Lecture Notes in Earth Sciences Edited by Somdev Bhattacharji, Gerald M. Friedman, Horst J. Neugebauer and Adolf Seilacher
6 Werner Ricken
Diagenetic Bedding A Model for Marl-Limestone Alternations
Springer-Verlag Berlin Heidelberg NewYork London Paris Tokyo
Author
Dr. Wemer R~cken until October 1986: University of Colorado, Department of Geologfcal Sciences Campus Box 250, Boulder, CO 80309, USA after October 1986: UnJversit&tTublngen, Institut fur Geologie und Pal~.ontologie Slgwartstr. 10, D-7400 TL~blngen, FRG
ISBN 3-540-16494-4 Spnnger-Verlag Berlin Heidelberg New York ISBN 0-387-16494-4 Spnnger-Verlag New York Heidelberg Berlin
This work is subject to copyright All rights are reserved, whether the whole or part of the material is concerned, specifically those of translation, repnntlng, re-use of illustrations, broadoastlng, reproductJon by photocopying machine or slmiFar means, and storage in data banks Under § 54 of the German Copyright Law where copies are made for other than private use, a fee is payabre to "Verwertungsgesellscha{t Wed", Munich © Spnnger-Verlag Berlrn Heidelberg 1986 Printed in Germany Pnntlng and binding Beltz Offsetdruck, Hemsbach/Bergstr 2132/3140-543210
P R E F A C E
The in
study
of
calcareous
Geology.
Often
representations of
any
of
large
and
affect
intends
to
quantify This
and
is
to
data
independent This
book
is
Department
of
by
ideas out
is
in
development
of
of
of
Paleontology
diagenetic
were
ago with
C.
1979 to 1981.
Tfibingen,
the m a j o r
cyclic
ideas
sedimentation
provided
which
combine
can
ideas.
also
which
Pal~kologie" W.
was
at
the
Germany).
formulated
~y
during
alternations
core
which
HEMLEBEN ( T f i b i n g e n )
for this
study
developed
models.
I gratefully
the s t u d y
in c r i t i c a l
encouraging
The
be
problem.
and
were during
spanning
support.
in r e s p o n s e
thank
G.
I also
wish
and w h o
to t h a n k C.
for p r o v i d i n g
f i e l d trips with A.G. FISCHER (Los Angeles) and
T. HERBERT (Princeton) in Italy, who showed me the Gubbio s e c t i o n explained
their
marl-limestone (Liverpool),
view
of
a preferentially
alternations, who
were
independently
very
cyclic
stimulating.
developed
formation R.
to my c o l l e a g u e s
at the B o u l d e r D e p a r t m e n t
P.
HARRIES,
author
E. K A U F F M A N ,
would
also
llke
about
of Earth who
especially R. DINER, D. EICHER, W. ELDER,
J. K I R K L A N D , to
of
he could.
Sciences (Colorado), where I did a part of the t r a n s l a t i o n work, s u s t a i n e d me in m a n y ways,
and
BATHURST
a similar model
dlagenetic bedding, gave a lot of support and h e l p e d w h e r e I am g r a t e f u l
to
EINSELE
discussions
HEMLEBEN, F. LIPPMANN, and A. SEILACHER (all Tfibingen) valuable
to
After my return from G~ttingen University to
(T~bingen), who p r o m o t e d always
of one
discussions with W. EDER and M. WALTHER (both at G ~ t t i n g e n ) the y e a r s
it
exchanges.
my d i s s e r t a t i o n
marl-limestone
years
mass
(Tfibingen,
bedding
First,
methods
alternation
translation
carbonate
allows
methods
These
usually
processes
approach
terms
effects
are
of
the
as
however,
twofold.
of
measurements.
stylolitic
several
rhythm
new
the
study, which
"Sonderforschungsbereich
and
about of
this
marl-limestone
the
Geology
examinations
the
an updated
funded
carried
the
and
diagenesis
compaction
showing
processes
textbook
field
interpreted
This
understanding
Secondly,
of
partially first
better
through
with
this
an important
simply
without
amplitude of
understand
possible
chemical used
a
bedding.
cycles
diagenetic
the
purpose
provide
become
are
overprinting.
the
both The
diagenetic
climatic
with
has
rhythms
diagenetic
predominantly
oscillations.
rhythms
bedding
primary
appreciable
deals
bedding
these
B.
acknowledge
SAGEMAN,
T. W A L K E R .
The
several
colleagues
for
IV
discussions, BARCHERT FRANKE LANG
written
communications,
(Erlangen),
(GSttingen),
(Erlangen),
U. B A Y E R
LOWENSTAM
(Tfiblngen), U.
(Dublin),
J.
VEIZER
ideas
ROSENFELD
(Ottawa),
(Tfibingen), W. W I L L E
(Pasadena),
(GSttlngen),
NEUGEBAUER
of
These are T. (Lyon),
W.
E. F L S G E L (Erlangen), H. FOCHTBAUER (Bochum), B.
H.A.
(Tfibingen), D. M E I S C H N E R
exchange
and field trips.
(Tfibingen), P. C O T I L L O N
(Mfinster),
H.R.
WANLESS
(Tfibingen), and A.
with
my
H.P.
G. N A P O L E O N E W.
J.
SCHWARZACRER
(Miami),
WETZEL
fellow T6bingen
LUTERBACHER (Florence),
J. W I E D M A N N
(Tfibingen).
doctoral
The
s t u d e n t s was
instructive, especially with D. RUPP (field trip to s o u t h e r n F r a n c e ) , T. A I G N E R ,
C. RUCH,
as w e ] l
as G. G E B H A R D
and W. RIEGRAF (who both
helped with the identification of fossils). M.
HECKENBERGER,
H. W I N D E R
(both of Tfibingen) and L. W I T T O C K
(Brussels) did some of the a n a l y t i c a l w o r k extensive
n u m b e r of raw samples.
and h e l p e d
to r e d u c e
the
The acetic acid disintegration and
the determination of minor elements were performed in the G e o c h e m i c a l Central
Laboratory
t o g e t h e r with
M. F E T H
and H. FRIEDRICHSEN.
The
sampling of interesting quarry walls was possible due to T. R A T H G E B E R (Ludwigsburg), rope.
s u p p l i e d me with a steel rope ladder and climbing
W. WETZEL (Tfibingen) made reproductions of some of the figures.
Several with
who
p e r s o n s were very helpful with improving the English text and
c o r r e c t i n g the p r o o f s .
HERRMANN,
L.
HOBERT,
(Boulder) typed the text
and
These H.
are
WINDER
of the E n g l i s h
P.
HARRIES
(Boulder),
(all Tfibingen). edition.
E.
J. S A F F E L L
To all
these,
my
grateful thanks.
Boulder, ~arch
Colorado
1986
Werner
Ricken
C O N T E N T S III
PREFACE SYMBOLS
OF
THE
MOST
COMMONLY
USED
PARAMETERS
VIII
INTRODUCTION i.I
ConcePt
of
1.2
Studied
Marl-Limestone
METHODS
FOR
CARBONATE
2.1
Diagenetic
THE
Bedding Alternations
QUANTIFICATION
DISSOLUTION
Evaluating
AND
Basic
2.1.1
Carbonate
2.1.2
Compaction
2.2
Derivation
of
2.3
Carbonate
Mass
OF
DIAGENETIC
CEMENTATION
Diagenetic Content
PROCESSES
Parameters
7
Porosity
7
and
7
the
Compaction
Balance
12
Law
and
Primary
Sediment 17
Composition 2.3.1
Closed
or
Burial
Diagenesis
2.3.2
Uncertainties
2.3.3
Sampling
2.3.4
Testing
2.3.5
3
Carbonate
19
Resulting
from
Primary
Evaluation
Compositional
of
the
Mean
2.3.6
Carbonate
Mass
Balance
2.3.7
Important
Definitions
Balance
Marl-Chalk
Sicily
the 29
DIAGENESIS
IN
33 Marl,
Pliocene, 35
Alternation,
Pelagic
to
3.3.2
from
(PE) Basin
3.3.1
CARBONATE
Foraminiferal
Saxony
Vocontian
25
Calculation Resulting
30
ALTERNATIONS
3.2
22
23
Lithification
MARL-LIMESTONE
Uncemented
21
Porosity
Method
OF
3.1
Method
Differences
Primary
Decompaction
of
the
22
from
Onset
During
Procedure
QUANTIFICATION
3.3
System
Resulting
Mass 2.4
Open
Cenomanian,
Lower 38
(R)
Neritic Basin,
Marly
Alternations Lower
Alternation,
Rhythmic Hauterivian
the France
Valanginian
Marl-Limestone (A2)
of
Cretaceous,
(AI)
42 44
Alternation, 48
VI 3.3.3
Black
3.3.4
Barremian (A3) Neritic Marl-Limestone
Shale-Limestone
Hauterivian 3.4
Epicontinental Southern
56 Alternations
3.4.1
Middle
3.4.2
Upper
Cretaceous
61
Oxfordian
Alternation
Oxfordian
to
67
Tertiary
Deep
Stylolitic Stylolitic
3.5.3
Marly
Results
DIAGENETIC
and
Silty
4.1
Carbonate
Profiles
4.2
Thickness
of
4.3
Development
of
4.4
Diagenetic 4.4.1
4.4.2
5.1
the
of
and
the
Related
to
the
Bedding of
Rhythm
106 Variations
in
Maximum
Compaction
Between
Cementation
Differential
of
109
Zones
Particles
Due
110
Compaction
Diagenetic
Bedding
Rhythms
112
Diagenetic
Bedding
Rhythms
114
CAUSES
Processes
AND
of
SIMULATION
Burial
MODELS
Burial
5.3
Calculation Carbonate
5.4
Simulation
117
Carbonate
117
Redistribution 5.2
106
Primary
107
and
BEDDING:
Causes
97 as
Number
Enrichment
of
91
91
Layers
Content
Differential
Simulation
DIAGENETIC
of
Oscillations
Relative
81
99
Carbonate
Conclusions:
RHYTHMICITY
Layers
in
4.6
BEDDING
Layers
Enhancement
4.5
(G3)
Events
Dissolution
5
AND
Reduction
to
Oligocene
85
Limestone
Carbonate
4.4.4
79
(G2)
Types
Limestone
Diminution
4.4.3
71
(G1)
Oligocene
in Limestone
the
the
Alternation,
FORMATION
Depositional
from
Boundary
Alternation,
to
Limestones, 69
Limestones
Bedding
LEDGE
Water
Italy
Cretaceous-Tertiary 3.5.2
63
(N1)
Well-Bedded
(N2)
