8, 535 p. Bretz, J.H., 1965, Geomorphic history of the Ozarks of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, 2nd Series, v. 41, 142 p. Burrows, W.E., 1976, Vigilante!: New York, Harcourt Brace Jovanovich, 311 p. Castel, A., 1968, General Sterling Price and the Civil War in the West: Baton Rouge, Louisiana State University Press, 300 p. Castleman, H.N., 1944, The Bald Knobbers: The Story of the Lawless Nightriders Who Ruled Southern Missouri in the 80’s: Girard, Kansas, Haldeman-Julius Publications, 29 p. Conrad, C.P., and Husson, L., 2009, Influence of dynamic topography on sea level and its rate of change: Lithosphere, v. 1, no. 2, p. 110–120, doi: 10.1130/L32.1. Cox, R.T., 2009, Ouachita, Appalachian, and ancestral Rockies deformations recorded in mesoscale structures on the foreland Ozark plateaus: Tectonophysics, v. 474, p. 674–683. Cruz, D.C., and Evans, K R., 2007, High-resolution stratigraphy of the subMississippian unconformity in southwestern Missouri and northern Arkansas: Geological Society of America Abstracts with Programs, v. 39, no. 6, p. 308. Eby, G.N., and Vasconcelos, P., 2009, Geochronology of the Arkansas alkaline province, southeastern United States: The Journal of Geology, v. 117, no. 6, p. 615–626. Fellman, M., 1989, Inside war: the guerilla conflict in Missouri during the American Civil War: New York, Oxford University Press, 352 p. Fenneman, N.M., 1938, Physiography of the eastern United States: New York, McGraw-Hill Book Company, 714 p. Hannibal, J.T., and Evans, K.R., 2010, this volume, Civil War and cultural geology of southwestern Missouri, part 1: The geology of Wilson’s Creek Battlefield and the history of stone quarrying and stone use, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, doi: 10.1130/2010.0017(04). Hartman, M., and Ingenthron, E., 1988, Bald knobbers, vigilantes on the Ozarks frontier: Gretna, Louisiana, Pelican Publishing Company, 306 p. Herr, J.K., and Wallace, E.S., 1953, The story of the U.S. cavalry, 1755–1942: Boston, Little, Brown and Company, 275 p.

97

Hildebrand, S.S., Keith, A.W., and Evans, J.W., 1870, Autobiography of Samuel S. Hillenbrand, the renowned Missouri bushwacker, in Ross, K., ed., Autobiography of Samuel S. Hillenbrand, the renowned Missouri bushwhacker (2005 edition with commentary): Fayetteville, The University of Arkansas Press, 280 p. Hooper, V., 1983, Who the heck was Alf Bolin? Forsyth remembers an outlaw: Bittersweet, v. 10, no. 3, p. 15–19. Hudson, M.R., 2000, Coordinated strike-slip and normal faulting in the southern Ozark dome of northern Arkansas: Deformation in a late Paleozoic foreland: Geology, v. 28, no. 6, p. 511–514. Hudson, M.R., and Murray, K.E., 2003, Geologic map of the Ponca quadrangle, Newton, Boone, and Carroll counties, Arkansas: U.S. Geological Survey Miscellaneous Field Studies Map, MF-2412, 1 sheet. Ingenthron, E., 1961, The Boston road: White River Valley Historical Quarterly, v. 1, no. 1, p. 8–9. Ingenthron, E., 1974, The land of Taney, a history of an Ozark common wealth: School of the Ozarks Press, Ozark Regional History Series, Book II, 523 p. Ingenthron, E., 1980, Borderland Rebellion, a history of the Civil War on the Missouri–Arkansas border: The Ozark Mountaineer, Ozark Regional History Series, Book III, 373 p. Jackson, J.S., and Evans, K.R., 2009, Sequence Stratigraphy of the Lower and Middle Mississippian Subsystem in Southwestern Missouri: American Association of Petroleum Geologists, Eastern Section Meeting, Evansville, Indiana, 20–22 September, Abstracts volume. Kalen, K., and Morrow, L., 1993, Nat Kinney’s Sunday school crowd: White River Historical Journal Quarterly, v. 33, no. 1, p. 6–13. Keefe, J.F., and Morrow, L., eds., 1994, The White River Chronicles of S.C. Turnbo: Man and Wildlife on the Ozarks Frontier: Fayetteville, Arkansas, University of Arkansas Press, 424 p. Kemp, H.A., 1973, Forsyth: curtain-raiser for Wilson’s Creek: White River Valley Historical Quarterly, v. 5, no. 1, p. 1–8. Kiersch, G.A., and Underwood, J.R., Jr., 1998, Geology and military operations, 1800–1960: An overview, in Underwood, J.R., Jr., and Guth, P.L., eds., Military geology in war and peace, Geological Society of America Reviews in Engineering Geology, v. 13, p. 5–27. Kisvarsanyi, E., 1976, Studies in Precambrian geology with a guide to selected parts of the St. Francois mountains, Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Contribution to Precambrian Geology, no. 6, 200 p. Lowe, R.G., ed., 2005, A Texas Cavalry Officer’s Civil War: The Diary and Letters of James C. Bates: Baton Rouge, Louisiana State University Press, 366 p. Lucia, F.J., 2007, Carbonate reservoir characterization: an integrated approach, 2 ed.: Springer-Verlag, Berlin, 336 p. Mahnkey, D., 1975, Hill and holler stories: Point Lookout, Missouri, School of the Ozark Press, 232 p. McCall, E., 1961, The Branson story: White River Valley Historical Quarterly, v. 1, no. 2. McCauley, J., Brosius, E., Buchanan, R., and Sawin, R., 2003, Geology of south-central Kansas field trip: Kansas Geological Survey Open-File Report 2001-41, 14 p. Merriam, D.F., 1999, Geologic map of Woodson County, Kansas: Kansas Geological Survey, Map M-52, scale 1:50,000, 1 sheet. Mulvany, P.S., 2004, Field Trip II: Geology of the Crooked Creek Ring Structure, Crawford County, Missouri, in Gilman, J., ed., Association of Missouri Geologists Field Trip Guidebook, 51st Annual Meeting, Rolla, Missouri, 1–2 October 2004, p. 13–29. Myers, R.A., 2009, Lead and zinc mining: The Encyclopedia of Arkansas Culture and History, Central Arkansas Library System, http://www .encyclopediaofarkansas.net/. National Oceanic and Atmospheric Administration, Office of Services, 2009, Natural Hazard Statistics, http://www.weather.gov/os/hazstats.shtml (accessed 20 December 2009). Nichols, B., 2004, Guerrilla warfare in Missouri, 1862: Jefferson, North Carolina, MacFarland and Company, Inc., 256 p. Nichols, B., 2006, Guerrilla warfare in Missouri, volume II, 1863: Jefferson, North Carolina, MacFarland and Company, Inc., 389 p. North American Commission on Stratigraphic Nomenclature, 2005, The stratigraphic code: The American Association of Petroleum Geologists Bulletin, v. 89, no. 11, p. 1547–1591. Overstreet, R.B., Oboh-Ikuenobe, F.E., and Gregg, J.M., 2003, Sequence stratigraphy and depositional facies of Lower Ordovician cyclic carbonate

98

Evans

rocks, southern Missouri: Journal of Sedimentary Research, v. 73, p. 421–433. Parris, D., 2006, Chronister site investigations: new information on the Cretaceous of Missouri: Association of Missouri Geologists Field Trip Guidebook, 53rd Annual Meeting, p. 9–13. Parrish, W.E., ed., 1973, A history of Missouri, volume III 1860–1875: Columbia, University of Missouri Press, 332 p. Petersen, M.D., Frankel, A.D., Harmsen, S.C., Mueller, C.S., Haller, K.M., Wheeler, R.L., Wesson, R.L., Zeng, Y., Boyd, O.S., Perkins, D.M., Luco, N., Field, E.H., Willis, C.J., and Rukstales, K.S., 2008, Documentation of the 2008 update of the United States national seismic hazard maps: U.S. Geological Survey, Open-File Report 2008-1128, 61 p. Petersen, P.R., 2003, Quantrill of Missouri, the making of a guerrilla warrior: Nashville, Cumberland House Publishing Inc., 504 p. Phelps and Watson, 1862, Phelps and Watson’s historical and military map of the border and southern states: New York, Watson and Phelps, pub., 1 map sheet. Plymate, T.G., Evans, K.R., Thomson, K.C., Miller, J.F., Rovey, C.W., II, Davis, G.H., and Cutler, J., 2003, Field trip III: Ordovician and Mississippian stratigraphy and structural geology of the Springfield-Branson area, Southwestern Missouri: Missouri Department of Natural Resources Division of Geology and Land Survey Report of Investigations, no. 75, field trip 26, p. 43–62. Potter, P.E., 1955, The Petrology and Origin of the Lafayette Gravel Part 2: Geomorphic History: Journal of Geology, v. 63, no. 2, p. 115–132. Prather, R., 1994, The Springfield-Harrison road: White River Valley Historical Quarterly, v. 33, no. 3-4, p. 15–23. Rafferty, M.D., 1980, The Ozarks, Land and Life: Norman, University of Oklahoma Press, 282 p. Ray, J., 2007, Missouri chipped-stone resources, a guide to the identification, distribution, and prehistoric use of cherts and other siliceous raw materials: Missouri Archaeological Society Special Publications, no. 8, 423 p. Reynolds, R.L., Goldhaber, M.B., and Snee, L.W., 1997, Paleomagnetic and 40 Ar/39Ar results from the Grant intrusive breccia and comparison to the Permian Downey’s Bluff Sill; evidence for Permian igneous activity at Hicks Dome, southern Illinois Basin: U.S. Geological Survey Bulletin 2094-G, 16 p. Schroeder, W.A., 1981, Presettlement prairie of Missouri: Missouri Department of Conservation, Natural History Series, no. 2, 37 p. Schultz, G., 1937, Early history of the northern Ozarks: Jefferson City, Missouri, Midland Printing Company, 192 p. Seevers, W.J., 1969, Geology and ground-water resources of Linn County, Kansas: Kansas Geological Survey Bulletin, v. 193, 65 p. Spencer, T.M., 2004, The bald knobbers, the anti–bald knobbers, politics, and the culture of violence in the Ozarks, 1860–1890, in Spencer, T.M , ed., The Other Missouri History: Columbia, University of Missouri Press, 241 p. Stiles, T.J., 2002, Jesse James, last rebel of the Civil War: New York, Alfred A. Knopf (Random House), 510 p. Stinchcomb, B.L., 2006, Field trip 1: Chronister Mesozoic vertebrate fossil site Bollinger County, Missouri: Association of Missouri Geologists Field Trip Guidebook, 53rd Annual Meeting, p. 4–8.

Thom, R., 1998, Common as dirt: Missouri Department of Conservation, Missouri Conservationist, v. 59, no. 2, http://mdc.mo.gov/conmag/ 1998/02/20.htm. Thompson, T.L., 1986, Paleozoic Succession in Missouri, Part 4—Mississippian System: Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigations 70, no. 4, 189 p. Thompson, T.L., 1991, Paleozoic Succession in Missouri, Part 2—Ordovician System: Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigations 70, no. 2, 163 p. Thompson, T.L., and Fellows, L.D., 1970, Stratigraphy and conodont biostratigraphy of Kinderhookian and Osagean rocks of southwestern Missouri and adjacent areas: Missouri Department of Natural Resources, Geological Survey and Water Resources, Report of Investigations, no. 45, 263 p. Thomson, K.C., 1982a, Bedrock geology of the Hollister 7.5-minute quadrangle, Taney County, Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, unpublished map HA8437, scale 1:24,000, 1 sheet. Thomson, K.C., 1982b, Geologic map of Taney County: Taney County Planning Commission, scale 1:63,360, 1 sheet. Thomson, K.C., 1984, Bedrock geology of the Mincy 7.5-minute quadrangle, Taney County, Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, unpublished map HA8445, scale 1:24,000, 1 sheet. Turnbo, S.C., dates uncertain, unpublished manuscript, in Springfield-Greene County Library District, Springfield, Missouri, 2010, The Turbo Manuscripts, http://thelibrary.org/lochist/turnbo/toc.html, v. 1, no. 3; v. 2, no. 46; v. 2, no. 47. United States War Department, Moody, J.S., Cowles, C.D., Ainsworth, F.C., Scott, R.N., Lazelle, H.M., Davis, G.B., Perry, L.J., and Kirkley, J.W., 1888, The war of the rebellion: a compilation of the official records of the Union and Confederate armies, series 1, v. 22, ch. 34, 1265 p. Upton, L.M., 1939, Bald knobbers, second edition: School of the Ozarks Press, Point Lookout, Missouri, 253 p. Van Buskirk, K., 1979, Outlaw for my neighbor, the Jake Fleagle story: White River Valley Historical Quarterly, v. 7, no. 1, p. 4-11. Van Buskirk, K., 1984, Powersite dam: program of June 10, 1984 meeting: White River Valley Historical Quarterly, v. 8, no. 8, p. 6–7. Wagner, R.E., and Kisvarsanyi, E.B., 1969, Lapilli tuffs and associated pyroclastic sediments in the upper Cambrian strata along Dent Branch, Washington county, Missouri: Missouri Geological Survey and Water Resources, Report of Investigations, 80 p. Ware, E.F., 1907, The Lyon campaign in Missouri: Crane and Company, Topeka, Kansas, 377 p. Wright, H.B., 1907, The shepherd of the hills: New York, A.L. Burt Company Publishers, 352 p. Zen, E-an, and Walker, A., 2000, Rocks and war, geology and the Civil War campaign of second Manassas: Shippensburg, Pennsylvania, White Mane Books, 102 p. MANUSCRIPT ACCEPTED BY THE SOCIETY 11 FEBRUARY 2010

Printed in the USA

The Geological Society of America Field Guide 17 2010

Rift-related volcanism and karst geohydrology of the southern Ozark dome Gary R. Lowell Earth & Environmental Sciences, University of Texas–Arlington, Arlington, Texas 76019, USA Richard W. Harrison David J. Weary U.S. Geological Survey, MS 926A, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA Randall C. Orndorff U.S. Geological Survey, MS 908, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA John E. Repetski Herbert A. Pierce U.S. Geological Survey, MS 926A, 12201 Sunrise Valley Drive, Reston, Virginia 20192, USA

ABSTRACT This field trip examines the geology and geohydrology of a dissected part of the Salem Plateau in the Ozark Plateaus province of south-central Missouri. Rocks exposed in this area include karstified, flat-lying, lower Paleozoic carbonate platform rocks deposited on Mesoproterozoic basement. The latter is exposed as an uplift located about 40 mi southwest of the St. Francois Mountains and form the core of the Ozark dome. On day 1, participants will examine and explore major karst features developed in Paleozoic carbonate strata on the Current River; this will include Devil’s Well and Round Spring Cavern as well as Montauk, Round, Alley, and Big Springs. The average discharge of the latter is 276 × 106 gpd and is rated in the top 20 springs in the world. Another, Alley Spring, is equally spectacular with an average discharge of 81 × 106 gpd. Both are major contributors to the Current and Eleven Point River drainage system which includes about 50 Mesoproterozoic volcanic knobs and two granite outcrops. These knobs are mainly caldera-erupted ignimbrites with a total thickness of 7–8 km. They are overlain by post-collapse lavas and intruded by domes dated at 1470 Ma. Volcaniclastic sediment and air-fall lapilli tuff are widely distributed along this synvolcanic unconformity. On day 2, the group will examine the most important volcanic features and the southernmost granite exposure in Missouri. The trip concludes with a discussion of the Missouri Gravity Low, the Eminence caldera, and the volcanic history of southern Missouri as well as a discussion of geologic controls on regional groundwater flow through this part of the Ozark aquifer.

Lowell, G.R., Harrison, R.W., Weary, D.J., Orndorff, R.C., Repetski, J.E., and Pierce, H.A., 2010, Rift-related volcanism and karst geohydrology of the southern Ozark dome, in Evans, K.R., and Aber, J.S., eds., From Precambrian Rift Volcanoes to the Mississippian Shelf Margin: Geological Field Excursions in the Ozark Mountains: Geological Society of America Field Guide 17, p. 99–158, doi: 10.1130/2010.0017(06). For permission to copy, contact [email protected]. ©2010 The Geological Society of America. All rights reserved.

99

100

Lowell et al.

I. GEOLOGY OF THE SOUTHERN OZARK DOME

Physiographic Setting

This field trip visits various locations in the Current River drainage basin in the south-central portion of Missouri. Most of these locations are within or near the Ozark National Scenic Riverways, a National Park which includes parts of the upper Current River and its major tributary, the Jacks Fork (Figs. I.1, I.2). We visit outcrops of Mesoproterozoic igneous basement rocks exposed in the area between the towns of Eminence and Big Spring (Fig. I.1, Stops 7, 8, 9). The age, origin, and micro-scale and macro-scale characteristics of these rocks will be discussed in detail. This field trip will also examine some characteristics of, and relationships between, the overlying Paleozoic stratigraphy, geologic structure, physiography and karst hydrology of the dissected Ozark Plateaus in southern Missouri. Several of the Paleozoic stratigraphy and karst localities (Stops 3, 4, 5, 6) were visited in a previously published field trip sponsored by the Association of Missouri Geologists (Vineyard, 1985). Stops 5 and 6 were visited by a field trip run in conjunction with the 15th International Congress of Speleology (Stafford and Fratesi, 2009).

The Current River drains well-developed karst terrane along the southeastern margin of the Salem Plateau of the Ozarks Plateaus physiographic province (Fenneman, 1938; Bretz, 1965) of the midcontinent United States. Karst refers to a type of topography and unique subsurface conditions created by the dissolution of soluble rock material, which is typically of carbonate or evaporite composition. Karst is characterized by losing streams, sinkholes, caves, and springs. Typically, there are rapid and complex surface-water and groundwater exchanges in karst terrane. A regional digital elevation model reveals a ragged, rough topography of relatively high relief, compared to the low-relief of the rest of the Salem Plateau and Mississippi River floodplain (Fig. I.2). River flow is in an overall southeast direction away from the Salem Plateau and toward the Mississippi River floodplain. The Current is a tributary of the Black River, which occupies the western lowlands of the Mississippi River Valley in northeast Arkansas. In the field trip area, altitudes range from a high of 1359 ft at the summit of Thorny Mountain to a low of ~430 ft at Big Spring

3

1 2 4

5 6 7 8

9 11 10

Figure I.1. Highway map showing approximate locations of field trip stops. Modified from AAA Road Atlas of the United States.

Southern Ozark dome

101

90˚

95˚

60 Miles

30

0

40˚

40˚

Central Lowland

MISSOURI

US EA

O gfield Sprin

St. Francois Mountains

Salem Plateau

FIELD TRIP AREA

Cu

rre

nt Ri ve r Jacks Fork P Eleven oin t

Plateau

River

Branson

95˚ 36˚

in the southeastern corner of the area. In the headwaters of the Current River, the crest of the Salem Plateau is typically above 1000 ft and with relatively flat topography except for karstic and epikarstic features. The latter produce gentle rolling hills and depressions and ephemeral losing streams (Gann et al., 1976, Harvey, 1980). Most of the population and economic development of the area is in the upland headwater areas. Downstream incision, chiefly in the eastern portion of the area, has produced a relatively steep, mountainous topography with local relief of hundreds of feet; this region is typically heavily forested and accessibility is poor. Groundwater Hydrology In the incised eastern portion of the Ozarks, numerous large springs (Table 1) discharge into the Current River and also into the Eleven Point River drainage, just to the south, producing a world-class natural resource unrivaled elsewhere in North America. Flow from the two largest of these springs, Big Spring and Greer Spring, ranks in the top twenty largest springs in the world (Vineyard and Feder, 1982). Numerous dye traces delineate large, well-integrated, karst drainage systems feeding the large springs (Fig. I.3). Geologic Mapping The field trip area was the focus of U.S. Geological Survey (USGS) geologic mapping projects for the years 1998–2009.

Mississippi Embayment ssi flo ssipp od i R pla ive in r

K

R ZA

Figure I.2. Shaded relief map of Missouri showing major physiographic features, topography, and location of the field trip area.

Mi

AT

PL

N

90˚ 36˚

This mapping was completed in association with USGS studies on the potential effects of expanded base metal mining and mineral exploration in the Viburnum Trend and a prospecting area in the Mark Twain National Forest to the south (Fig. I.1). In addition, detailed geologic mapping of quadrangles along the Ozark National Scenic Riverways was supported by the National Park Service (NPS) as part of the NPS Geologic Resources Inventory. Most data and interpretations presented in this report have been developed from geologic mapping and field observations made while preparing various geologic maps. Scales used in map preparation were a mixture of detailed at 1:24,000 and reconnaissance at 1:100,000. These 24,000-scale geologic maps, as well as those still in review, are indicated in Fig. I.4. The Grandin SW, Briar, and Poynor quadrangles, located in the southeastern corner of the study area (Fig. I.4), were mapped by Baker (1999), Starbuck TABLE 1. AVERAGE FLOW VALUES FOR LARGE SPRINGS IN THE CURRENT AND ELEVEN POINT RIVER DRAINAGE BASIN Spring County Quadrangle Average discharge (gallons per day) Big Carter Big Spring 276,000,000 Greer Oregon Greer 214,000,000 Blue Shannon Powder Mill Ferry 90,000,000* Alley Shannon Alley Spring 81,000,000 Welch Shannon Cedar Grove 75,000,000* Blue Oregon Billmore 61,000,000 Montauk Dent Montauk 53,000,000 Round Shannon Round Spring 26,500,000 Note: From Vineyard and Feder (1982). *Estimated.

102

Lowell et al.

(1999), and Wedge (1999) of the Missouri Department of Natural Resources. A small, structurally complex area near the town of Thayer was mapped in detail by Hedden (1968); with some reinterpretations, this is incorporated into Fig. I.5. Early mapping at 1:62,500 in the Current River and Jacks Fork area was published by Bridge (1930). Heyl et al. (1983) mapped at 1:24,000 scale ~30 square miles in the southeastern quadrant of the study area, as part of a mineral resource potential investigation. Based on the geologic setting, and on aeromagnetic data and interpretations (Spector, 1982; Moss, 1984) Heyl et al. (1983) concluded that “the potential for mineral resources of the Viburnum-type or lead-zinc deposits in the Potosi Dolomite is rather high—better than many areas, but since none are exposed at the surface, their existence cannot be confirmed or ruled out without deep drilling and more detailed geophysical surveys.” A new geologic map, based on these sources is presented here as Fig. I.5. Proterozoic Rocks Metamorphic rocks are shown as basement by Sims (1990) beneath the Current River basin, but their presence has not been confirmed by drilling. If present, these rocks record the Southern Central Plains orogen, which formed 1700–1600 Ma ago (Van Schmus et al., 1996; Sims and Peterman, 1986). It is inferred that these rocks host the younger Mesoproterozoic intrusions

91° 30'

92° 00' 37° 30'

91° 00'

Montauk Springs

MISSOURI

Dye trace recovery locations injection point

C

ur

re

Current River Watershed

nt R

37° 15'

Round Spring

iv

Fork

J

a

c

k

s

USA Ozark Plateaus Province

er

Alley Spring

37° 00'

Big Spring Curre nt

7 Miles

Mammoth Spring

Paleozoic Stratigraphy

r

36° 30'

10 Kilometers

River

0

ve

nt

0

Ri

oi

Greer Spring

N

P

Eleven

36° 45'

of the St. Francois terrane (Van Schmus et al., 1993) that consist mainly of granitic and rhyolitic volcanic rocks belonging to two age groups: those of the eastern granite-rhyolite province (≈1.47 Ga) and those of the southern granite-rhyolite province (≈1.38 Ga) according to Sims (1990) and Van Schmus et al. (1996). Both provinces are part of a larger anorogenic terrane extending from New England to the southwestern United States (Anderson, 1983). The orthogonal tectonic fabric of Paleoproterozoic basement in the mid-continent influenced structural development of the St. Francois Terrane at all scales of observation (Harrison et al., 2003). At the largest scale, the NW-trending Missouri Gravity Low (MGL) is now recognized as a major rift zone defined by gravity and magnetic anomalies (Lowell et al., 2005). Geophysical models (Darnell et al., 1995) suggest the MGL is filled by 12–20 km of granite, rhyolite, and clastic equivalents covered by a relatively thin veneer of Paleozoic sediments. At the southeastern end of the MGL (Fig. I.6), rocks attributed to the anomaly are exposed in southern Missouri, where two riftmargin volcanic fields erupted during a major strike-slip event and were subsequently deformed by multiple episodes of postvolcanic shear (Lowell et al., 2005). The southwestern boundary of the rift is coincident with the Shannon County Fault (Fig. I.6) and the NE boundary coincides with the Black Fault (Lowell et al., 2005). Both boundaries are regional vertical faults with net sinistral slips. In the Current River basin, a cluster of ~50 knobs of Mesoproterozoic rocks protrude to the surface through the Paleozoic section. Two knobs are granite; the others are rhyolites that are referred to as the Eminence–Van Buren volcanic field by Lowell et al. (2005), Lowell and Harrison (2001), and Harrison et al. (2000). The base of the exposed volcanic section is the lower unit of Coot Mountain which is succeeded by the upper unit of Coot Mountain, tuff of Little Thorny Mountain, rhyolite of Russell Mountain, rhyolite of Sutton Creek, and rhyolite of Story Creek. This lower sequence of volcanic rocks exhibit 65–90° dips and are mainly ignimbrites related to caldera collapse. The probable thickness of the intracaldera fill is 4–5 mi (6–8 km) with a volume estimated to be ~360 km3. The lower ignimbrite sequence is unconformably overlain by post-collapse, subhorizontal effusive and volcaniclastic rocks with a thickness of ~300 m; they are intruded by contemporaneous, steep-walled domes dated at 1470 ± 2.7 Ma (Pb/U age). A distinctive air fall tuff unit generally marks this syn-volcanic unconformity. These units are discussed in detail later sections dealing with Stops 8 and 9.

Figure I.3. Dye traces to major springs in the Current River watershed area in southern Missouri (Aley and Aley, 1987; Imes and Kleeschulte, 1995).

Paleozoic units in the Current and Eleven Point River basins consist of marine carbonates, dominantly dolomite of mixed primary and secondary genesis, and lesser siliciclastic rocks that were deposited on the floor of late Cambrian shallow open seas, as well as in valleys between topographic highs formed by Mesoproterozoic knobs. As a result of the irregular submarine

Southern Ozark dome floor, locally there are great variations in the thickness and intraformational facies; this is particularly true for Cambrian units. Further complications to an otherwise “layer-cake” stratigraphy arise from syndepositional draping due to differential compaction above and adjacent to the Mesoproterozoic highs (Bridge, 1930), regional and local transgressive-regressive cycles, and a

92° 00'

Prescott

3

Licking

91° 00'

Montauk Spring

Montauk Weary in progress

Grove 2 Cedar Weary, 2008 Gladden

Welch Spring Big Piney River Basin Houston

significant but unknown amount of probable syndepositional tectonism active during the Cambrian. In the early stages of Late Cambrian sea-level rise, sedimentation in southern Missouri is viewed as a series of large- and small-scale depositional cycles (He et al., 1997). This is especially true in the region of the Current and Eleven Point River basins

91° 30'

1

Cu

rr

en

Loggers Lake

Raymondville

Hartshorn

5 Alley Spring Weary and Orndorff Summersville Summersville NE in progress

Eunice

6 Cu ent

Clear Springs

Pine Crest Weary, in progress

Jam Up Cave F Weary, in progress

o

The Sinks

iv

Midridge

Corridon SE

Redford

Powder Mill Ferry McDowell and Harrison (2000)

Exchange

Ellington

er

Eminence Orndorff and others (1999)

Alley Spring

Blue Spring

7

rk Bartlett

Jacks

Winona Orndorff and Harrison (2002)

Stegall Mountain Harrison and others (2002)

8

Van Buren North Weary and Weems (2004)

Garwood

Big Spring

9

Van Buren

Peck Ranch

37° 00'

Mountain View

Trask

Montier

Birch Tree

Pomona

Weary (2007)

Brandsville

Rover

Alton

Many Springs

Grandin SW Baker (1999)

Riverton

Bardley

er

Lower Black River Basin

Spring River Basin Moody

Lanton

Koshkonong

Thayer Hedden (1968)

Couch

Blue Spring Myrtle

Briar Starbuck (1999)

Gatewood

Billmore

r

West Plains

Handy Harrsion and McDowell (2003)

ve

P E l e v e n Greer o i nt Spring

Wilderness Harrsion and McDowell (2003)

Big Spring Van Buren Weary and South McDowell Weary and 10 (2006) Schindler (2004)

Ri

South Fork

Greer McDowell (1998)

Fremont Orndorff (2003)

Riv

North Fork White River Basin

White Church Peace Valley Thomasville

Piedmont Hollow

11

rent

Eleven Point River Basin

Low Wassie Weems (2002)

Cur

Willow Springs South

Centerville

Upper Black River Basin

Current River Basin

36° 45'

Corridon

t

Round Spring Orndorff Lewis Hollow and Weary (2009) R

Round Spring

Willow Springs North

Bunker

4

37° 15'

Elk Creek

103

Poynor Wedge (2000)

5 Miles 36° 30'

100 Miles

MISSOURI

Study Area

Ozark National Scenic Riverways (National Park Service)

State parks, forests, and wildlife management areas

Mark Twain National Forest

Approximate location of Viburnum Trend (southern part)

Prospecting Permit Application Area (PPAA)

River drainage basin divide Boundary of Fig. I.5

Figure I.4. Location of geographic and geologic features in the study area. Box outlines area of Fig. I.5. White rectangles delineate 7.5-minute quadrangles, authors and publication dates; grey rectangles are unpublished quadrangles in U.S. Geological Survey review. Numbered boxes are field trip stops.

17

re

Ri

Moun ain View 60

6

8 Miles 10 Kilometers

Alley Spring

Round Spring

4

19

3

5

19

Winona

Eminence

lt

fa u

Mesoproterozoic igneous rocks Wilderness-Handy fault zone

19

on

gt

lin

El

8

Alt 8

fault (primarily strike-slip)

7

37°30' N

60

106

21

10

9

Van Buren

11 Big Spring

21

Ellington

92°W

60

Figure I.5. Generalized geologic map of the Current River and Jacks Fork area. Surficial deposits not shown. Map based on detailed and reconnaissance geologic mapping by the U.S. Geological Survey. Numbers in white boxes correspond to field trip stops. The Ellington Fault is discussed in conjunction with Stop 3; the Hartshorn Fault is discussed in Stop 6.

dd Derby-Doe Run Dolomite

Map Location

r

lt

fau

ve

106

ho rn

Ha r ts

nt

J a c k s MISSOURI

17

ur

Summersville

C

2

Ojc Jefferson City Dolomite Or Roubidoux Formation Og Gasconade Dolomite

60

17

APPROXIMATE MEAN DECLINATION, 2006

37°15' N

TRUE NORTH

Montauk Springs

F

1

k or

MAGNETIC NORTH

92°30’ W.