Apennines,
3.5.1
4
of
Germany
Umbrian
3.6
52 Alternation,
(L)
Jurassic
Limestones 3.5
Alternation,
Reduction
and
of
Cement
the
"Inversion"
Content
and
Diagenetic
Porosity
123
Primary
125
Content of
of
Separation
130
VII
5.5
Diagenetic
Bedding:
Stratiform
Process
5.6
Discussion
of
5.7
Conclusions
APPLICATIONS
Standardized
6.2
Porosity
6.3
Compaction
6.4
Primary
6.5
Cement
6.6
Primary
THE
9
I0
Fraction
Alternations
(NC d)
147
(n)
149
149 150
OF
Content
MINOR
150
(C o )
ELEMENTS
CONTAINED
IN 154
FRACTION
Time
and
the
During
Problem
of
Incongruent
Disintegration
of
the 154
Fraction of M i n o r
Interpretation Minor
Elements
Contained 156
Fraction
of M i n o r Element
Enrichment
Element
Mass
160
Behavior
Balance
of M i n o r
Differential
Calculation
Elements
Due
of
the P o r e
164
Solution
DEPOSITION
EXAMPLE
FROM THE UPPER
The
8.2
Processes
OF
MARL-LIMESTONE
JURASSIC,
GERMANY
174 176 181
of D e p o s i t i o n
8.2.1
Lag Deposits
8.2.2
Channel
8.2.3
Graded
182
and F a n
Systems
Calcilutites
DIAGENETIC
182 188 191
Conclusions
REFERENCES
ALTERNATIONS:
SOUTHERN
Bedding
CONCLUSIONS:
171 173
Conclusions
8.1
160
to
Compaction
Composition
PRIMARY
8.3
147
(n o )
in the C a r b o n a t e
7.4
QUANTIFICATION
( Z c , Z d)
Carbonate
Concentrations
7.3.3
THE
149
Porosity
Carbonate
7.3.2
FOR
(K)
Content
Reaction
7.3.1
143
Model
REDISTRIBUTION
Noncarbonate
Dissolution
7.3
METHODS
in L i t h i f i e d
CARBONATE
7.2
Seibold
RAPID
DIAGENESIS
7.1
the
CARBONATE
6.1
BURIAL
142
145
AND
OF DIAGENETIC
A Predominantly
BEDDING
192 196
S Y M B O L S
OF
THE
MOST
C O M M O N L Y
USED
P A R A M E T E R S
a,b
Large (a) and small (b) axes of deformed, originally cylindrical burrows (perpendicular to the burrow tube). Carbonate content (volume or weight%). Carbonate content expressed as a percentage of the decompacted (primary) sediment volume (vol%). Statistically neutral carbonate content at the boundary between dissolution and cementation zones (%). Carbonate c o n t e n t at t h e w e a t h e r i n g b o u n d a r y b e t w e e n marl and limestone (%). C a r b o n a t e content of the p r i m a r y sediment (vol%). Primary carbonate content expressed as a percentage of the decompacted (original) sediment volume (vol%). Amount of calcium in a solution (s) and in calcite (cc) which is precipitated from this solution. Burrow deformation, expressed as the amount of reduction of the original thickness (%). Density gradient in existing carbonate ooze, which is dependent on overburden, after HAMILTON ( 1 9 7 6 ) . Quotient describing the relative enrichment of insoluble particles in a given volume of the marl beds relative to that of the adjacent limestone layers. Factor calculating the diagenetic enhancement between original and postdiagenetic carbonate fluctuations. Thickness of a compacted rock interval. Thickness of a decompacted rock interval. Compaction of primary sediment volume by a certain amount (vol%). Mean compaction in the middle of the limestone layers in an alternation, defined as the amount of compaction at the onset of lithification. This is equivalent to the mechanical compaction (MK, v o l % ) . Compaction at the statistically neutral zone between the intervals of carbonate dissolution and cementation (vol%). Compaction in the middle of adjacent limestone and marl layers (vol%). Mean compaction in the zones of carbonate dissolution and cementation within a given marl-limestone alternation (vo1%). Distribution coefficient describing t h e m o l a r r a t i o of a trace e l e m e n t (TE) a n d c a l c i u m b e t w e e n t h e p r e c i p i t a t i n g mineral phase (cc) and the solution. Mechanical compaction, equivalent to the degree of compaction at the onset of litbification K1 ( v o l % ) . Porosity, expressed as a percentage of the rock or sediment volume (vol%). Porosity, expressed as a percentage of the decompacted (primary) sediment volume (vol%). Porosity of the sediment at t h e o n s e t of l i t h i f i c a t i o n (vol%). Mean decompaction p o r o s i t y (vol%) r e s u l t i n g from n u m e r i c a l d e c o m p a c t i o n of the entire section studied. Amount of insoluble particles contained in a g i v e n (compacted) rock volume.
C Cd Cn Cw Co Cod
Cas,Cacc D d e F h h* K K1
Kn KL,K M K_z,K Z k Tca E
MK n
nd nI no N
AN NL,N M No NC NC d
NCdr
P,R
P~o S G t TE ATE
TE n
TEp,TE R
TEs,TEcc TE_z,TE Z
V_z,V Z X
z
-Z,Z
-Zd,Z d
-Zc,Z c
I n c r e a s e of i n s o l u b l e p a r t i c l e s c o n t a i n e d in a given volume of rock after compaction. A m o u n t of insoluble p a r t i c l e s c o n t a i n e d in a given volume of rock in adjacent limestone (L) and marl beds (M). Original amount of i n s o l u b l e p a r t i c l e s c o n t a i n e d in an u n o o m p a c t e d sediment or rock volume. Noncarbonate f r a c t i o n , e x p r e s s e d as a p e r c e n t a g e of the total volume of solids (vol%). Noncarbonate f r a c t i o n , e x p r e s s e d as a p e r c e n t a g e of the d e c o m p a c t e d (primary) sediment v o l u m e ; a l s o r e f e r r e d to as "absolute clay content" (vol%). Noncarbonate f r a c t i o n , e x p r e s s e d as a p e r c e n t a g e of the d e c o m p a c t e d ( p r i m a r y ) s e d i m e n t v o l u m e in d e n s e or n e a r l y dense rock with no or low p o r o s i t y (vol%). "Primary" c a r b o n a t e f r a c t i o n (P) w i t h i n the c e m e n t a t i o n zone, relic c a r b o n a t e f r a c t i o n (R) w i t h i n the d i s s o l u t i o n zone. D e n s i t y of sediment (g/cm 3) w i t h o v e r b u r d e n (h). Density of mineral grains (g/cm3). Density of the d e c o m p a c t e d (primary) sediment (g/cm3). Amount of p o r e - f r e e solids (vol%). Standard deviation. Time since deposition. Concentration of a g i v e n m i n o r e l e m e n t c o n t a i n e d in the carbonate fraction (ppm). Increase or decrease in c o n c e n t r a t i o n of a g i v e n m i n o r element c o n t a i n e d in the c a r b o n a t e fraction due to c h e m i c a l compaction (ppm). Concentration of a g i v e n m i n o r e l e m e n t c o n t a i n e d in the carbonate fraction at t h e n e u t r a l boundary between dissolution and c e m e n t a t i o n zones (ppm). Concentration of a g i v e n m i n o r e l e m e n t c o n t a i n e d in the "primary" (P) a n d r e l i c (R) carbonate fractions, r e s p e c t i v e l y (ppm). Concentration of a g i v e n m i n o r e l e m e n t c o n t a i n e d in the solution (s) and in the p r e c i p i t a t i n g c a l c i t e p h a s e (cc), r e s p e c t i v e l y (ppm). Concentration of a g i v e n m i n o r e l e m e n t c o n t a i n e d in the dissolved (-Z) and cemented (Z) c a r b o n a t e fractions, r e s p e c t i v e l y (ppm). Decompacted (primary) sediment volume for d i s s o l u t i o n zones (V_ z) and c e m e n t a t i o n zones (Vz), respectively. D e g r e e of c l o s u r e in the s y s t e m of the d i s s o l u t i o n zones to influx or outflux of a given minor element c o n t a i n e d in the c a r b o n a t e f r a c t i o n (%). 1 0 0 % c l o s u r e is e q u i v a l e n t to a complete retalnment of a given m i n o r e l e m e n t c o n c e n t r a t i o n in the d i s s o l u t i o n zone. C e m e n t n u m b e r , the r a t i o b e t w e e n the n o r m a l i z e d amounts of the d i s s o l v e d or c e m e n t e d c a r b o n a t e f r a c t i o n (Z d) and the primary c a r b o n a t e fraction (Cod). D i s s o l v e d c a r b o n a t e f r a c t i o n (-Z) and c e m e n t e d c a r b o n a t e fraction (Z); a l s o u s e d to d e s c r i b e the processes of d i s s o l u t i o n and cementation. Amounts of d i s s o l v e d (-Z d) a n d c e m e n t e d c a r b o n a t e (Zd), r e s p e c t i v e l y , e x p r e s s e d as a p e r c e n t a g e of the d e c o m p a c t e d (primary) sediment v o l u m e ( v o l % ) ; a l s o r e f e r r e d to as the "absolute amounts" of d i s s o l v e d a n d c e m e n t e d c a r b o n a t e (vol%). R e l a t i v e a m o u n t s of d i s s o l v e d (-Z c) and c e m e n t e d c a r b o n a t e (Zc) , r e s p e c t i v e l y , e x p r e s s e d as a p e r c e n t a g e of the total carbonate content (vol or weight%).