92°52'30"W

Southern Ozark dome where these cycles were, in large part, controlled by topography related to the northeast-trending structural fabric of the Cambrian Reelfoot rift (Palmer, 1989; He et al., 1997; Seeger and Palmer, 1998). This produced a complicated Late Cambrian pattern of sediment facies including a deep depositional basin centered over the Reelfoot rift, carbonate shelves along uplifted rift margins and paleo-topographic highs, and relatively shallow intrashelf basins. Late Cambrian shallow-water, oöid-skeletal barrier complexes, and stromatolitic banks and bioherms developed on the leading edge of prograding carbonate ramps and migrated across this shelf-basin terrane toward the paleo–St. Francois Mountains (He et al., 1997). These “edge” facies later became favorable sites for Mississippi Valley–type base-metal mineralization in the Late Paleozoic. Variations in uplifted rift shoulder morphology, from narrow and discontinuous to wide and continuous, contributed to variations in sedimentation in intrashelf basins from limestone-dominated (typical of Bonneterre Formation) to shale-dominated facies (typical of Davis Formation) according to Seeger and Palmer (1998). Late Cambrian continental separation failed along the Reelfoot rift, but succeeded in opening a basin off the southern boundary of the North American craton. Deeper intracontinental basins in the tectonically quiescent midcontinent were filled with sediment and ultimately their floors were leveled, except adjacent to steep basement highs, which persisted as islands. Increasing water depths, coupled with increasing distance from major sources of sediment from the Canadian Shield, resulted in continental-shelf deposition on the trailing edge of

105

Laurentia for the remainder of geologic time recorded by the uppermost Cambrian and lower Ordovician section in southern Missouri. During that time, this region was located in tropical to subtropical latitudes and deposition was dominated by relatively shallow-water carbonate sediments (Repetski et al., 1998). All of the carbonate section in the uppermost Cambrian and lower Ordovician interval is dolomite, formed by both primary-digenetic and secondary-alteration processes (Repetski et al., 1998). Fig. I.7 summarizes the generalized lithology and thickness of sedimentary units in the map area. The color alteration index of conodonts reported from the lower Ordovician rocks of southern Ozarks of Missouri is 1–1.5, indicating low levels of longterm post-burial heating in the range of less than 50 °C to ~90 °C (Repetski et al., 1998). This suggests that total burial depth did not exceed ~5000–9000 ft (1500–2700 m) (Epstein et al., 1977). Outcropping Paleozoic Stratigraphy The Derby-Doerun Dolomite ( dd) is the oldest exposed Paleozoic unit in the map area (Fig. I.5). The upper part of the formation is exposed in outcrops along the Middle and West forks of the Black River in the extreme northeastern corner of the map area. The oldest exposed Paleozoic unit in the Current River basin is the Potosi Dolomite ( p), which crops out in several locations in the river valley and along some of the main tributaries. The type locality for this unit is the area of Potosi, Washington County, eastern Missouri (Winslow, 1894) but no type section has been designated. Potosi Dolomite is a massive

BF = Black fault

SCF = Shannon Co. fault

SGFZ = St. Gen. fault

SMFZ = Simms Mt. fault

NMSZ = New Madrid seismic zone

CGL = Commerce geophysical lineament

Red = Exposed Recambrian

Figure I.6. Location of major faults and exposed Mesoproterozoic rocks (red) in southeastern Missouri. Eminence–Van Buren volcanic rocks visited on this fieldtrip occur in the extreme southwestern portion of the outcrop area (just northeast of the Shannon County Fault).

EXPLANATION OF LITHOLOGIC SYMBOLS

Shale

Sandy dolomite

Limestone

Quartz drusy, vuggy, dolomite Shaley dolomite

Cherty Limestone Sandstone and orthoquartzite

Formation (Map Unit)

ST. FRANCOIS CONFINING UNIT

DerbyDoerun Dolomite

Davis Formation

CAMBRIAN

100 FEET

OZARK AQUIFER

CAMBRIAN Yv

UPPER

Lamotte Sandstone PROTEROZOIC IGNEOUS ROCKS are locally exposed adjacent to overlying units upsection into the Gasconade Dolomite

Roubidoux Formation

Cryptozoon chert upper part

middle part lower part

Lower

Bonneterre Formation

UPPER

ST. FRANCOIS AQUIFER

“Quarry ledge”

Upper

Elvins Group

Found in subsurface only

Lithology

Middle

Hydrostratigraphic Unit

Jefferson City Dolomite (part) LO W E R O R D O V I C I A N

x

Dolomite

Gasconade Dolomite (Og)

x

x

Cherty dolomite

Age

x

Cryptozoon chert

Buff-colored dolomite interval

Gunter Sandstone Member

Eminence Dolomite

x

x

x

x

x

x

x

x

x

x

x x

x x

x x

Yg

x

x

x x

x

x

x

Potosi Dolomite

x

Unnamed quartz sandstone interval, in southeastern part of field trip area only

x x

x x

x x

x

x

Figure I.7. Generalized stratigraphic column for Paleozoic rocks in the Current River drainage basin modified from Thompson (1995).

Southern Ozark dome to thick-bedded, fine- to medium-grained cherty dolomite and is characterized by secondary quartz druse that lines vugs and coats chert. It is typically brown to brownish gray in color and fetid. The Potosi Dolomite grades upward into the Eminence Dolomite. The contact between these units is indistinct and probably related to secondary alteration (silicification) rather than to deposition. This is supported by the observation that in several well logs the thickness of the Potosi is inversely proportional to the thickness of the Eminence. In addition, Potosi exposures often completely circle exposed Mesoproterozoic knobs at higher elevations than Potosi exposures elsewhere, suggesting mineralizing fluid-flow up and around the knobs. This outcrop pattern was noted by Bridge (1930). The Potosi ranges from ~50 to 525 ft thick in the upper Current River basin. Overlying the Potosi Dolomite is the Eminence Dolomite ( e). The Eminence was named by Ulrich (1911) for exposures near the town of Eminence, Missouri. It is exposed extensively in the map area in the lower valleys of the Current and Black River drainages. Except for a few areas of Potosi Dolomite outcrop in the Eminence–Stegall Mountain area, the main-stem Current River flows almost exclusively on the Eminence Dolomite from ~2 mi (3 km) downstream of its headwaters at Montauk Springs to a point 5.5 mi (8.9 km) southeast of the town of Van Buren. The Eminence consists of massive to thick-bedded, medium- to coarse-grained, light- to medium-gray cherty dolomite. The massive dolomite beds of the Eminence typically weather to short, stubby pinnacles. Many beds are stromatolitic with pits and vugs developed between the laminae; some are cross-bedded. In downstream areas of the Current River basin a 10- to 20-ft-thick (3–9 m) interval containing interbedded thin, friable to silicified quartz sandstone and sandy dolomite is present ~50–80 ft (15–24 m) below the upper contact. This sandy interval has not been observed west of the Powder Mill Ferry quadrangle. Although Bridge (1930) described the sandstone in the Eminence to be localized lenses, this sandstone-dolomite interval was observed in outcrops throughout the Van Buren area. Assuming that this interval is correlative across the area, it may mark a regressive event similar to, but less widespread than, the regression indicated by the unconformity beneath the basal Gunter Sandstone Member of the overlying Gasconade Dolomite. The variation in thickness of the Eminence above the sandstone-dolomite interval is probably due to erosion of uppermost Eminence before deposition of the overlying Gunter Sandstone Member. The upper part of the Eminence is cavernous, with caves often developed beneath the sandy interval and beneath the upper contact with the overlying Gunter Sandstone Member of the Gasconade Dolomite. Bridge (1930) reported the Eminence to be abundantly fossiliferous, especially with trilobites and gastropods in residual cherts. The fossils observed during the course of this study were mainly gastropods. The Eminence Dolomite ranges in thickness from ~130 to 840 ft (40 to 256 m) in the Current River basin. Earlier maps produced by the latest U.S. Geological Survey project placed the Cambrian-Ordovician boundary in the upper part of

107

the Eminence Dolomite (McDowell, 1998; Orndorff et al., 1999; McDowell and Harrison, 2000; Orndorff and Harrison, 2002; Harrison et al., 2002; Weems, 2002; Harrison and McDowell, 2003). However, a recent international redefinition of this boundary requires that it be placed at the contact between the Eminence and Gasconade Dolomites (Cooper et al., 2001). Bridge (1930) speculated that an important unconformity exists at the base of the Gasconade. Conodont biostratigraphy suggests that, in fact, there may be multiple unconformities within the basal Gasconade interval (Repetski et al., 2000b). The Gasconade Dolomite (Og) overlies the Eminence Dolomite and was named by Nason (1892) for exposures along the bluffs of the Gasconade River in Laclede, Pulaski, and Phelps Counties in central Missouri. The Gasconade Dolomite crops out extensively in the uplands adjacent to the Current River, in the upper Jacks Fork Valley, and in the northeastern part of the map area (Fig. I.5). The basal 15–45 ft (5–14 m) consists of interbedded sandstone, orthoquartzite, and thin-bedded dolomite and sandy dolomite named the Gunter Sandstone Member by Ball and Smith (1903) for exposures along the Niangua River at Gunter (now Hahatonka Springs), Camden County, central Missouri. The thickness and composition of the Gunter Member varies locally within the Current River basin. In the southeastern part of the area, in the Van Buren North, Van Buren South, and Big Spring quadrangles (Fig. I.4) the lower part of the Gunter is relatively thin quartz sandstone and dolomite and is often buried in residuum from the beds above. The upper part of the Gunter is typically thick-bedded or massive quartz sandstone as much as 15 ft (5m) thick and produces a prominent topographic bench on many hillsides. The total thickness of the Gunter is in the range of 20–45 ft (6–14 m) within this part of the basin. The Gunter progressively thins and contains less quartz sand in areas to the northwest of the Van Buren area where the total thickness rarely exceeds 15 ft (5 m), and the lower sandstones are usually more prominent than the upper sandstones. In the northwestern part of the basin, in the area of the Cedar Grove and Montauk quadrangles, the Gunter quartz sandstone forms discontinuous lenses less than 24 in (61 cm) in thickness. In some places quartz sandstone is absent, making identification of the base of the Gasconade difficult. Conodont biostratigraphy indicates that unconformities exist both at the base and within the Gunter (Repetski et al., 2000b). Bridge (1930) used the name “Van Buren Formation” for medium-bedded cherty dolomite above the Gunter and below an oölite bed in the middle part of the Gasconade Dolomite. The Van Buren Formation was defined by faunal content, but the name is no longer used. Pratt et al. (1992) discussed a lower and upper part of the Gasconade Dolomite that is divided by a persistent Cryptozoon chert. This distinctive Cryptozoon chert is located 80–100 ft (24–30 m) below the top of the Gasconade and provides a reliable marker for the upper Gasconade throughout the area of Fig. I.5. In the southeastern part of Fig. I.5, an algal facies or a diagenetic change coincides with the location of the Wilderness-Handy fault zone. Northwest of this zone the

108

Lowell et al.

Cryptozoon chert usually comprises parallel columns, a few inches wide, of convex upward algal laminae. Southeast of the zone, the bed is white chert with varied fabrics and may be difficult to distinguish from chert derived from the overlying Roubidoux Formation. This change might be associated with paleotopographic effects related to southeastward down-stepping across faults in the Wilderness-Handy fault zone, or to silicification of different beds at slightly different stratigraphic levels near the boundary of the middle and upper parts of the Gasconade. The upper part of the formation above the chert is thickbedded dolomite (Fig. I.7). When not buried in residuum from the overlying Roubidoux Formation, this interval tends to form dolomite glades on south-facing and west-facing slopes. The Gasconade Dolomite is one of the richest cave-bearing units in this part of the Ozarks. Caves are numerous in the upper part of the Gasconade beneath the overlying Roubidoux Formation. Jam Up Cave, exposed in cliffs along the Jacks Fork River in the Jam Up Cave quadrangle, is an example. Caves are also concentrated in the dolomites below the Cryptozoon chert horizon that separates the middle and upper part of the formation. Lost Man Cave and Coal Bank Cave in the Big Spring quadrangle are examples. Macrofossils, other than of algae, are rare in the Gasconade, although the presence of planispiral gastropods and cephalopods from cherts in this unit was reported from Fort Leonard Wood and northeast of Van Buren (Harrison et al., 1996). Conodonts collected from just above the Gunter Sandstone in the Van Buren North quadrangle indicate early Ordovician age (early Ibexian, middle part of the Rossodus manitouensis Biozone; see section II). Conodonts collected from the Gasconade in the Low Wassie quadrangle also are indicative of early Ordovician (early Ibexian). Thickness of the Gasconade Dolomite ranges from as much as 700 ft (214 m) to as little as 280 ft (85 m) adjacent to volcanic knobs. It is the youngest Paleozoic unit observed in contact with the igneous rocks in the Current River basin. The Roubidoux Formation (Or) overlies the Gasconade Dolomite. The Roubidoux Formation was named for exposures in the area of Roubidoux Creek ~80 mi (130 km) northwest in Pulaski County by Nason (1892). This unit consists of thin- to thick-bedded, fine- to coarse-grained sandstone and orthoquartzite, intercalated with thin- to medium-bedded, mediumto coarse-grained dolomite and sandy dolomite. Sandy, oölitic, porcelaneous, and “dry-bone” varieties of chert are common throughout the formation. Symmetrical and asymmetrical ripple marks, polygonal desiccation cracks, and cross bedding are all common in sandy intervals. The contact between the Roubidoux and the underlying Gasconade is probably conformable and is placed at the base of the first significant sandstone or orthoquartzite in the Roubidoux. The lower 20–30 ft (6–9m) of the Roubidoux is usually sandstone-rich and commonly produces a topographic bench that sheds sandstone float onto the slopes below. In some locations, however, the basal Roubidoux is chiefly thick-bedded dolomite

through an interval ~50 ft (15 m) above the basal sandstone. In these locations, identification of the Roubidoux-Gasconade contact is difficult. The middle part of the Roubidoux is chiefly thick-bedded gray dolomite resembling the dolomite in the upper part of the Gasconade. A well-exposed section comprising rocks of uppermost Gasconade Dolomite through the middle part of the Roubidoux Formation can be seen in road cuts along Missouri State Highway 17 just north of its crossing of the Jacks Fork River in the Pine Crest quadrangle. This section was originally described in detail by Muilenberg and Beveridge (1954) and their description is repeated by Thompson (1991). The conodont biostratigraphy of this section is reported in Repetski et al. (1998). Highway widening, completed in 2006, has slightly modified the road cuts relative to published accounts. The upper part of the Roubidoux is sandstone-rich and forms a topographic bench. Upon weathering, the Roubidoux produces a sandy, orange-colored soil littered in places with tabular sandstone and orthoquartzite float blocks as well as white chert cobbles and boulders. Fossils are rare in the Roubidoux, though impressions of snails (mostly Lecanospira) locally are common in cherts and sandstones. Heller (1954) reported the occurrence of brachiopods, cephalopods, and trilobites from this formation elsewhere within the Salem Plateau, and Harrison et al. (1996) and Repetski et al. (1998) reported the occurrence of conodonts indicative of early Ordovician (early to middle Ibexian) age. The Roubidoux Formation ranges from ~200 to 280 ft (60 to 85m) thick in the Current River basin. The youngest Paleozoic unit in the Current River drainage basin is the Jefferson City Dolomite named by Winslow (1894) for exposures near Jefferson City, Missouri. The unit consists primarily of thin- to thick-bedded, light-brown, medium- to fine-grained dolomite and argillaceous dolomite. Lenses of quartz sandstone and orthoquartzite as well as beds and nodules of white chert are common. Some areas exhibit an interval of thick- to massivebedded, brown, medium-grained, siliceous, pitted-weathering dolomite informally known as the “Quarry Ledge.” The Quarry Ledge is 25–40 ft (8–12 m) above the base of the Jefferson City and is a useful marker for the Roubidoux–Jefferson City contact which is seldom exposed. The Quarry Ledge, although regionally persistent, does not crop out everywhere, requiring mapping based on float or soil color. The Jefferson City Dolomite weathers to a characteristic yellowish color and produces a silty, sand-poor soil compared with the underlying Roubidoux Formation. Residual sandstone and orthoquartzite float from the Jefferson City are usually less tabular in shape than those produced from the Roubidoux. These characteristics enable differentiation between Roubidoux and Jefferson City bedrock in areas with no outcrop. The unit averages ~200 ft (60 m) in thickness in Missouri (Thompson, 1991) but is considerably less than this value in the Current River basin. The Jefferson City Dolomite is sparsely fossiliferous, but has yielded trilobites and conodonts as reported by Repetski et

Southern Ozark dome

The regional style of deformation in the field trip area is brittle failure with vertical jointing and strike-slip faulting predominant along northeast and northwest trends (Clendenin et al., 1989; Harrison and Schultz, 2002). Strata in the area are generally subhorizontal to gently dipping with gentle, open folds developed in compressional (or transpressional) domains near faults and in subsidence features related to large karstic voids. Rocks in the field trip area are pervasively jointed. The two primary joint sets trend north-northwest and northeast and are indicative of development under a regional stress field. Cox (1995) interpreted similarly oriented joints throughout the Ozarks as far-field deformation related to the Ouachita and Appalachian orogenies. Cataclastic deformation bands occur locally in sandstones within the field trip area (Fig. I.10). All those observed were found in float blocks, diminishing their usefulness. The deformation bands are of tectonic origin and are created by millimeter-scale shear displacements that involve porespace collapse, fracturing, and grain comminution (Davis, 1999; Harrison and Schultz, 2002). This strain-hardening mechanism (Davis, 1999) produces resistant bands that often stand in relief on the surfaces of sandstone boulders. These deformation bands will be examined at Stop 3.

JEFFERSON CITY DOLOMITE SINKHOLES (lower part) SINKHOLES

ROUBIDOUX FORMATION

GASCONADE DOLOMITE

100 FEET 30 METERS

BIG ROOM BIG ROOM

EMINENCE DOLOMITE

SINKHOLES

ALLEY SPRING CAVE

The Salem Plateau contains numerous caves, springs, sinkholes, and other karst features. Measurement of joint structures, exposed in caves in the field trip area, indicate little or no joint control on cave passage direction (Šebela et al., 1999). An example from one of the caves studied, Round Spring Cavern, is discussed in Stop 5. On the other hand, evidence for bedding control on cave and conduit development is strong; this includes a relationship between cave horizons and stratigraphic position, the branching morphologies of the caves, and caves parallel or subparallel to bedding planes. Palmer (1991) showed that branching cave systems are indicative of bedding control where curvilinear passages of branch-work morphology are controlled by bedding plane parting porosity. Dom and Wicks (2003) confirmed that cave systems of the Salem Plateau are dominated by branch-work morphology, with nearly 72% of the caves having branch-work passage morphologies. Cave passages in the Current River drainage basin are concentrated at particular stratigraphic levels, particularly in the upper part of the Eminence Dolomite and in the uppermost part of the Gasconade Dolomite. Both of these levels are characterized by thick- and massive-bedded stromatolitic dolomite beneath caps of quartz sandstone. The sandstones are the basal Gunter Sandstone Member of the Gasconade Dolomite and the basal sandstones of the Roubidoux Formation, respectively. These observations lead to the concept of phreatic conduit formation under at least partially confined conditions beneath the sandstones (Orndorff et al., 2006; Fig. I.8). Although sinkholes occur throughout the Current River basin, the greatest concentration occurs in areas underlain by the Roubidoux Formation and Jefferson City Dolomite (Orndorff et al., 2000). GIS analysis shows that this high concentration of sinkholes occurs adjacent to major fault zones. Fig. I.9 illustrates sinkholes density in the Ozark Plateaus of Missouri and Arkansas. Sinkhole concentrations with rectilinear map patterns, as in south-central Missouri, are probably controlled by preexisting tectonic features. The distribution of sinkholes in the Ozarks is profoundly affected by the thickness of ubiquitous residuum

Structural Geology

ORDOV C AN SYSTEM (lower part)

Karst

above the Paleozoic bedrock. This residuum, usually quartz sandstone and chert derived from the weathering of the predominantly carbonate strata, can be several hundred feet thick. Variation in residuum thickness is one factor influencing the distribution and density of sinkholes at the surface. Presumably, there are many solution voids in the carbonate bedrock, as well as in the overlying regolith, now buried. Most sinkholes are closed-throat type, however, historical records indicate several catastrophiccollapse-sinkholes (Aley et al., 1972) beneath the residuum.

CAMBR AN SYSTEM (upper part)

al. (1998). The Quarry Ledge is paleontologically significant because its top and the immediately overlying beds have produced most of the trilobites known from the lower Jefferson City. At the town of Vichy, ~45 mi (72 km) north of Montauk Springs, a short section in the lower part of the Jefferson City Dolomite produced both trilobites and conodonts. This trilobite taxa marks the Jeffersonian Stage assemblage and the conodonts permit recognition of the Acodus deltatus–Oneotodus costatus Biozone from the appearance of Ulrichodina deflexa and Eucharodus toomeyi (Repetski et al., 1998). Another Jefferson City section at Jim’s Creek, ~48 mi (77 km) northwest of Montauk Springs, yielded conodonts that suggest the boundary between the Macerodus dianae Zone and the Acodus deltatusOneotodus costatus Zone may fall near or at the base of the Quarry Ledge.

109

POTOSI DOLOMITE quartz sandstone

bedded chert

Figure I.8. Generalized conceptual model of cave and sinkhole distribution related to stratigraphy in south-central Missouri. From Orndorff et al. (2006).

110

Lowell et al.

Faults mapped in the field trip area (Fig. I.5) strike NW-SE and NE-SW but are difficult to observe directly due to vegetation and residuum. Most are inferred from indirect evidence which includes: (1) vertical offset of strata with insufficient observed dip to explain the change; and (2) cataclastic deformation bands observed in outcrop or in float blocks of sandstone (Fig. I.10). Faults in this area are interpreted as strike-slip even though only vertical offset is observed; this is based on analysis of similar faults exposed in mines of the Viburnum trend in the northeastern part of the map area (Clendenin et al.,1989). Faulting in rocks in the Current River drainage basin is polyphase. A few faults are interpreted to be strictly of Mesoproterozoic age since they do not extend into the Paleozoic section and at places they are mineralized or altered by high-temperature hydrothermal fluids interpreted as syn- or slightly post-volcanic age (Lowell and Clendenin, 2003). The Mesoproterozoic faults are interpreted as products of two different stress fields: (1) an east-

northeast to west-southwest oriented maximum horizontal stress direction; and (2) a northwest-southeast–oriented maximum horizontal stress direction. Both are thought to have had orthogonal horizontal least principal stress directions and are therefore strikeslip structures. The larger structures, and many of the small-scale structures identified in Fig. I.5, formed under the east-northeast– oriented stress field and interpreted as approximately contemporaneous with 1.48 Ga volcanism (Lowell and Clendenin, 2003). The other set includes small-scale structures thought to be younger and coeval with 1.37 Ga plutonism. The majority of manganese oxide deposits in the area occur along northwest-southeast trends (Lowell and Noll, 2001); this is consistent with dilation along the axis of compression in the younger stress field. Later faulting affecting Lower Paleozoic rocks often occurred by reactivation of Proterozoic faults. The most intense post-Cambrian faulting is Late Paleozoic in age and is ascribed to far-field deformation related to the Ouachita and Allegheny orogenic events (Harrison

ILLINOIS MISSOURI

FIELD TRIP AREA

ARKANSAS

0-0.1 sinkholes/km2 0.5-5 sinkholes/km2 5-42 sinkholes/km2 Areas underlain by dolomite Areas underlain by limestone

Figure I.9. Sinkhole density in areas underlain primarily by carbonate rocks in the Ozark Plateaus province of Missouri and Arkansas. Sinkhole location data for the Missouri portion of the map from Missouri Department of Natural Resources (2003). Sinkhole data for the Arkansas portion of the map derived from U.S. Geological Survey topographic maps with contour intervals of either 10 or 20 ft.

Southern Ozark dome and Schultz, 2002). In the Mississippi embayment and around its northern and northwestern periphery, middle Ordovician faulting (Harrison and Schultz, 1994, 2002; Clendenin and Diehl, 1999) as well as Mesozoic and Cenozoic faulting (Harrison and Schultz, 1994, 2002; Harrison and Litwin, 1997; Harrison et al., 2002) has been documented; some of the faults in the Current and Eleven Point River basins are likely of similar age. The trace of the Wilderness-Handy fault zone (Fig. I.5), an important tectonic feature, intersects the southeastern corner of the field trip area. It is described and discussed in detail in Stop 11. II. CONODONT-BASED UPPERMOST CAMBRIAN AND LOWER ORDOVICIAN BIOSTRATIGRAPHIC FRAMEWORK FOR THE OZARK REGION The Ozarks region, comprising that part of Missouri south of the Missouri River and the part of Arkansas north of the Buffalo and White Rivers, contains one of the largest areas of exposed Upper Cambrian and Lower Ordovician, or Ibexian Series, rocks in the United States. Due to its inboard location on the trailing margin of Laurentia, in tropical to subtropical latitudes during this time, this area accumulated chiefly shallow-marine carbonate sediments. Most of the section is now dolomite, much of it primary or early diagenetic, but also much of it is coarse-grained cherty dolostone, reflecting one or more periods of later dolomitizing episodes. Periods of massive diagenesis related to subsurface fluids moving through Pennsylvanian and Permian strata associated with the Ouachita orogeny are an example of such a process. The Latest Cambrian to Ibexian section in the Ozarks reaches more than a thousand feet in thickness. The units considered

Figure I.10. Cataclastic deformation bands in a float boulder of Roubidoux Formation quartz sandstone. Lighter-colored anastamosing features (arrows) are deformation bands. Brunton transit for scale. Photo by D. Weary, February 2010.

111

here are, in ascending order: the Eminence Dolomite, only the upper part of which is Ibexian; the Gasconade Dolomite, 150– 300 ft (45–90 m) thick; the Roubidoux Formation, 100–300 ft (30–90 m) thick; Jefferson City Dolomite, 125–350 ft (40– 110 m) thick; and the Cotter/Powell formations, 100–300+ ft (30–90+ m) thick. Figs. II.1 and II.2 illustrate relative age and regional stratigraphic correlation of these units. Although dominantly dolomite, the section does contain sandstones, mostly quartz sands, and most of them are multiply reworked, as the region was hundreds of miles from the lowlying exposed sources of Precambrian and Cambrian rocks in the upper Midwest. Most of these Ozarks sandstones are thin lenses, stringers, and channels of local lateral extent. However, intervals contain laterally persistent horizons that have been used both for subdividing the section into formations and for local and long-distance correlations. Some of the sand horizons have been incorporated into sequence stratigraphic schemes of various scales. Little biostratigraphic control exists for this succession of rock, especially considering its areal extent. Certainly pervasive dolomitization destroyed much of the original fossil record, but the depositional environments for most of the units were hypersaline with restricted circulation and probably did not produce diverse faunas in the first place. Most of the macrofauna known from the Ibexian Series of the Ozarks is from preservation as molds or casts in chert. Because much of the record is from chert float blocks, precise occurrence and range data are lacking. Mollusks are the most abundant and diverse of these macrofossils. Trilobites are known from relatively few intervals, but brachiopods are useful in some of the Cambrian units. Most of these faunas were described in works of the 1930s, 1940s, and 1950s. Conodont microfossils have proven to be the most abundant and useful fossils for biostratigraphy in Ozark carbonate rocks. Conodonts are the phosphatic (fluorapatite) food-gathering structures (teeth) of a group of primitive swimming chordate animals. These teeth are small, usually between 0.25 and 1 mm in the Ibexian. They are the only mineralized skeletal parts of these animals and are scattered through the sediment after death. For the stratigrapher, especially working in otherwise poorly fossiliferous successions such as the Ozarks, conodonts are extremely valuable: their apatitic composition allows them to be extracted from carbonate rocks relatively easily and inexpensively using acetic and formic acid; their composition also made them resistant to most diagenetic and mineralizing processes that affected the host rocks; their small size permits recovery from drill cuttings; and conodonts were widespread and evolved rapidly through this time interval. In fact, they underpin the current biozonation through the Ibexian. The strategy used here for conodont stratigraphy in the Ozarks involves location and measurement of multiple sections of each unit, including type sections where possible. This especially includes sections which contain formational boundaries and other marker horizons. Samples of 4–6 kg are collected with the object of bracketing these boundaries and markers. Large

112

Lowell et al.

samples are necessary because productive samples yield only a few conodont elements per kg. We run samples through 170- or 200-mesh sieve. Accessory mineral content in the heavy residues is minimal so that following magnetic separation only snowy dolomite requires hand separation. Conodont separation from the heavy-fraction insoluble residues is facilitated by low conodont color alteration index values of 1–1.5. Preservation in Ozark samples is generally good. True conodonts (euconodonts) first appeared in the mid-Late Cambrian but, thus far, the oldest euconodonts recovered from the southern Ozarks are from the upper part of the Eminence Dolomite (Fig. II.1). Recovery is sparse in numbers of specimens per kg of rock (as is the case in most samples from the Ozarks dolomites); however, the uppermost Cambrian Eoconodontus and Cordylodus proavus Zones are documented in sections near Eminence and Van Buren. Kurtz (1981) reported conodonts from Eminence strata exposed near Van Buren, and used them to place the Cambrian-Ordovician boundary within these upper Eminence beds. However, because the base of the Ordovician has been standardized globally at a level somewhat higher than was used traditionally in North America when Kurtz published (Cooper et al., 2001), these Eminence conodonts now fall into the

Ozark Formations

[revised] Upper Cambrian, and no Ordovician faunas are known from the Eminence using the revised systemic boundary. The Gunter Sandstone Member of the Gasconade Dolomite lies on the top of the Eminence. The contact is sharp and at some sites shows some erosional relief. This contact will be examined at Stops 2, 4, and 5. The Gunter has resisted precise age-dating thus far; numerous large samples have yielded small faunas of longranging or abraded conodont elements that in most places do not constrain the age to either the Cambrian or the Ordovician. An exception is a section near Round Spring (Stop 5), where a sample from approximately one meter above the base of the Gunter contained basal Ordovician conodonts. The carbonate succession above the Gunter, while not prolific in conodonts, contains taxa of the Lower Ordovician Cordylodus angulatus Zone followed by Rossodus manitouensis Zone faunas. The latter biozone is represented through the lower and middle parts of the Gasconade. However, there is an abrupt change in the faunas ~2/3 of the way up through the Gasconade section. This level coincides with a regional chertified horizon above a prominent interval of microbial stromatolite and thrombolite development. This horizon is informally referred to as the “cryptozoon chert” and will be seen at Stop 6. Above this chertified interval, which may be a silicified

Conodont Zones

Trilobite Zones J Zonation not yet established

?

?H-?I

Oepikodus communis

Cassinian Stage

?

?

Bolbocephalus clairi

Jefferson City Dolomite Jeffersonian Stage

Acodus deltatus Oneotodus costatus

Petigurus cullisoni

G

Lutesvillia bispinosa Ranasasus brevicephalus ?

Demingian Stage

Roubidoux Formation

Macerodus dianae

Low Diversity interval

Gasconade Dolomite Gasconadian Stage

Rossodus manitouensis

Poorly fossiliferous

? ? Paraplethopeltis Bellefontia-Xenostegium

Eminence Dolomite

Cordylodus angulatus & lapetognathus Cordylodus lindstromi & Cordylodus intermedius

Cordylodus proavus from Ross and others, 1997

Symphysurina Missisquoia from Arbuckle Mts. Oklahoma (Loch, 2007)

?D-?F

Ibexian Series

Ordovician System (Lower)

Reutterodus andinus

?

C

B Utah

Figure II.1. Stratigraphic framework of the southern Missouri Ozarks region from uppermost Cambrian to lower Ordovician. Conodont symbol indicates horizons of conodont recovery. Vertical ruling indicates missing strata.

Cincinnatian

Gamachian

Conodont Zones/ Subzones

S. Oklahoma

Richmondian

divergens

Maysvillian

grandis robustus velicuspis

Edenian

Keel Fm. A. ordovicicus

A. superbus

Mohawkian

tenuis

Fernvale Ls.

Viola Springs Fm.

Viola Springs Fm.

Bigfork Chert

Corbin Ranch Fm. A. tvaerensis

Joachim Dol.

quadri-

“Chazyan” friendsvillensis

P. anserinus Pygodus serra

Simpson Group

Whiterockian

Ordovician

sweeti

Bromide Fm.

gerdae subz.

aculeata

Lower

Tulip Creek Fm.

Womble Shale

.

McLish Fm.

. Oil Creek Fm.

H. holodentata H. sinuosa H. altifrons T. laevis R. andinus

Joins Fm.

Blakely Sandstone

West Spring Creek Fm.

Kindblade Fm. Cool Creek Fm.

Low Diversity Interval Rossodus manitouensis C. angulatus I. fluctivagus C. lindstromi Cordylodus intermedius Cordylodus proavus

Croixan

Trempealeauan

Crystal Mountain Ss.

Signal Mountain Fm.

Collier Shale

Proconodontus muelleri

Fort Sill Ls. Timbered Hills G.

Franconian

Cotter Dol. Jefferson City Dol. Roubidoux Fm.

Eminence Dol.

Potosi Dol.

.Pposterocostatus

P. tenuiserratus

Smithville Fm.

Gasconade Dol.

McKenzie Hill Fm.

Eoconodontus

Cambrian (part)

Mazarn Shale

M. dianae

Demingian Arbuckle Group

Ibexian (Canadian)

A. deltatus -O. costatus

Everton Fm.

Powell Dol.

Oepikodus communis

“Gasconadian”

Dutchtown St Peter Fm. Ss

Phr. “pre-flexuosu”

Cassinian

Jeffersonian

Kimmswick Ls. Plattin Fm.

dactylus

Middle

Cason Sh.

undatus

compressa

Blackriveran

Polk Creek Shale

Welling Fm.

confluens

Rocklandian

Ozarks

Sylvan Sh.

Shermanian Kirkfieldian

Ouachitas

oolitic unit

shatzeri

Viola Gp.

System/ Series/ Stage

Honey Creek Ls.

Elvins Gp.

Reagan Ss. ?

Dresbachian

Bonneterre Fm.

Figure II.2. Regional correlation of stratigraphic units and conodont zones in the upper Cambrian and Ordovician of the south-central USA. Black areas represent hiatus. Modified from figures 1 and 2 of Derby et al. (1991).

114

Lowell et al.

unconformity surface, faunas of the “Low Diversity Interval” occur through the remaining Gasconade carbonates as well as the lower 1/3 of the overlying Roubidoux Formation. This abrupt faunal change at the top of the Rossodus manitouensis Zone is recognized over most of Laurentia, not only in the conodonts but also in other groups such as the trilobites; this almost certainly reflects a craton-wide eustatic regression-transgression couplet (Ethington et al., 1987; Ji and Barnes, 1993). The Low Diversity Interval faunas give way upward in the lower Roubidoux to species demarking the Macerodus dianae Zone (Fig. II.3). The boundary between the M. dianae Zone and the overlying Acodus deltatus-Oneotodus costatus Zone has not been located precisely, but it is near the contact between the Roubidoux and the overlying Jefferson City Dolomite (Repetski et al., 1998, 2000a). In central and eastern Missouri, the Jefferson City extends upward into the Cassinian Stage (of Laurentian stadial nomenclature), as it contains conodonts of the Oepikodus communis Zone in that region. However, in the southern and south-central Ozarks, the A. deltatus–O. costatus Zone faunas continue through the Jefferson City and into the Cotter Dolomite, at least in the Rolla area (Repetski, unpublished, USGS collections). Examples of conodonts from Upper Gasconade Dolomite, Roubidoux Formation, and the lower part of the Jefferson City Dolomite are shown on Figure II.4. Stratigraphic and facies relationships of the Jefferson City, Cotter, and Powell Dolomites in southern Missouri are not clear and are beyond the scope of studies related to the Ozark National Scenic Waterways. Conodonts probably are the best fossil group with which to address these relationships, but such studies remain to be undertaken. STOP 1. MONTAUK SPRINGS Location (Figure 1.1) About 10 mi (16 km) east-southeast of the town of Licking, Missouri, and 14 mi (23 km) southwest of the town of Salem, Missouri: NE1/4 of Section 22, T32N, R7W, Dent County, Montauk 7.5 min quadrangle. UTM coordinates 4,146,780 mN, 616,443 mE, Zone 15, NAD83 Datum. Road Directions From the town of Salem, Missouri, follow State Highway 32 southwest ~11 mi (18 km), left onto State Route 119 and follow to the south ~8 mi (13 km); turn left at the base of a steep hill, just prior to crossing the bridge over Pigeon Creek, onto County Road DC6660 and follow to the east ~0.8 mi (1.3 km); turn right into a parking lot for Montauk Springs. A very short (0.1 mi; 0.2 km), flat trail leads to the south and a view of one of the spring rise pools. Site Description Named by early residents after Montauk in Suffolk County, Long Island, New York, this area became a milling center with

a total of four mills extant at various times. A grist mill built in 1896, still stands in the park. The mill contains most of its original machinery and is open to visitors during much of the year. Montauk became a state park in 1926 and houses a trout hatchery which produces non-native fish that are stocked in the local spring-fed waters and in rivers and streams statewide. Montauk is one of the most popular vacation spots in Missouri, especially during the trout fishing season. Field work has recently (2008–2009) been completed on 1:24,000 scale geologic mapping of the Montauk quadrangle and a published map is planned by the USGS within the next few years. Montauk Springs is a group of several springs that issue from quartz-sand choked basins in the valley floor. The primary source of the sand is from weathering of sandstones in the Roubidoux Formation, which is exposed on ridge crests and upland surfaces locally and to the west. The sand is transported locally down the hillsides and then downstream along the valley of Pigeon Creek. The springs are estimated to produce an aggregate flow of ~53 million gallons of water per day (82 ft3/sec; 2.3 m3/sec). The influx of groundwater at Montauk Springs marks the official headwaters of the Current River. The channel of the surface stream continues upstream to the northwest for another 9 mi as Pigeon Creek. Downstream from the springs, the Current River flows in a southeastward direction through the Ozark Plateaus physiographic province for ~90 mi. where it enters the Mississippi Embayment near the Arkansas state line. The river then changes direction and flows southwestward, parallel to the northwestern margin of the embayment to join the Black River near Pocahontas, Arkansas. The Black River continues southward to join the White River which enters the Mississippi River in southeastern Arkansas. The Current is one of the premier canoeing rivers in the United States, with clean water, fine scenery, and chiefly class I and II whitewater, making it very popular for group float and canoe trips. A large part of the river and the immediate shore areas are protected by Missouri Department of Conservation lands and by the Ozark National Scenic Riverways (ONSR) which begins ~1.5 mi. southeast of here. The ONSR extends downriver for ~60 linear miles (many more river miles!) to near the town of Doniphan, Missouri, making it possible to float and camp within the park for several days. Stratigraphy and Geohydrology The bluffs adjacent to the springs area and most visible to the east are exposures of the lower Gasconade Dolomite. Based on the local stratigraphic and structural context and observations at other large springs in the Current River system, we infer that the conduit feeding Montauk Springs flows, at least for a time, in the Eminence Dolomite, beneath the basal Gunter Sandstone Member of the Gasconade which is only a few tens of feet below the surface at this spot. Figure I.8 is a generalized conceptual model of karst conduit development in this area. This main cluster of springs is at ~930 ft elevation (above mean seal level [MSL]),

B

Gasconade

Roubidoux Formation JF-E

JF-D

JF-C

JF-B

JF-A

JF-O

JF-N

JF-M JF-L JF-K RC-113

RC-100

RC-46

RC-26 RC-17 RC-16 RC-09 RC-02

JF-F

aff. Colaptoconus quadraplicatus “Oneotodus” gracilis Eucharodus paralellus Aloxoconus staufferi Histiodella donnae Eucharodus c.f. E. paralellus Ulrichodina c.f. U. abnormalis aff. Oneotodus simplex aff. Laurentoscandodus triangularis Ulrichodina n. sp. 1 of Repetski Eucharodus ? sp. Aloxoconus sp. Colaptoconus quadraplicatus cf. Histiodella donnae Protopanderodus ? sp. Drepanodus sp. Juanognathus ? felicitii Eucharodus aff. E. toomeyi

RC-160

JF-J

JF-H 10 feet

RC-126

Striatodontus? proificus

RC-136

Laurentoscandodus ? n. sp. Striatodontus ? prolificus Eucharodus aff. E. parallelus aff. Oneotodus simplex cf. Colaptoconus quadraplicatus Aloxoconus sp. cf. A. iowensis Colaptoconus quadraplicatus Histiodella donnae

RC-55

RC -37.5

n. gen. ?, n. sp. Oneotodus simplex

Jefferson City RC-169

Striatodontus? aff. S. prolificus

Drepanodus sp.

Roubidoux Formation RC-149

Aloxoconus iowensis

Oneotodus simplex Oneotodus cf. O. simplex

Gasc.

A RC-177

?

Low Diversity Interval

Acodus deltatus Oneotodus costatus Zone ?

RC-75 ?

?

Macerodus dianae Zone

RC-88

?

RC-64

Low Diversity Interval

Quartz Sandstone Dolomite

Conodont collection

Macerodus dianae Zone

?

JF-G

Figure II.3. Conodont biostratigraphy of sections from the Upper Gasconade dolomite and the lower part of the Roubidoux Formation in the Missouri, Ozarks. (A) Roubidoux Creek section. (B) Jacks Fork Crossing section (Repetski et al., 1998).

Southern Ozark dome

Figure II.4. Typical conodont fauna from the Gasconade Dolomite, Roubidoux Formation, and Jefferson City Dolomite in southeastern Missouri (from Repetski et al., 1998). Scanning electron microscope photomicrographs of some representative conodont elements from the Gasconade, Roubidoux, and Jefferson City formations in southeastern Missouri from Repetski and others (1998). (A–B) Juanognathus? felicitii (Ji and Barnes); posterolateral views of two specimens from sample RC-149 (very high Roubidoux Formation) at Roubidoux Creek section, X 85, USNM 498496 and 498497. (C) Drepanodus sp., inner lateral view of drepanodontiform element, from sample RC-149 (very high Roubidoux Formation), Roubidoux Creek section, X 85, USNM 498498. (D–E) Colaptoconus quadraplicatus (Branson and Mehl); posterolateral (D) and lateral (E) views of triplicatiform and quadraplicatiform elements, respectively; (D) from sample JF-H (Roubidoux Formation), Jacks Fork section, X 110, USNM 498499; (E) from sample JC-J (lower part of Jefferson City Dolomite at a section along U.S. Highway 63, sec. 2, T.39N, R9W, Maries County), X 64, USNM 498500. (F) Cf. Colaptoconus quadraplicatus (Branson and Mehl); shallowly grooved specimen, from sample JF-J (Roubidoux Formation), Jacks Fork section, X 90, USNM 498501. (G) Ulrichodina deflexa Furnish; posterolateral view of immature(?) specimen from lower part of Jefferson City Dolomite at same Maries County section as specimen E, sample JC-J, X 110, USNM 498502. (H) Paroistodus? sp.; inner lateral view of scandodontiform element, same sample and location as G, X 110, USNM 498503. (I–L) Histiodella donnae Repetski; posterior views of blade-like elements (I, K, L) and inner lateral view of coniform element (J), from samples JF-H (K) and JF-J (I, K, L), Roubidoux Formation, at Jacks Fork section; I and J—X 90, K—X 170, L—X 110, USNM 498504-507. (M) Laurentoscandodus? n. sp.; inner posterolateral view of shortbased element, from sample JF-J, Roubidoux Formation, at Jacks Fork section, X 70, USNM 498508. (N) Drepanoistodus sp.; inner lateral view of drepanodontiform element, from sample JF-J (Roubidoux Formation), Jacks Fork section, X 90, USNM 498509. (O) Juanognathus? n. sp.; posterior view of nearly symmetrical element, from sample JF-J (Roubidoux Formation), Jacks Fork section, X 90, USNM 498510. (P–Q) Striatodontus? prolificus Ji and Barnes; posterolateral views; P from sample JF-J (Roubidoux Formation), Jacks Fork section, X 90; Q from upper part of Gasconade Dolomite (sample RC02) at Roubidoux Creek section, X 95, USNM 498511 and 498512. (R–S) Oneotodus aff. O. simplex (Furnish); posterior and lateral views of two specimens from lower part of upper Gasconade Dolomite at Phillips Quarry, Bartlett 7-1/2 minute quadrangle, Shannon County, Missouri, X 65, USNM 498513 and 498514. (T) Chosonodina herfurthi Müller; posterior view of specimen from upper part of middle Gasconade Dolomite at Phillips Quarry, X 75, USNM 498515. (U) Rossodus manitouensis Repetski and Ethington; inner lateral view of coniform element; Gasconade Dolomite, same sample as T, X 50, USNM 498516. (V) Loxodus bransoni Furnish; inner lateral view; specimen broke during preparation; from upper part of middle Gasconade Dolomite at a section near Rolla, Missouri, X 45, USNM 498517. (W) Acanthodus uncinatus Furnish; lateral view of non-serrate suberectiform element, Gasconade Dolomite, same sample as T, X 50, USNM 498518. (X) Variabiloconus bassleri (Furnish); Gasconade Dolomite, same sample as T, inner lateral view, X 60, USNM 498519. (Y) Oneotodus simplex (Furnish); Gasconade Dolomite, same sample as T, lateral view, X 75, USNM 498520. (Z) Scolopodus sulcatus Furnish; inner lateral view of scandodontiform element, X 75, Gasconade Dolomite, same sample as T, USNM 498521. Illustrated specimens are reposited in the type collections of the Paleobiology Department, U.S. National Museum (USNM), Washington, D.C. 20560.

117

the nearest outcrop of the top of the Eminence Dolomite, ~2 mi to the southeast, is at 990 ft (302 m). A log for the nearest well, ~0.4 mi (0.6 km) to the south-southwest, indicates the contact elevation at 849 ft (259 m). However, structure contours derived from recent geologic mapping (Fig. 1.2) indicate that these springs are on the flank of a structural high and that the elevation of the contact extrapolates, at the springs, to ~919 ft (280 m). We will examine this contact at Stops 2, 4, and 5. The basal 250 ft (76 m) of bluffs to the east are lower Gasconade Dolomite which consists of silty, buff-colored dolomite, massive gray dolomite, and cherty dolomites. The interval of buff-colored dolomite is a consistent stratigraphic marker for the lowest part of the Gasconade Dolomite above the Gunter Sandstone Member. At an elevation of ~1180 ft, there is a topographic bench held up by the top of a Cryptozoon chert interval; this is the top of the lower Gasconade Dolomite (Fig. I.7). We examine this chert at Stop 6. The upper hill slopes above the chert, for ~80 ft, are thick-bedded, non-cherty, pitted gray dolomites of the upper Gasconade Dolomite. These are capped by resistant, quartz sandstone-rich basal beds of the Roubidoux Formation, which form the relatively flat top of the hill. Structural Geology Bedding in the vicinity of Montauk Springs is flat-lying to gently dipping. Dips measured in the Montauk quadrangle do not exceed 14° and are usually in the 1°–3° range. Broad undulations in the bedrock, illustrated by the structural contour map of the base of the Roubidoux Formation are probably tectonic, the result of transpression between strike-slip faults like the Gladden Creek Fault northwest of the park (Fig. 1.2). This fault was named for stratigraphic offsets observed in the Cedar Grove quadrangle to the east (Weary, 2008a). The fault trace extends to the northwest to a point ~1.7 mi (2.7 km) north of Montauk Springs, and ~30 mi (48 km) to the southeast to a point in the northwestern corner of the Powder Mill Ferry quadrangle (McDowell and Harrison, 2000). The topography on the bedrock structural surface has affected the local physiography in the Montauk area. Note that elevation highs on the structural contour map coincide with local highs in the topography. In addition, the valley of Pigeon Creek and the Current River is located in troughs in the structural surface (Fig. 1.2) winding between areas of higher elevation (Roubidoux Formation). The structural high located east of the spring is probably a factor in localizing groundwater rise here. STOP 2. UPPER CURRENT RIVER, OZARK NATIONAL SCENIC RIVERWAYS BAPTIST CAMP RIVER ACCESS Location About 12 mi (19 km) east-southeast of the town of Licking, Missouri, and 15 mi (24 km) southwest of the town of Salem, Missouri: NW1/4 of Section 36, T32N, R7W, Dent County,

118

Lowell et al. The farthest upstream exposures of the Gunter Sandstone Member of the Gasconade Dolomite and the underlying Eminence Dolomite in the Current River valley crop out in this area (Fig. 1.2). The last exposure of the top of the Eminence is a point on the river about 0.7 mi upstream (north) of here. Under normal and low flow conditions the Gunter Sandstone is visible in the base of the bluff directly across the river from the boat ramp (Fig. 2.1). Under flood conditions, that part of the outcrop is inundated. This is an important stratigraphic interval because it marks the Cambrian-Ordovician boundary, a regional unconformity, the Eminence Dolomite–Gasconade Dolomite formational contact, and, at least locally, the major hydrologic features are confined in the upper Eminence Dolomite beneath the Gunter Sandstone. See Section II for discussion of the conodont biostratigraphy of this interval. The Gunter Sandstone Member is also an important factor affecting the local physiography. Because it is resistant to both physical and chemical weathering, it produces topographic benches on hillsides, small waterfalls, and streams that are “perched” on the sandstone and flow down dip. With the exception of the structurally high area of basement rocks exposed in the Stegall Mountain area, the gradient of the Current River approximates the regional dip of bedrock from this locality southeastward ~51 mi to a point just southeast of Big Spring

Montauk 7.5 min quadrangle. UTM coordinates 4143986mN, 618772m E, Zone 15, NAD83 Datum. Road Directions Turn right onto state park road from the Stop 1 parking lot; Follow to the south for ~0.9 mi (1.4 km); turn left onto main park road and follow to the east for ~2.8 mi (4.5 km). This road becomes State Road YY on exiting the park. Turn right onto the Baptist Camp Access Road (NPS 100) and follow ~1.5 mi (2.4 km) to the south; it will terminate in a parking lot and concrete boat ramp at the Current River. Park and walk down to the boat ramp to look across the river. Site Description This is Baptist Camp, the second farthest upstream put-in for the Ozark National Scenic Riverways (ONSR). Please keep in mind that we are in a National Park; hammering on the rocks and collection of samples is prohibited without a National Park Service (NPS) collecting permit. The ONSR, the first national scenic river, was authorized in 1964 and established in 1972. There are trash cans and a restroom at this stop.

Stop 1 k ree

Pig

nC

eo

r

t Rive

Curren

Figure 1.1. Map of Montauk State Park showing location of Stop 1.

to Stop 2

Southern Ozark dome

STOP 3. STANDING ROCK, AN ANOMALOUS OUTCROP OF CHERTY QUARTZ SANDSTONE AND BRECCIA Location About 8.7 mi (14 km) south-southeast of the town of Salem, Missouri: NE1/4 of Section 34, T32N, R5W, Dent County, Doss 7.5 min quadrangle. UTM coordinates 4,153,448N, 635260E, Zone 15, NAD83 Datum.

Og

Or

Gl ad de n

Cr

0

Or

ee k

11 2

The contact between the Cambrian Eminence Dolomite and Ordovician Gasconade Dolomite is marked by an unconformity and overlain by the Gunter Sandstone Member of Gasconade. The bluffs visible to the west above the Gunter here are all lower Gasconade Dolomite culminating with the Cryptozoon chert at the ridge crest. The Gunter here contains a single bed of quartz sandstone up to 2 ft thick (Fig. 2.1). The sand was deposited as starved ripples and sand waves in a shallow subtidal environment. The bed contains low-angle cross beds and pinches and swells in thickness. As is typical of the Gunter in the Current River basin, parts of the sandstone are quartz-cemented, producing a very hard quartz arenite. At many localities in this area the sandstone is discontinuous, with quartz sand being absent or very sparse at this horizon, so that detecting it requires breaking dolomite with a hammer and inspecting for grains with a hand lens.

0

Stratigraphy

Commonly, lensoidal slabs of white Gunter Sandstone are found lying about the hillsides with no continuous outcrop. Because the Gunter is the marker for the Eminence Dolomite–Gasconade Dolomite contact, this variable and cryptic nature makes field mapping difficult. The sandstone is overlain at this locality by a few thin silty dolomite beds overlain by ~10 ft (3 m) of thick- and medium-bedded gray dolomite. Above the gray dolomite is the sequence of silty, medium-bedded, buff-colored dolomite mentioned at Stop 1.

11 4

(Fig. I.5). This Eminence Dolomite-Gasconade Dolomite contact interval will be revisited and discussed at Stops 4, 5, and 6.

119

0 126

fau

lt

Or

Og 1280

D

1

U

Og

Or 1200 1220

118 0

1240

Or Or

Og

Og 1160

0 12

1140

0

122

Or

0

4 12

Or

Og

Og 0

1260

1180

Og 0 0

0.25 0.5

1200 0.5

2

1 Miles 2 Kilometers

Figure 1.2. Preliminary geologic map of the Montauk area with locations of Stops 1 and 2 (labeled with white numbered boxes). Bedrock map units are: e—Eminence Dolomite, Og—Gasconade Dolomite, Or—Roubidoux Formation. Structural contours are elevation, in feet above sea level, of the base of the Roubidoux Formation. Apparent vertical offset across the Gladden Creek Fault is indicated by U (up) and D (down). The fault is actually a strike-slip feature. Base is U.S. Geological Survey 1:24,000-scale Montauk quadrangle.

120

Lowell et al.

Road Directions From Stop 2, return to State Road YY and turn right. Follow State Road YY for ~4.6 mi (7.4 km) to the northwest and turn right onto County Road 649. Follow County Road DC 6490 ~1.2 mi (1.9 km) east and then north to an intersection with State Road K. Turn acutely to the right onto K and follow for ~1.5 mi (2.4 km) to the southeast. Turn left onto State Road BB and follow toward the east for ~2.2 mi (3.5 km). Continue to the east on the same road, which becomes County Road DC 6240 (where pavement stops, gravel begins), for another 5.3 mi (8.5 km) until it intersects with State Highway 19. Turn left on 19 and drive ~1.6 mi (2.6 km) to the north-northwest. Immediately after crossing a conspicuous steel bridge over Little Gladden Creek, a large rock outcrop is visible on the left; pull into the gravel parking area just past it. Walk just a few yards to inspect the outcrop. Caution, there is usually poison ivy growing around and on the rocks. Outcrop Description Standing rock is elongated in a northwest-southeast direction and stands ~8 m above the adjacent stream bed of Standing Rock Creek. It comprises sandstone and lesser chert of the Ordovician Roubidoux Formation. Brecciation is extensive and the mass is mostly devoid of bedding or other sedimentary features. Anastomosing deformation bands are abundant in the outcrop. Discussion Standing Rock is described as an example of a paleokarst feature by Vineyard (1985) based on geometric similarities to rock bodies in Miller County described by Ball and Smith (1903). Evidently, it formed either by collapse or cave fill,

although neither was specified by Vineyard (1985). The rock material is typical of that found in the Roubidoux Formation; however, the contact between the Roubidoux and underlying Gasconade Dolomite is placed ~20 m uphill from Standing Rock on an unpublished geologic map of the Stone Hill 15′ quadrangle (Hayes, 1960). The purpose of this stop is to showcase the deformation bands (Fig. 3.1) that occur in Standing Rock and to highlight the nature of these structural features, which were utilized in the geologic mapping of the Current River region by the U.S. Geological Survey. Deformation bands (Aydin, 1978; Davis, 1999) are of tectonic origin. They are formed by millimeter-scale displacements through shearing that involves a combination of pore-space collapse, fracturing and comminution (i.e., cataclasis). This is a strain-hardening mechanism (Davis, 1999) that is characteristic of deformation in porous sandstones and imparts a mesoscopic fabric resembling quartz stringers (Fig. 3.2). The deformation bands that cut Standing Rock are interpreted as having a tectonic origin. Standing Rock lies on the projection of the Ellington Fault (Fig. I.5) STOP 4. DEVIL’S WELL, OZARK NATIONAL SCENIC RIVERWAYS Location About 3.5 mi (5.5 km) east of Akers Ferry, Missouri: SW1/4 of Section 16, T31N, R5W, Shannon County, Gladden7.5 min quadrangle. UTM coordinates 4,137,694N, 633,357E, Zone 15, NAD83 Datum. Road Directions From Stop 3 turn back toward the south on State Highway 19 and follow it for ~8.6 mi (13.8 km). Turn right onto State

Gasconade D Gasconade Dolomite olomite

Gu ter Sa Gun Gunter Sandstone ndston nds ton one eM Member ember emb er

Do omi Dolomite omite te Q Qua Quartz Sa Sands Sandstone ndston nds ton o e

Ordovician Ordo Or dovi do vici vi cian ci an Camb Ca Cambrian mbri mb rian ri an

Eminence Dolomite Current River

Figure 2.1. View of contact between the Eminence and Gasconade Dolomites at the Ozark National Scenic Riverways, Baptist Camp boat ramp. The black dashed line marks the base of the Gunter Sandstone Member. Photo by D. Weary, March 2009.

Figure 3.1. Photomicrograph deformation band (lower portion of photo) and undeformed sandstone; comminuted grains of quartz microbreccia are set in very fine-grained recrystallized matrix (ultracataclasite). Photo is not of Standing Rock material, it is St. Peters Sandstone in a road cut along Interstate Highway 55, near St. Marys, Missouri (Harrison and Schultz, 2002, figure 10).

Southern Ozark dome Road KK and follow ~2.1 mi (3.4 km) to the southwest. Turn left onto Devil’s Well Road (there is usually a sign for Devil’s Well). Follow road ~1.6 mi (2.6 km) to the south to its terminus. Park in parking lot and walk a short distance to Devil’s Well. There is a walkway into the sinkhole as well as information kiosks. Site Description Devil’s Well is a sinkhole opening up into a large cave chamber partially filled by a deep underground lake. This feature has been developed by the NPS, which maintains a stepped walkway down into the sinkhole to a viewing platform above the cave. Electric lights, operated by a timer button just above the platform, allow a partial view of the cave chamber. In wet weather, a small waterfall forms, drenching the platform; a raincoat or umbrella may be desirable. In cold weather, ice may form on the walkways, making them hazardous. The Gunter Sandstone Member of the Gasconade Dolomite as well as the underlying uppermost Eminence Dolomite are both exposed in the throat of the sinkhole. This locality was described in detail in a previous field trip guide for the Association of Missouri Geologists and in Springs of Missouri (Vineyard 1985; Vineyard and Feder, 1982). Dye traces introduced into Devil’s Well were recovered at Cave Spring on the Current River ~1 mi (1.6 km) to the southsouthwest (Fig. 4.1).

121

Stratigraphy This stop is located at about the same stratigraphic horizon seen at Stop 2. Medium- and thick-bedded dolomite of the lower Gasconade Dolomite are exposed above the sinkhole leading into the cave. Quartz sandstone of the basal Gunter Sandstone Member of the Gasconade Dolomite is exposed in a small natural bridge just above the lower viewing platform. The Gunter is also visible in the stream channel ~300 ft (91 m) to the southeast of the sinkhole. The sandstone is 2–3 ft thick, and very well indurated. About 15 ft (4.6 m) of medium and thin-bedded silty dolomite of the Gunter Member are exposed above the sandstone in the lower part of the sinkhole. Above these beds, part of the interval of buff-colored silty dolomite discussed at Stops 1 and 2 is exposed. The cave and cave lake below are developed in the Eminence Dolomite (Fig. 4.2). The cave has stoped upward through the upper part of the Eminence Dolomite to the base of the solution-resistant Gunter Sandstone. Eventually, a large collapse may occur, producing a feature similar to Grand Gulf, a large collapsed cave in the Jefferson City Dolomite, ~58 mi (93 km) to the south in Oregon County, Missouri. Discussion This cave is unusual for this area in that the main level for solution inception and conduit formation is not confined beneath the

State highway 19, 2.1 mi (3.4 km)

Stop 4

Figure 3.2. Cut block of St. Peter Sandstone showing intense deformation banding. Photomicrograph in Figure 3.1 is from this block (Harrison and Schultz, 2002, figure 10).

Figure 4.1. Location of Devil’s Well and dye trace to the Cave Spring and Wallace Well area of the Current River after Vineyard and Feder (1982).

122

Lowell et al.

Gunter Sandstone, but rather, occurs lower in the Eminence Dolomite (compare Figure 4.2 with Fig. I.8). In the southeastern part of the field trip area, near the town of Van Buren and Big Spring, a quartz sandstone horizon occurs ~80 ft (24 m) below the top of the Eminence. This horizon is lithologically similar to the Gunter Sandstone and may also mark a hiatus in deposition or unconformity. Numerous caves in the Van Buren area are concentrated just beneath this unnamed sandstone in the Eminence Dolomite (Figs. I.7, I.8). Similarity of cave level relations at the two sites is striking. It is possible that the cave inception horizon at Devil’s Well is at the same stratigraphic level as at the unnamed Eminence sandstone interval and that some subtle lithologic feature has contributed to focused solution and conduit formation at that level. STOP 5. ROUND SPRING CAVERN AND ROUND SPRING Location About 10 mi (16 km) north-northwest of the town of Eminence, Missouri: SE1/4 of Section 19, T30N, R4W, Shannon County, Round Spring 7.5 min quadrangle. UTM coordinates 4,127,157N, 640,478E, Zone 15, NAD83 Datum. Road Directions From Stop 4 drive north ~1.6 mi (2.6 km) on the Devil’s Well road to its intersection with State Road KK. Turn right

and follow KK for ~2.1 mi (3.4 km) to the northeast and its intersection with State Highway 19. Turn right onto 19 and follow to the south-southeast for ~11.8 mi (19 km). Immediately after crossing the 2 bridges over the Current River and then Spring Creek, turn left into the Round Spring NPS facility. Bear to the left and the road that curls back around under the highway bridge and ends in the Round Spring Cavern parking lot. Park here. Site Description Round Spring and Round Spring Cavern are located at the confluence of Spring Valley Creek and the Current River in the Round Spring quadrangle, Shannon County, and are among the major attractions of the Ozark National Scenic Riverways (Fig I.1). The spring issues out of the Eminence Dolomite at the edge of the floodplain of the Current River. Its name is derived from the circular feature where the water rises through a collapsed cavern, part of which remains as a natural bridge where the water exits and flows into the Current River (Fig. 5.1). The spring averages 26 million gallons per day (40 ft3/sec; 1.1 m3/sec) and has had a maximum discharge of 336 million gallons per day (520 ft3/sec; 14.7 m3/sec) in 1933 (Vineyard and Feder, 1982). It is suspected that a tubular conduit similar to other Ozark springs occurs at depth in Round Spring. Divers were able to investigate the spring to a depth of 55 feet, but their access to the conduit was blocked by breakdown blocks. Dye traces have shown that the groundwater that feeds Round Spring comes from

Figure 4.2. Profile of Devil’s Well after Vineyard and Feder (1982). View south (left) to north (right).