1
1.1
I N T R ODU
Concept
Numerous widespread
of
C T I O N
Diagenetic
contradictory phenomenon
marl-limestone
Bedding explanations
of
rhythmic
alternations
have
(EINSELE,
1982).
were made to distinguish such a l t e r n a t i o n s generated by repeated depositional events Later,
cyclic depositional p r o c e s s e s
bedding in marl-limestone
been
bedding,
cycles, which form by variations of 20,
40,
for
In the past, efforts
from sequences thought
which
to c a u s e
Such explanations
based on a model of rhythmic climatic oscillations, have periodicities
for the
(EINSELE & SEILACHER,
were
alternations.
proposed
particularly
are
1982).
rhythmic
are usually
named Milankovitch
in the Earth's orbital parameters and
I00,
and
400Ka
(e.g.,
GILBERT,
CQEO3 SEDIMENT WEATHERING
EIVETIC PDING Fig. 1 Concept of "dlagenetlc transformation of primary sediment marl-limestone alternation (right).
bedding" (left) into
Diagenetic a rhythmic
1895;
MILANKOVITCH, 1 9 3 0 ; 1982; RIO,
1984; This
FISCHER e t
study
alternations
al., of
According
cementation.
to this diagenetic
rhythmicity
principle,
similar
concepts
alternations HALLAM, 1 9 6 4 ;
TRURNIT & AMSTUTZ, 1 9 7 9 ;
present element
mass
discussed compaction carbonate
1.2
in
content,
Studied
In o r d e r
to
applicable
South
2,
to
In
explain
SUJKOWSKI,
1958;
CAMPOS & HALLAM, 1 9 7 9 ; BATHURST, 1 9 8 4 ;
these
have
attempts
somewhat
These on
been
unconvincing.
by u s i n g
based
more
In
to
carbonate
methods
to
quantify which
evaluate
between
the
an d m i n o r
calculations,
relationship
more
are rock
compaction,
Alternations
regional
conclusions,
selected
and Lower Alps),
pecularities
and to p r o d u c e
ten different with
various
sections degrees
from
different
areas.
Saxony
Basins
(Germany),
the Umbrian Apennines,
The studied alternations
Fig. 2
used
1926;
with
WALTHER, 1 9 8 2 ;
processes are
processes
sediment.
new m e t h o d s h a v e b e e n d e v e l o p e d
alternations
(French Maritime 2).
are
mathematical
eliminate
were
German
However,
primary been
whether
the
sequences
in the
WEPFER,
1982;
importance
Fig.
and p o r o s i t y .
generally overprint
frequently
rhythmic
Bankung";
because
generate
enhance
generate
of minor
have
carbonate
considerably
thereby
found
and
Marl-Limestone
marl-limestone
always
of marl-limestone
"diagenetische
only
calculations.
section
and on t h e
or
(e.g.,
cementation
balance
EINSELE,
COTILLON &
diagenetic
or stochastic,
EDER,
therefore, and
of
HENNIGSMOEN, 1 9 7 4 ;
qualitative
study,
dissolution
1984;
existence
that
SIMPSON, 1 9 8 5 ) .
solely
al.,
processes and
is
bedding than
BARRET, 1 9 6 4 ; GLUYAS, 1 9 8 4 ;
it
cyclic
marl-limestone
less
These bedding"
was
pronounced
the zones
variations
theory,
bedding
which produce
or
to explain
"diagenetic
original
FISCHER, 1 9 8 0 ;
BERGER e t
repeating
carbonate
(i.e.,
1982;
1985).
attempt
terms
and
primary
bedding 1).
will in
dissolution slight
the
FISCHER & ARTHUR, 1 9 7 7 ;
SCHWARZACHER & FISCHER,
more
of m i c r i t i c
of d i a g e n e t i c
These
are
from the
the Vocontian Basin
and Sicily
are from the Upper Jurassic,
(Italy, Fig. Cretaceous,
Marl-limestone alternations studied. R=Rheine (Upper Cretaceous), N=Neuffen (Upper Jurassic), GS=Geisingen (Upper Jurassic), A = A n g l e s (Lower C r e t a c e o u s ) , L = L o g i s du Pin (Lower Cretaceous, F = F o s s o m b r o n e ( M a a s t r i c h t i a n to Paleogene), G=Gubbio (Maastrichtian to Paleogene), P E = P o r t o Empedocle (Pliocene).
/.
8
confinenfel
16
epiconfinenfal, pelagic
20
furbidife deposif
,llll,ll
Tertiary . . . .
~1!1~1!1
\ ~ .\ .'~\-,c."
Cretaceous ,,..~'_x,x.~ Jurassic Triassic
12
iJ'f fj-~ f-"
N
Pa/eozoic
pi
and crystalline rocks
,u.,~. ~ ,
JpJ'f
~
"I?,,'3;-tl o'oJ~aJ
i
and T e r t i a r y . because
No s e c t i o n s
modern
calcareous
(SCHOLLE et al., 1983). be
based
older
partially
than U p p e r
plankton
did not
Jurassic were exist
before
Therefore, interpretations in this
on
the
diagenetic
behavior
chosen, this
age
study
can
of m o d e r n p e l a g i c
sediments. Sections with
diagenetic mobilization
of the
s i l i c a t e fraction
(e.g., those containing chert concretions) and dolomitized z o n e s w e r e not u s e d
due to theoretical restrictions (see section 2.2).
were restricted to relatively simple, but, very
promising
parameters,
such
parameters,
which
parameters. as r o c k include
These
compaction
for d i a g e n e t i c
include and
the c a r b o n a t e
not
porosity, content
minor and trace elements in the carbonate fraction.
Analyses
questions,
only
physical
but
chemical
and the a m o u n t of
M E T H O D S OF
D
FOR
I A G EN
THE
Q U A N T I F I C A T I O N
E T I C
D I S S O L U T I O N
C A R B ON
AND
A T E
C E M E N T A T I O N
P R O C E S S E S
Up t o
this
order
point,
methods
to provided
carbonate
contents
experiments
for
cementation
in
have
various
of
Since
the
micritic, for
been
as those
carbonates
marl-limestone
and c a l c a r e o u s
in
alternations
and
are
(Fig.
in this not
3) a r e
spheroidal,
law d e s c r i b e s
the n o n c a r b o n a t e
which
provides
Thereafter,
content
evidence
These
1978; cement
sections
are
completely methods content,
They are mathematically law
(section
2.2).
The
or rock composition in
of the o r i g i n a l
of the p r i m a r y
other
are c a r b o n a t e
sediment
According to this
v o l u m e is calculated
compositional
variations.
a carbonate mass balance calculation is performed based on
mathematical decompactlon (section 2.3). gives
the
w h i c h d e p e n d on t h e
relation to both degree of compaction and porosity. law,
and
be c i t e d
thin
study
suggested
and compaction (section 2.1).
compaction
to evaluate
peels
related in the derived c a r b o n a t e c o m p a c t i o n carbonate
theoretical
e dissolution
VINOPAL & COOGAN,
acetate
in
dissolved
models should
attempts
measurement of three basic parameters. rock porosity,
The
pressur
packing
and
1987).
particles
diagenesis
processes
cemented
developed. of
MANUS & COOGAN, 1 9 7 4 ;
MEYERS & HILL,
quantifying
diagenetic of
amounts
of sphere
as well
skeletal
(COOGAN, 1 9 7 0 ;
the
types
(RITTENHOUSE, 1 9 7 7 a , b ;
quantifying evaluation
scarcely
calculating
MITRA & BEARD, 1 9 8 0 ) content
for
a numerical
the m e a n
primary
The mass balance calculation
sediment composition of the existing marl and
limestone layers and the amounts of dissolved and cemented c a r b o n a t e . Compaction
and k n o w n
p o r o s l t y - o v e r b u r d e n data determine the porosity
at the onset of cementation and the timing of
llthlflcatlon
(section
2.4). The above-mentioned in
section
alternations.
3
for
measurements
ten
different
and c a l c u l a t i o n s profiles
of
were carried
out
marl-limestone
The resulting data were combined in sections 4 and 5 to
develop general models. Simple and somewhat imprecise methods (section 6)
are
applicable
calculations
and
to
diagenetic
other
methods
mass to
exchanges.
determine
the
Mass
balance
amount
and
QUANTIFICATIONOF DIAGENETICPROCESSES MEASUREMENT OF BASIC DIAGENETIC PARAMETERS: CARBONATE CONTENT, ~ POROSITY, COMPACTION ~ (SECTION 2.1)
CALCULATION OF THE NONCARBONATE FRACTIONNORMALIZED TO THE PRIMARY SEDIMENT VOLUME USING THE CARBONAIE COMPACTION LAW (SECTION 2.2 )
MEASUREMENT OF MINOR ELEMENTS CONTAINED IN THE CARBONATE FRACTION (SECTIONS 3, 7)
~
DETERMINATION OF MECHANICAL COMPACTION AND TIMING OF THE ONSET OFCEMENTATION (SECTION2./*)
CALCULATIONS:
CARBONATE MASS BALANCE CALCULATION:
MINOR ELEMENT MASSBALANCE
MEAN DECOMPACTION POROSITY(SECTION2.3.5)
COMPACTIONALENRICHMENT OFMINOR ELEMENTS
CEMENT MASSBALANCE (SECTION 2.3.6) COMPOSITION OF PRIMARYSEDIMENT, AND AMOUNTOF CEMENT CONTAINEDIN THE EXISTING ROCK
RELATIVE COMPOSITION OF PORE WATERS (SECTION 7)
GENERAL MODELS OF OIAGENESIS IN MARL-LIMESTONE ALTERNATIONS CARBONATE CURVES AND BEDDINGRHYTHMICITY (SECTION 4) DIAGENETIC SEPARATIDN (SECTIDN5)
APPLICATIONS AND RAPID DETERMINATIONS (SECTION 6)
Fig. S carbonate
redistribution presented
Methods used in o r d e r to dissolution and cementation
of
minor
in s e c t i o n
marl-limestone
7.
elements The
alternations
in
primary
quantify processes.
the
diagenetic
carbonate
depositional
fraction
are
processes
of
are d i s c u s s e d in only one example - from
the e x t r e m e l y w e l l - b e d d e d Upper J u r a s s i c in southern G e r m a n y
8).