Southern Ozark dome the west and southwest (Aley and Aley, 1987; Imes and Kleeschulte, 1995; Fig. I.3). The entrance to Round Spring Cavern is in a bluff 60 ft (18 m) above Spring Valley Creek, a tributary of the Current River (Fig. 5.2). It is located ~1600 ft (500 m) southwest of Round Spring. The entrance is 20 ft (6 m) wide by 13 ft (4 m) high and is at 740 ft (225 m) altitude. The cave is well known for its speleothems and has had a commercial history since 1932. It is now owned by the U.S. National Park Service. Round Spring Cavern was described by Bretz (1965) and detailed geology of the cave system was described by Šebela et al. (1999). Stratigraphy Most of the cave is developed in the upper part of the Eminence Dolomite just below the basal Gunter Sandstone member of the Gasconade Dolomite. The entrance passage is within the Eminence Dolomite (Orndorff and Weary, 2009). Beyond the entrance passage, the cave splits into passages referred to as the

123

Right-Hand Route and Left-Hand Route (Fig. 5.3). For this trip, we will traverse the Left-Hand Route. The Right-Hand Route is within cherty strata of the Eminence Dolomite and ends stratigraphically higher at the base of the Gasconade Dolomite where sandstone is exposed in the ceiling. The Left-Hand Route climbs through the Eminence Dolomite to where ripple marks can be seen in the sandstone ceiling of the cave at the base of the Gasconade Dolomite between cave features, Theater Hill and Bat Hill. At Bat Hill the sandstone is not visible because the ceiling lowers back into the Eminence Dolomite. West of Tobacco Barn the sandstone is again exposed in the ceiling, and the cave stopes up through the sandstone and terminates in the Gasconade Dolomite (Fig. 5.3). Structure In the entrance passage, beds predominantly dip toward the southwest and southeast at ~3°. Several gentle synclines and anticlines occur in the Right-Hand Route with their axes in various orientations. Near Onyx Mountain and Dragon’s Mouth, the bedding is subhorizontal. In the Left-Hand Route, strata have a consistent dip toward the west. In the southern part of the Right-Hand Route near the junction with the entrance passage, well-developed joints have a dip direction of 60°. Where the smaller western passage intersects the Right-Hand Route, the principle dip direction of joints is 130°. Here, the cave passage trends N-S. Where the Right-Hand Route makes an abrupt turn to the east, the frequency of vertical joints increases noticeably; they trend E-W. Near the Fountain of Youth, two prominent joint sets occur; one trends about E-W with a dip direction of 170°, the other trends NE with a dip direction of 140°. The eastern terminus of the Right-Hand Route is in breakdown and flowstone where the dip direction of joints is 140°. The Left-Hand Route at Theater Hill is a collapse chamber that exhibits well-developed joints with a dip direction of 140°. The southern side passage at the Tobacco Barn follows the trends of joints with dip directions of 80°, 90°, 105°, and 130°. Just west of the Tobacco Barn in the Left-Hand Route, joints are moderately well developed with dip directions of 30° and cross the passage. Where the Left-Hand Route turns to the southwest, joint dip directions are 150°–160°. The terminus of the Left-Hand Route is a collapse area with joint trends of E-W and N-S. Passages in Round Spring Cavern are developed along four prominent trends, 0°–10°, 60°–70°, 330°–340°, and 280°–290°. Dominant joint trends are 80°–90° and 50°–60°. Comparison of rose diagrams of cave passages and joints shows poor correlation, even though several areas of the cave have moderately welldeveloped joints parallel to the cave passage (Fig. 5.3). Hydrology

Figure 5.1. Round Spring. The spring rises from a circular pool, partially visible in the lower right part of photo. Discharge occurs under a natural bridge (beneath figures) of massive Eminence Dolomite. Photo by D. Weary, May 2000.

The initial development of Round Spring Cavern was probably phreatic and has been modified by recent water flow in the vadose zone and stoping. Water flow in the stream in the

124

Lowell et al.

Right-Hand Route is southeast toward Spring Valley Creek; flow in the Left-Hand Route is also to the east toward Spring Valley Creek. Bedding dips are generally to the west and southwest. Both streams have cut small lower subsidiary passages that drain to Spring Valley Creek from other parts of the bluff near the entrance to the cave. The entrance passage is probably younger than the main passages and during high precipitation events water drains from Round Spring Cavern into Spring Valley Creek. Red clay is found throughout the cave and occurs in joints in the ceiling and walls indicating that the cave was filled with red clay in the past. The stratigraphic position of Round Spring Cavern, in the uppermost Eminence Dolomite and lowermost Gasconade, is nearly identical to that of the large conduit feeding Alley Spring (Stop 6) and is probably similar to that of the conduit feeding Montauk Springs (Stop 1). This fact makes the fossil conduit of Round Spring Cavern a valuable analogue for understanding parts of the current conduit system. Cave Development Initial phreatic development of Round Spring Cavern occurred in the upper part of the Eminence Dolomite, similar to the model shown in Figure I.8. Early water flow was probably from south-southwest to north-northeast since the Left-Hand Route is higher than the Right-Hand Route. This

direction is toward the Current River. Changes in surface and groundwater flow have caused drainage in the vadose zone to flow eastward to Spring Valley Creek. Later modifications to the cave include stoping up to and through the basal sandstone of the Gasconade Dolomite. STOP 6. ALLEY SPRING Location About 4.7 mi (7.6 km) west of the town of Eminence, Missouri: SE1/4 of Section 25, T29N, R5W, Shannon County, Alley Spring 7.5 min quadrangle. UTM coordinates 4,113,157mN, 638,402mE, Zone 15, NAD83 Datum. Road Directions From Stop 5, exit the Round Spring Caverns parking lot via the park road to State Highway 19. Turn left and follow ~12.2 mi to the south-southeast. Just after entering the town of Eminence and crossing over the Current River, turn right onto State Highway 106. Follow for ~5.9 mi (9.5 km) to the west. Just after crossing a bridge over the Jacks Fork River, turn right into the NPS Alley Spring parking area. Park at the north end of the lot and take walkway to Red Mill.

Stop 5

1 Kilometer

1 Mile Eminence 12.2 mi

Figure 5.2. Geologic map of the Round Spring and Round Spring Caverns area based on Orndorff and Weary (2009). Map units: e—Eminence Dolomite; Og—Gasconade Dolomite; Or—Roubidoux Formation; QTrr—residuum of Roubidoux Formation; Qt—alluvial terrace deposits; Qa—alluvium.

Southern Ozark dome Site Description

125

Conservation Corps work camp for World War I veterans in the middle 1930s. The area of Alley Spring, part of the Ozark National Scenic Riverways (ONSR), has been developed by the National Park Service as a historical and recreational site with preserved historic buildings, river access, and campground facilities. The most prominent building on the site is the bright red Alley Spring Mill. The mill was built in 1893–1894 and houses working machinery for converting part of the impounded spring flow into power for grinding grain. The spring orifice is located in the mill pond just to the northeast of the mill building. The mill pond is

Alley Spring (Fig. 6.1) flows at an average rate of ~81 million gallons per day (125 ft3/sec; 3.6 m3/sec) and is ranked as Missouri’s seventh largest spring (Table 1; Vineyard and Feder, 1982). Discharge flows for ~0.6 mi (0.9 km) before joining the Jacks Fork River, the largest tributary of the Current River. The confluence of the two rivers is ~9.4 mi (15 km) east-northeast of the spring and ~5.4 mi (8.7 km) northeast of the town of Eminence. Formerly a state park, Alley Spring served as a Civilian

60/0-3 10 180/80

80 150 150 0 60/4 110/03 170 120/3 140 140 110 170 30/3 180

0

150

340/0-3 90 90 350/0-8

900'

30 170 Onyx 170

Dragon's Mouth

bedding showing direction and angle of dip

30 25

d

horizontal beds fissured zone (closely spaced joints) fissured zone (widely spaced joints) prominent joint and dip direction distinct, but less prominent joint and dip direction reverse fault (?), box on downthrown side broad anticline, approximately located

ute

Ro

240/8 10 10

Contour interval 20 feet (6.096 meters)

120 120 170

Mountain

Han

1000'

50/0-3 160

LEGEND for CAVE MAP STRUCTURE SYMBOLS 60/0-5

130 140 90 130 160 160 290/0-5 50 90/0-3 10 90/0-3 50 120 120 50 50 180/5

900'

110

Right

20 20 90 140 30

1000'

Fountain of Youth

140 80 140

broad syncline, approximately located

260/0-5 40/3 10 100 120

170 Entrance passage 170 170 160 250/0-3 60 170 300/0-5 100 10 70 170 160/0-5 160/3 160 130 60 170 90 200/3 Entrance 20/80 170 Route 100/3

200 feet 60 meters

Hand Cave below Gunter Sandstone

ft Le

250/0-3 30 140

150 70 150 200/3

200/3 130

30

80 170

280/0-3

Tobacco Barn

250/2

150

90

250/3

Theater Hill 140

160/3

Bat Hill

105

50

260/0-3 150 160 170 300/4 160 160 90 50 60 0 280/3

150 350/3 150/80 80 140 10 50

Nm

80 140 130

10

Cave above Gunter Sandstone Cave passages, 1982 meters

Figure 5.3. Map of structural features at Round Spring Cavern after Šebela et al. (1999).

Joints, N=143

126

Lowell et al. graphic level coincident with the top of the Eminence Dolomite, at a depth of ~130 ft (39 m) below the surface (Fig. 6.2). The mapped portion of the conduit is relatively horizontal with the elevation of the main conduit at ~532 ft (162 m) meters. The cave maintains this level for the rest of its known extent, except where collapses of the overlying basal Gunter Sandstone Member of the Gasconade Dolomite occur and the conduit has migrated vertically over the top of the breakdown piles. Compare the cave profile (Fig. 6.2) with the conceptual model for caves in the Current River drainage basin area (Fig. I.8). An accessible walking path circles the mill pond/rise pool giving visitors a good view of the spring and spring run. A separate path, diverging from the main loop northwest of the mill, leads to a relatively steep, but smooth, switchback trail up the flank of the bluffs to a viewing platform above the spring. Near the top of the climb, an excellent example of bedded white Cryptozoon chert from the uppermost part of the Lower Gasconade Dolomite is exposed on the north side of the trail. From this platform, the upland surface of the Salem Plateau, the incised valley of the Jacks Fork River, and the Alley Spring millpond are visible.

Figure 6.1. Alley Spring. The spring rises near bluffs of Gasconade Dolomite visible in the background. Photo by D. Weary, July 2007.

partially enclosed in an amphitheater-like alcove in steep bluffs of dolomite rising nearly vertical more than 100 ft above the water surface. The spring orifice is usually not visible from the pond banks, but rising bubbles and small water boils indicate the flow out of it. About 3000 ft (914 m) of the surveyed passage of Alley Spring Cave has been mapped by divers of the Ozark Cave Diving Alliance (OCDA, 2005). The cave descends at an angle of ~24° to the northwest of the spring where it levels out at a strati-

Stratigraphy Alley Spring rises from thick-bedded dolomites in the lower part of the Gasconade Dolomite. Some earlier reports indicated that the spring flows from the Eminence Dolomite, but this is definitely not the case (Vineyard, 1985). Data from recent detailed geologic mapping of the Alley Spring quadrangle (USGS,

eak ky P c u t Ken

N 100 Feet 30 Meters

De

ath

Val ley

Coal Chute

Big

Ro

om

Location of AMT station ASP-3 on ground surface above cave

Edge of sharp drop in floor Sloping floor (lines indicate direction)

Spring Pool

continues

WEST 0

2900’

Location of AMT station ASP-3 on ground surface above cave

Collapse of Gunter Sandstone 500 meters ceiling Coal Chute Big Room Kentucky Peak Death Valley

2500’

100 Feet below pool Side view 3/4 scale to map surface

2000’

1500’

1000’

Spring Pool

500’

Gasconade Dolomite Eminence Dolomite

100’

EAST Elevation (above mean sea level) 675 ft 206 m 575 ft Gunter Sandstone 165 m

Figure 6.2. Map and profile of Alley Spring Cave simplified from a map produced by the Ozark Cave Diving Alliance (OCDA, 2005). Geologic interpretation by D. Weary, based on surface geologic mapping, observations by OCDA divers, video footage, and analogy to geologic control seen in air-filled caves in the region. Dashed line indicating 165 m elevation is the level of the electromagnetic resistivity map (Fig. 6.7).

Southern Ozark dome Audio-Magnetotelluric Studies of Alley Spring

unpublished data) combined with observations and sample collections by divers of the OCDA, confirm that the basal Gunter Sandstone Member of the Gasconade Dolomite lies ~140 ft (43 m) below the ground surface at the spring (Fig. 6.2). However, most of the mapped part of the conduit upstream of the rise tube is developed in the uppermost Eminence Dolomite. About 100 ft (30 m) of thick, non-cherty dolomite beds in the lower Gasconade Dolomite are exposed in the bluffs above the rise pool. Above this is an interval of dolomite and bedded white Cryptozoon chert, ~40 ft (12.2 m) thick, marking the uppermost part of the Lower Gasconade Dolomite (Fig. I.7). Above the highest chert bed is an interval, ~80 ft (24.4 m) thick, of thick- and medium-bedded, non-cherty dolomite in the Upper Gasconade Dolomite. The final 60 ft (18.3 m) of the knob to the north-northwest of the spring is Roubidoux Formation dolomite and quartz sandstone (Fig. I.7). The best place to observe the Gasconade-Roubidoux contact in the area is the road cut on State Highway 106, about 0.75 mi (1.2 km) west of Alley Spring and just west of the peak of the hill (Fig. 6.3). Here a thick, basal quartz sandstone in the Roubidoux overlies the dolomite beds of the uppermost Gasconade.

94 0

920

127

Groundwater flow in karst areas is often poorly understood and difficult to model because of the heterogeneous permeability of karstic aquifers. Dye traces have been used to delineate the major groundwater basins; these yield an average flow velocity over a straight-line distance but provide little information on the actual path of groundwater flow. Mapping discrete karst conduits will enable more realistic modeling of the fast flow component of the aquifer. Audio-magnetotelluric (AMT) data was collected by the USGS in the vicinity of the spring in an attempt to identify the electromagnetic signature of the conduit (Fig. 6.4), and to map its probable location. Unlike induction resistivity techniques, AMT uses natural-source multi-frequency electromagnetic signals from lightning or atmospheric disturbances as an energy source. These AMT soundings consist of electric and magnetic field measurements over a range of frequencies from 10 to 100,000 Hz with fixed receiver locations. Since low-frequency signals penetrate to greater depths than high-frequency signals, measurements of the electromagnetic response at several frequencies

Or Og

Og

900

96 0

Or

Or

Og Og

Or

0 94 Mapped part of Alley Spring Cave

940

960

Or

Fo r k

0.5

0.75 1

rn

Fa u

Jac ks

lt 880

900

920

0.5

940

960

0.25

960

980

1020

980

0.125 0.25

Og

ho

Or Og

1 Miles 1.5

920

N

2 Kilometers

940 860

1000 0

0 88

860

1000

Ha

Og

0

0 90

Or

r ts

Or

Stop 6

?

Eminence 5.9 mi

Figure 6.3. Geologic map of the Alley Spring area. Dashed lines with arrows are dye traces to Alley Spring (Aley and Aley, 1987; Imes and Kleeschulte, 1995). Map units: Og—Gasconade Dolomite; Or—Roubidoux Formation. Structural contours are elevation above mean sea level drawn on base of the Roubidoux Formation. Topographic base is the Alley Spring 7.5 minute quadrangle, contour interval 20 ft.

128

Lowell et al.

contain information on the variation of resistivity at depth. Conduits should be visible in the processed AMT data as volumes of low resistivity due to water-saturated rock as well as electrical streaming potential oriented along the conduit. Advantages of AMT over most other resistivity methods are portability of equipment and depth of exploration, typically ~1 km. The AMT sensors are two ground electrodes and two magnetic coils that can be set up by one person and that require an area of ~50 × 50 m. A team of two persons can easily collect ~6–8 soundings per day. Traditional resistivity studies require line lengths 4–5 times the intended depth of investigation, limiting their use as reconnaissance tools. Although resolution is limited to discrete anomalies ~250 m wide, AMT surveys should be adequate for use in regional groundwater models. Preliminary analysis of the data from Alley Spring indicates low-resistivity anomalies which may be associated with groundwater flow through the spring conduit and along faults. AMT line P-3 clearly delineates the location of the Hartshorn Fault, a strike-slip feature identified at the surface by geologic mapping (D. Weary, USGS, unpublished data). The fault (Fig. 6.5) appears as a set of tight, vertically arranged, low-resistivity anomalies that offset broader areas of high resistivity to the northwest from area of generally low-resistivity values to the southeast. Aley and Aley (1987) recognized this fault trace as

their Alley Hollow lineament and speculated that fractures along it played a role in guiding groundwater from uplands in the northwest to Alley Spring. Data from a line of soundings orthogonal to the trends of two dye traces, collected 4.7 mi (7.5 km) WNW of the spring, show a subtle, low-resistivity anomaly that might indicate the main spring conduit or a major subsurface tributary (Fig. 6.6). The vertical chain of low-resistivity areas just to the southeast of this anomaly may also be associated with fracturing along the Hartshorn Fault. The fault is not recognizable at the surface and is mapped at reconnaissance scale in this area. It is possible that the actual fault plane is located further southeast of where it is indicated on Figure 6.6. Alternatively, the structure may be a fault zone rather than a discrete, fault plane. Figure 6.7 presents AMT data in map-view of the Alley Spring area at an elevation of 165 m (541 ft) above MSL. This is the approximate elevation of the main cave level, beneath the Gunter Sandstone, in the mapped part of the system (Fig. 6.2). This map shows a low-resistivity saddle, coinciding with the western part of the mapped cave that turns to the northwest and leads to a low-resistivity anomaly under AMT station ASP-34. If this is the location of the cave beyond the explored zone, it would require an abrupt turn in the passage. Such turns are not uncommon in caves in the Ozarks. See the map of Round Spring

ASP-12 Audio-magnetotelluric sounding station P-4 Audio-magnetotelluric profile line sinkhole Fault, bar and ball on downthrown side Dye trace, arrow indictes direction of flow Mapped part of Alley Spring cave Jacks Fork River Intermittent Stream Major road

30 0

0 00 30

ASP-40

ASP-35

Alley

M

O

ASP-36

ASP-5

300

Bran

ch

ASP-12

P-4

Forty Acre Sinkhole

ASP-34

ASP-38

ASP-4

ASP-11

ALLEY SPRING

P-3

00 300

ASP-6 ASP-10ASP-31

ASP-39

ASP-25

0

1 contour interval 100m

1 Kilometer 0

1 Mile

Jacks

Ri

ve

300

1

ASP-32

ASP-19 ASP-18 ASP-29 ASP-13 ASP-1 ASP-14 ASP-23 ASP-28 ASP-7 ASP-15 ASP-20 ASP-8 ASP-17 ASP-16 ASP-22 k ASP-26 r ASP-2 Fo ASP-21

r

MO HWY 106

ASP-27

ASP-33 ASP-30 ASP-3

ASP-9

ASP-24

300

ASP-41

200

HW

Y

D

WESTERN TRACE Ha r ts ho ASP-37 rn fau lt

Figure 6.4. Location of audio-magnetotelluric sounding stations in vicinity of Alley Spring. Northern dye trace extends 10.9 miles (17.5 km) from the northwest; southern trace extends 14 miles (22.4 km) from the west northwest. Trace of the Hartshorn Fault (U.S. Geological Survey unpublished data) approximates the Alley Hollow lineament of Aley and Aley (1987). Contours indicate 200 and 300 m (656 and 984 ft) elevations.

Area of high resistivity

Hartshorn fault

Area of low resistivity

Figure 6.5. Audio-magnetotelluric and topographic profile line P-3. 5× vertical exaggeration. See Fig. 6.4 for line and station locations. Horizontal black line marks approximate elevation (165 m) of the known cave to the east.

Area of low resistivity (conduit?)

Hartshorn fault

Figure 6.6. Audio-magnetotelluric and topographic profile line “Western Trace.” See Fig. 6.4 for line and station locations. 5× vertical exaggeration. Lower horizontal black line marks approximate elevation of the known cave to the east (165 m). Upper horizontal black line marks approximate base of Roubidoux Formation and top of the potentiometric surface based on local water well data.

Area of high resistivity

Area of high resistivity

ASP-12 Audio-magnetotelluric sounding station

Ha

r ts

ho

rn

sinkhole Fault, bar and ball on downthrown side dye trace, arrow indicates general direction of flow

fau

mapped part of Alley Spring cave

HW

Y

D

lt

M

O

Alley

Bran

ch

Forty orty ty y Ac A Acr Acre cre cr Sin S in nk kho ho e Sinkhole

Ri

ve r

MO HWY 106

1

0

rk Fo

1 Kilometer 0

1 Mile

Jacks

1

Figure 6.7. Subsurface audio-magnetotelluric apparent resistivity map of the Alley Spring and “Western Trace” areas at an elevation of 165 m above mean sea level.

130

Lowell et al.

Cavern (Fig. 5.3) for an example. Where the cave/conduit may extend beyond is, at this point, speculative. We expect it to trend generally to the west-northwest and possibly flow through the nearby low-resistivity anomalies back to the southwest to reach the Hartshorn Fault (Fig. 6.7). The size of the conduit and its associated electromagnetic signature are probably just below the functional resolution of this (AMT) method, at least at the station spacing used here. The conduit may also bifurcate upstream into a few or numerous tributaries, becoming even smaller and more difficult to resolve. Another complication is the 3-dimensional nature of the conduit. It may oscillate vertically through the strata, becoming difficult to image and visualize at the elevation used by our modeling software. A conceptual model for this karst spring system (Aley and Aley, 1987) is that rainfall in areas to the west and northwest of Alley Spring percolates down through the surface residuum and into the bedrock. This water capture is particularly effective in areas where numerous sinkholes exist in uplands underlain by the Roubidoux Formation. The latter then collapses into caves in the underlying Gasconade Dolomite (Fig. I.8). Water must then travel via conduits, several miles to the spring. The rapid connection between precipitation events and spring flow is demonstrated by the flash discharges recorded at Alley Spring (Fig. 6.8). The two dye traces to Alley Spring indicate a fast flow connection between the surface recharge and outflow from of the spring. One trace traveled 11 mi (18 km) at a velocity of 300 ft (91 m)/hr and the other traveled 14.5 mi (23 km) at 228 ft (69 m)/hr (Aley and Aley, 1987). In addition to traversing horizontally, the water has to travel downward both topographically and stratigraphically to a level below spring level and then maintain sufficient head to emerge at Alley Spring. We believe that fracturing associated with faults probably plays a major role in allowing water down through the stratigraphic stack (Fig. I.8). This involves passing, from the recharge areas, through the Roubidoux Formation, all of the Gas-

Tropical Storm Claudette

Figure 6.8. Daily discharge measured at Alley Spring for 1979, the last year the spring was routinely gauged (U.S. Geological Survey data). Tropical storm Claudette dropped record rainfall over widespread areas of the south-central United States.

conade Dolomite, and into at least the upper part of the Eminence Dolomite. The phreatic loop is completed when, at the spring rise tube, the water passes back up through the basal Gasconade and emerges to the surface 130 ft above the contact with the underlying Eminence Dolomite. The density and chemically resistant nature of the Gunter Sandstone restricts, at least locally, groundwater flow to the top of the Eminence. STOP 7. PROTEROZOIC-CAMBRIAN UNCONFORMITY: CAMBRIAN EMINENCE DOLOMITE OVERLYING MESOPROTEROZOIC RHYOLITE OF SHUT-IN MOUNTAIN Location About 8.9 mi (14.3 km) east-southeast of the town of Eminence, Missouri: SE1/4 of Section 6, T28N, R2W, Shannon County, Stegall Mountain 7.5 min quadrangle. UTM coordinates 4109501mN, 659756mE Zone 15, NAD83 Datum. Road Directions From the intersection of U.S. Highway 60 and State Route 19 in the town of Winona, Missouri, take State Route 19 to the north for about 0.8 mi (1.3 km). Turn right onto State Road NN and follow ~8.7 mi (14 km) toward the northeast. Turn right onto State Road Y and follow ~3.2 mi (5.1 km) to the northeast. Turn left onto an unnamed access road and follow toward the northwest about 0.1 mi (0.2 km) and park. Take footpath downstream along Rocky Creek a few hundred yards to the north side of the shut-in for inspection of dipping carbonate strata along the west side of Rocky Creek. The footpath is along a portion of the Current River section of the Ozark Trail, which is maintained by the Ozark Trail Association. This stop is also within the boundaries of the Ozark National Scenic Riverways, U.S. Park Service. Please observe all Park Service regulations. “Shut-in” is the local term in the Missouri Ozarks for a stream segment that flows over erosion-resistant igneous bedrock, producing waterfalls and pools in a narrow gorge. Outcrop Description Exposed along the west side of Rocky Creek at this locality are strata of the Eminence Dolomite that were deposited on the flank of a paleo-topographic high composed of Mesoproterozoic igneous rocks (Fig. 7.1). The Eminence beds here strike approximately N50°W and dip from 28° to 38° to the NE. Igneous rocks below the unconformity consist of rhyolite of Shut-in Mountain (Harrison et al., 2002); this unit is visible in the narrow shut-in and along the trail leading to the outcrop, and it will be seen again at the next stop. At this stop, as well as elsewhere around the periphery of Buzzard Mountain to the west of the shut-in (Fig. 7.1), the dip of the sedimentary strata is away from the mountain’s summit,

Southern Ozark dome forming a radial pattern (Harrison et al., 2002). As such, Eminence strata on the opposite side of Buzzard Mountain from this stop dip toward the SW at ~20°. Similar radial patterns of moderately dipping sedimentary strata peripheral to Mesoproterozoic knobs are recognized at many locations in the Current River area and St. Francois Mountains to the north, as well as in the underground mines of the Viburnum trend. The geometry of the dipping Eminence beds at this stop also provides evidence for the existence of a paleo-channel that occupied the same location as the shut-in prior to deposition of the carbonate strata. If conditions are favorable (i.e., low water level), small exposures of Eminence Dolomite can be found in the bed of Rocky Creek immediately north of the shut-in. Beds in these small exposures have a strike of approximately E-W and dips of 15° to 20° to the north. Coupled with the attitude of beds on the west bank of Rocky Creek, a partial V-shaped pattern is revealed, indicative of a paleo-valley. Discussion

+

1000

The surface upon which middle to late Cambrian and Ordovician sediments accumulated in the midcontinent of North America was highly irregular and marked with steep-sided hills and mountains with hundreds to thousands of feet of topographic relief. This surface had been created by extensive subaerial erosion during the Neoproterozoic and Early Cambrian. Bedrock was

800

Qt Qal

Og

5 25

Qt 0

70

80

38 0

80

Stop 7 +

Ysi

Ysi

900

Buzzard Mt.

12 80

0

15

0

Mill Mt. 8

composed principally of granites, silicic lavas, and welded ashflow tuffs in the Missouri Ozarks’ region. The more resistant igneous rocks typically held up the topographically higher elevations. Initially, sediments laid down on this irregular surface pinched out against the hills and mountains, which then would have been islands in the sea. As sea level rose, higher topography was progressively submerged and sedimentation ultimately blanketed all but the highest summits. The resulting stratigraphy is one of Mesoproterozoic igneous rocks protruding upward hundreds to thousands of feet into relatively flat-lying Early Paleozoic carbonate and clastic rocks. Bridge and Dake (1929) and Bridge (1930) were the first to recognize that the moderately dipping (20° to 40°) beds of sediment on the flanks of igneous knobs in the Current River area are the result of deposition on a slope related to the buried topography. They also recognized that in the vicinity of Mesoproterozoic knobs, many present-day stream valleys coincide with valleys that existed prior to deposition of Paleozoic sediments. The irregular paleo-topographic relief on the Precambrian-Paleozoic unconformity has had profound influence on groundwater flow since diagenesis, localizing Mississippi Valley type base-mental mineralization in the Late Paleozoic, as well as development of modern karst features. This influence is due to the contrast in permeability between the igneous protrusions below the unconformity and overlying sedimentary rocks and from facies changes, strata pinch outs, slumping, and dissolution. In the midcontinent region, a close relationship between the location of Mississippi Valley type deposits and buried Precambrian features has long been recognized as an ore control (Snyder and Gerdemann, 1968; Gerdemann and Gregg, 1986). Mouat and Clendenin (1975) emphasized ore location control exerted by a buried Precambrian high at the Ozark Lead Company’s Sweetwater Mine located ~20 km north-northeast of Stop 7. Paarlberg and Evans (1977) described similar ore control in the Fletcher Mine located ~15 km north of the Sweetwater deposit. Unpublished and proprietary mining company subsurface data between the Sweetwater deposit and Stop 7 indicate that there are numerous occurrences of base-metal mineralization in proximity to buried basement highs. Aspects of basement topography’s influence of modern groundwater flow and karstification will be discussed further at subsequent stops.

Qt

19 17

Og

3 + Qal

10

00

20

131

Ysi

+

1 km Figure 7.1. Geologic map of area around Stop 7. Stop 7 will visit dipping Paleozoic carbonate strata near the 38° attitude in the center of the map. Rocky Creek is the bold dashed and dotted line through the middle of the map; the Rocky Creek shut-in is located where stream flows between Buzzard and Mill Mountains. Qal—Quaternary alluvium; Qt—Quaternary terrace deposits; Og—Gasconade Dolomite; Ce—Eminence Dolomite; Ysi—rhyolite of Shut-in Mountain.

STOP 8. UNCONFORMABLE CONTACT BETWEEN UPPER AND LOWER VOLCANIC SEQUENCES OF MESOPROTEROZOIC ROCKS EXPOSED ON STEGALL AND MULE MOUNTAINS Location About 9.0 mi (14.4 km) southeast of the town of Eminence, Missouri, and ~8.3 mi (13.4 km) northeast of the town of Winona: SE1/4 of Section 24, T28N, R4W, Shannon County, Stegall Mountain 7.5 min quadrangle. UTM coordinates 4104500mN, 658324mE Zone 15, NAD83 Datum.

132

Lowell et al. and implications and regional tectonic significance of the unconformity. There are two alternate field exposures where this stop can be held, depending upon time considerations and accessibility. One is on the southern side of Mule Mountain (Fig. 8.1) and the other is on the southern and eastern sides of Little Thorny Mountain (Fig. 8.2); because of the distance required to hike into the Mule Mountain area, this stop will probably visit Little Thorny Mountain. At both sites, moderately to steeping dipping tuff of Little Thorny Mountain is overlain by subhorizontal tuff of Mule Mountain, which is overlain by outflow lava of the rhyolite of Shut-in Mountain. The contact between these first two units is an angular unconformity, the existence of which dates the rotation of the Little Thorny Mountain unit as syn-volcanic. At the stop, participants will inspect moderately to steeply dipping primary foliation in the tuff of Little Thorny Mountain, indicating that these pyroclastic flows have been rotated to moderate and/or steep dips. Participants will also see the stratigraphic sequence of the air-fall tuff (tuff of Mule Mountain) and rhyolite lava (rhyolite of Shut-in Mountain), which were deposited directly upon an intra-caldera erosional surface that developed after rotation.

Road Directions From Stop 7 turn around and follow the unnamed road back to State Road NN, turn right and follow for ~3.2 mi (5.1 km) toward the southwest. At the intersection with State Road H, bear left and follow H for ~0.5 mi (0.8 km) to the southwest. Turn left and follow County Road H-525 to the south about 0.5 mi (0.8 km), turn left onto County Road 527 and follow toward the southeast ~1.2 mi (2 km) to an intersection with the Peck Ranch Road (County Road P-159). Turn left onto the Peck Ranch Road and follow for ~1.3 mi (2.1 km) toward the east-southeast. Turn left onto the Stegall Mountain Road (County Road P-159) and follow for ~1.0 mi (1.6 km) toward the north-northeast. A small unnamed access road turns off to the left. If road is impassible, park vehicles here. Hike, or drive part way, along the road to the west-northwest ~0.6 mi (1 km) to the outcrop area. Outcrop Description This stop will focus on a Mesoproterozoic angular unconformity, stratigraphic units above and below the unconformity,

91° 12' 30" W 700 Qt

Og

19

Ysi

AM

AM

8

00

10

900

Qt

800QTr

70

00

37° 5' N

AM

Ysi

0

4 Og 21

90

QTr

Og

10

80Yltm 25

50

Ysi 1300 Mule

1200

AM

60

1100

Stegall Mt.

52

Mt.

70

Ysm

42

QTr

56

Ymm

60 45 25

1100

87

1000

AM

58 65

Stop 8

65

QTr

60

Yltm 48

Ysm 63

Qt

Ymm

AM

AM

80

1 km Figure 8.1. Geologic map of the Mule Mountain–Stegall Mountain area (simplified after Harrison et al., 2002). Ysi— rhyolite of Shut-in Mountain; Ysm—rhyolite of Stegall Mountain; Ymm—tuff of Mule Mountain; Yltm—tuff of Little Thorny Mountain; Ce—Eminence Dolomite; Og—Gasconade Dolomite; QTr—Peck Ranch unit of Harrison et al. (2002); Qt—Quaternary terrace deposits; Quaternary alluvium in stream valleys is solid white. AM—aeromagnetic lineaments. Contour interval is 100 feet. See text for description of units.

Southern Ozark dome Overview of Regional Mesoproterozoic Stratigraphy Mesoproterozoic igneous and metamorphic rocks form the basement of the Current and Eleven Point River basins in southeast Missouri (Sims, 1990). Most of these rocks are confined to the subsurface and their boundaries and relations are poorly known. However as noted at Stops 3 and 7, there is a cluster of more than 50 knobs of Mesoproterozoic rocks that protrude through the Paleozoic section and crop out at the surface in the Current River basin (Fig. 8.3). They have been referred to as the Eminence–Van Buren volcanic field by Lowell et al. (2005), Lowell and Harrison (2001), and Harrison et al. (2000) because all but two of these protrusions are composed of volcanic rocks; the two exceptions are granite outcrops, one of which will be visited at Stop 9. The volcanic knobs consist of two stratigraphic sequences. Neither sequence displays any metamorphic characteristics, implying that they have never been buried to depths of greater than a few kilometers. The lower sequence consists predominantly of caldera-forming ignimbrites and flow-dome complexes that commonly exhibit 65°–90° dips and strikes that trend predominantly NW-SE (Fig. 8.4), and minor hypabyssal intrusive domes. Lower-sequence rocks have a probable thickness of 6.4–8.0 km and a volume estimated to be ~360 km3. These lower-sequence

QTr

800

35-60

800

+

Ysi Ymm Qt

Qt

QTr

Yltm

AM

Og

Or Og

20

60 45

Alt. Stop 8 +

+

Qt

Qt 800

700

900 AM

Og

Yltm 35

0

80

Og

AM

Og

1 km Figure 8.2. Geologic map of area around Little Thorny Mountain (simplified after Harrison and others, 2002). Ysi—rhyolite of Shut-in Mountain; Ysm—rhyolite of Stegall Mountain; Ymm—tuff of Mule Mountain; Yltm—tuff of Little Thorny Mountain; Ce—Eminence Dolomite; Og—Gasconade Dolomite; Or—Roubidoux Formation; QTr—Peck Ranch unit of Harrison et al. (2002); Qt—Quaternary terrace deposits; Quaternary alluvium in stream valleys is solid white. Contour interval is 100 feet. See text for description of units.

133

rocks are overlain by an upper sequence of post-caldera collapse units that are subhorizontal. The rhyolite of Shut-in Mountain in the upper sequence has been dated by the U/Pb technique at 1470 ± 2.7 Ma (Harrison et al., 2000). This age is contemporaneous with dates for Mesoproterozoic volcanic eruptions in the St. Francois terrane reported by Lowell (2000). Accordingly, the Eminence–Van Buren volcanic rocks are considered an outlier of the St. Francois volcanic field. Lower Sequence Units Lower sequence units of the Eminence–Van Buren volcanic field are the tuff of Little Thorny Mountain (Harrison et al., 2002), rhyolite of Russell Mountain (Harrison et al., 2002), rhyolite of Storeys Creek, rhyolite of Sutton Creek (Orndorff et al., 1999), upper unit of Coot Mountain (Orndorff et al., 1999; McDowell and Harrison, 2000), and lower unit of Coot Mountain (Orndorff et al., 1999; McDowell and Harrison, 2000). The Coot Mountain units occupy the lowest stratigraphic position in the sequence but stratigraphic relations between other units are uncertain. Only the tuff of Little Thorny Mountain will be described in this guidebook; see citations above for descriptions of other units in this sequence. Tuff of Little Thorny Mountain The tuff of Little Thorny Mountain (Harrison et al., 2002) directly underlies the angular unconformity in the Stegall Mountain– Little Thorny Mountain area. It is a densely to moderately welded, crystal-rich, quartz-poor ash-flow tuff. It is estimated to be several thousand feet thick (Harrison et al., 2002) and roughly correlative to the ash-flow tuff unit of Sinha and Kisvarsanyi (1976). Microscopically, the rock is aphanophyric with alkali feldspar in the size range of 5–10 mm as the sole phenocryst (15%–20%) set in a matrix that varies from felsitic to “snowflake” type. The matrix is strongly foliated due to compaction, indicating that these rocks are welded ash-flow tuffs. Lithic fragments, spherulites, relict shard structures, and fiamme are, however, absent. The feldspar phenocrysts preserve Carlsbad twinning and are somewhat less altered to sericite or clay than other volcanic units in the area. Relict perthite is disturbed, but retained, in a few samples; this is expressed chemically by relatively high Na2O content (Table 2). The matrix contains minute dispersed grains of hematite due to devitrification which are responsible for the reddish-brown color of the rocks. Secondary hematite also replaces a Fe-Mg phenocryst phase and fills fine fractures; it may comprise as much as 5% of the rock. A trace of fluorite was observed in one sample. Table 2 presents the average of 5 analyses of the tuff of Little Thorny Mountain. SiO2 ranges from 69.16 to 74.51 wt% and K2O/Na2O varies between 3.2 and 28.8 in the sample set. Relative to other map units, the former range is somewhat wider, suggesting more intense silicification, and the latter is somewhat narrower, reflecting less intense alkali exchange alteration. The average classifies as rhyodacite by the method of Winchester and Floyd (1977) and alkali rhyolite by the IUGS method (Wohletz, 2004). One sample in our data set is anomalous in terms of low

95°

90°

o ur

St. Francois Mountains Enlarged Area

R ver

MAP LOCATION

M ss

90°

0 30 60 MISSOURI Miles

36°

40°

Ycu

Ysc

Ycl

Low Wassie

Winona

Winona

l

Ycl

Ycu

Eminence minen Ycu

Ysc

Ycl

Ysc

Ysi

Ycu

Ycu

Ycl

Ycu

Ysi

Yltm

Ysi

0

0

Ymm

Yltm Ymm

Ysi

1

Ysi

Yltm

Ysi

Yrm

4 Miles

Yltm

Ymm

Yrm

Yrm

91 7 30

5 Kilometers Fremont

2.5

2

Stegall Mountain ta an ai

Ymm

Ysm

Ysi

Ysi

Yltm

0

Yrm

Ycu

Powder Mill Ferry

Ymm

Ysi

Yltm

Yrm

Ysi

Yrm

Ycu

Yvc

5

Upper Coot Mountain unit Lower Coot Mountain unit

Ycu Ycl

Yvc ?

Van Buren ren South uth Yg

Yg

3 00 37 Big Spring

Garwood arw

MESOPROTEROZOIC

Van Buren

Ymm Unconformity Ycu ? Yltm Yrm Yscr ? Ysc Ycl

Ysi Ysm

CORRELATION OF MAP UNITS

granite

Rhyolite domes of Sutton Creek Ysc

Yg

Rhyolite of Storys Creek

Rhyolite of Russell Mountain

Tuff of Little Thorny Mountain

Tuff of Mule Mountain

Rhyolite of Stegall Mountain

Rhyolite of Shut-In Mountain

volcanic and volcaniclastic rocks

Yscr

Yrm

Yltm

Ymm

Ysm

Ysi

Yvc

Van Buren re Nor North

Yg

Elling Ellington

MESOPROTEROZOIC MAP UNITS

FAULTS

Exchange ng

Figure 8.3. Map of exposed Mesoproterozoic protrusions in the Eminence–Van Buren area of the Current River basin in southeast Missouri. The darker-shaded units in the center of the map belong to the upper volcanic sequence; all other units belong to the lower volcanic sequence or are granite exposures.

36°

40°

95°

Bartlett rtlett e

7 7 3

Ycl

Eminence

Alley A ll Yscr Spring pring ring

91 22 2 30

Southern Ozark dome

light rare earth elements (REE) and high As (139 ppm); another sample shows 11.3 ppm W.

N 6 4

8

2

Upper Sequence Units

E

W

4

135

2

6

S

Figure 8.4. Lower-hemisphere equal-area plot of poles to foliation for Mesoproterozoic lower sequence volcanic rocks of the Stegall Mountain–Little Thorny Mountain area. N = 127. Contour interval is 1%. Thick solid line represents trend of the Missouri gravity low and the dominant structural fabric in volcanic rocks of southeastern Missouri.

The upper sequence volcanic units of the Eminence–Van Buren volcanic field consists of the tuff of Mule Mountain, rhyolite of Stegall Mountain, and the rhyolite of Shut-in Mountain in that stratigraphic order (Orndorff et al., 1999; McDowell and Harrison, 2000; Harrison et al., 2002). Of these units, the Shutin Mountain unit is by far the most widespread; its oval-shaped outcrop pattern covers ~100 km2 (Fig. 8.3). Tuff of Mule Mountain The tuff of Mule Mountain is a poorly outcropping, thin, widespread, friable unit. It is, however a unit of major importance because it marks a pronounced angular unconformity between the early pyroclastic, caldera-forming stage of volcanism and the later, predominantly effusive volcanic episode. The only known exposures of this unit occur in the Stegall Mountain 7.5′ quadrangle (Harrison et al., 2002), where it occurs in an east-west– trending, linear outcrop belt ~8 km long. The tuff of Mule Mountain is correlative to the air-fall tuff unit of Sinha and Kisvarsanyi (1976). The thickness of this unit ranges from a few meters to as much as 30 m. The rock is a fine-grained dark-gray to purple, crystal-lithic– poor tuff that lacks clastic texture and well-defined sedimentary

TABLE 2. GROUP AVERAGES OF MAJOR OXIDE AND TRACE ELEMENTS IN STEGALL MOUNTAIN VOLCANIC ROCKS BY LITHOLOGIC UNIT SiO2 TiO2 Al2O3 Fe2O3 MgO MnO CaO Na2O K2O P2O5 LOI Total Ymm (n=1) 74.07 0.18 10.81 2.53 0.02 0.03 0.02 0.16 9.61 0.84 0.55 98.82 Yltm (n=5) 72.64 0.32 11.57 3.90 0.06 0.03 0.11 1.02 8.28 0.10 0.63 98.65 Ysm (n=4) 74.70 0.19 11.49 2.56 0.05 0.02 0.07 0.74 8.63 0.02 1.45 99.90 Ysi (n=21) 75.07 0.19 11.35 2.54 0.07 0.02 0.06 0.84 8.21 0.09 0.96 99.39 Ymm (n=1) Yltm (n=5) Ysm (n=4) Ysi (n=21)

La 46.0 35.5 22.7 38.5

Ce 84.8 80.9 57.5 75.8

Ymm (n=1) Yltm (n=5) Ysm (n=4) Ysi (n=21)

V 0 20 0 2

Ga 7 47 13 13

Ymm (n=1) Yltm (n=5) Ysm (n=4) Ysi (n=21)

Th 9.8 11.6 12.7 11.9

U 1.8 3.3 3.3 3.1

Pr 12.07 9.42 6.76 9.68

Nd 48.2 40.6 28.2 38.8

Sm 9.0 9.9 5.9 7.9

Rb 324 113 293 307

Cs 3.3 23.4 5.0 5.9

Ba 1741 585 1084 1807

F 100 262 405 286

Cu 0.0 0.0 5.3 0.0

Be 0.0 1.8 0.5 1.0

Eu 0.89 1.25 0.69 0.92 Sr 17 6 25 26 Ge 1.0 1.8 0.8 1.0

Gd 8.2 9.6 5.9 7.5

Tb 1.3 1.7 1.1 1.3

Dy 7.4 9.7 6.6 7.5

Ho 1.5 2.0 1.5 1.5

Er 5.0 6.3 4.8 5.1

Tm 0.81 0.96 0.77 0.81

Yb 5.4 6.2 5.4 5.5

As 87 33 19 72

Sb 12 5 7 8

Tl 1 5 2 1

Bi 0 1 0 0

Sn 1 4 4 4

W 4 2 3 3

Mo 2 4 3 3

Cr 292 128 210 418

Ni 45 20 33 17

Co 2 2 2 1

Sc 3 1 2 6

Ag 0.0 0.1 0.1 0.2

Pb 5.0 27.4 16.2 0.2

Zn 22.0 36.4 29.2 0.2

Lu 0.87 0.98 0.94 0.90

Ta Nb Hf Zr Y Nb/Hf Zr/Nb Zr/Hf Sc/Nb Ce/Nb Yb/Ta Y/Nb Rb/Sr Ymm (n=1) 0.78 11.10 8.1 278.0 49.0 1.37 25.04 34.32 0.27 7.64 6.92 4.41 19.06 Yltm (n=5) 0.85 12.52 9.0 313.0 62.0 1.38 25.00 34.57 0.61 6.43 7.33 4.93 9.15 Ysm (n=4) 0.82 11.81 8.6 295.5 55.5 1.24 26.57 32.96 0.61 5.44 6.76 4.55 12.79 Ysi (n=21) 0.80 10.80 8.2 269.3 50.3 1.33 24.84 33.04 0.51 7.06 6.58 4.61 14.58 Note: Ymm—tuff of Mule Mountain; Yltm—rhyolite of Little Thorney Mountain; Ysm—Stegall Mountain rhyolite; Ysi—Shut-in Mountain rhyolite. Major elements in wt%, trace elements in ppm.

136

Lowell et al.

fabric. The devitrified matrix commonly displays vapor-phase silicification and fabrics that may be variously dominated by shard forms, accretionary lapilli, felsitic texture, or spherulites. Secondary Fe is generally present as opaque blebs and patches of hematite comprising <1 modal %. In shard-dominated fabrics, relic shard outlines display cuspate to contorted shapes that define a weak compaction foliation. This shard fabric encloses lenticular domains of coarse vapor-phase crystals oriented parallel to the foliation. This facies lacks spherulites, pumice, and accretionary lapilli and carries 1%–2% feldspar crystals up to 3 mm that are altered to clay; trace amounts of opaque granules are present. The rock is cut by numerous discordant quartz veinlets and appears to be an unwelded, moderately compacted, air-fall facies. A second facies of the tuff of Mule Mountain is characterized by the presence of 1%–5% accretionary lapilli set in a very fine-grained (0.01 mm) felsitic matrix cut by numerous quartz veinlets. Complete lapilli range up to 5 mm in diameter (Fig. 8.5A) and exhibit classic concentric structure defined by finegrained (<0.04 mm) rims enclosing an interior of contorted shards ~0.4 mm in size. No nucleating particle was noted in the sphere centers but most lapilli are fragments of spheres in which the center is not present. Many of these fragments are preserved in unstable orientations (Fig. 8.5B) that preclude impact fracture and require aerial fragmentation and rapid burial. Fragmentation of lapilli may be the result of aerial shock waves. This facies is very

Figure 8.5. Accretionary lapilli in tuff of Mule Mountain. (A) Complete lapillus 5 mm in diameter. (B) lapilli fragments buried in unstable position. Depositional surface is from SW to NE corner in photograph B. Photos by G. Lowell, 2005.

poor in crystal content (<1%), but does contain quartz, altered feldspar, and a minute trace of opaque granules. No pumice, lithics, or spherulites are present and there is only weak development of stratification. This facies also records air-fall deposition. A third variety of the tuff of Mule Mountain exhibits felsitic texture consisting of intergrown quartz and alkali feldspar grains 0.10–0.15 mm in size. No shard structure, accretionary lapilli, lithics, or spherulites are present, but it does contain ~1% of angular pumice lapilli ranging up to 3.2 mm in size. Evidence of sorting and stratification are absent in this variant, again suggesting air-fall origin. The spherulitic fabrics are composed of spherulites (60%) 0.4–0.5 mm in diameter, lenticular domains of vapor-phase quartz (30%), and spherical lithophysae (10%). The spherulites are radial intergrowths of quartz and acicular alkali feldspar and, in some cases, are nucleated on microphenocrysts. Lenticules of anhedral quartz range up to 4 mm in length and indicate the initial porous nature of the rock. Lithophysae, ~2 mm in diameter, are lined by acicular alkali feldspar and filled with anhedral quartz. Microphenocrysts amount to ~1%–2% of this rock and include abraded quartz, lath-shaped clay pseudomorphs after alkali feldspar, and a relict mafic mineral that is extensively replaced by opaque phases. Table 2 presents chemical data for one sample of the tuff of Mule Mountain. Rhyolite of Stegall Mountain The rhyolite of Stegall Mountain was named by Harrison et al. (2002) for exposures on the south side of Stegall Mountain in secs. 19 and 20, T. 28 N., R. 2 W. This unit was interpreted by Harrison et al. (2002) as a variation of the rhyolite of Shutin Mountain. It differs from Shut-in Mountain in that it has less quartz and a lesser phenocryst content; otherwise it is identical and is interpreted as a genetically related unit. It is as much as 60 m thick. Where it has been mapped (Harrison et al., 2002), it directly overlies the tuff of Mule Mountain. This unit combined with the rhyolite of Shut-in Mountain is correlative to the rhyolite porphyry unit of Sinha and Kisvarsanyi (1976). The Stegall Mountain unit is a pinkish-brown aphanophyric rock with contorted flow-banding that lacks compaction foliation, shard structure, lithic and pumice fragments, and stratification. It is characterized by 12% phenocrysts of alkali feldspar and quartz set in a matrix (88%) of spherulitic domains and cavities ~4 mm diameter. The latter are filled by euhedral vapor-phase crystals (0.4 mm) of quartz, alkali feldspar, and fluorite. Alkali feldspar is the principal phenocryst (10%) and forms grains of Baveno habit in the size range of 0.4–2.0 mm. These grains are extremely altered but relict Carlsbad twinning and perthitic exsolution of the “herringbone” type are present; the exsolved sodic phase is totally replaced by sericite and clay. Feldspars show evidence of intense resorption followed by euhedral growth prior to eruption as well as a tendency to form glomerocrysts. Quartz phenocrysts (2%) are sparse and small (0.4–0.5 mm) and exhibit a slightly rounded, euhedral to subhedral habit. The sole accessory phase is zircon and it is very minor.

Southern Ozark dome Table 2 presents whole rock chemistry for the average of 4 samples of the Stegall Mountain unit. The SiO2 range is 75.76– 73.75 wt% and the K2O/Na2O ratio ranges between 11.7 and 45.7 in the data set. The average rock composition is alkali rhyolite by the IUGS (Wohletz, 2004) classification and rhyolite by Winchester and Floyd (1977) system. The average trace element ratios Nb/Hf, Zr/Nb, Zr/Hf, and Zr/Y for Stegall Mountain rhyolite approximate those of the Russell Mountain map unit located in northeastern Stegall Mountain quadrangle. The outcrop distribution for these two map units forms an annular pattern around the Shut-in Mountain lava sequence that could indicate emplacement controlled by a ring-fracture zone. The only anomalous trace element in the Stegall Mountain data is Pb = 386 ppm in one sample; this is the highest Pb-value among the 110 rocks we have analyzed. Rhyolite of Shut-in Mountain The uppermost unit in the post-caldera volcanic sequence is the rhyolite of Shut-in Mountain (Orndorff et al., 1999; McDowell and Harrison, 2000; Harrison et al., 2002). It consists of coalesced quartz-bearing lava flows and domes. Together with the underlying rhyolite of Stegall Mountain, outflow lavas have a thickness in excess of 300 m. U/Pb analysis of five single-crystal zircon fractions from the Shut-In Mountain rhyolite yields an age of 1470.4 ± 2.7 Ma (Harrison et al., 2000). These lavas are typically massive and display autobrecciated basal zones. Flow structures are generally absent or poorly developed but, where present, produce impressive contorted outcrops interpreted as flow fronts. Localized areas of brecciation containing inclusions of foreign volcanic fragments are interpreted as probable vent sites. The Shut-in Mountain lavas typically exhibit ~20%–25% phenocrysts consisting of alkali feldspar (15%), quartz (5%), and a Fe-Mg silicate phase (3%) that is altered to opaque material. Pods of fluorite are commonly visible in hand specimen. Zircon is present as a minor accessory phase and a trace of secondary pyrite is sometimes present. The feldspar is intensely altered to brown clay but in some cases preserves relict Carlsbad twins and disturbed perthite patches. The high crystal content of these younger lavas suggests lower eruption temperatures than earlier crystal-poor units but probably still above the 830 °C minimum for A-type melts (Clemens et al., 1986). The phenocrysts are set in a matrix of polygonal spherulitic domains arranged in a closepacked mosaic structure. The domains contain numerous opaque granules disseminated between radially arranged fibrous crystallites; often a small crystalline nucleus is present at the spherulite center. These spherulites appear to be products of devitrification. Other radial-arrangements of fibrous crystallites occur on the surfaces of alkali feldspar phenocrysts and may record rapid meltgrowth due to undercooling. No relict shard structures, fiamme, or eutaxitic fabric have been recognized in Shut-in Mountain rocks. Table 2 presents the average of 21 analyses of the Shut-in Mountain lava sequence which show SiO2 values between 72.19 and 78.12 wt% and an extreme range of K2O/Na2O ratios from 2.3 to 65.4. The average composition is alkali rhyolite by the IUGS scheme (Wohletz, 2004) and rhyolite in the Winchester

137

and Floyd (1977) classification. Inter-element correlation analysis indicates that SiO2 has no meaningful positive correlation with other major elements and a strong inverse correlation exists between Na and K. A high K-Rb correlation (+0.97) in the rhyolite of Shut-in Mountain indicates that Rb was involved in the subsolidus reactions. The Rb/Sr ratio in the complete data set for this unit ranges from 4.24 to 32.89 and is a better indicator of the alteration history of these rocks than any pristine trait. The only significant positive correlation within the major element group is for the pair TiO2-Fe2O3 (+0.74) and this is probably a primary igneous trait. Meaningful positive correlations among the trace elements that may be related to mineralization events include Ba-Pb (+0.70) and As-Sb (+0.81). Ba shows moderate to strongly positive correlations with the group Pb, As, Sb, Tl. One sample of the rhyolite of Shut-in Mountain (PM 244) shows the second highest Ba content (4751 ppm) in our entire data set. This rock, collected near the SW corner of the Powder Mill Ferry quadrangle (McDowell and Harrison, 2000), contains numerous cavities (0.5 mm in diameter) in alkali feldspar phenocrysts. These cavities are lined with purple fluorite and filled by colorless fluorite and lesser amounts of barite. Calculations based on rock density of 2.67 g/cm3 indicate that the analyzed values of Ba = 4751 ppm and F = 1592 ppm equate to ~0.48 and 0.27 modal % of barite and fluorite respectively, if Ba and F are restricted to these phases. Since petrographic observations suggest that barite is less abundant than fluorite it follows that 50%–75% of the Ba must be in secondary phases other than barite or there is cryptic barite hidden in matrix constituents. Another sample of this unit (Ysi 9) shows an anomalously high value of 1.27 wt% P2O5 and 0.00 wt% CaO. Apatite is clearly ruled out as host for the P2O5 as are xenotime and monazite by low values of Y, light REE, and Th in this sample. The relatively high Ba content (1515 ppm) suggests the possibility of the Ba-Sr phosphate mineral gorceixite but this has not been confirmed. Gorceixite, barite, and fluorite, were reported in breccia cement in the Silvermine greisen deposits of the St. Francois Mountains (Taylor et al., 1984). Discussion of Geochemistry An extensive discussion of the whole-rock chemistry is not possible here but Table 2 shows the major and trace element chemistry of the group averages of the volcanic rocks on Stegall Mountain. Data within each individual rock unit is fairly constant with a few exceptions due to alteration. The group averages in Table 2 are, however, remarkably uniform in terms of major and trace element abundance. This is most surprising in the case of the tuff of Mule Mountain because of its air-fall origin and presumed high initial porosity. The trace-element signature of all of these rocks places them in the “within plate” granitoid field of Pearce et al. (1984) which is equivalent to the anorogenic granitoid (“A-type”) designation defined by Loiselle and Wones (1979) and described by White and Chappell (1983). Because of relatively constant incompatible element ratios in Table 2 (e.g., Y/Nb or Yb/Ta), there can be little doubt that all of

138

Lowell et al.

these Mesoproterozoic rock units share a common origin. They also exhibit parallel chondrite-normalized REE patterns with very little spread between the group averages as demonstrated in Figure 8.6 for the Stegall Mountain volcanic sequence. The REE patterns for the lower and upper Coot Mountain units have not been included in this diagram but fall within the cluster of the averages shown in Figure 8.6. REE data for the Big Springs granite is given under Stop 9. In all of these rock units, the light REE show a moderate negative slope beginning at La values of ~100× chondrite values followed by a well-defined moderately negative Eu anomaly and nearly constant heavy REE concentrations of ~25× chondrite values. Our complete REE data set does include some anomalous samples with high Ge and Ga that present REE patterns that differ significantly from those in Figure 8.6. These are interpreted by Lowell and Harrison (2009) as products of acidic, oxidizing hot-spring activity. Eby (1990) has reviewed the chemical characteristics of A-type granitoids and demonstrated the significance of the Y/Nb and Yb/Ta ratios in assessing the origin of such rocks. The high Y/Nb and Yb/Ta ratios shown in Table 2 can be taken as an indication that the origin of rocks of the Eminence–Van Buren volcanic field record crustal melting combined with significant contamination by MORB-like basalts. Discussion of Caldera-Forming Processes, Syn-Volcanic Tectonics, and Implications for Interpreting the Missouri Gravity Low Why is recognition of the angular unconformity visited at this stop important? The answer is that the unconformity dates the rotation of lower volcanic sequence rocks in the Eminence caldera as syn-volcanic and therefore part of the caldera-forming process and controlling tectonics active in the Mesoproterozoic. The predominant northwest strike of rotated beds (Fig. 8.4) is aligned with the pronounced Precambrian basement structural fabric in the midcontinent region (Kisvarsanyi and Kisvarsanyi,

1976; Kisvarsanyi, 1981) and to major linear trends in both gravity data (the Missouri gravity low of Guinness et al., 1982; Arvidson et al., 1984; Hildenbrand and Hendricks, 1995; Hildenbrand et al., 1996) and magnetic data (Kisvarsanyi, 1984). This implies that a northwest-trending basement structural fabric was in place at ~1.47 Ga and influential on both the source of the Missouri gravity low and caldera development. Missouri Gravity Low The Missouri gravity low (MGL; Fig. 8.7) is a prominent, 50–60-mile-wide gravity low that extends for a distance of over 400 miles in a northwest-southeast direction from the Midcontinent rift system to the Reelfoot rift (Arvidson et al., 1984; Hildenbrand et al., 1996). Its great extent and prominent geophysical signature (local amplitudes range from 19 to 44 mGal) make the basement source of the MGL a major intracratonic geologic structure (Hildenbrand et al., 1996). Based on study of Nd isotopic data, Bowring et al. (1988) interpreted the MGL as representing the boundary between two lithospheric sections. The intersection of the MGL with the Reelfoot rift coincides with the area of intense earthquake activity of the New Madrid seismic zone. The source of the MGL is controversial. Guinness et al. (1982) named the feature and, based on analysis of gravity, magnetic, topographic, geologic, and remote sensing data, concluded that the MGL expresses a Precambrian failed rift. Kane and Godson (1989) identified the source of the MGL as relatively shallow in Earth’s crust and placed a maximum depth to its center at ~10 km. Further, Kane and Godson (1989) postulated that the MGL possibly reflects a Precambrian batholith of felsic igneous rocks associated with a subduction-related magmatic arc. In a synthesis of the regional geophysical setting of the Reelfoot rift and New Madrid seismic zone, Hildenbrand and Hendricks (1995) interpreted the MGL as a series of batholiths of unspecified ages in the upper crust. Hildenbrand et al. (1996) used quantitative methods to investigate the overall lateral extent of the MGL, to model the shape of its low-density source, and to interpret its origin.

Figure 8.6. Chondrite-normalized rare earth element diagram for Stegall Mountain sequence. Normalization factors from Anders and Grevesse (1989).

- 6 000

4,000

0

e iev ev

0

e

,00

te Y1vg ct on ic

eld zo n

0

e

-C

G

fau

lt z on

e

L G M

e

e

lt z on

SM

0

n zo

Y2mg

-1

St. Franco St Francois s terrane 1 47 & 1.37 1.47 1 37 Ga magmatism

0

Y1vg Y vg

fau

0

n zo

liv te ar-M cto a nic ns fi

ILLINO S ILLINOIS 38˚ N

Granite Eastern GraniteRhyolite Province

Bo

00

M

2,

GL

Eastern Eas e n Granite GraniteRhyo ite Province Rhyolite

en

G e.

X3m

rocks

i

X3m

St

Riv er ic ton

1.6 - 1.8 .8 Ga

00

0

Central Plains Pla ns

ur Misso

metamorphic

3

tec

Southern

0

ra l

00

nt

d an Gr

-1

Ce

Mississippi embayment 36.5˚ N

Southern Granite-Rhyolite 2,000 Province 1.37 Ga plutonism 92˚ W

Ys Y2mg Y1vg

lfo

ot

ARKANSAS

e Re

TENNESSEE

- 4,000

100 km

Clastic sedimentary rock; presumably of Mesoproterozoic age Mesozonal granite; Southern Granite-Rhyolite Province; ~ 1.37 Ga Epizonal granite & silicic volcanics, undivided; Eastern Granite-Rhyolite Province, ~ 1.47 Ga

XYgb

Gabbro

X3m

Metamorphic rocks, undivided; Southern Central Plains orogen; ~1.6-1.8 Ga

t rif

90˚ W

Coastal Plain sediments of Mississippi embayment; Cretaceous and Cenozoic Location of well to basement

Structural contours on top of Precambrian basement; in feet

Figure 8.7. Geologic map of basement rocks in southeastern Missouri and surrounding areas. Modified from Sims (1990). Black star marks the Eminence caldera.

140

Lowell et al.

They concluded that the source of the MGL is an upper crustal batholith, the Missouri batholith, which extends from the Midcontinent rift system to the Reelfoot rift. Further, Hildenbrand et al. (1996) proposed a tectonic model that relates the origin of the MGL to hotspot activity in the Late Proterozoic, at ~1300 Ma. In contrast, Darnell et al. (1995) concluded that the MGL represents a steep-sided graben of Mesoproterozoic age; they based their interpretation on density distribution models of the upper crust around the southeastern terminus of the MGL. Our observations indicate that the volcanic rocks were rotated around axes parallel to the trend of the MGL in the Current River basin by caldera collapse. Harrison et al. (2000, 2002) conclude that: (1) both the source of the MGL and caldera collapse were controlled by a preexisting structural fabric; and (2) the age of the MGL source is, at least in part, ~1470 Ma. Coincident with the boundaries of the anomalous MGL are two northwest-trending linear magnetic anomalies (Zietz, 1982; Committee for the Magnetic Anomaly Map of North America, 1993) that extend from the Reelfoot rift across Missouri and into Kansas and Nebraska and are considered major geophysical features in the crust of the midcontinent (Bickford et al., 1986). Kisvarsanyi (1984) named these two bounding anomalies the Grand River tectonic zone and the Central Missouri tectonic zone; both intersect the upper Current and Eleven Point River basins (Fig. 8.7). On his Precambrian basement map, Sims (1990) juxtaposes rocks of different lithologies across the Central Missouri tectonic zone and classifies rocks to the southwest as dominantly mesozonal granites with an inferred age of ~1380 Ma and rocks to the northeast as dominantly epizonal granites and volcanic rocks of the St. Francois terrane, which were considered to be ~1480 Ma. Based on additional age dates (Van Schmus et al., 1996; Harrison et al., 2000; Lowell et al., 2005), it is now known that development of the St. Francois terrane in southeast Missouri involved at least two, and perhaps three, datable igneous events: (1) an older bimodal (granite/rhyolite-basalt) suite yielding ages of 1470 ± 30 Ma; (2) a granitic suite ~100 Ma younger than (1) represented by minor surface exposures of the Graniteville and Munger granites that record ages near 1370 ± 30 Ma (Van Schmus et al., 1996); and (3) the Skrainka basaltic suite ~1300 Ma (Lowell and Ramo, 1999). Kisvarsanyi (1988) used drill and geophysical data to show that the subsurface distribution of “Graniteville-type” plutons in the subsurface is quite extensive (14 individual plutons) although their younger age status was unknown at that time. It is important to note that no volcanic rocks have been identified as belonging to the second igneous event, suggesting that there were no associated surface eruptions of magma. The older suite is part of Van Schmus et al.’s (1996) eastern granite-rhyolite province and consists of both volcanic and plutonic rocks; the younger suite is part of their southern granite-rhyolite province and consists of only plutonic rocks, if Skrainka basalt emplacement is considered a younger event. Kisvarsanyi’s (1984) Central Missouri tectonic zone appears to be the southwestern boundary of 1.47 Ga St. Francois magmatism. This indicates that the Central Missouri tectonic zone is a major crustal boundary.