(section
For
the
available 59).
most
These
from
important
(RICKEN, 1 9 8 5 b ) programs
laboratory
porosity, overburden;
carbonate
the
marl
layers
(Figs.
2.1
carbonate
Basic
Carbonate
Both carbonate reaction
time
expressed excess
curves
in
in
an d p o r o s i t y
minor
element
sediment
limestone
piles
are 58,
of carbonates balances;
with
increasing
and
with
decreasing
and c u b i c
(TI
mass
layers;
and c o m p a c t i o n integration
and p r o g r a m s
calculators
development
sphere
of
porosity
packing
in
models
67a).
Evaluating
2.1.1
and
time
content
due t o c e m e n t
66a,
density
carbonate and
instructions
Texas Instruments
calculate:
data;
compaction,
both
calculations using
as
Diagenetic
Content
content
and Porosity
and p o r o s i t y
o f 20 m i n u t e s CaCO3,
BC1 u s i n g
Parameters
was
can be e a s i l y
using
quantitatively
a solution
evaluated.
warm 1 M RC1, t h e
of
determined
0.5
M NaOB.
by
comparing
After
carbonate by
a
content,
titration
The
relative
the
weight
of
error
is
+0.02%. Rock sample its
porosity
in air
mineral
specific and
densities
then
shellac.
2.1.2
mineral
carbonate
was
from
the
The s a m p l e s
a desiccator
resulting
density
from the
and
obtained fractions
were dried with
coating
using
from
proportions
and coated shellac
of a given
principle)
and n o n c a r b o n a t e and
sample studied. in
(Archimedes
(2.71 of
for a thin
the
those
24 h o u r s layer
of
were corrected.
Compaction
addition
of
to the
RITTENROUSE,
clay
1977a,b; 1980),
reduction
to
due
presentation
of
in shales
and
previously
MITRA & BEARD,
(1974),
The
respectively)
cooled
Errors
Many s t u d i e s
curves
in water
of the
3,
in the
80oc
evaluated
that
density.
2.75g/cm
fractions at
was
versus
the
shale
compaction
mentioned
have
theoretical
MANUS & COOGAN, 1 9 7 4 ; other
experiments
overburden problem
were given
have and
conducted.
been
In (in
VINOPAL & COOGAN, 1 9 7 8 ;
an d m e a s u r e m e n t s carried
compilation
of
b y BALDWIN ( 1 9 7 7 ) ,
PERRIER & Q U I B L I E R ( 1 9 7 4 ) ,
been
considerations
ROLL ( 1 9 7 4 ) ,
out.
of porosity The
best
porosity-overburden
RIEKE & CHILINGARIAN an d BALDWIN & BUTLER
(1985).
Although
deformation
some
limestones
(PRAY, 1 9 6 0 ;
t h e Deep Sea D r i l l i n g
Project
holes,
experiments
an d c o m p a c t i o n
FRIEDMAN, does
1983;
indeed
1974;
1984)
occur,
done.
There
similar the
carbonate 1968;
ZANKL,
compaction
depending
(e.g.,
1969;
that
from
from drill
BHATTACHARYYA &
carbonate
compaction
(SCHLANGER & DOUGLAS,
in
carbonates
of deformed
al.,
1978;
yet
on
the
to
ooids,
b e t w e e n a few p e r c e n t
mainly
1970;
1977;
is
fossils,
to
overburden
EINSELE & MOSEBACH, I 9 5 5 ;
JANOWSKY,
CHAND e t
1977;
LOCKRIDGE & S C H O L L E ,
Compaction varies
content
data
measurements
al.,
calcilutites
1977;
observations
thickness,
MANGER, 1 9 7 1 ; 1983;
of
several
structures.
original
compactional
KOPF, 1 9 8 3 ) .
evaluation are
porosity
evidence
in
SCHOLLE,
little
BATHURST, 1 9 8 0 a , b ) ,
(SHINN e t
clear
especially
SCHMOKER & HALLEY, 1 9 8 2 ; Systematic
(DSDP),
provide
HAMILTON, 1 9 7 6 ;
display
STEINEN, 1 9 7 8 ;
90% o f and t h e
KAHLE, 1 9 6 6 ;
BALDWIN, 1 9 7 1 ;
be an d
WOLFE,
KETTENBRINK &
BEACH & SCHUMACHER, 1 9 8 2 ;
BATHURST,
MEYERS & HILL, 1 9 8 3 ) .
In
this
study,
the
evaluation
amount o f d e f o r m a t i o n
found in
Burrow
(D),
deformation
diameter,
of compaction
originally
expressed
is
based mainly
cylindrical
as
on t h e
burrow
percentage
loss
of
tubes.
original
equals:
100b D[%]
where
(a)
is
minor axis to
the
of the
if
paleoslope
the
the length
deformation or
at
should
4).
major
axis
major
the
due
various
more
the during
and more
sites grain
(b)
the
length
The a x e s
an d
are
perpendicular
the
major
axis
steep.
It
axis to
(1)
very
remained
Burrow deformation
within
stretched
become
the
was n o t
sediment
microseams) laterally
of
,
burrow tube;
of the
(Fig.
semilithified space
length
100
deformed burrow ellipse.
length
bedding that
the
of the
=
the
compaction,
in the
in the
compaction the in
or pore
(e.g., axis
aseismic
they are subject
1
burrow
of the
major
to
eq.
soft
dissolution If
sediments
folded when
during
either
pressure
structure.
parallel
assumed
constant
occurs
mechanical of
must lie is
of the
was
basins
to i n c r e a s i n g
overburden! In
order
well-preserved then measured
to
avoid
burrows using
used to test w h e t h e r
oblique were
cross
extricated
a m m scale.
sections
of
from
rock.
Burrows
the
the
perpendicular
or not the tubes were
originally
burrow The
tubes,
axes
were
to b e d d i n g were cylindrical.
/ If
t~
I
,,"
t~
i /
K-I :
~ I
1.f /
,i
I
Ill%-I
/
ou
II
....~::::i::i::iiiiiiiiiiii~iiiiiiiiiiiiiiiiiiiiiiiiii! ::~.... ~ ! i ! i ! ~ i ~
~.::~:.ii~::~i~::~::~::~?~i~:.~i~::~i~i~i~i~:~ii~i~i:.:
O = 60%
D=/+0%
C1 F i g . 4 How t o e v a l u a t e r o c k c o m p a c t i o n ( a l l c r o s s - s e c t i o n s cut perpendicular to both bedding and burrow tube). a: Primary volume of sediment containing a circular, sediment-filled burrow. b: It is assumed that in most cases the degree of compaction (K) i s p r o p o r t i o n a l to the degree of burrow deformation (D). c: B u r r o w s w h i c h a r e c e m e n t e d e a r l y i n d i a g e n e s i s show l e s s d e f o r m a t i o n (D) t h a n t h e a c t u a l c o m p a c t i o n o f t h e t o t a l r o c k (K). An e x a m p l e o f i n d i r e c t evaluation of rock compaction is given in the text. Direct
Evaluation
As PLESSMANN structures they
a part
as
Except
CRIMES ( 1 9 7 5 )
pointed
sediment.
itself.
usually
Thus,
loss
of
the
the
to
the
upper
sediment
3 to
10cm
of
(Fig.
which fossils
this
came f r o m t h e u p p e r m e t e r o f s e d i m e n t
carbonates
al.,
1984).
(WETZEL, 1 9 8 1 ) . tubes,
which
(Planolites)
Modern
(KENNEDY,
1975)
The t r a c e were
and
H~NTZSCHEL, 1 9 7 5 ) ;
used
trace
occur
fossils in
this
IV ( C h o n d r i t e s , level
III'overlies
in with
(BERGER e t
fossils five
originally
study,
all
Teichichnus, level
IV.
commonly is
of
al.,
in
in
1979;
found
in
bioturbation
circular lie
often
used
commonly
levels
the
4A,B).
trace
btoturbation,
as
(expressed is
sediment,
m i x e d due t o i n t e n s e
EKDALE e t
compaction,
same degree volume)
completely study
resist
the
degree of rock compaction
original
since
to the compactional
or partly
deform
bioturbation
of compaction,
Contrary
to the degree of burrow deformation for
out,
for the evaluation
which can completely
structures
percentage
proportional
and
suitable
of the sediment
of fossils,
bioturbation surrounding
Compaction
(1977)
are highly
are
behavior
of
levels
burrow III
and Thalassinoides;
10
Repeated
measurements
inaccurate.
Errors
measurements, curves,
the
etc.),
degree and
sorting,
best
were
Chondrites,
is
possible,
different of
by
and
excretion
the
feeding the
the
compaction of
irregularities
Usually, of
of
inexactness
caused
from
±10%
value
the
preservation,
obtained
using a mean
evaluation
from
compaction,
below
measurements single
of
and Teichichnus.
compaction
that
inhomogenities
displacement, results
show
resulting
types
the
in
of
the
of
from The
Planolites,
measurement
several
burrows.
was
itself
material.
burrows
value
of
(branching, animal
of
error
mean
compaction
the
is
burrow
of
repeated
Therefore,
calculated
from
if
several
measurements.
If
adequate
bioturbation
measurements
can
aragonitic early
shells,
burial
filled
be
living
since
out the
et
chambers
straight
solely
the
slightly-deformable
has
to
of
know the
al.,
shells or
original
to
those
not often
For
coiled ratio
get
this
of
formerly
dissolved
purpose,
axes,
during sediment-
are
for
These from
compaction of
ammonites
aptychi. obtained
available,
"steinkerns"
1976).
calcitic
equivalent
are
using
hard
(SEILACHER
one
usually
structures
carried
suitable;
instance,
from
measurements
are
deformed
bioturbation
structures. Very often
resistant
deform
cannot examples
be
calculate
Evaluation
Very often
shells
maintaining
described
to
Indirect
while
calcite by
of
a constant
eq.
these
1.
grains,
volume.
RAMSEY & HUBER
types
of
such
Their (1983)
as
ooids,
deformation give
several
deformations.
Compaction
it is i m p o s s i b l e
compaction.
and massive
The a b i l i t y
to d i r e c t l y
ascertain
the
degree
of
to p e r f o r m this calculation depends on the
amount of early cementation of certain burrows and fossils as compared to
that
of
the s u r r o u n d i n g
rock.
In early,
burrows, the degree of burrow compaction is less of the
total
selectively than the
cemented
compaction
rock, thereby representing only the amount of compaction
prior to the onset of cementation inside the burrow (K>D, Fig. 4C). However,
the t o t a l
rock
compaction
can be d e t e r m i n e d
f r o m the
degree of partial compaction of selectively cemented burrows or shelly fossils using are b a s e d
the c o m p a c t i o n law given in section 2.2.
on the s i m p l e
surrounding
sediment
assumption
that
the b u r r o w
Calculations
infill
and the
c o n s i s t of the same material; thus the absolute
clay content in the Burrow and in the n e i g h b o r i n g s e d i m e n t
s h o u l d be
11
the
same
(the
sediment absolute
clay
porosity
of
calculated
carbonate CaCO 3 .
rock lost
content
of
the
surrounding spite
does
compositional for
accurately with
while
with
3).
Since
(and
if
same as
for 60~
the
the
content
compaction
and
can
be
(eq.
useful
the
the
A selectively
thickness
surrounding of
rock the
then
and has
burrow
carbonate
absolute
burrow),
only
75% to
content
the
loss
of
evaluation
of
the
a
amounts
content
clay
has
of
the
of
the
volume
in
4).
simplifications,
indirect results between
However, deformation
(Table burrow
1).
or
such
errors
selectively
bioturbation
Errors
steinkern
measurements
well-preserved,
non-cemented
original
obtains
neglected):
content
eq.
when
the
one
carbonate rock
original
clay
75~
give
the
here
its the
absolute
is
to
Once
total
is
40% o f
83.3~
sediment.
compensated
porosity
differences
neighboring
and
the
is
rock of
burrow
law, rock
was
the
normalized
4.
4C,
compaction
than
eq.
resulting
is
section).
rock,
tube
(compaction
In
of
surrounding
(Fig.
neighboring
content
following
burrow The
sediment
clay the
content
the
Example
the
see
by solving
cemented
10%
absolute
volume,
can are
cemented
total arise
inf111 be
rock from
and
the
partially
carried burrows
out
more
rather
tubes.
T a b l e I: D i f f e r e n c e b e t w e e n d i r e c t and i n d i r e c t d e t e r m i n a t i o n of compaction. In the calculations, the existing amount of rock porosity was ignored. Sample
Carbonate content
o1~o
Gubbio 1 Gubblo 2 Logis du Pin
166 181 62 72 75 6 40
47.43 77.90 86.20 78.68 65.37 74.76 69.63
87.94 83.44 90.24 92.69 87.30 86.11 83.93
Compaction
o~
43.0 35.0 58.1 47.8 54.4 36.0 47.0
D~fference between the measured and calculated amount of compaction in the rock matrix
~
80.0 50.8 84.5 80.0 82.6 71.0 75.7
86.9 51.3 70.4 82.1 83.3 64.8 71.9
-6.9
-1.3 14.1 -2.1 -0.7 6.2 3.8
12
2.2
Derivation
The
"carbonate
between
of
the
compaction
carbonate
diagenetic
Compaction
law"
content,
parameters).
calcareous
sediment
The
or
rock
Law
describes
the
general
relationship
compaction,
and p o r o s i t y
(the b a s i c
relationship
is v a l i d
any
sample,
independent
for
of the
llthology and irrespective of whether or not the dlagenetlc system is closed.
The carbonate compaction
and the pore
s h o u l d be dlagenetically mobile and that the original volume
of n o n c a r b o n a t e
solids
should
be e s s e n t i a l l y
immobile.
original volume or absolute amount of the noncarbonate be a constant factor fraction
carbonate
law stipulates that during
dlagenesis the original values of the carbonate fraction solutlon
given
specific
consists
during
mainly
This does not exclude, noncarbonate
carbonate
the
(the n o n c a r b o n a t e
of clay minerals and silt-slzed sillcates).
however,
fraction
dlagenesis
Thus,
fraction should
that
(e.g.,
individual
clay minerals)
constituents
of the
may undergo isochemical
alterations during diagenesis. In
fact,
these
conditions
carbonate and clay (WEDEPOHL, opal,
which
the
in m a n y
Except
in the
formation
of clay m i n e r a l s
found
1970).
can be r e c o g n i z e d
thus be a v o i d e d ) , dewaterlng
are
the
Often
limestone
(BERNER,
high overburden
composition 1982;
have
(SUJKOWSKI,
BURGER,
carbonate
the n o n c a r b o n a t e
layers 1982;
simllar
compaction
and the
(BOLES & FRANKS,
in the marl beds and in
the
1958; HOLLER & WALITZI,
POLLASTRO
1984),
of (and
fraction can be u s u a l l y
fraction if not
of
for the m o b i l l z a t i o n
1979), diagenetic changes of the noncarbonate neglected.
composed
form of chert concretions
of p y r i t e
during
rocks
& MARTINEZ,
same
mineralogical
1965; BAUSCH et al.,
1985).
Supposedly,
the
law can be applied to more than 90% of existing
sediments or rocks consisting of carbonate and clay. Derivation diagenetlc terms
changes
of volume.
grains Most
(Fig.
(Co),
of t h e s e
during
5):
noncarbonate parameters The
and chemical compaction the
carbonate
compaction
law explains the
for a given calcareous sediment or rock sample in Original
dlagenesis:
provide
The
present
calcareous sediment consists of carbonate grains
become original
(NC),
and water-filled pores (no).
absolutely volume
(K) and the original rock
porosity
and r e l a t l v e l y
altered
decreases due to mechanical
(n).
pore
space
Moreover,
decreases
to
the o r i g i n a l
carbonate volume can either increase or decrease due to cementation or dissolution; (C).
this
gives
the
The noncarbonate volume
carbonate (NC)
content
changes
of the existing rock
relative
to the c h a n g i n g
13 amount
of c a r b o n a t e .
However,
content remains c o n s t a n t primary
sediment
during
diagenesls,
if it is e x p r e s s e d
volume
(or
normalized
to the d e c o m p a c t e d ,
Hereafter,
the
standardized
"NCd,"
the
primary
noncarbonate
sediment
noncarbonate
of the
fraction
volume,
content
referred to simply as the "absolute clay content". constant
the n0ncarbonate
as a p e r c e n t a g e
Fig.
will
often
Commonly,
5). be
it is a
factor during carbonate diagenesls.
tumuli
1
I
I
I
I
B
NEd
Fig. 5 R e l a t i o n s h i p b e t w e e n p r i m a r y s e d i m e n t (left) and r e s u l t i n g c a r b o n a t e r o c k (right) e x p r e s s e d in t e r m s of volume. K = c o m p a c t l o n , n = p o r o s l t y , C = c a r b o n a t e fraction, N C d = s t a n d a r d i z e d noncarbonate fraction. During dlagenesls, the NC d f r a c t i o n remains constant only when it is expressed as a percentage of the primary sediment volume.
If the primary sediment volume is I00%, the
sediment
or
rock)
is
compacted volume is (100-n);
(100-K). this
equals
related to the original sediment volume.
the c o m p a c t e d
The
amount
of s o l i d s
(100-K)((100-n)/100), Again,
is
(100-C)
of the p o r e - f r e e
derived when NC is e x p r e s s e d volume (NCd):
solids.
(of
in the when
the solids consist of
both the carbonate volume (C) and the noncarbonate volume NC
volume
(NC),
where
The following expression is
as a p o r t i o n
of the o r i g i n a l
sediment
(100-K)(100-n)(100-C) NCd[vOl~]
=
(2)
10000
where
K
is
the
percentage
of c o m p a c t i o n
of the p r i m a r y
sediment
volume, n is the porosity expressed as a percentage of the sediment or r o c k volume, and C is the carbonate volume expressed as a percentage of the volume of pore-free solids.
14 Eq.
2 is
named t h e with
the
general
carbonate
zero
porosity
compaction.
Hence,
nearly
rocks
dense
form of the
compaction the the
carbonate
law b e c a u s e
law
relates
standardized
(NCdr)
in
compaction dense,
only
law.
carbonate
noncarbonate
It
lithified
is
rocks
content
to
of dense
or
fraction
is (IO0-K)(IO0-C)
NCdr[V°l%]
(this
is
the
equation (n)
special
=
form
(2)
for
compaction
one gets
the
following
100
of
the
'
(3)
compaction
(K),
carbonate
basic
equations:
law).
volume
If
(C),
one
and
solves
porosity
NCd K [ v o l % ] = 100 -
(4)
(l-O.Oln)(l-O.OIC)
NCd C[vol%]
= i00
-
n[vol%]
=
-
(5)
(l-O.OIK)(l-O.Oln)
NCd
As a l r e a d y
shown,
independent
of the
compaction
law
types
distinction
is
mechanical
versus
specific
(about
(carbonate volume the
(as
and does
(e.g.,
2.7g/cm3),
used
in the
errors
of
enable
one
different
the
compaction
resulting
carbonate).
law)
is
Moreover,
residue
of the usually slight
not
no
(such
as
Since
the
often
very
are
percentage as
The
different
5.4).
analyses)
from these
pores.
of compaction
nonsoluble
from
and
distinguish
section
expression
resulting
volumes which are
grains
types
compaction, and t h e
with
to
c e m e n t and p r i m a r y
chemical
data
law deals
distribution not
of calcite
content
most part,
size
(6)
(l-O.OIK)(l-O.OIC)
compaction
made b e t w e e n t h e
weights
similar
the
alone
of carbonate
100
of weight
a percentage
of
necessary.