Several aspects of the geology discussed above suggest that the MGL is inherently a tectonic feature and not related to a mantle plume. (1) Termini of the MGL are geologic structures (i.e., the Mid-Continent Rift, ≈1.1 Ga, on the northwest and the Reelfoot Rift, ≈0.6 Ga, on the southeast); (2) the margins of the MGL are tectonic zones; and (3) the rotational axis of volcanic rocks is parallel to the trend of the MGL (Fig. 8.8). The later statement points to control by a preexisting structural fabric (Fig. 8.8). The 1470 Ma and 1370 Ma igneous suites are intermixed within the MGL (Van Schmus et al., 1996) suggesting that tectonics influenced magmatism for a period of ~100 Ma. Lowell et al. (2005) discuss the implications of the riftmargin setting of the Eminence–Van Buren volcanic field and concluded that left-lateral strike-slip faulting across the MGL tapped syntectonic magma leading to intra-rift volcanic events. They attributed the localization of the Eminence caldera to a releasing bend or transtensional pull-apart structure along a left step in the left-lateral system. This is consistent with mapped structures of Mesoproterozoic age found in the Eminence–Van Buren volcanic field (Harrison et al., 2002; McDowell and Harrison, 2000; Orndorff et al., 1999). Eminence Caldera The oldest Mesoproterozoic faulting observed in the basement rocks of the Current River drainage basin is related to collapse of the Eminence caldera (Kisvarsanyi, 1981; Harrison et al., 2000). Based on geological, geophysical, and geochemical considerations, Harrison et al. (2000) and Lowell et al. (2005) argue that the Eminence caldera developed in a transtensional setting as a result of a left step in a northwest-trending left-lateral, strike-slip zone. This volcano-tectonic setting is similar to the transtensional rift system proposed by Darnell et al. (1995) to explain the MGL anomaly. We disagree with the classical pistonlike caldera collapse model described by Kisvarsanyi (1981) and Kisvarsanyi and Kisvarsanyi (1990) because it does not explain the strong rotation of caldera-fill rocks or the extreme heterogeneity of caldera-fill rocks; also it does not fit the syn-volcanic style of deformation that has been determined for the midcontinent during the Mesoproterozoic (Lowell et al., 1977; Diehl et al., 1995; Lowell et al., 1995; Lowell and Clendenin, 2003; Harrison et al., 2003); these works record left-lateral ductile deformation in the 1470 Ma suite of volcanic rocks along the northwest-striking Black and Ironton faults in the nearby St. Francois Mountains. They argue that ductile deformation in the volcanic rocks implies elevated geothermal conditions related to regional

Figure 8.8. (A) Geologic map of Precambrian basement beneath the Upper Current River drainage basin. Basement lithology references in (B). Faults from unpublished U.S. Geological Survey data, magnetic anomalies from unpublished map of Tom Hildenbrand (USGS, Menlo Park). (B) Legend for basement geologic map of the Upper Current River drainage basin. MGL—Missouri gravity low.

92˚ 00’ 37˚ 30’

45’

30’

15’

91˚00’ v

Y1v

v v v v

v

Y1g

Y1v

v

90˚ 52.5’

v

v v

v v

g

mafic-intermediate ring- racture dikes

v

g

g

g

Y2g

g g

g w dd

a 5M

g

g

ou

so

v v

cgl

cgl v gp cgl gp gp gp cgl cgl v cg

ic

zo n

Y1v

ut he rn

37˚

v

v

v

bo un da ry

v

1,3

gp

23

g

ar

v v

09

v

g v

g

v

mylonized g gp

g

g

g

g g g

g

g

g g

v

g

g Y2g Y Y2 2g 2 g Y1g g

g

g

g

g

v

gp

gp

p

qsp

v gp

ag

1

g

v

v

v

±6

qsp

g p

1,473 ± 12Ma 1 1,470 470 4 47 7 70 0 ± 6Ma 6M 6 Ma M a

m

GL

p

v v v

gp

Ma

lin e of M

v

gp

v

v v

e

magnetic c high

v

gp v gp v gp gp gp

on

p

d gp v v d gp gp

2.7Ma

iss

ct

d g

p

M

te

gp gp gp gp gp p p gp gp v gp dd d gp gp gp cgl gp gp cgl gp gp gp

gp g gp gp gp gp

ri

g gp

gp

1,470 ±

15’

d

1

nt

ra l

g

1 g

1,480 ± 42Ma

Ce

3± ,47

g

g

v v

low

v

v v

mag llow

v v

v g

mafic

Y1v v

v v

mag low

YX gabbro

v

mag low

v

v

MO S

45’ g

no deep drill data to basement mag low

lin

magnetic high

r

g

mag high

low

mag high g

36˚ 30’

ea

ma

mag low

SCA E 1 00 00 1

0 1

1 0

3

2 1

2

3

5

4 4

5

6

7

6 8

7 9

8ML S

1 K L ME E S

1,376 ± 4Ma Drill hole to basement with age determination

Trend of foliation in volcanic rocks

Lineament from magnetic anolomy map Fault mapped at surface Wilderness-Handy fault zone Outline of Eminence caldera Major rivers or streams in Upper Current River Basin

~1.37 Ga Igneous Suite, all plutonic

~1.47 Ga Igneous Suite,

Y2g

Graniteville-type (tin) granite of Kisvarsanyi (1981)

Yv

mag low

Magnetic lows, both those associated Y2g granites and others interpreted as having a similar aeromagnetic signature consistent with analyses of Cordell and Knepper (1987)

Y1g

Y2mg province of Sims (1990): mesozonal granite; mapped as Xm (Paleoproterozoic schist, gneiss, and anphibolites in westerly contiguous area, Kisvarsanyi, 1987); limited drill data indicates that a boundary between these 2 units exists near the western edge of map area

Volcanic rocks, all age dates are ~1.47 Ga; based on outcrops, drill data, and intrepreted from aeromagnetic data Granite of Sim’s (1990) Yig province and Kisvarsanyi’s (1981) Silvermine-Slabtown-type granite; based on outcrops, drill data, and interpreted from areomagnetic data Granite porphyry; interpreted as ring dike of Eminence caldera by Kisvarsanyi and Kisvarsanyi (1990); pattern shown is modified from Kisvarsanyi and Kisvarsanyi (1990) based on drill data; outer boundary is considered the margin of Eminence caldera Mafic-intermediate intrusives of Kisvarsanyi (1981)

Unit of uncertain age Volcaniclastic conglomerate; Unit could be of Mesoproterozoic, Neoproterozoic, or Early Paleozoic age

Area of no subsurface drill data

YX gabbro

Gabbro unit of Sims (1990);analyses of Van Schmus and others (1996) indicate a date of 1.47 ± .063 Ga and that magma source was Mesoproterozoic depleted juenile crust (juvenile subcontinental lithosphere?) Magnetic high similar to YX grabbro unit of Sims (1990)

142

Lowell et al.

magmatism (Lowell et al., 1995; Diehl et al., 1995; Harrison et al., 2000; Lowell and Clendenin, 2003). We envision caldera collapse as having been incremental and the result of multiple event ring-fracture eruptions from shifting eruptive loci at ~1470 ± 30 Ma (Lowell, 2000; Harrison et al., 2000; Harrison et al., 2002). Collapse of the Eminence caldera was controlled by a transtensional setting along a preexisting northwest-trending tectonic fabric in upper crustal rocks in southeastern Missouri. The genetic link between magma emplacement and dilational step-overs in strike-slip faulting has long been established (Hutton, 1990; Schmidt et al., 1990; Glazner, 1991; Tikoff and Teyssier, 1991; Román-Berdiel et al., 2006). We envision magma ascent and volcanism to have been localized in areas of tension located at the initiation point of step over and along vertical highrelief accommodation zones aligned with the axis of compression. Petrographic observations (Lowell and Clendenin, 2003) indicate that foliation-parallel ductile shear occurred during cooling of the lower volcanic sequence. We interpret this shear as syn-rotational and contemporaneous with collapse of the volcanic pile into the Eminence caldera. Magnetic data and geologic maps of the basement and bedrock surface show that the southwestern margin of the Eminence caldera coincides with prominent linear geophysical anomalies (Fig. 8.8). This spatial coincidence of the southwestern boundary of the MGL, the Central Missouri tectonic zone, a caldera boundary, and mapped faults in Paleozoic rocks suggests an intimate interplay between volcanic and tectonic events with preexisting basement structures in the Current River and Eleven Point River Basins.

and follow for ~3.4 mi (5.5 km) to the east. At this point the Peck Ranch Road bends to the south. Turn left (north), just past a parking lot for the Ozark Trail onto a service road. The road may be gated; access can be requested from the Missouri Department of Conservation. Follow service road ~2 mi (3.2 km) to the northeast, the road will turn to the southeast at this point. Continue for about 0.5 mi (0.8 km) to the southeast. Stay left at the fork in the road here, continue for about 0.1 mi (0.16 km) and find a place to pull off of the road. Hike up the hillside to the north, gaining ~140 ft (43 m) in elevation to see outcrops of the rhyolite of Little Thorny Mountain below and tuff of Mule Mountain and then rhyolite of Shut-in Mountain above. This hike requires crossing the Peck Ranch Conservation Area boundary fence; look for a break or place to slide under.

ALTERNATE STOP 8. UNCONFORMABLE CONTACT BETWEEN UPPER AND LOWER VOLCANIC SEQUENCES OF MESOPROTEROZOIC ROCKS EXPOSED ON LITTLE THORNY MOUNTAIN

Road Directions

Location About 12.2 mi (19.6 km) southeast of the town of Van Buren, Missouri, and ~11 mi (17.7 km) northeast of the town of Winona: SW 1/4 of Section 22, T28N, R2W, Carter County, Stegall Mountain 7.5 min quadrangle. UTM coordinates 4104531mN, 663874mE Zone 15, NAD83 Datum. Road Directions From Stop 7, turn around and follow the unnamed road back to State Road Y, turn right and follow for ~3.2 mi (5.1 km) toward the southwest. At the intersection with State Road H, bear left and follow H for about 0.5 mi (0.8 km) to the southwest. Turn left and follow County Road H-525 to the south about 0.5 mi (0.8 km), turn left onto County Road 527 and follow toward the southeast ~1.2 mi (2 km) to an intersection with the Peck Ranch Road (County Road P-159). Turn left onto the Peck Ranch Road

Site Description This stop is located within the Peck Ranch Conservation Area, a large area (23,048 acres) administered by the Missouri department of Conservation for camping, hunting, hiking, and conservation of natural areas. STOP 9. BIG SPRING GRANITE QUARRY Location About 2.6 mi (4.2 km) southeast of the town of Van Buren, Missouri: SW 1/4 of Section 29, T27N, R2W, Carter County, Big Spring 7.5 min quadrangle. UTM coordinates 4093605N, 680064E Zone 15, NAD83 Datum.

From Stop 8 return to the Stegall Mountain Road (County Road P-159) and follow for ~1 mi (1.6 km) toward the southsouthwest. Turn left onto the Peck Ranch Road (County Road P-159) and follow for ~3.4 mi (5.5 km) to the east. At this point the road turns to the south. Continue another 0.8 mi (1.3 km) south then turn to the right (west) onto County Road P-159 follow it ~2 mi (3.2 km) to the west. From Alternate Stop 8 return to the Peck Ranch Road via the service road, ~3.3 mi (5.3 km) to the northwest and then southwest. Continue south on the Peck Ranch Road for about another 0.8 mi (1.3 km) then turn to the right (west) onto County Road P-159. Continue on ~6.6 mi (10.6 km) total from the turn onto P-159 (road becomes paved) to the intersection with State Road P. Bear to the right onto P toward the south and follow ~2.7 mi (4.3 km) to the south and southsouthwest to an intersection with U.S. Highway 60. Turn left onto Highway 60 and follow ~12.5 mi (20 km) to the east. As of this writing Highway 60 is being realigned, so this mileage may be a little off. Just after crossing the Current River Bridge on Highway 60, turn left onto James Street and into the town of Van Buren. After one block, turn left again onto Sycamore Street. Go three blocks and turn left again onto William Street. Go one

Southern Ozark dome block and turn right onto Brown Road which will lead under Highway 60 and toward the southeast. Follow Brown Road ~3.8 mi (6.1 km) toward the east and then south to the field trip stop. Outcrops of reddish and gray granite will become visible to the left of the road and the road itself will become rough with angular granite cobbles in the roadbed. Find a wide spot along the road to pull vehicles off. Site Description The Big Spring granite is a Mesoproterozoic outlier enclosed by Paleozoic strata (Fig. 9.1). It is the southernmost granite exposure in the state. This granite produced a U/Pb zircon age of 1461.8 ± 5.5 Ma (Harrison et al., 2000) which is slightly younger than the volcanic rocks exposed in the Current River basin as well as elsewhere in the St. Francois terrane. Outcrop and Petrographic Description The Big Spring Granite is medium-grained red granite with textures that include equigranular, seriate, and semigraphic.

143

Clots of amphibole are set in a semi-graphic intergrowth of quartz and alkali feldspar producing a glomerophyric aspect to the rock. The alkali feldspar exhibits Carlsbad twinning and minor relict herringbone perthite but most perthite is disturbed and exhibits patch texture, chessboard character, and swapped rims. Accessory minerals are fluorite, zircon, and magnetite (rock is moderately magnetic). The petrographic features suggest cotectic crystallization of quartz and hypersolvus alkali feldspar at ~880 °C (zircon saturation T) under modest PH O 2 followed by subsolidus alteration of feldspar and amphibole to clay, sericite, and epidote. Chemistry The average of two analyzed samples (Table 3) from this quarry yields 74.41 wt% SiO2 and K2O/Na2O = 1.30; the latter value indicates that this granite did not experience the profound alkali exchange alteration that characterizes the affiliated volcanic rocks. The rock classifies as alkali feldspar granite by IUGS nomenclature, plots in the subalkaline field of the total alkaliversus-silica diagram, and is slightly peraluminous. In terms of

Van Buren 3.8 mi

Stop 9

S Stop 10 U.S. Highway 60 3.4 mi Figure 9.1. Geologic map of the Big Spring Granite (Stop 9) and Big Spring (Stop 10) area (after Weary and McDowell, 2006). Map units are: e—Eminence Dolomite; Og—Gasconade Dolomite; Or—Roubidoux Formation; QTrr— residuum of Roubidoux Formation; Qt—alluvial terrace deposits; Qa—alluvium. Dashed and dotted lines are traces of strike-slip faults. Structural contours are elevation above mean sea level, on base of the Roubidoux Formation.

144

Lowell et al.

SiO2

TiO2

BS 110 BS 111

74.39 74.43 La

Ce

BS 110 BS 111

34.8 32.5

70.2 68.1

BS 110 BS 111

0 0

V

Th

0.21 0.21

Ga 17 17

12.08 12.11 Pr 9.25 8.71 Rb 145 132

0.15 0.19

0.03 0.04

0.30 0.45

3.58 3.89

4.98 4.74

0.00 0.01

0.93 1.07

98.90 99.53

Nd

Sm

Eu

Gd

Tb

Dy

Ho

Er

Tm

Yb

Lu

REE*

37.2 34.7

8.2 7.2

0.95 1.01

7.9 7

1.4 1.2

8.6 7.4

1.8 1.6

5.8 5

0.92 0.8

6.2 5.4

1.08 0.94

256 235

Sr

As

Sb

Tl

Bi

Sn

W

Mo

0 0

1.2 0.9

0.5 0.2

0 0

4 4

2.1 1.8

5.1 6.2

Ni

Co

Sc

Ag

0.9 0.9

7 6

0 0

Ce/Nb

Yb/Ta

5.75 6.25

6.53 7.61

Cs 0.8 1

Ba 872 1024

22 29

Be

Ge

0 0

2 2

1 1

Zr

Y

BS 110 0.95 12.2 10.5 320 BS 111 0.71 10.9 8.5 276 Note: LOI—loss on ignition; n = 2. *Sum of rare earth element concentrations.

62 53

14.39 14.41 Ta

4.56 4.25 Nb

F

2.25 2.39

Cu

BS 110 BS 111

U

TABLE 3. MAJOR AND TRACE ELEMENT DATA FOR THE BIG SPRING GRANITE Al2O3 Fe2O3 MgO MnO CaO Na2O K2O P2O5 LOI Total

1400 1000 Hf

Cr 382 574

19 12

Nb/Hf

Zr/Nb

Zr/Hf

Sc/Nb

1.16 1.28

26.23 25.32

30.48 32.47

0.6 0.6

major element composition, samples BS 110 and BS 111 are virtually identical with only slight differences in trace element abundance. These include: A/CNK = 1.09–1.25, FeOt /MgO = 11.3–13.5, CaO = 0.30–.45 wt%, F = 1000–1400 ppm, 10,000Ga/Al = 2.65–2.66, Y/Nb = 4.86–5.08, Yb/Ta = 6.53– 7.61, Zr+Nb+Ce+Y = 408–464 ppm, and Rb/Sr = 4.55–6.59. The chondrite-normalized REE patterns of the two samples are identical (Fig. 9.2) and resemble those reported in the eastern St. Francois terrane by Lowell (1991). REE ratio variation between the two samples is: [Ce/Yb]N = 2.90–3.23, [La/Yb]N = 3.71–3.97, [La/Lu]N = 3.30–3.54, and [Eu/Sm]N = 0.31–.37. Incompatible element ratio variations are: Nb/Hf = 1.16–1.28, Zr/Nb = 25.32–26.23, and Zr/Hf = 30.48–32.47. The latter are related to the higher concentration of incompatible elements that indicate slightly more evolved character for sample BS 110.

Pb

Zn

41 31

37 27

Y/Nb

Rb/Sr

5.08 4.86

6.59 4.55

Both samples are slightly enriched in Mo, a common trait of high silica, F-rich granites. Discussion These data, particularly the REE values, serve to distinguish the Big Spring granite from the granites in the eastern St. Francois terrane. The trace element data and petrography indicate that it is a hypersolvus granite with an anorogenic (Whalen et al., 1987) or A-type signature. This, in turn, suggests an intra-plate, rift origin. The latter point is significant considering the location of the quarry on the western margin of the MGL. Y/Nb >> 1.2 for the Big Spring granite places it in the A2 category of Eby (1992) which suggests an origin by basaltic under-plating of the crust. This rock represents the evolved, roof facies of a high-level

Figure 9.2. Chondrite-normalized rare earth element diagram for Big Spring Granite. Normalization factors from Anders and Grevesse (1989).

Southern Ozark dome subvolcanic pluton that intrudes slightly older coeval volcanic rocks of the Eminence–Van Buren volcanic field. Paleozoic Stratigraphy The Big Spring Granite is unconformably overlain by the Potosi Dolomite, a light-brownish-gray, thick-bedded dolomite with locally developed vugs lined with drusy quartz. About 160 ft (49 m) of Potosi are exposed adjacent to the granite at this locality. The Potosi beds drape off the knob in a fashion similar to that seen in the Eminence Dolomite at Stop 7, with dips oriented radially away from the granite (Fig. 9.1; Weary and McDowell, 2006). The Potosi is apparently conformably overlain by the Eminence Dolomite in the bluffs above the Granite quarry which is, in turn, succeeded by the Gasconade Dolomite. The Eminence is unusually thin in this location, only ~100 ft (30 m) thick. The contact between the Potosi and Eminence is indistinct and probably related to secondary alteration (silicification) rather than to deposition. This is supported by the observation that in several wells in the region the thickness of the Potosi is inversely proportional to the thickness of the Eminence. In addition, as we see here, Potosi exposures often completely circle exposed Mesoproterozoic knobs at higher elevations than Potosi exposures elsewhere, suggesting mineralizing fluid-flow up and around the knobs. This outcrop pattern was also noted by Bridge (1930). Outcrops of the basal Gunter Sandstone Member of the Gasconade Formation just south of the granite knob contain 10 ft (3 m) thick cross-bedded, quartz sandstone beds. These unusually thick sandstone beds suggest channelization and filling of the Gunter Sandstone depositional surface, perhaps in response to movement or weathering along the strikeslip fault bounding the southwestern edge of the granite body (Fig. 9.1; Weary and McDowell, 2006). Sandstone beds in the Gunter to the north of the fault are thin. Weathered residuum of the Roubidoux Formation ultimately caps the hill directly above the quarry with slabs and cobbles of quartz sandstone and a sandy, acidic soil. The high knob to the southeast of the quarry is capped by the Roubidoux Formation.

145

Highway 60, turn left onto William Street. After one block turn right onto Sycamore Street. After 3 blocks, turn right onto James Street. At the intersection with Highway 60 turn right and cross the Current River on the bridge. Turn left after crossing the bridge onto State Highway 106. Follow 106 for ~3.4 mi (5.5 km) toward the south to the entrance of the Big Spring ONSR park area. Follow the road about another 0.8 mi (1.3 km) as it turns to the east and then north. After crossing the bridge over the spring branch, turn left into the Big Spring parking lot and park. Trails from the parking area lead a short distance to the spring rise pool. Site Description Big Spring is the largest spring in Missouri and one of the largest single orifice karst springs in the world. Flow averages 289 million gallons per day (447 ft3/sec; 12.7 m3/sec) and issues primarily from a single outlet, with a few small, flanking, overflow outlets within a few meters of the main orifice (Hauck et al., 1997). A park service information kiosk in front of the spring illustrates dye traces, some longer than 50 mi (80 km) that delineate the Big Spring catchment basin (also see Fig. I.3). In 1933, a Civilian Conservation Corps camp was established at Big Spring by the National Park Service. The workers built roads, trails, and other infrastructure, including the stone buildings in what was then, Big Spring State Park (Fig. 10.1). Stone for several of the park buildings was quarried from a location ~2.5 mi (4 km) southeast of the spring. This stone is from the silty, buff-colored dolomites in the lower Gasconade Dolomite. These are the same beds as those exposed just above Montauk Springs (Stop 1) and just above the Devil’s Well sinkhole (Stop 2). This nicely illustrates the fact that the gradient of the Current River from its headwaters to Big Spring conforms to the regional dip of the bedrock.

STOP 10. BIG SPRING Location About 3 mi (4.8 km) south-southeast of the town of Van Buren, Missouri: Central Section 6, T26N, R1E, Carter County, Big Spring 7.5 min quadrangle. UTM coordinates 4091451mN, 678579mE Zone 15, NAD83 Datum. Road Directions From Stop 9, turn vehicles around and follow Brown Road to the west and north ~3.8 mi (6.1 km). It may be necessary to drive a bit south and east on Brown Road from Stop 9 to find a suitable spot to turn large vehicles. After passing under U.S.

Figure 10.1. The Big Spring dining lodge was built by Civilian Conservation Corps in the early 1930s and is still in use. The lodge and other park buildings were constructed from local stone and timber. Photograph from the National Park Service.

146

Lowell et al.

STOP 11. VIEW FROM SKYLINE DRIVE OF THE DISSECTED SALEM PLATEAU TO THE NORTHWEST AND DISCUSSION OF THE WILDERNESS-HANDY FAULT ZONE AND SEDIMENTARY FACIES CHANGES ACROSS THE HINGE ZONE INTO THE REELFOOT RIFT

Road Directions

Location (Figure 11.1)

Stop 11

U.S .

Hig

hw ay 6

0

About 1.5 mi (2.4 km) south-southwest of the town of Van Buren, Missouri: Southeast ¼ Section 26, T27N, R1W, Carter County, Van Buren South 7.5 min quadrangle. UTM coordinates 4093945mN, 675,956mE Zone 15, NAD83 Datum.

From Stop 10, exit parking lot to the right and follow State Highway 106 back ~3.3 mi (5.3 km) to the north to an intersection at the top of the major topographic ridge. Turn left onto Skyline Drive (NFS Road 3281). Follow Skyline Drive about 0.7 mi (1.1 km) and find a place to pull to side of road. There are clearings and houses along the ridge that afford a view to the northwest. These are private properties and should not be accessed away from the road without permission of the landowners. After Stop 11, continue to the southwest ~4 mi (6.4 km) to an intersection with State Road Y. Turn right on Y and follow ~2 mi (3.2 km) northwest to an intersection with U.S. Highway 60. Turn left to head

Drillhole VB-23 Big Spring 2.2 mi

Figure 11.1. Geology in the area of Stop 11 (Weary and Schindler, 2004). Map Units: e—Eminence Dolomite; Og— Gasconade Dolomite; Or—Roubidoux Formation; QTrr—residuum of Roubidoux Formation; Qtl—loess-covered terrace deposits; Qt—alluvial terrace deposits; Qa—alluvium. Wavy symbols indicate cataclasis. Black triangles indicate top of the Cryptozoon chert in the Gasconade Dolomite.

Southern Ozark dome west toward Springfield and Branson, or turn right to head east toward Poplar Bluff. Stop Description This stop will look at examples of the Roubidoux Formation as it occurs in an alteration zone along the Wilderness-Handy fault zone. We will discuss the Wilderness-Handy fault zone and its history, and its role as a conduit for hydrothermal fluids. We also discuss a facies change that occurs in the Cambrian section across the Wilderness-Handy fault zone. We conclude with a discussion of the influence of faulting and facies change on groundwater flow to Big Spring. The subsurface stratigraphy at this stop is augmented with data from core hole VB-23 (Fig. 11.2), which was drilled to basement ~1.5 mi (2.4 km) southsouthwest of Stop 11. Addition subsurface data related to minerals exploration in this area was obtained from the files of the Bureau of Land Management.

1,247

1,276

Potosi Dolomite coarse- to medium-grained dolomite; numerous vugs lined with euhedral, zoned dolomite and late-stage white clay (dickite?), traces of sulfide (py or cpy) 4 in shale seam

1.285 1,295 1,305 1,314

3 ft rotten zone; w/ glauconitic green clay

1,324

styolitic contact

1.334

Derby-Doerun Dolomites

1,343

1,371

1,457 1,466 1,475

1,494 1,503

1,522

1,647

siltstone & sandstone 1.7 ft of 70% shale galena, sphalerite, and chalcopyrite disseminations & in small vugs sharp contact across an irregular surface with ~1.5 in of relief

1,657

Bonneterre Formation limely dolomite and dolomitic limestone

trilobites 2 to 10 ft cycles; intervals of pinhole porosity w/dolomite druse, sulfides (py or cpy) and white clay (dickite?)

1,667 1,676 1.686 1,695 1,704

1.5 ft of 50% rotten green clay and 50% coarse. recrystallized dolomite

1,714

Bonneterre Formation dominantly dolomite

1,724

1,532

1,550 1,560

1,733 1,742 1,752 1,762

1,570

dominantly limestone

1,771 1,580

1,390

1,589

1,399

1,599

1,781 1,791 1,800

1,408

1,428

light-colored, fine-grained dolomite; pinhead porosity, some sulfides (py or cpy)

1,513

1,381

1,418

The Wilderness-Handy fault zone is a northeast-trending belt of deformation that is ~5 miles wide and consists of as many as five individual mapped fault strands and numerous smaller unmapped structures (Harrison and McDowell, 2003; Weary and Schindler, 2004; Weary and Weems, 2004). Holes drilled within this zone typically encountered shear surfaces, brecciation, and gouge. The fault zone lies along a southwestward projection of another fault zone to the northeast known as the Greenville Fault (McCracken and McCracken, 1965; McCracken, 1971; Clendenin et al., 1989, 1993) which is known only from subsurface data. Clendenin et al. (1989, 1993) describe the Greenville Fault as an extensional structure related to Early Paleozoic development of the nearby Reelfoot Rift (Fig. 8.7). In the drainage basins of the Eleven Point and Current Rivers, the Wilderness-Handy fault zone shows characteristics of both right- and left-lateral strike-slip faulting (Harrison

1,541

1,352 1,361

Wilderness-Handy Fault Zone

Davis Formation 1,447

1.486

Potosi Dolomite

147

1,609 rust-stained disconformity- paleosol? styolitic contact

Davis Formation 1,438

1,810

1,618 1,627 1,637

abrupt change to light-gray limestone with numerous clay seams

1,820 1,829 1,839 1,848

Summary log of core hole VB-23

1,858 top of transition to Lamotte Sandstone

collar elevation- 580 ft numbers to left of stratigraphic column are depth of core from collar elevation and correspond to box intervals logged by John Repetski, USGS-Reston in 1999

1,871

Lamotte Sandstone 2,148

Mesoproterozoic granite 2,155- BOH at -1,575 ft elevation

Figure 11.2. Diagrammatic geologic column for drill-hole VB-23. UTM coordinates: 4091200mN, 675242mE; center of sec. 2, T. 26 N., R. 1 W., Carter County, Missouri. This well was drilled about 1.5 mi (2.4 km) south-southwest of Stop 11.

148

Lowell et al.

SF33

885

900

at Stop 3, deformation bands are of tectonic origin and are created by millimeter-scale displacements by shearing that involves pore-space collapse and grain comminution (Davis, 1999; Harrison and Schultz, 2002). Linear traces of the deformation bands, unaffected by topography, indicate that the faults are steeply dipping to vertical. A section across part of the Wilderness-Handy fault zone just south of this stop is shown in Figure 11.3. This cross section is derived from core log descriptions of Cominco Mining Company and re-logging of the core by USGS in the late 1990s. The logs for drill hole SF-22 describe multiple intervals (as much as 10 ft in core length) of steeply dipping fractures lined with pyrite and calcite and numerous vugs lined by hydrothermal white clay (dickite?) in the Derby-Doerun Formation of the Elvins Group. Intervals of white rock (secondary recrystallized dolomite) are present in hole SF-22 in both the Derby-Doerun and Bonneterre Formations. The log of drill hole SF-36 describes a possible fault marked by a 2-ft-zone of breccia and white clay in the Potosi Dolomite; in the underlying Derby-Doerun Formation, this log reports vugs lined with hydrothermal dickite and pyrite, intervals of rotated bedding, vertical open fractures. Near the base of the Derby-Doerun, a breccia zone occurs that includes a 3 ft interval described in the log as “very broken…, highly rotten, Fe stained, probable fault.” Lower in SF-36 in the Davis Formation, a possible fault is indicated by a 1.5 ft interval of broken, re-cemented, iron-stained rock. Other features mentioned in this log are

SF27

SF36

SF22 840

mapped fault at surface

and McDowell. 2003; Weary and Schindler, 2004; Weary and Weems, 2004; Weary and McDowell, 2006). However, the age and sequence of these movements has not been determined. Overall, there is a slight down-to-the-southeast stratigraphic throw across this fault zone. No individual fault strand in the Wilderness-Handy fault zone has stratigraphic separation of more than ~100 ft, yet most can be traced for many miles. The relatively long strike length and small vertical offset, plus the occurrence of vertical and conjugate Riedel shears containing subhorizontal slickenside striations, are indications that faulting in these Paleozoic rocks was dominantly by strike-slip displacement (Harrison and McDowell, 2003). A linear aeromagnetic feature identified during a mineralpotential investigation of the Irish Wilderness Roadless Area by Spector (1982) suggests that a major northeast-trending shear zone exists in the basement beneath the Wilderness-Handy fault zone. Using Spector’s (1982) data, Moss (1984) interpreted this shear zone as a dextral strike-slip fault zone intruded by a Mesoproterozoic felsic to intermediate dike; this interpretation implies that some faulting was of Mesoproterozoic age. The most prominent manifestations of faulting in Paleozoic rocks along the fault zone are cataclastic deformation bands in sandstones of the Roubidoux Formation, similar to those seen at Stop 3. Deformation bands are common in the WildernessHandy fault zone and some can be traced for thousands of feet at the surface. Most, however, are found in float blocks, thus diminishing their usefulness for kinematic study. As mentioned

Feet

955

1000

thick residuum

thick residuum

500 SL

Ce Cp ZnS Celhydrothermal dolomite and clay

ZnS strongly

Cb

Ce

Cp A

brecciated

Ce

Ce

Cp

Cp

Cel

Cel Cb

sea level 500

T PbS, ZnS

1000

slump breccia

slump breccia

Cl

Cl 2X vertical exaggeration Drill-hole data from Cominco logs, with additional logs by John Repetski

2000 ft

Fault surfaces. fault zones, or fault breccia observed in drill core, all are at high angle to core’s axis Dip-slip striations Area of “white rock” alteration Void and/or >50% open space; possible cave passage

A

T

Location of subhorizontal striations; A- away, T- towards

ZnS Sphalerite PbS Galena

1500

Figure 11.3. Diagrammatic cross section through 4 drill holes located approximately 2 km south of Stop 10 based on unpublished logs by John Repetski, U.S. Geological Survey, 1999. Ce—Eminence Dolomite; Cp—Potosi Dolomite; Cel—Elvins Group (upper Derby-Doerun Dolomite and lower Davis Formation); Cb—Bonneterre Formation; Cl—Lamotte Sandstone. Locations of wells: SF-22: UTM 4090165N, 673037E, SW 1/4SW1/4, sec. 3, T. 26 N., R. 1 W; SF-36: UTM 4089548N, 673441E, SE1/4NW1/4 sec. 10, T. 26 N., R. 1 W; SF33: 4089105N, 673772E, NW1/4SE1/4 sec. 10, T. 26 N., R. 1 W; SF-27 UTM 4089328N, 674773E, NW1/4SW1/4 sec.11, T. 26 N., R. 1 W.

Southern Ozark dome intervals of white rock alteration, fractures covered with unidentified orange-colored oxides, a 3 ft interval of solution-widened fractures, hydrothermal dickite coatings on fractures and bedding planes, open vugs lined by calcite, and some fault-related fracturing. In the underlying Bonneterre Formation, the log of SF-36 reports a 2.5 ft interval of presumed faulting, scattered occurrences of hydrothermal dickite, localized intervals of pronounced vertical fractures, a 1 ft interval of vuggy, recrystallized dolomite, zones of brecciation with oxidation on fracture surfaces, intervals of coarsely crystalline calcite, intervals of solution-widened fractures, several intervals (up to 21 ft in length) of chaotic breccia that the logger interpreted as slump breccia, and an 18 ft interval of “white rock” (local usage for dolomitized and silicified rock). The drill log of SF-33 includes description of three intervals of fault breccia in the Potosi Formation. In the Derby-Doerun Formation this log describes two intervals of possible fault breccia, as well as intervals of vertical to steeply inclined fractures, intervals possessing fine to coarse pores and pits, and intervals of vugs lined by hydrothermal dickite. In the Davis Formation, the SF-33 log reports zones of white-rock alteration and a notable 14 ft interval of strongly fractured vuggy rock that is stained yellow. This log describes the lower Bonneterre Formation as containing a 60-ft-long interval of 60% vuggy recrystallized white rock followed by a 112 ft interval described as “slump breccia”; the latter contains abundant disseminations and seams of sphalerite. In addition to multiple intervals of fractured rocks in the Potosi Dolomite, the logs of SF-27 identify five intervals of faulting in the Potosi, several of which possess slickenside surfaces with striations plunging 45° to the core’s axis; this indicates oblique slip. The log of SF-27 reports the following sequence of tectonic-related features with depth in the Derby-Doerun Dolomite: (1) abundant white dickite in small vugs followed by a 20 ft interval of intensely fractured, oxidized pink and yellow mottled rock; (2) a 7 ft interval of soft and broken altered rock; (3) a 6 ft interval of soft, yellowish-pink rock; (4) a 30 ft interval of fractured, soft, spongy, porous rock; and (5) a 20 ft oxidized interval of substantial core loss. Near the base of the DerbyDoerun, the SF-27 log describes three fault intervals (1 ft, 2 ft, and 1 ft wide, respectively) of extremely fractured, broken, and oxidized rock containing slickenside surfaces. More than half of the ~60-ft-thick Davis Formation in SF-27 is logged as very oxidized (bleached white and yellow), fractured, rotten, soft, and mildly to moderately vuggy. The Bonneterre Formation cored by SF-27 contains numerous fault intervals and more than 150 ft of slump breccia. This deep faulting cannot be correlated to faulting in the Ordovician units at the surface and is interpreted as evidence of Cambrian tectonics (Seeger and Palmer, 1998; Harrison and McDowell, 2003; Weary and Schindler, 2004) which is consistent with deformation on the Greenville Fault (McCracken and McCracken1965; Clendenin et al., 1989, 1993). Approximately 9 mi (15 km) to the southwest of Stop 11, descriptive logs of several drill holes (STH-1, 112-A, 112-B, 112D, 112-G, PK-16, SF-22, SF-36, SF-33, SF-27; on file Bureau of Land Management, Rolla) that were collared in the Wilderness-

149

Handy fault zone describe high-angle faults and open fractures in the Bonneterre Formation and overlying Elvins Group zone (Harrison and McDowell, 2003). Several of these core logs also describe intense fracturing in the underlying Mesoproterozoic basement rocks and minor quantities of base-metal sulfides. The log of drill hole PK-16, collared ~6 mi (10 km) southwest of Stop 11 along the Wilderness-Handy fault zone, reports: (1) 20 ft of intensely fractured, open rock in the Derby-Doerun Formation; (2) intervals of calcite-lined vugs in both the Elvins Group and Bonneterre Formation; and (3) traces of disseminated sphalerite in the upper Bonneterre. It also describes zones of brecciation and massive calcite-fill in the Davis Formation that we interpret as fault zones. The log of PK-16 reports intervals of brecciation, massive calcite-fill, high-angle fracturing, vugs lined by dickite, numerous disseminations of pyrite and sphalerite in the Bonneterre Formation. Alteration and Base-Metal Mineralization along the Wilderness-Handy Fault Zone The Ozark region of the United States midcontinent is host for numerous occurrences of Mississippi Valley–type (MVT) mineralization, including the world-class economic district of the Viburnum Trend, which extends into the Current River basin. There has been considerable exploration for new MVT type deposits throughout both the Current and Eleven Point River basins, particularly during the period 1960–1990. Both surface exposures and drill core recovered from the subsurface show that large volumes of rock from the entire stratigraphic column are intensely silicified and brecciated along the Wilderness-Handy fault zone; extensive carbonate dissolution and increased porosity accompanied these changes. Cherts and chert breccias are conspicuous at the surface in virtually all exposures of the Roubidoux Formation from the Current River to the Eleven Point River along this fault zone. All carbonate material has been removed from these silicified rocks. Excellent exposures of this paleokarst texture occur along Coward’s Hollow in the Handy 7.5′ quadrangle (Harrison and McDowell, 2003). Several cores from drill holes in the fault zone show that the entire Paleozoic section from Ordovician Gasconade Dolomite to the Cambrian Bonneterre Formation consists of “white rock alteration” so intense it was impossible to distinguish the stratigraphic units. This faulting produced high fracture-permeability for the MVT mineralization and silica deposited by circulating hydrothermal fluids. This alteration is most pronounced along the Wilderness-Handy fault zone near Big Spring. The following excerpts from logs of drill holes along the fault zone are of interest. DDH 112-C logs a zone of highly broken dolomite and high-angle fractures with traces of galena in the Derby-Doerun Formation ~100 ft above its contact with the Davis Formation; numerous high-angle fractures associated with traces of galena and sphalerite in the lower 100 ft of the Davis Formation; high-angle fractures and traces of galena and sphalerite in the upper 100 ft of the Bonneterre Formation. DDH 112-E logs

150

Lowell et al.

abundant high-angle fractures in the lower 65 ft of the DerbyDoerun Formation with minor pyrite disseminations; abundant high-angle fractures in the lower 100 ft of the Davis Formation with traces of sphalerite; abundant high-angle fractures lined with pyrite blebs and disseminations, in the upper Bonneterre formation. DDH 112-B logs abundant high-angle fractures and sparry dolomite-lined vugs in the lower 200 ft of the Derby-Doerun Formation, pyrite disseminations throughout; sporadic traces of sphalerite; some high-angle fractures and traces of sphalerite in vugs in the lower 100 ft of the Davis Formation; high-angle fractures and minor sulfides throughout the upper Bonneterre Formation. DDH 112-G logs abundant high-angle fractures in the lowermost Potosi Dolomite; high-angle fractures and 1.3 ft zone of breccia in the Derby-Doerun Formation; abundant high-angle fractures throughout the lower 50 ft of the Davis Formation; abundant high-angle fractures and sulfide disseminations, a 1.75 in veinlet of massive galena, sphalerite, and pyrite. DDH 112-D logs calcite-filled high-angle fractures in the lower 125 ft of the Derby-Doerun Formation; traces of sphalerite and galena in the upper part of the Bonneterre Formation. DDH 112-A logs healed high-angle fractures, pyrite disseminations, and sparry dolomitelined vugs in the lower 100 ft of the Davis Formation; traces of sphalerite and chalcopyrite in fractures in the upper 100 ft of the

Bonneterre Formation; abundant vertical fractures in the Mesoproterozoic volcanic rocks. Facies Change across the Wilderness-Handy Fault Zone Our surface and subsurface geologic investigations indicate that the Wilderness-Handy fault zone has influenced sedimentary deposition. Cross sections and facies distribution maps constructed from drill-core logs indicate that a major facies change occurred across the fault zone during accumulation of the Cambrian Davis Formation. Northwest of the fault zone, the Davis Formation of the Elvins Group is dominated by shale facies and southeast of the fault the dominant facies is carbonate. This facies change was noted by Howe et al. (1972), but not correlated to the Wilderness-Handy fault zone. The transition occurs across a margin between a shallow marine intrashelf basin, the central Missouri Basin of Seeger and Palmer (1998), and the uplifted shoulder of the Reelfoot Rift (Fig. 11.4). Several periods of transgression and regression are recorded in these syntectonic sediments (Seeger and Palmer, 1998). Our interpretation of the Wilderness-Handy fault zone during the Cambrian is consistent with interpretations of the of Greenville Fault by Clendenin et al. (1989, 1993).

NW

SE

rift shoulder

intracratonic basin

ites

p dolom

rou Elvins G

or

Davis Fm. 'Rim carbonates' paleokarst

.

Davis Fm shale

pro de grad ep in rim g ra car mp bo na tes

Bonneterre

paleoka

rst

Wilderness-Handy fault zone

Formation

area of future "white rock" alteration

Reelfoot rift

Lamotte Sandstone

dolomite

dark dolomites

Davis Format io

n

Bonnete

paleokars t dolomite

rre Form ation

black

paleokars t dolomite

crystalline

shales

paleokarst

basement

Lamotte Sandstone

Lamotte Sandstone

Figure 11.4. NW-SE cross section across the structural margin of the Cambrian Reelfoot Rift illustrating relations between structure, sedimentary facies, and paleokarst horizons. Modified from unpublished model of J. Palmer, Missouri Department of Natural Resources. Based on the Amimco Spense well in the Reelfoot Rift, deep seismic profiles, and other data.

Southern Ozark dome Influence of the Wilderness-Handy Fault Zone and Facies Change on Groundwater Flow to Big Spring The overall flow of groundwater in this portion of Missouri is from west to east. Three distinct hydrogeologic systems control flow according to the nature of their subsurface features. They are: (1) the Ozark Plateaus hydrogeologic system (Gann et al., 1976; Imes, 1989; Imes and Smith, 1990; Imes, 1990a, 1990b; Kleeschulte, 2001); (2) a transitional hydrogeologic system; and (3) the northern Mississippi embayment hydrologic system (Grubb, 1984; Arthur and Taylor, 1990; Hosman and Weiss, 1991). Ozark Plateaus Hydrogeologic System Hydrogeologic units for the Ozark Plateaus physiographic province, which includes the upper reaches of the Current and Eleven Point River drainage basins west of the WildernessHandy fault zone, are referred to as the Ozark Plateaus hydrogeologic system (Gann et al., 1976; Imes, 1989; Imes and Smith, 1990; Imes, 1990a, 1990b; Kleeschulte, 2001). This system extends throughout southwestern Missouri, northwestern Arkansas, and eastern parts of Oklahoma and Kansas and consists of four major hydrogeologic units (Gann et al., 1976; Imes, 1989; Imes and Smith, 1990; Imes, 1990a, 1990b; Kleeschulte, 2001) which in ascending order are: (1) the basement confining unit; (2) the St. Francois aquifer; (3) the St. Francois confining unit; and (4) the Ozark aquifer. Figure I.7 shows the relations between these hydrogeologic units and stratigraphy. The basement confining unit consists of 1.47 Ga igneous rocks of the St. Francois terrane (Imes, 1989) and older metamorphic rocks (Sims, 1990) that are mostly impermeable, except in fracture zones where small water yields are possible. The St. Francois aquifer is composed of Upper Cambrian strata above the basement confining unit and below the St. Francois confining unit (Imes, 1990a). In the Current and Eleven Point River basins, the St. Francois aquifer consists of a basal conglomerate that rests on the PrecambrianPaleozoic unconformity and is succeeded by the Lamotte Sandstone and the Bonneterre Formations. From drill data, the basal conglomerate appears to be ubiquitous, although it is generally less than 20 ft thick. The Lamotte Sandstone is absent adjacent to many basement highs but, in general, thickens toward the west in this area. The St. Francois confining unit lies above Bonneterre strata of the St. Francois aquifer and is composed of the Cambrian Elvins Group (i.e., the basal Davis Formation and overlying Derby-Doerun Dolomite) as defined by the Missouri Geological Survey (1979). Typically, these units contain moderately thick beds of shale, shaley mudstone, and thinly bedded, dense finegrained dolomites that are low in porosity and permeability (Kleeschulte and Seeger, 2000; Kleeschulte and Seeger, 2001). No studies have evaluated the secondary porosity characteristics of these rocks. The Ozark aquifer (Imes, 1990a) extends from the top of the St. Francois confining unit to the topographic surface and

151

includes the Potosi Dolomite, Eminence Dolomite, Gasconade Dolomite, Roubidoux Formation, Jefferson City Dolomite, and the Cotter Dolomite in the Current and Eleven Point River basins. This aquifer is unconfined and is the principal domestic water source for most of southeastern Missouri, except for the St. Francois Mountains where near-surface St. Francois aquifer is the usual water source. Transitional Hydrogeologic System The principal subsurface difference between the Ozark Plateaus hydrogeologic system and the transition zone hydrogeologic system is the absence of the Ozark confining unit in the latter. Instead of the low-permeability shales and fine-grained carbonates typical of the Elvins Group in the Ozark Plateaus system, the Elvins Group in the transition zone consists of shallowwater carbonate facies that include digitate- and planar-algal bioherms and breccias with notable porosity. In effect, there is an unconfined aquifer extending from the basement to the surface in the transitional system. The margin of the transition system closely follows the facies change in the Elvins Group which is fault controlled and corresponds to the northeast-southwest– trending Wilderness-Handy fault zone (Fig. 11.4). Northern Mississippi Embayment Hydrogeologic System The northern Mississippi Embayment hydrologic system (Grubb, 1984; Arthur and Taylor, 1990; Hosman and Weiss, 1991) has two subsystems: (1) unconsolidated to semi-consolidated sands, silts, and clays of Coastal Plain origin that range in age from Eocene to Late Cretaceous (Campanian); and (2) overlying Mississippi River Valley alluvial deposits. Extensive and high-water-bearing sands in the Coastal Plain subsystem slope and thicken eastward in Missouri toward the axis of the Mississippi Embayment. In southeast Missouri, groundwater moves southeastward down dip of the sand beds in Coastal Plain aquifer subsystem under the Mississippi River with no discharge to the river (Miller and Appel, 1997). The Mississippi River Valley alluvial subsystem consists of Pleistocene braided stream deposits of the paleo-Ohio and paleo-Mississippi Rivers that are overlain by point-bar and over-bank deposits of the modern Mississippi River. These deposits are saturated to within a few feet of the flatlying alluvial surface of the Mississippi embayment and produce relatively rapid flow to the south. Groundwater Flow to Big Spring Dye-tracing studies for the upper Current River basin (Imes and Kleeschulte, 1995; Kleeschulte, 2000) indicate that groundwater flow commonly crosses surface drainage divides and is more complicated than surface flow; the latter is, itself, complicated by the karst features of the area. For example, some groundwater traces to Big Spring originated from more than 50 mi (80 km) away and crossed beneath the entire Eleven Point River surface basin (Imes and Kleeschulte, 1995; Kleeschulte, 2000). Other dye traces show inconsistent patterns of crossing flow

152

Lowell et al.

paths (see Imes and Kleeschulte, 1995) that are best explained by an overriding karst control on groundwater flow. When the effects of losing streams are taken into account (Imes and Kleeschulte, 1995), there is little similarity between surface-water and groundwater flow. This is characteristic of karst control on regional hydrology. A regional potentiometric surface (Fig. 11.5) was created from water-table data provided by the Missouri-USGS Water Science Center in Rolla (Imes et al., 2007) to determine correlations between groundwater flow and geologic structures. We are particularly interested in the relations between mapped faults, the subsurface facies change, and groundwater flow toward Big Spring. Upper water levels from more than 100 wells were measured during the low flow period 25 October– 17 November 2000. These data were hand-contoured using strict rules of interpolation to produce maps similar to those of Imes and Kleeschulte (1995). Our maps show features similar to those Imes and Kleeschulte (1995) as well as significant differences. These differences arise from different contour methods (program grid contouring versus hand contouring) and the fact that our contours cover a much larger area with a database three times that of Imes and Kleeschulte (1995). Our potentiometric surface (Fig. 11.5) is irregular in shape and consists of a series of northwest-trending troughs and ridges interrupted by an elongated northeast-trending groundwater high. The latter feature coincides with the Wilderness-Handy fault zone and the regional subsurface facies changes. This correlation is especially striking in the area between the intersection of Wilderness-Handy fault zone and the Teresita Fault (~19 mi southwest of Big Spring) and Big Spring. Adjacent to this elongated groundwater high (Fig. 11.5), are two prominent closed depressions connected by a trough. One of these depressions occurs at the confluence of the Eleven Point River and Hurricane Creek; the other is in the Pike Creek basin south of Fremont, Missouri. The trough connecting our depressions is similar to that in the potentiometric surface of Imes and Kleeschulte (1995), who emphasized the necessity of groundwater flow in this trough in order to explain dye traces to Big Spring; we agree with their assessment. In addition to a close correlation between the northeasttrending groundwater high and the Wilderness-Handy fault zone, there is close correlation between two northwest-trending groundwater troughs and mapped faults cutting the Paleozoic section. Specifically, relatively steep-sided groundwater troughs follow the Teresita and Low Wassie Faults for tens of kilometers (Fig. 11.5). This suggests that increased permeability along these structures is responsible for the troughs. We think that the groundwater high along the Wilderness-Handy fault zone represents upwelling of deep water from the St. Francois aquifer where it is unconfined and enters a zone of increased permeability. When areas of elevated basement topography are plotted on the potentiometric map (Fig. 11.5) an additional spatial relation to groundwater flow is apparent (Fig. 11.6). We note that the basement highs (Fig. 11.6) vary greatly in elevation with the largest in the north (outcrops visited on this field trip) and

decrease progressively to the southeast with the regional dip. It is suggested that in addition to becoming unconfined eastward, the St. Francois aquifer also becomes somewhat restricted along its base. These factors, plus a hydraulic head derived from higher elevations to the west drive deep groundwater flow upward. CONCLUSIONS Hydrologically, the transition zone in the upper Current River basin separates the Ozark Plateaus system (up dip to the west) from the Mississippi embayment system (down dip to the southeast). This transition zone possesses unique hydrologic characteristics, the most importance of which is the absence of a regional confining unit. This zone is related to syntectonic depositional facies within the Cambrian stratigraphic section. The largest springs in southern Missouri (Big Spring and Greer Spring) and northern Arkansas (Mammoth Spring) occur in this transition zone. Faulting in the Current River basin exerts structural control on regional groundwater flow, particularly along the WildernessHandy fault zone, which coincides with the boundary between the Ozark Plateaus hydrogeologic system and the transitional hydrogeologic zone. A groundwater high exists today along the Wilderness-Handy fault zone; rock alteration patterns indicate that this fault zone has been a conduit for upwelling flow, especially during the late Paleozoic mineralizing event that formed the MVT deposits. The Teresita Fault and the Low Wassie Fault also closely coincide with major groundwater troughs, suggesting further structural control of flow. The rugged basement topography of the Current River basin also plays an influential role on flow regimes. ACKNOWLEDGMENTS The authors thank Kevin Evans, Jim Aber, and Mark Hudson for their comments on an early draft of the manuscript. The final version is significantly improved by their efforts.

Figure 11.5. Map of potentiometric surface for a portion of the upper Current River basin, including recharge area for Big Spring, overlain with mapped faults and suggested groundwater-flow paths. Data base is water-well levels collected during a lowstand from 25 October to 17 November 2000 by U.S. Geological Survey Water Science Center in Rolla, Missouri. Faults are from USGS maps. Stop 10 indicated by white-lined black hexagon near Big Spring. Big Spring, Greer Spring, and Mammoth Spring are marked by black stars. Mississippi Valley–type mineralization is denoted by white-lined star north of Greer Spring. White arrows are suggested flow paths to Big Spring. Small black-lined white hexagons mark dye-trace origins recovered at Big Spring (Imes and Kleeschulte, 1995). Topography decreases from west to east. Dye traces were introduced into the Ozark aquifer (Gann et al., 1976; Imes, 1989; Imes and Smith, 1990; Imes, 1990a, 1990b; Kleeschulte, 2001). Big Spring issues from the transitional hydrogeologic system.

1331

W

es

1300

tP

la in s

er

1148

South Fo k

ult

1026

1017

1020

932

94

973

763

907

974

1120

1200

9 8

5 10

0 95

778

906

784

ch

W st P a ns

80

W te

950

835

845

818

838

944

846

149

829

814

832

845

0 110

800

897

726

Trask

945

757

874

0

1201

1210

884

843

892

947

716

761

642

740

800

800 1000 ft 600 800 ft

859

641

765

831

605

843

600

743

615

680

803

711

717

e

850

895

642

Tha e

631

659

589

931

625

905

25

622

89

563

954

9 729

645

811

636

762

687

823

806

746

800

Rover

796

792

705

Thomasv e

819

754

812

766

<500 ft

819

747

800

800

883

760

861

Mammoth mmoth h Sprin Spring

500 600 ft

812

822

Mapped fault

711

B andsv e

646

724

Peace Va ey

842

786

799

807

859

930

900

Jam Up Cave

590

01

60

0

733

855

640

63

813

684

677 692 691

67

740

97

776

89

791

594

525

846

713 7

61

766

515

0

60

464

697

493

555

506

612

62

509

zo

504

683

503

Myrt e

463

0

80

473

18

480

574

533

0 490

624

746

1 11

882

727

546

618

lt

420

413

58

nt 15

554

674

581

584

B more

497

R verton

731

753 W de ness

633

602

Fr

488

597

545

423

fau

Stega Mounta n

w lo Ho

514

g

728

872

n nn De

91˚ 15'

526

525

610 625

483

835

768

590

ne 727 an pr ng

518 509

627

fa

541

Gree

578

Wass e

t ul

786

675

Lo

808

644

691 654

529

60 0 ((575)

7 5

8

819

y nd a -H ss ne

836

830

er ild W

825

A ton

863

761

800

833

762

W non

815

fau Wa lt ssi e

Greer e Spring Spri S p priing ing

773

789

730

801

819

P edmont Ho ow

B rch Tree

80 0

~ 10 km

698

889

769

596

603

787

771

841

Bart e t

800

751

504

558 523

6 1

607

571

653

569

528

816 803

585

800 0

550

451

60 0

511

60 0

444

826

th

Gatewood

589

Bard ey

622

662

Han y

800

6 465

508

460

500

n Bu

609

558

502

594

t fau

509

492 4 502 476 494

ek

Van Buren North

re

57

566

0

2

Te re s ta

fau

lt

600

564

769

502

440

445 472

445

60

618

4

427

91˚

600

Poynor

488

557

439

36˚ 30'

582

Br r

363

Grand n SW

418

36˚ 45'

637

433

B g Spr ng

442

433

(433)

Big Spring

628

469

606

423

415

447

Garwood

fa

Predicted pathway

100 0

1071 1097 1063

Mounta n V ew

821

684

832

811

1039

t

lt

fa u

810

770

ul

lC

n

Point of entry of dye trace to Big Spring

fa

1126

0 100

1061

1134

1115

C ear Spr ngs

870

737

726

Mil

ha

>1000 ft

Th ay

1000

P mona

1060

985

920

ow Spr ng South

1145

1279

1245

W ow Spr ngs No

Te re sit a

826

ult fa ap G

Th or ny

91˚ 30' Lo w

W ild e

fa ult dy

-H an s ne s

91˚ 45'

0 60

nip Do ultlt

1331

W

es

1300

tP

la in s

ha y

er

1148

South Fork

ult

0

1026

1017

1020

932

94

973

763

907

974

1120

9 8

5 10

0 95

778

906

784

ch

W st P a ns

80

Wh te C

950

835

94

845

818

838

846

1149

829

814

832

845

0 110

800

897

726

Trask

945

757

874

0

1201

1210

884

843

892

947

716

761

642

740

800

600 800 ft

859

641

765

831

605

843

600

743

615

680

803

711

717

te

850

895

642

Thay

631

659

589

931

625

905

25

622

89

563

954

9 729

645

811

636

762

687

823

806

746

800

Rover

796

792

705

Thomasv e

819

754

812

766

<500 ft

819

747

800

800

883

760

861

Mammoth mmoth h Sprin Spring

500 600 ft

812

822

Mapped fault

711

B ndsv e

646

724

Peace Va ey

842

786

799

807

859

930

900

Jam Up Cave

590

01

0 60

733

855

640

603

96

825

80 0

78

776

89

791

846

7 3

61

525

594

766

0

60

464

515

697

493

555

506

612

zo

509

504

683

503

Myrt e

463

625

80 0

526

473

618

480

574

533

490 0

624

746

61

882 2 882

727

546

618 18 8

au

ltlt

488

420

413

587

nt 515

554

674

581

584

B more

497

R ver on

731

753 W derness

633

602

597

545

423

loow

Stega Mounta n

Ho

514

iinng

728

872 872 2

nn De

91˚ 15'

525

610 625

483

835

68 8 768

590

ne 727 any Spr ng

518 509

627

fa

541

Gree

578

ss e Wass ss

t ul

786

675

L

80 08 808

644

691 654

529

60 0 ( (575)

7 5

~ 10 km

684

677 692 691

8

7

740

97

819

Greer e Spring Spr Spri S pri p ing ng

800

833

762

W non

8 5

fau Wa lt ssi e

y nd a H ss ne 836

830

er ild

813

A on

863

761

P edmont Ho ow

773

789

730

801

819

B rch Tree

W

763

6

698

889

769

787

771

841

Bart e t

800

751 751 1

60

511

0

607

571

653

5 9 569

528

8 6 803 80 8 0 03 3

611 6

504

558 523

585

800 80 8 00 0 0

550

451

60 0 609

444

o th

826 8 26

Gatewood

589

Bard ey

622

662

Han y

800 80

47

57

Te re si

502

52

a fa

ult

600

564

769

566

72

440

445

445

0 60

618

469 465

508

460

500

V n Bu

558

502

594

lt fau

509

492 48 502 476 494

ek

Van Buren North

re

427

91˚

600

439

36˚ 30'

Poynor

488

557

Br r

363

418

36˚ 45'

Grand n SW

582

637

433

B g Spr ng

442

433

(433) 3)) 3

Big Bi B iig g Spring S prin ng g

628

469

606

423

415

447

Garwood

fa

Figure 11.6. Areas of elevated Mesoproterozoic basement topography (dark pattern) overlain on Fig. 11.5. Symbols same as in Fig. 11.5.