For
fluctuations
can
be
neglected. The
porosity
therefore, form
of
and t h e law
of
calcareous the
compaction
absolute
shows
lithified rocks
clay
a nonlinear
law
content
carbonates
can usually (eq. is
3).
be
When p o r o s i t y
constant,
relationship
can
be e v a l u a t e d the
between
largely with is
carbonate carbonate
ignored;
the
special
insignificant compaction content
and
15
CARBONATE COMPACTION LAW
C C C o'°° ~ ' ° ° ~ I ° ° ~0 50
NCd 10%
90
K 7O
E % Compaction TTfIIIT I°° 1001
i i i i i !i i- 701 YiiJiiJ:,o iYjiYi'i'i)
o
5Ko
II ....
C
o
IKI
,
13oi
L___
~
z
!ii!iiiiiii:o o
oo,o,oo° C°C° 85
Fig. 6 Simplified derivation of the compaction law, neglecting porosity. Example resulting from chemical compaction: A carbonate r o c k w i t h 90% CaCO 3 i s c h e m i c a l l y compacted to K=30, 50, 70, and 90% o f t h e original thickness. Carbonate content (C) diminishes nonlinearly, b e c a u s e t h e a b s o l u t e c l a y c o n t e n t (NCd=10%) r e m a i n s c o n s t a n t during diagenesis. Note: T h e s a m e d a t a r e s u l t if t h e p r i m a r y s e d i m e n t ( c o n t a i n i n g the same absolute clay content) first undergoes mechanical compaction and subsequently complete cementation.
compaction present
(Fig.
6).
porosity
This
relationship
is below 30% (Fig. 7).
changes
somewhat
if
the
The influence of pore volume
is clearly recognizable only when the porosity is high (see Fig. 65). 1.
Curves the 7)
from
degree are
high;
the
of compaction
approximately whereas
approximately that
compaction for
parallel rock
study
have
to the
carbonate to
the
can
spite of strong compaction. this
various
parallel
when
calcareous
law r e p r e s e n t i n g
absolute
carbonate
absolute
clay
CaCO 3 a x i s
content
is
compaction
contents the
It
curves
becomes
clay
example, contents
typical between
is are
clear
still have a high carbonate content, For
and
(Fig.
when c o m p a c t i o n
high,
axis.
content
limestones 2.5 and 10%.
in in A
limestone with an absolute clay content of NCd=5% would correspond to a p r i m a r y primary
carbonate content of Co=83.3% if we assume a typical
porosity
of 70%.
If this
sediment
cemented without suffering compaction, be 95% (Fig. 7). by
50% and then
If the sediment becomes cemented,
the
becomes
completely
the carbonate content would
carbonate
mechanically content
compacted
would
be 90%.
16
n=0%
I00 ~ ~ = = = = = ~ 90 " i ,--i---'i
, I~
n=10%
100 ~_ . ~ 80 70
M
~ ~i
~
6O
h I\l
io
0 I0
100 % 90[ 800
M P A C T
I
0 N
20
~ ~ 50 ~ 70 80
~
30
--
I
\
100 % CARBONATE 90
n:20% I
50
0
I0 20 30 &0 50 60 70 80 ~ I00 % CARBONATE
n=30%
100 z5
7060
60
5040
40
L-">-.,L \...~ N
,o
30 2O 10-
20 10 20 30 40 50 60 70 80 90 100 % CARBONATE
0
~
\
\, \
10 20 30 40 50 60 70 80 90 100 % CARBONATE
Fig. 7 Relationship b e t w e e n c o m p a c t i o n and c a r b o n a t e content for d i f f e r e n t a b s o l u t e clay c o n t e n t s (NC d) and porosities (n) calculated after the compaction law. Examples: They show d e n s e c a l c a r e o u s rocks (n=0%) w i t h absolute clay contents of 10%. Sample containing a carbonate content of approximately 85% displays a compaction of 30%. However, s a m p l e containing a carbonate content of 50% shows a compaction of 80%.
ly
After 80% m e c h a n l c a l and c h e m i c a l would
still
content w o u l d
decrease
became extreme 2.
Carbonate
compaction
alternations presented
considerably,
but
(e.g., 90% compaction,
content
and
should
in
Fig.
plot 7,
on o n e
if
the
not
resulting
measured
of
the
compaction
0k porosity). in m a r l - l i m e s t o n e
absolute
existing
rock
The c a r b o n a t e
before
50% CaCO3,
compaction
g e n e r a t e d from a u n i f o r m l y - c o m p o s e d , constant
the
h a v e 75~ CaCO 3 if its p o r o s i t y is low.
clay
alternation
basic s u b s t a n c e
curves
is m a i n l y
containing
or n e a r l y constant a b s o l u t e clay content.
a
Nevertheless,
one cannot expect that the paths of the t h e o r e t i c a l curves will be c o m p l e t e l y identical to those p r o d u c e d by field data. to p r i m a r y c o m p o s i t i o n a l history
of
the
variations
sediment
and
(e.g.,
due
the
to
the
amount
This is due compactional
of
mechanical
compaction).
2.3
Carbonate Sediment
Since
the
amounts
of
diagenetic several
both
law
does
and
is c a r r i e d
out w h i c h
carbonate
meters.
beds
cemented
system
The
composition
marl
alone
dissolved
mass
decompaction and
and
the
carbonate,
a
closed
mass
within
balance
an
balance
interval
calculation
in
order
of
carbonate
layers.
During
amount
limestone
not c a l c u l a t e the m o v e m e n t s and
is b a s e d on the c o n d i t i o n that the
remained
carbonate
on m a t h e m a t i c a l
original
and Primary
Composition
compaction
calculation
relies
Mass Balance
to
of
(Fig.
reconstruct
8) the
redistribution
in
decompaction,
reconstructed
limestone sediment has too low a primary p o r o s i t y due to
cementation,
while
high
porosity
calculation
due
the to
reconstructed carbonate
redistributes
m a r l sediment has a r e l a t i v e l y
dissolution. the
The
carbonate
mass
content
balance between
d l s s o l u t l o n - a f f e c t e d and c e m e n t e d zones (i.e., marl beds and l i m e s t o n e layers,
respectively),
so that the same primary pore space is o b t a i n e d
for r e c o n s t r u c t e d sediments of both zones system
was
closed
during
diagenesls,
(Fig. S).
the
mass
If the
balance
calculation
d e t e r m i n e s the amounts of the different c a r b o n a t e f r a c t i o n s cemented,
dissolved,
and relic carboaate).
carbonate
(primary,
18
SCHEME OF CARBONATE MASS BALANCE CALCULATION % CaCO3 50 100 | I
0
oo# 20
.
::::::::::::::::::::::::::::::::::::::::::::::
I.......................... I
80Iii~ii~
. . .
!!iiiiii~i~ii~i~!~ii
.
.
.
.
.
.
.
.
.
.
.
.
.
.
li::i::ii::::i:.:::iii::::::ii::i~::::iiiiii::iiiii! o~::i!::::
............................................................................... ,
'
.:::i!....
.:.:.:-:--:
< -
cJii~,~iii~i,,';iiiiiii;,iiiiiiiiil ~iiii~#,!iiliG~(iiiii]lii~,iiiiiiiii'~iiiiii]ii~,iil
liiiiiiiiiiiiiiiiiiiiiiiil
/i
8oliii~::~ .......
/i
' 0 Iiiiiiiiiiiiiiiiiiii~iii~iiiiiiiiiii5i
~1111111
0
, °~//////~ , ~K///////q
I'l"irn'i'Ii~~[l'j~]'~[
ll'rl'~'lrT110
C
D
i~i~:#:~:#m~:::;~i:;i~:;:;:~ NC 0
80 Iiii~i!I
B
A Fig.
8 Simplified, s c h e m a t i c d i a g r a m r e p r e s e n t i n g the carbonate mass balance calculation. A: Marl-limestone alternation. L i m e s t o n e layers: 90% CaCO3, 20% compaction. Marl layers: 50% CaCO3, 80% compaction. Degree of compaction can be r e c o g n i z e d by the deformation of cylindrical burrows. B: Separate description of two beds, s h o w i n g clay c o n t e n t (NC, v e r t i c a l l y s t r i p e d areas) and c a r b o n a t e c o n t e n t (C, shaded areas). C: C a l c u l a t e d d e c o m p a c t l o n of a limestone layer and marl bed. The d e f o r m e d b u r r o w a g a i n a p p e a r s c i r c u l a r . The d e c o m p a c t e d l i m e s t o n e layer shows too low an original pore space, w h i l e the d e c o m p a c t e d marl layer has a r e l a t i v e l y high primary porosity. D: If the p r i m a r y p o r e space in both layers is equal (no, hatched areas), the reconstructed marl layer sediment has an a d d i t i o n a l amount of p o r o s i t y due to carbonate dissolution (n o is the a v e r a g e d e c o m p a c t i o n p o r o s i t y of both layers). In the reconstructed limestone layer sediment, the dissolved c a r b o n a t e from the m a r l layer fills a part of the primary pore space due to cementation (Z).