800 1000 ft

Predicted pathway

100 0

1071 1097 1063

Moun a n V ew

821

684

832

811

1039

t

fa ul t

810

770

u

ll C

n

Point of entry of dye trace to Big Spring

fa

1126

100

1061

1134

1200

1115

C ear Spr ngs

870

737

726

M

ha

>1000 ft

-T

1000

Pomona

1060

985

920

W ow Spr ng South

1145

1279

1245

W ow Spr ngs No

es ita

Te r

Lo w

26 26

t fa u ap G

Th or ny

91˚ 30'

rn W ild e

fa ult dy

-H an es s

91˚ 45'

0

60

nip Do t

Southern Ozark dome REFERENCES CITED Aley, T.J., and Aley, C., 1987, Groundwater study—Ozarks National Scenic Riverways: Protem, Missouri, Ozark Underground Laboratory, National Park Service Contract CX 6000-4-0083, 222 p. Aley, T.J., Williams, J.H., and Masello, J.W., 1972, Groundwater contamination and sinkhole collapse induced by leaky impoundments in soluble rock terrain: Engineering Geology Monographs, series 5, Missouri Geological Survey and Water resources, 32 p. Anders, E., and Grevesse, N., 1989, Abundances of the elements: meteoritic and solar: Geochimica et Cosmochimica Acta, v. 53, p. 197–214, doi: 10.1016/0016-7037(89)90286-X. Anderson, J.L., 1983, Proterozoic anorogenic granite plutonism of North America, in Medaris, L.G., Jr., et al., eds., Proterozoic geology: Selected papers from an international Proterozoic symposium: Geological Society of America Memoir 16, p. 133–154. Arthur, J.K., and Taylor, R.E., 1990, Definition of the geohydrologic framework and preliminary simulation of ground-water flow in the Mississippi Embayment aquifer system, Gulf Coastal Plain, United States: U.S. Geological Survey Water-Resources Investigations Report 86-4364, 97 p. Arvidson, R.E., Bindschadler, D., Bowring, S., Eddy, M., Guinness, E., and Leff, C., 1984, Bouguer images of the North American craton and its structural evolution: Nature, v. 311, p. 241–243, doi: 10.1038/311241a0. Aydin, A., 1978, Small faults formed as deformation bands in sandstone: Pure and Applied Geophysics, v. 116, p. 913–930, doi: 10.1007/BF00876546. Baker, H., 1999, Geologic map of the Grandin SW 7.5′ quadrangle: Missouri Department of Natural Resources, Division of Geology and Land Survey OFM-99-342-GS, 1:24,000 scale. Ball, S.H., and Smith, A.F., 1903, The geology of Miller County: Missouri Geological Survey 2d Series, v. 1, 207 p. Bickford, M.E., Van Schmus, W.R., and Zietz, I., 1986, Proterozoic history of the midcontinent region of North America: Geology, v. 14, p. 492–496, doi: 10.1130/0091-7613(1986)14<492:PHOTMR>2.0.CO;2. Bowring, S.A., Arvidson, R.A., and Podosek, F.A., 1988, The Missouri gravity low: evidence for a cryptic suture?: Geological Society of America Abstracts with Programs, v. 20, no. 2, p. 91. Bretz, J.H., 1965, Geomorphic history of the Ozarks of Missouri: Missouri Geological Survey and Water Resources [Reports], 2d Series, v. 41, 147 p. Bridge, J., 1930, Geology of the Eminence and Cardareva quadrangles: Missouri Bureau of Geology and Mines, 2d ser., v. 24, 228 p., scale 1:62,500. Bridge, J., and Dake, C.L., 1929, Initial dips peripheral to resurrected hills: Missouri Bureau of Geology and Mines, Appendix I, 55th Biennial Report, 7 p. Clemens, J.D., Holloway, J.R., and White, A.J R , 1986, Origin of an A-type granite: experimental constraints: The American Mineralogist, v. 71, p. 317–324. Clendenin, C.W., and Diehl, S.F., 1999, Structural styles of Paleozoic intracratonic fault reactivation: a case study of the Grays Point fault zone in southeastern Missouri, USA: Tectonophysics, v. 305, p. 235–248, doi: 10.1016/ S0040-1951(99)00007-4. Clendenin, C.W., Niewendorp, C.A., and Lowell, G.R., 1989, Reinterpretation of faulting in southeast Missouri: Geology, v. 17, p. 217–220, doi: 10.1130/0091-7613(1989)017<0217:ROFISM>2.3.CO;2. Clendenin, C.W., Lowell, G.R., and Niewendorp, C.A., 1993, Sequencing Reelfoot extension based on relations from southeast Missouri and interpretations of the interplay between offset preexisting zones of weakness: Tectonics, v. 12, p. 703–712, doi: 10.1029/93TC00109. Committee for the Magnetic Anomaly Map of North America, 1993, Magnetic anomaly map of part of the conterminous United States and some adjacent parts of Canada: Boulder, Colorado, Geological Society of America, Decade of North American Geology, v. C-2, plate 3, scale 1:5,000,000. Cooper, R.A., Nowlan, G.S., and Williams, S.H., 2001, Global stratotype section and point for base of the Ordovician System: Episodes, v. 24, p. 19–31. Cordell, L., and Knepper, D.H., 1987, Aeromagnetic images: fresh insight to the buried basement, Rolla quadrangle, southeast Missouri: Geophysics, v. 52, no. 2, p. 218–213. Cox, R.T., 1995, Intraplate deformation during the Appalachian-Ouachita orogeny as recorded by mesoscale structures on the Ozark plateau of North America [unpublished Ph.D. dissertation]: University of Missouri, Columbia, 229 p. Darnell, B.D., Al-Shukri, H.J., and Lowell, G.R., 1995, Density distribution model of the upper crust beneath the St. Francois igneous terrane and

155

the Missouri gravity low [abs.]: Geological Society of America Abstracts with Programs, v. 27, no. 6, p. 193. Davis, G.H., 1999, Structural geology of the Colorado Plateau region of southern Utah, with special emphasis on deformation bands: Geological Society of America Special Paper 342, 157 p. Derby, J.R., Bauer, J.A., Creath, W.B., Dresbach, R.I., Ethington, R.L., Loch, J.D., Stitt, J.H., McHarque, T.R., Miller, J.F., Miller, M.A., Repetski, J.E., Sweet, W.C., Taylor, J.F., and Williams, M., 1991, Biostratigraphy of the Timbered Hills, Arbuckle, and Simpson Groups, Cambrian and Ordovician, Oklahoma: a review of tools and techniques available to the explorationist: Oklahoma: Geological Survey Circular, v. 92, p. 15–41. Diehl, S.F., Clendenin, C.W., and Lowell, G.R., 1995, The Ironton faultadditional observations and interpretations of the significance of a Proterozoic mylonitic shear zone [abs.]: Geological Society of America Abstracts with Programs, v. 27, no. 6, p. 222. Dom, J.E., and Wicks, C.M., 2003, Morphology of the caves of Missouri: Journal of Caves and Karst Studies, v. 65, p. 155–159. Eby, G.N., 1992, Chemical subdivision of the A-type granitoids: petrogenetic and tectonic implications: Geology, v. 20, p. 641–644, doi: 10.1130/0091-7613(1992)020<0641:CSOTAT>2.3.CO;2. Eby, G.N., 1990, The A-type granitoids: a review of their occurrence and chemical characteristics and speculations on their petrogenesis: Lithos, v. 26, p. 115–134, doi: 10.1016/0024-4937(90)90043-Z. Epstein, A.G., Epstein, J.B., and Harris, L.D., 1977, Conodont color alteration— An index organic metamorphism: U.S. Geological Survey Professional Paper 995, 27 p. Ethington, R.L., Engel, K.M., and Elliot, K.L., 1987, An abrupt change in conodont faunas in the Lower Ordovician of the Midcontinent province, in Aldridge, R.J., ed., Palaeobiology of conodonts: Chichester, UK, Ellis Horwood, p. 111–127. Fenneman, N.M., 1938, Physiography of the eastern United States: New York, McGraw-Hill, 714 p. Gann, E.E., Harvey, E.J., and Miller, D.E., 1976, water resources of southcentral Missouri: U.S. Geological Survey Hydrologic Investigations Atlas HA-550, 4 sheets. Gerdemann, P.E., and Gregg, J.M., 1986, Sedimentary facies in the Bonneterre Formation (Cambrian), southeast Missouri and their relationship to ore distribution: Society of Economic Geologists Guidebook, pre-meeting field trip no. 1, San Antonio, Texas, 10–14 November 1986, p. 52–75. Glazner, A.F., 1991, Plutonism, oblique subduction, and continental growth: An example from the Mesozoic of California: Geology, v. 19, p. 784–786, doi: 10.1130/0091-7613(1991)019<0784:POSACG>2.3.CO;2. Grubb, H.F., 1984, Planning report for the Gulf Coast regional aquifer system analysis in the Gulf of Mexico Coastal Plain, United States: U.S. Geological Survey Water Resources Investigations Report 84-4219, 30 p. Guinness, E.A., Arvidson, R.E., Strebeck, J.W., Schulz, K.J., Davies, G.F., and Leff, C.E., 1982, Identification of a Precambrian rift through Missouri by digital image processing of geophysical and geological data: Journal of Geophysical Research, v. 87, p. 8529–8545. Harrison, R.W., and Litwin, R.J., 1997, Campanian coastal plain sediments in southeastern Missouri and southern Illinois-significance to the early geologic history of the northern Mississippi Embayment: Cretaceous Research, v. 18, p. 687–696, doi: 10.1006/cres.1997.0080. Harrison, R.W., and McDowell, R.C., 2003, Geologic map of the Wilderness and Handy quadrangles, Oregon, Carter, and Ripley Counties, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2801, scale 1:24,000, 1 sheet. Harrison, R.W., and Schultz, A., 1994, Strike-slip faulting at Thebes Gap, Missouri and Illinois: Implications for New Madrid tectonism: Tectonics, v. 13, no. 2, p. 246–257, doi: 10.1029/93TC03190. Harrison, R.W., and Schultz, A., 2002, Tectonic framework of the southwestern margin of the Illinois basin and its influence on neotectonism and seismicity: Seismological Research Letters, v. 73, no. 5, p. 698–729. Harrison, R.W., Orndorff, R.C., and Weems, R.E., 1996, Geology of the Fort Leonard Wood Military Reservation and adjacent areas, south-central Missouri: U.S. Geological Survey Open-File Report 96-60, 10 sheets, scale 1:24,000. Harrison, R.W., Lowell, G.R., and Unruh, D.M., 2000, Geology, geochemistry, and age of Mesoproterozoic igneous rocks in the Eminence-Van Buren area: a major structural outlier of the St. Francois terrane, south-central Missouri [abs.]: Geological Society of America Abstracts with Programs, v. 32, no. 3, p. A-14.

156

Lowell et al.

Harrison, R.W., Orndorff, R.C., and Weary, D.J., 2002, Geology of the Stegall Mountain 7.5-minute quadrangle, Shannon and Carter Counties, south-central Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2767, scale 1:24,000, 1 sheet. Harrison, R.W., Lowell, G.R., Dolde, J.L., and Clendenin, C.W., 2003, Basement-cover tectonic relationships in southeastern Missouri, in Cox, R.T., ed., Fieldtrip guidebook for joint meeting of South-Central and Southeastern sections of the Geological Society of America: Tennessee Department of Environment and Conservation, Division of Geology, Report of Investigations 51, p. 105–144. Harvey, E.J., 1980, Ground water in the Springfield-Salem Plateaus of southern Missouri, and northern Arkansas: U.S. Geological Survey water-resources Investigations Report 80-101, 66 p. Hauck, H.S., Huber, L.G., and Nagel, C.D., 1997, Water resources data Missouri, water year 1996: U.S. Geological Survey Water-Data Report MO-96-1, 292 p. Hayes, W.C., 1960, Geologic map of the Stone Hill 15″ quadrangle, Missouri: Missouri Department of Natural Resources, Division of Geology and Land Resources, scale 1:65,000. He, Z., Gregg, J.M., Shelton, K.L., and Palmer, J.R., 1997, Sedimentary facies control of fluid flow and mineralization in Cambro-Ordovician strata, southern Missouri, in Montañez, I.P., et al., eds., Basin-wide fluid flow and associated diagenetic patterns: Integrated petrologic, geochemical, and hydrologic considerations: SEPM (Society for Sedimentary Geology) Special Publication 57, p. 81–99. Hedden, W.J., 1968, Bedrock geology (80%) of the Thayer 7.5-minute quadrangle, Ripley County, Missouri: unpublished data on file at the Missouri Department of Natural Resources, Division of Geology and Land Survey, Rolla, Missouri, 1:24,000 scale. Heller, R.L., 1954, Stratigraphy and paleontology of the Roubidoux Formation of Missouri: Missouri Division of Geological Survey and Water Resources: Second Series, v. 35, p. 118. Heyl, A.V., Odland, S.K., Moss, C.K., and Ryan, G.S., 1983, Mineral resource potential map of the Irish Wilderness Roadless Area, Oregon County, Missouri: U.S. Geological Survey Miscellaneous Field Studies Map MF1511A, scale 1:24,000. Hildenbrand, T.G., and Hendricks, J.D., 1995, Geophysical setting of the Reelfoot rift and relations between rift structures and the New Madrid seismic zone: U.S. Geological Survey Professional Paper 1538E, 30 p. Hildenbrand, T.G., Griscom, A., Van Schmus, W.R., and Stuart, W.D., 1996, Quantitative investigations of the Missouri gravity low; A possible expression of a large, Late Precambrian batholith intersecting the New Madrid seismic zone: Journal of Geophysical Research, v. 101, no. B10, p. 21,921–21,942, doi: 10.1029/96JB01908. Hosman, R.L., and Weiss, J.S., 1991, Geohydrologic units of the Mississippi Embayment and Texas coastal uplands aquifer systems, south-central United States: U.S. Geological Survey Professional Paper 1416-B, 19 p. Howe, W.B., Kurtz, V.E., and Anderson, K.H., 1972, Correlation of Cambrian strata of the Ozark and Upper Mississippi Valley regions: Missouri Geological Survey and Water Resources Report of Investigations No. 52, 68 p. Hutton, D.H.W., 1990, A new mechanism of granite emplacement: Intrusion in active extensional shear zones: Nature, v. 343, p. 452–455, doi: 10.1038/343452a0. Imes, J.L., 1989, Major geohydrologic units in and adjacent to the Ozark Plateaus province, Missouri, Arkansas, Kansas, and Oklahoma-basement confining unit: U.S. Geological Survey Hydrologic Investigations Atlas HA-711-B, scale 1:750,000, 1 sheet. Imes, J.L., 1990a, Major geohydrologic units in and adjacent to the Ozark Plateaus province, Missouri, Arkansas, Kansas, and Oklahoma-Ozark aquifer: U.S. Geological Survey Hydrologic Investigations Atlas HA-711-E, scale 1:750,000, 3 sheets. Imes, J.L., 1990b, Major geohydrologic units in and adjacent to the Ozark Plateaus province, Missouri, Arkansas, Kansas, and Oklahoma–St. Francois aquifer: U.S. Geological Survey Hydrologic Investigations Atlas HA711-C, scale 1:750,000, 2 sheets. Imes, J.L., and Kleeschulte, M.J., 1995, Seasonal ground-water level changes (1990–1993) and flow patterns in the Fristoe Unit of mark Twain National Forest, southern Missouri: U.S. Geological Survey Water Resources Investigations Report 95-4096, 1 sheet. Imes, J.L., and Smith, B.J., 1990, Areal extent, stratigraphic relation, and geohydrologic properties of regional geohydrologic units in southern Missouri: U.S. Geological Survey Hydrologic Investigation Atlas HA-711-I, scale 1:750,000, 3 sheets.

Imes, J.L., Plummer, L.N., Kleeschulte, M.J., and Schumacher, J.G., 2007, Recharge area, base-flow and quick-flow discharge rates and ages, and general water quality of the Big Spring in Carter County, Missouri, 2000– 2004: U.S. Geological Survey, Scientific Investigations Report 20075049, 79 p. Ji, Z., and Barnes, C.R., 1993, A major conodont extinction event during the Early Ordovician within the Midcontinent Realm: Palaeogeography, Palaeoclimatology, Palaeoecology, v. 104, p. 37–47, doi: 10.1016/0031 -0182(93)90118-3. Kane, M.F., and Godson, R.H., 1989, A crust/mantle structural framework of the conterminous United States based on gravity and magnetic trends, in Pakiser, L.C., and Mooney, W.D., eds., Geological Society of America Memoir 172, p. 383–403. Kisvarsanyi, E.B., 1981, Geology of the Precambrian St. Francois terrane, southeastern Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigations no. 64, (Contribution to Precambrian Geology Number 8) 58 p. Kisvarsanyi, E.B., 1984, The Precambrian tectonic framework of Missouri as interpreted from the magnetic anomaly map: Missouri Department of Natural resources, Contributions to Precambrian Geology No. 14, part B, 19 p. Kisvarsanyi, E.B., 1988, Precambrian ring complexes and mineralization in southeast Missouri, in Kisvarsanyi, E.B., and Grant, S.K., eds., Proceedings Volume North American Conference on tectonic Control of ore deposits and the vertical and horizontal extent of ore systems: Rolla, Missouri, University of Missouri, p. 312–321. Kisvarsanyi, E.B., and Kisvarsanyi, G., 1990, Alkaline granite ring complexes and metallogeny in the Middle Proterozoic St. Francois terrane, southeastern Missouri, U.S.A., in Gower, C.F., Rivers, T., and Ryan, B., eds., Mid-Proterozoic Laurentia-Baltica: Geological Association of Canada Special Paper 38, p. 433–446. Kisvarsanyi, G., and Kisvarsanyi, E.B., 1976, Orthopolygonal tectonic patterns in the exposed and buried Precambrian basement of southern Missouri, in Hodgson, R.A., ed., Proceedings of the 1st International Conference on the New Basement Tectonics: Utah Geological Association Publication no. 5, p. 169–182. Kleeschulte, M.J., 2000, Ground- and surface-water relations in the Eleven Point and Current River Basins, south-central Missouri: U.S. Geological Survey Fact sheet 032-00, 6 p. Kleeschulte, M.J., 2001, Effects of lead-zinc mining on ground-water levels in the Ozark aquifer in the Viburnum trend, southeastern Missouri: U.S. Geological Survey Water-Resources Investigations Report 00-4293, 28 p. Kleeschulte, J.M., and Seeger, S.C.M., 2000, Depositional environment, stratigraphy and vertical hydraulic conductivity of the Fristoe Unit of the Mark twain National Forest, Missouri: U.S. Geological Survey WaterResources Investigations Report 00-4037, 65 p. Kleeschulte, J.M., and Seeger, S.C., 2001, Stratigraphy and vertical hydraulic conductivity of the St. Francois confining unit in townships 25–27 N. and ranges 01–02 W., southeastern Missouri: U.S. Geological Survey WaterResources Investigations Report 00-4270, 64 p. Kurtz, V.E., 1981, The Cambrian–Ordovician boundary in Missouri as determined by conodonts, in Taylor, M.E., ed., Short papers for the Second International Symposium on the Cambrian System, Golden, Colorado, U.S.A.: U.S. Geological Survey Open-File Report 81-743, p. 115–117. Loch, J., 2007, Trilobite biostratigraphy and correlation of the Lower Ordovician Kindblade Formation of Carter and Kiowa Counties, Oklahoma: Oklahoma Geological Survey Bulletin, v. 149, p. 1–157. Loiselle, M.C., and Wones, D.R., 1979, Characteristics and origin of anorogenic granites: Geological Society of America Abstracts with Programs, v. 11, p. 468. Lowell, G.R., 1991, The Butler Hill Caldera: a mid-Proterozoic ignimbrite-granite complex: Precambrian Research, v. 51, p. 245–263, doi: 10.1016/0301-9268(91)90103-H. Lowell, G.R., 2000, eruptive styles of Mesoproterozoic A-type calderas in southeastern Missouri, USA: Revista Brasileira de Geociencias, v. 30, p. 745–748. Lowell, G.R., and Clendenin, C.W., 2003, Recognition of Mesoproterozoic ductile shear along the Black fault in southeastern Missouri: Geological Society of America Abstracts with Programs, v. 35, no. 1, p. 70. Lowell, G.R., and Harrison, R.W., 2001, The Eminence-Van Buren volcanic series: a rift-related caldera: Geological Society of America Abstracts with Programs, v. 33, p. A-19.

Southern Ozark dome Lowell, G.R., and Harrison, R.W., 2009, Germanium: a novel pathfinder for Sn-W in the western St. Francois Terrane of Missouri: Geological Society of America Abstracts with Programs, v. 41, no. 2, p. 33. Lowell, G.R., and Ramo, O.T., 1999, Petrology and geochemistry of the Shepard Mountain Gabbro: implications for basalt genesis at 1.33 Ga in southeast Missouri: Geological Society of America Abstracts with Programs, v. 31, no. 5, p. A-32. Lowell, G.R., Osburn, G.R., and Roth, S.J., 1977, Cataclastic features of a section across the Roselle Fault Zone near Patterson, Missouri: Geological Society of America Abstracts with Programs, v. 9, no. 5, p. 623–624. Lowell, G.R., Darnell, B.D., and Young, G.J., 1995, The Ironton fault: identification of a Proterozoic mylonitic shear zone: Geological Society of America Abstracts with Programs, v. 27, no. 3, p. 69. Lowell, G.R., and Noll, P.D., 2001, Fe-Cu-Au-bearing scapolite skarn in moat sediments of the Taum Sauk Caldera, southeastern Missouri, USA: Mineralogical Magazine, v. 65, no. 3, p. 373–396, doi: 10.1180/002646101300119466. Lowell, G. R., Harrison, R. W., and Unruh, D. M., 2005, Contrasting rift-margin volcanism in the St. Francois terrane of Missouri at 1.47 Ga: Geochimica et Cosmochimica Acta (abstracts of the 15th Goldschmidt conference), v. 69, no. 10S, p. A-81. McCracken, M.H., 1971, Structural features of Missouri: Missouri Geological Survey and Water Resources Report of Investigations 49, 99 p. McCracken, E., and McCracken, M.H., 1965, Subsurface maps the lower Ordovician (Canadian Series) of Missouri: Missouri Geol. Survey and Water Resources, 6 sheets, scale 1:1,000,000. McDowell, R.C., 1998, Geologic map of the Greer 7.5-minute quadrangle, Oregon County, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2618, scale 1:24,000. McDowell, R.C., and Harrison, R.W., 2000, Geologic map of the Powder Mill Ferry 7.5-minute quadrangle, Shannon and Reynolds Counties, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2722, scale 1:24,000. Miller, J.A., and Appel, C.L., 1997, Ground water atlas of the United States: Missouri, Kansas, and Nebraska: U.S. Geological Survey Hydrologic Atlas HA-730-D. http://pubs.usgs.gov/ha/ha730/ch_d/index.html. Missouri Geological Survey, 1979, Geologic map of Missouri: Division of Geology and Land Survey, Rolla, Missouri, scale 1:1,000,000. Missouri Department of Natural Resources, Division of Geology and Land Survey, Missouri Environmental Atlas (MEGA), 2003, Missouri Department of Natural Resources, Division of Geology and Land Survey, CD-ROM. Moss, C.K., 1984, Geophysical map of the Irish Wilderness Roadless Area, Oregon and Ripley Counties, Missouri: U.S. Geological Survey Miscellaneous Field Studies Map MF-1511B, 1:100,000 scale. Mouat, M.M., and Clendenin, C.W., 1975, Ozark Lead Company mine, Viburnum trend, southeast Missouri: Missouri Department of Natural Resources, Geological Survey Report of Investigations No. 58, Guidebook to the geology and ore deposits of selected mines in the Viburnum trend, Missouri, p. 49–56. Muilenberg, G.A., and Beveridge, T.R., 1954. Kansas Geological Society, Seventeenth Regional Field Conference: Missouri Geological Survey and Water Resources, Report of Investigations 17, 63 p. Nason, F.L., 1892, A report on the iron ores of Missouri: Missouri Geological Survey, 2d series, v. 2, 366 p. Orndorff, R.C., 2003, Geologic map of the Fremont quadrangle, Shannon, Carter, and Oregon Counties, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2775, scale 1:24,000. Orndorff, R.C., and Harrison, R.W., 2002, Geologic map of the Winona 7.5-minute quadrangle, Shannon County, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2749, scale 1:24,000. Orndorff, R.C., and Weary, D.J., 2009, Geologic map of the Round Spring quadrangle, Shannon County, Missouri: U.S. Geological Survey Scientific Investigations Map 3073, scale 1:24,000. Orndorff, R.C., Harrison, R.W., and Weary, D.J., 1999, Geologic map of the Eminence quadrangle, Shannon County, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2653, scale 1:24,000. Orndorff, R.C., Weary, D.J., and Lagueux, K.M., 2000, Geographic information systems analysis of geologic controls on the distribution of dolines in the Ozarks of south-central Missouri, USA: Acta Carsologica, v. 29, no. 2, p. 161–175. Orndorff, R.C., Weary, D.J., and Harrison, R.W., 2006, The role of sandstone in the development of an Ozark karst system, south-central Missouri, in

157

Harmon, R.S., and Wicks, C., eds., Perspectives on karst geomorphology, hydrology, and geochemistry-A tribute volume to Derek C. Ford and William B. White: Geological Society of America Special Paper 404, p. 31–38, doi: 10.1130/2006.2404(04). Ozark Cave Diving Alliance, 2005, Alley Spring, Shannon County, Missouri [cave map]. Paarlberg, N.L., and Evans, L.L., 1977, Geology of the Fletcher mine, Viburnum trend, southeast Missouri: Economic Geology and the Bulletin of the Society of Economic Geologists, v. 72, p. 391–397. Palmer, A.N., 1991, Origin and morphology of limestone caves: Geological Society of America Bulletin, v. 103, p. 1–21, doi: 10.1130/0016-7606 (1991)103<0001:OAMOLC>2.3.CO;2. Palmer, J.R., 1989, Late Upper Cambrian shelf depositional facies and history, southern Missouri, in Gregg, J.M., Palmer, J.R., and Kurtz, V.E., eds., Field guide to the Upper Cambrian of southeastern Missouri: stratigraphy, sedimentology, and economic geology: Rolla, Missouri, University of Missouri, p. 1–24. Pearce, J.A., Harris, N.B.W., and Tindle, A.G., 1984, Trace element discrimination diagrams for tectonic interpretation of granitic rocks: Journal of Petrology, v. 25, p. 956–983. Pratt, W.P., Middendorf, M.A., Satterfield, I.R., and Gerdemann, P.E., 1992, Geologic map the Rolla 1° by 2 ° quadrangle, Missouri: U.S. Geological Survey Miscellaneous Investigations Series Map I-1998, scale 1:250,000. Repetski, J.E., Loch, J.D., and Ethington, R.L., 1998, Conodonts and biostratigraphy of the Lower Ordovician Roubidoux Formation in and near the Ozarks National Scenic Riverways, southeastern Missouri: National Park Service Paleontological Research, in Santucci, V.L, and McClelland, L., eds., Technical Report NPS/NRGRD/GRDTR-98/01, p. 109–115. Repetski, J.E., Loch, J.D., Ethington, R.L., and Dresbach, R.I., 2000a, A preliminary re-evaluation of the stratigraphy of the Roubidoux Formation of Missouri and correlative Lower Ordovician units in the southern Midcontinent, in Johnson, K.S., ed., Platform carbonates in the southern Midcontinent, 1996 Symposium: Oklahoma Geological Survey Circular 101, p. 103–106. Repetski, J.E., Orndorff, R.C., and Weary, D.J., 2000b, Conodont biostratigraphy of the Eminence Dolomite- Gasconade Dolomite contact interval in the Missouri Ozarks: Geological Society of America Abstracts with Programs, v. 32, no. 3, p. A-39–A-40. Román-Berdiel, T., Casas, A., Oliva-Urica, B., Pueyo, E., Liesa, C., and Soto, R., 2006, The Variscan Millares Granite (central Pyrenees): Pluton emplacement in a T fracture of a dextral shear zone: Geodinamica Acta, v. 19, p. 197–211, doi: 10.3166/ga.19.197-211. Ross, R.J., Jr., Hintze, R.L., Ethington, R.L., Miller, J.F., Taylor, M.E., and Repetski, J.E., 1997, The Ibexian, lowermost series in the North American Ordovician: U.S. Geological Survey, Professional Paper 1579, 50 p. Schmidt, C.J., Smedes, H.W., and O’Neill, J.M., 1990, Syncompressional emplacement of the Boulder and Tobacco Root batholiths (MontanaUSA) by pull-apart along old fault zones: Geological Journal, v. 25, p. 305–318, doi: 10.1002/gj.3350250313. Šebela, S., Orndorff, R.C., and Weary, D.J., 1999, Geological controls in the development of caves in the south-central Ozarks of Missouri, USA: Acta Carsologica, v. 28, no. 2, p. 273–291. Seeger, S.M., and Palmer, J.R., 1998, Synsedimentary tectonism in the St. Francois Mountains Region, southeast Missouri, in Seeger, S.M, and Palmer, J.R., eds., Syndepositional tectonics during the Late Upper Cambrian: Association of Missouri Geologists 45th Annual Meeting Guidebook, 25 and 26 September 1998, Farmington, Missouri, p. 1–24. Sims, P.K., 1990, Proterozoic basement map of the northern midcontinent, U.S.A: U.S. Geological Survey Miscellaneous Investigations Series Map I-1853A, scale 1:1,000,000, 1 sheet. Sims, P.K., and Peterman, Z.E., 1986, Early Proterozoic Central Plains orogen: A major buried structure in north-central United States: Geology, v. 14, p. 488–491, doi: 10.1130/0091-7613(1986)14<488:EPCPOA>2.0.CO;2. Sinha, B.N , and Kisvarsanyi, G., 1976, Precambrian volcanic rocks exposed on Stegall and Mule Mountains, Carter and Shannon Counties, Missouri; in Kisvarsanyi, E B , ed., Contribution to Precambrian Geology no. 6, Studies in Precambrian geology: Missouri Department of Natural Resources, Division of Geology and Land Survey, Report of Investigations no. 61, p. 114–121. Snyder, F.G., and Gerdemann, P.E., 1968, Geology of southeast Missouri lead district, in Ridge, J.D., ed., Ore deposits of the United States, 1933–1967, The Graton-Sales Volume, Volume 1: The American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc., New York, p. 326–358.

158

Lowell et al.

Spector, A., 1982, Interpretation of an aeromagnetic survey of parts of Shannon, Carter, Oregon, and Ripley Counties in southeastern Missouri: U.S. Geological Survey Open-File Report 82-832. Stafford, K.W., and Fratesi, B., 2009, Coast to coast excursion, eastern segment: Excursion guidebook for the 15th International Congress of Speleology of the International Union of Speleology, published under the auspices of the National Speleological Society, Huntsville, Alabama, 112 p. Starbuck, E., 1999, Bedrock geology of the Briar7.5′ quadrangle: Missouri Department of Natural Resources, Division of Geology and Land Survey OFM-99-332-GS, scale 1:24,000. Taylor, M., Smith, R.W., and Ahler, B.A., 1984, Gorceixite in topaz greisen assemblages, Silvermine area, Missouri: The American Mineralogist, v. 69, p. 984–986. Thompson, T.L., 1991, Paleozoic succession in Missouri Part 2, Ordovician System: Missouri Department of Natural Resources, Division of Geology and Land Survey Report of Investigations No. 70, 282 p. Thompson, T.L., 1995, The stratigraphic succession in Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, v. 40, 2nd series (revised), 190 p. Tikoff, B., and Teyssier, C., 1991, Dextral shearing in the east-central Sierra Nevada magmatic arc: Implications for Late Cretaceous tectonics and passive emplacement of granite: Geological Society of America Abstracts with Programs, v. 23, no. 5, p. A176. Ulrich, E.O., 1911, Revision of the Paleozoic systems: Geological Society of America Bulletin, v. 22, no. 3, p. 281–680. Van Schmus, W.R., Bickford, M.E., Sims, P.K., Anderson, R.R., Shearer, C.K., and Treves, S.B., 1993, Proterozoic geology of the western midcontinent basement, in Reed, J.C., Jr., et al., eds., Precambrian: Conterminous U.S.: Boulder, Colorado, Geological Society of America, Geology of North America, v. C-2, p. 239–259. Van Schmus, W.R., Bickford, M.E., and Turek, A., 1996, Proterozoic geology of the east-central Midcontinent basement, in van der Pluijm, B.A., and Catacosinos, P.A., eds., Basement and basins of eastern North America: Geological Society of America Special Paper 308, p. 7–32. Vineyard, J.D., 1985, Geology of Springs in the Jacks Fork–Current River area, in Vineyard, J.D., ed., Guidebook to the Geology of Springs in the Ozarks of South-Central Missouri: Association of Missouri Geologists 32nd Annual Meeting and Field Trip, Salem, Missouri, 27–28 September 1985, p. 21–56. Vineyard, J.D., and Feder, G.L., 1982 (revised 1974 edition), Springs of Missouri: Missouri Department of Natural Resources, Division of Geology and Land Survey, Water Resources Report 29, 212 p.

Weary, D.J., 2008a, Geologic map of the Cedar Grove quadrangle, Dent and Shannon Counties, Missouri: U.S. Geological Survey Geologic Investigations Map I-2980, scale 1:24,000. Weary, D.J., 2008b, Geologic map of the Piedmont Hollow quadrangle, Oregon County, Missouri: U.S. Geological Survey Geologic Investigations Map I-2979, scale 1:24,000. Weary, D.J., and McDowell, R.C., 2006, Geologic map of the Big Spring quadrangle, Carter County, Missouri: U.S. Geological Survey Scientific Investigations Map SIM-2804, scale 1:24,000. Weary, D.J., and Schindler, J.S., 2004, Geologic map of the Van Buren South quadrangle, Carter County, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2803, scale 1:24,000. Weary, D.J., and Weems, R.E., 2004, Geology of the Van Buren North 7.5-minute quadrangle, Shannon and Carter Counties, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2802, scale 1:24,000. Wedge, W.K., 1999, Bedrock geologic map of the Poyner 7.5′ quadrangle: Missouri Department of Natural Resources, Division of Geology and Land Survey OFM-99-348-GS, scale 1:24,000. Weems, R.E., 2002, Geology of the Low Wassie 7.5-minute quadrangle, Shannon and Oregon Counties, Missouri: U.S. Geological Survey Geologic Investigations Series Map I-2719, scale 1:24,000. Whalen, J.B., Currie, K.L., and Chappell, B.W., 1987, A-type granites: geochemical characteristics, discrimination and petrogenesis: Contributions to Mineralogy and Petrology, v. 95, p. 407–419, doi: 10.1007/ BF00402202. White, A.J.R., and Chappell, B.W., 1983, Granitoid types and their distribution in the Lachlan Fold Belt, Southeastern Australia: Geological Society of America Memoir 159, p. 21–34. Winchester, J.A., and Floyd, P.A., 1977, Geochemical discrimination of different magma series and their differentiation products using immobile elements: Chemical Geology, v. 20, p. 325–343, doi: 10.1016/0009-2541 (77)90057-2. Winslow, A., 1894, Report on lead and zinc, Part 1: Missouri Geological Survey, v. 11, 331 p. Wohletz, K, 2004, Kware Magma: a program copyrighted by Regents of the University of California, available from internet.cybermesa.com/~wohletz/ Kware.htm. Zietz, I., compiler, 1982, Composite magnetic anomaly map of the United States, Part A—Conterminous United States: U.S. Geological Survey Map GP954A, 2 sheets, scale 1:2,500,000. MANUSCRIPT ACCEPTED BY THE SOCIETY 19 FEBRUARY 2010

Printed in the USA