Z
19 2.3.1
Closed
or
Open Carbonate
During
Burial
System
Diagenesis
The carbonate mass balance calculation gives realistic results only if carbonate is not b r o u g h t
into or r e m o v e d
f r o m the
studied
sequence
during dlagenesls (that is, a closed system for carbonate). prevalent opinion that carbonate diagenesls usually o c c u r s system
with
the
participation
of h u g e
volumes
1977)
has b e e n
refuted
& VEIZER
have
According
micropores
MORROW & MAYERS,
by geochemical arguments (VEIZER, 1978; BAKER
In contrast to this, PINGITORE (1976, 1982)
(1980)
zones".
in an open
of m i g r a t i n g p o r e
solutions (PRAY, 1966; DUNHAM, 1969; BATHURST, 1976; et al., 1982).
The still
and B R A N D
p r o p o s e d the concept of "partly closed reaction to
this
predominantly
concept,
the
independent
macropores, thus r e q u i r i n g
less p o r e
diagenesis
of the p o r e
fluid.
occurs
solution
Nevertheless,
in
in the BRAND &
V E I Z E R still presume that minor element diagenesis occurs primarily as a result of reaction w i t h ELDERFIELD & GIESKES
meteoric water.
(1982)
BAKER
demonstrated,
et al.
(1980)
and
however, that removal and
enrichment of trace elements can a l s o o c c u r u n d e r m a r i n e
pore water
conditions.
concerning
Moreover,
numerous
data
are
available
lithification of pelagic carbonates (e.g., SCHLANGER & D O U G L A S , SCHOLLE,
1977;
GARRISON,
1981).
Authors
deep-sea carbonates and subaerial chalks,
usually
cement
agree
1974;
that
in
is g e n e r a t e d w i t h i n
the sediment column due to nearby dissolution-precipitation processes. MATTER (1974) characterized these processes as "autolithification". Isotopic
data
(~180, ~13C)
lithification u n d e r m a r i n e (HUDSON,
1977;
from
conditions
many
limestones
in a c l o s e d
CZERNIAKOWSKI et al., 1984).
point
carbonate
to
system
For this redistribution,
the long distance transport of enormous masses of carbonate cement are no l o n g e r
required.
Moreover,
accept mechanical c o m p a c t i o n
authors are currently more willing to
of c a r b o n a t e s .
This
reduces
the p o r e
space
to be cemented (e.g., mean amounts of cement calculated in this
study
are
limestone
approximately layers).
given by SHINN et al. The
following
marl-limestone
one
of t h e
total
discussions
carbonate
in
the
of this p r o b l e m are
(1977) and BATHURST (1980a,b).
results
alternations
carbonate system:
third
Comprehensive
c o n f i r m the o p i n i o n occurred
that
in a c l o s e d
diagenesis
or n e a r l y
in
closed
20
1.
As already observed from HARMS & CHOQUETTE (1981), MERINO et al.
(1983),
repreclpitated
close to stylolitic seams.
marl-llmestone
alternation
occurred planes
preferentially
(Fig.
against
the
PINGITORE,
9),
above
carbonate
Germany,
and b e l o w
transport
flow
(1985),
is
In the Upper Oxfordlan
in s o u t h e r n
suggesting
compaction
(1965), BUXTON & SIBLEY
and K O E P N I K
cementation
the s t y l o l l t l c bedding by
(EINSELE,
diffusion
1977;
with
WEDEPHOL,
and 1979;
1982; see section 5.1).
~
• 91.4
90.4. 91.0.
• 89.7 • 89,3 • 91.7
-93.0
• 92.8
• 92.5
9
0
~
9 2 ~ ~ 9 2
~------''~
9/*.I • "90.7 "96.5
"95.2
• 95.6
"94.9
89.4 • • 90.2
-9k7
-91.2
-957
-9Q3 94.5
.9,6.1t,.&~ 5. g53 93.7" 1"95.5__~95.0
923"
9ZS~t S8 9 5 1 ~ 7 6 2
95.1. 96~
9:i~2,.,~
{
95.2. • 94J
I
9+++ -92.7 94.1 •
94.0 • 953 •
94.2" 93.9"
95.5•
94.6-
95..9
95.0z:78.4 . . . . . .
o9311 77.1" "
9~3"
92.6 •
• 90+2
lOom
\ r95
"93.I
• 94.6
91.6 •
10" cm
95
"95.5
"920
~ ^ • '~,.u
92:,.
92
-90--
90.5" 94.3"
9S.3"
93.2 •
"
" ......
_--gO
77.6"'~
80
~
go
i
Fig. 9 Carbonate content in the neighborhood of a diagenetic styloltte. The h i g h e s t carbonate content (96%) was measured directly above and below the stylolite. Neuffen Quarry, Swabian Alb, Upper Oxfordian (see Fig. 30D).
2.
Mathematical
decompactlon of the 10 sections studied (each several
meters thick) yields mean p r i m a r y
porosities
between
65 and 80%
for pelagic to hemlpelagic alternations and about 60% for the more nerltlc profiles 10). modern
Porosities
of the R h e l n e
fine-gralned
environments
(KELLER
al., 1976; MAYER,
and L o g i s
du Pin
sections
(Fig.
of a similar order of magnitude were observed in carbonates & BENNETT,
1980).
from 1970;
shelf
HAMILTON,
and
deep-sea
1976; KELLER et
If substantial carbonate t r a n s p o r t
into
21 the systems of the studied sections had occurred,
one would obtain
smaller d e c o m p a c t i o n
hand,
porosities.
On the
amounts of carbonate had been released,
other
if l a r g e r
resulting porosities would
be larger.
MEAN DECOMPACTION POROSITY[%]
I
I
I
IIIII I i I 65 70 75 80
|
55
I
60
I
I
l
Fig. i0 The mean primary porosity in the sections studied, which is calculated from decompaction of the entire section. Stars indicate the decompaction porosities from the relatively nearshore sections Logis du Pin (southern France) and Rheine (northern Germany).
Uncertainties
2.3.2
Resulting
from
the
Nethod
The method of balancing the cement content contains several sources of error which reduce the possibility of yielding precise r e s u l t s primary
sediment
calculating
the
(decompacted)
composition. mass
One
balance
porosity,
source
of e r r o r value
of
from
with
a
small
differences in porosity must
although
mean
of the
results
primary
have actually existed in the original sediment. While
KELLER
& BENNETT
porosity between p e l a g i c deep-sea
clay
HAMILTON
(1974,
calcareous (1981)
(mean 1976)
cited
a 2% d i f f e r e n c e
72~,
porosity
73~,
material,
74%,
differences
differences
of
14~
(67%
for
in
and red
respectively), of
9%
(72%
calcareous
for
OSMOND
ooze
and
81% in silt and clay).
one can expect that the maximum porosity differences of 9
were
not p r e s e n t
marl-limestone differences
gave
only
and terrigenous ooze, 81% for red, deep-sea clay).
However, 14%
gave
terrigenous
porosities:
siliciclastic material, to
(1970)
carbonates,
alternations
between
in the p r i m a r y
since
lithified
(after diagenesis) usually h a v e
carbonate
30 to 50%.
sediment,
Therefore,
one can assume that the
original fluctuations in porosity were below 5% (see the prediagenetic
22
of
alternation account
porosity
78~ ±2.5~, primary degree
Porto
Empedocle,
differences
NC d = 3 to 1 1 % )
carbonate
of t h i s
in
section
the
must
3.1).
Taking
o r d e r of m a g n i t u d e
the m a x i m u m
differences
of u n c e r t a i n t y
Italy,
uncertainties
be b e t w e e n
primary
±0.5
composition
into
(n o = 58 to
in e v a l u a t i n g and ±5.8%.
The
will be given for
every b a l a n c e c a l c u l a t i o n c a r r i e d out (section 3.2 to 3.5). Another mentioned author's
uncertainty
results
measurements experience,
of
from
burrow
usually
inexactness
deformation.
more
than
of
the p r e v i o u s l y
According
to
this
30 e v a l u a t i o n s of c o m p a c t i o n
per section are n e c e s s a r y to obtain r e p r e s e n t a t i v e
average
values
in
the b a l a n c e calculations.
2.3.3 The
Sampling thickness
evaluations can
be
higher 15
of of
sections
should
within
The probability
thicker
meters
the
compaction
made. in
Procedure
sections.
thick
and
to
apply
of
be chosen
such
successive
marl
getting
a closed
Sections comprise,
used on
in
the
and
this
that
at
least
limestone
30
layers
carbonate
system
study
only
are
average,
28
is
3 to
carbonate
oscillations. In
order
determine every
the
site
the
carbonate
where
content
compaction
is c a r r i e d out i n d i r e c t l y in
Moreover,
and
compaction porosity
was measured.
If
of
burrows
a tight
or
law, the
the
steinkerns
sampling
should
one
rock
evaluation
(see section 2 . 1 . 2 ) ,
selectively-cemented
determined.
carbonate
of
has
matrix
also
at
compaction
carbonate
guarantee
to
content
has
to
that
every
be
c a r b o n a t e v a r i a t i o n in the section is c o m p l e t e l y recorded. In the studied sections, the c o m p a c t i o n
rock p o r o s i t y is b e l o w 15%.
A c c o r d i n g to
law, the i n f l u e n c e of rock p o r o s i t y on the c a l c u l a t i o n s
is small.
After several p o r o s i t y d e t e r m i n a t i o n s ,
expressed
in r e l a t i o n
to
carbonate
rock p o r o s i t y can be
c o n t e n t u s i n g r e g r e s s i o n curves.
Then p o r o s i t y can be i n d i r e c t l y evaluated.
2.3.4
Testing
Primary
Compositional
Differences
The a b s o l u t e clay content, w h i c h has to be s t a n d a r d i z e d to the p r i m a r y volume
of
sediment,
is c a l c u l a t e d from m e a s u r e d data u s i n g eq. 2.
no or only slight d i a g e n e t i c m o b i l i z a t i o n of the n o n c a r b o n a t e occurred
(see
section
2.2),
then
the
absolute
clay
If
fraction
content
is a
23
measure
of
in
primary
the
clay
the
variations
content
only since
mean absolute
clay
the
present
throughout
content
was
the
primary
then
the
due to
even of
According
Porto
studied
determination
the
first
(both
Empedocle of
powerful
clay
2.3.5
and
First, is
of
the
in
have
to
the
in
the
prediagenetic
~orosity below
noncarbonate
if
carbonate
primary
primary
form
porosity,
constant
probability,
Mean P r i m a r y
calculations
mean original
calculated
cemented
evaluate
must However,
was
and
was
carbonate
variations 5%.
content
compositional
Thus, provides
differences
Porosity
from Decompaction
balance
the
all
standardized
to
porosity
carbonate).
Evaluation
mass
3.1),
in
would
the
unchanged
primary
variations
2.3.2
in If
remains
original
content
section
(section
variations
redistribution.
sediment
absolute
accurately.
the
large
clay
were
the
tool
Resulting The
to
alternations
the
carbonate
absolute
the
CaCO 3 o s c i l l a t i o n s
significantly
the
the
then
present
primary
if
sections.
the
had
and
fraction
of
primary
measurements
layers
diagenetic
values
for
sediment,
and
reconstructed
sequence in
limestone primary
noncarbonate
be measured
various
and
the
evidence
from
constant
of
individual
cannot
the
sediment
variations studied
weak
content
also
predominantly
amount
compaction
marl
constant
the
However,
provide
composition, in
in
sediment.
(Fig.
carbonate
are
porosity
lla,b,c), is
carried
(based
and
determined
in
two
on mathematical
second, using
out the
mass
content
balance
major
steps:
decompaction) of
dissolved
calculation
and (Fig.
11d). Fig.
11a:
The
section
are
of
in
rock
CaCO 3. which
the
For is
Fig.
purpose,
be
divided (C),
which the
intervals
column into and
of
rock
mean volume
noncarbonate
contains
a
curve
(section
individual are
in
the
representing
carbonate
determined for
found
a histogram
section
integrated
Each
carbonate
oscillations into
carefully
20 carbonate
llb: must
total
this
very
graphically 10 to
carbonate transformed
studied the
given of
the
2.3.3)
amount
amount section, has
CaCO 3 i n t e r v a l s .
of
to
be
Usually,
formed. with
a
given
proportions content
(NC).
carbonate of
rock
content
porosity
(n),
24
CARBONATE
MASS
BALANCE
STUDIED SECTION
CARBONATE COMPACTION POROSITY NEd FREQUENCY OF ROCK WITH SPECIFC CARBONATE CONTEN]
Vz r-7 t I t I I I
V K iiiiiiiiiiiiiiii ii!iiiiiiiiiiiii
n
iiiiiiii!i!i!i!i i~i~iiiiii!iiiil
V
1
-.-.... -.-.-.., -.......-....,.,
B
-.-...-,-.-..,., .......... ....... • .. -.-.....-.-...., ............,
I
I
V-z n ~ n TF-I ~
-.-...-.-.-....,
........,.-.
"2":':':':':':': ":':':':':':':': ":':':':':':':': ':':':':':':':': ":':':':':':':': ":':':':':':':': ":':':':':':':':
iiiiiiiii!iii!i! ii!i!i!ilili!i!i ,....-.-.-....,
i!i!i!iiiii!iii!
HH! NC
i:i:i:i:i:i:i:i:
a
:::::::::::::::: :::::::::::::::: ......,.....-.-. ":':':':':':':': '.'." ' '.' "."
n
":':':':':':':': ":':':':':':':': ":':':':':':':':
iiiiiiiiiililili !iii!iii!iiiiiii iiiiiiiii!iiiiii
R
."...!'u
b
tli~ltl|
NC~
c
d
25
Fig.
llc: the
The
amount
histogram
content,
is
height
original
of of
rock
compaction
determined
absolute
Determination the
of
clay the
the
for
every
using
mean
content
and
existing
rock
allows
column
(h*)
values
class
of
(h)
(eq.
one to
by
in
carbonate
porosity
amount of compaction
column thickness
carbonate
4) .
decompact
calculating
the
with
i00
h* =
The to
original give
closed
the
rock
thickness
original
carbonate
100-K
in
sediment
system,
result
mean d e c o m p a c t i o n
the should
because
burrows
slightly
2.3.6
be
used
below the
Carbonate
The amount of composition
Mass
the
from a mass balance
to
for
carbonate
the
classes
If
original compaction interface
has
diagenesis
between
porosity
the
Balance
the
pore-free (no).
b e summed
occurred
original solids
in
of
measurement section
marl
carbonate
and limestone
and layers
of
the
rock
the
sediment,
are
generated
2.1.2).
the
mean
are
a
sediment
The mean d e c o m p a c t i o n
porosity (see
to
Calculation
and cemented
existing
(V).
amount of
sediment-water
dissolved of
added
equal
(7)
difference
separately
in
all
volume
the
volume and the porosity
x h
primary
ascertained
calculation.
F i g . 11 Carbonate mass balance calculation. Transformation of the entire section studied into a histogram representing the amount of rock volume with a certain carbonate content. a: Example shows two rock volumes with high and low carbonate content (shaded). b: The volumes of noncarbonate (NC), carbonate (C), and porosity (n) in the given rock volumes. c: Decompaction calculates the original s e d i m e n t v o l u m e (V) by u s i n g t h e g i v e n a m o u n t o f c o m p a c t i o n ( K ) . d: Subtraction of the mean primary porosity (no, which results from decompacting the entire histogram) from the original sediment volume. From this, one obtains the amounts of dissolved (-Z, dotted), cemented (Z, starred), relic (R, hatched), and "primary" (P, hatched) carbonate fractions for the two rock columns.
26
I
._j
GUBBIO 2
L--.,
lo
V ff---J I I
i!: i!i
E r --~
_I D
i
o ~.
u_
r -"t.
I I
I
v -I
ri r-"
i50
i5
60
J
Z
n.o
~ I I
/~
n ~ I
i ~ i ~
I~ ~ 1 ~ 1 " ~ ]
-Zl'.'~~1 65
70
75
8'0 8'5 90
~Cn
i5
% CaCO 3
F i g . 12 C a r b o n a t e m a s s b a l a n c e c a l c u l a t i o n for the Gubbto 2 section (Italy). The histogram represents a whole-rock balance calculation. V=volume of decompacted sediment, no=Primary porosity, n=rock porosity, -Z=dissolved CaCO3,
Z=cemented CaCO3, R , P = r e l l c or " p r i m a r y " c a r b o n a t e , r e s p e c t i v e l y , N C d = s t a n d a r d i z e d n o n c a r b o n a t e fraction, Cn=CaCO 3 neutral value.
27
GUBBIO 2 V_z
Vz
55.5
4L.5
I ..,11- - ~
227 Z ~-.
s.l K
n
-iN[ d
Fig.
13
o
b
c
a
b
Co
83.6
85.9
C
76.7
89.5
Box
model
of
a
carbonate
mass
balance
c
calculation
(derived from the histogram in Fig. 12). Outer frame of the model is equivalent to the decompacted or primary sediment volume for dissolution (V_ z) and cementation zones (Vz) , respectively. The existing amount of rock is shaded. no=mean primary porosity, S=original amount of solids, K=compaction, n=rock porosity, -Z=dissolved, Z=cemented, R=rellc, and P="prlmary" carbonate, NCd=standardized n o n c a r b o n a t e fraction. V a l u e s of K, -Z, Z, n, R, P, and NC d (small numbers) are e x p r e s s e d as a p e r c e n t a g e of a) the t o t a l s e d i m e n t v o l u m e , b) t h e v o l u m e of dissolution and cementation zones, respectively, a n d c) t h e a m o u n t of solids in the p o s t - d i a g e n e t i c rocks in both zones. C o = m e a n p r i m a r y c a r b o n a t e c o n t e n t of both zones. The c a l c u l a t l o n a s s u m e s p o r o s i t y d i f f e r e n c e s of n o = ± 2 . 5 % in the primary sediment ( t h e d i f f e r e n c e s are not s h o w n in the model). C = e x i s t i n g mean c a r b o n a t e c o n t e n t for b o t h z o n e s . F=factor of d i a g e n e t i c e n h a n c e m e n t of p r i m a r y c a r b o n a t e oscillations.
28
Fig.
11d:
The
subtracted every
mean
decompactlon
f r o m the
carbonate
reproduces
decompacted primary
class
both
of
the
original sediment.
porosity
the
sediment
histogram.
amount
of
(n o ) h a s
sollds
This and
In the c e m e n t e d p a r t s
be
thickness for manipulation
pore
of the
to
space
in the
sequence
(that
is, high calcareous rock in the histogram), the difference between the present and the original amounts of s o l i d s amount
of c e m e n t
sequence
(that
difference
(Z).
is,
correspond
In the s o l u t i o n - a f f e c t e d
low c a l c a r e o u s
rock
to the
portion of the
in the h i s t o g r a m ) ,
the
corresponds to the amount of dissolved carbonate (-Z).
Moreover,
the c a l c u l a t l o n
gives
carbonate
fractions
According
(R).
the
"primary"
(P)
and
relic
to the mass balance method,
the absolute amounts of dissolved and c e m e n t e d
carbonate must
be
equal in the entire section studied. For
a given
carbonate
neither
cement
section,
Fig.
neutral
carbonate
the
neutral
content
12).
of
content"
of
mass
cementation
zones
If
must
is
The
The
box
and
model
rock
the
is
12). for
in
was
closed,
carbonate 13)
(Fig.
value and
based
It
the
the
2
mean carbonate
dissolution
(Fig.
and
show Gubbio
"statistically
neutral
carbonate
the
system
to
composition
existing
is
the
carbonate
calculation
porosity the
named
the
of
calculations
example
be equivalent
a zone
balance
in
histogram, (an
sediment. into
cementation.
compaction,
the
value
(Cn).
content
primary
above-mentioned
in
carbonate
carbonate
histogram
carbonate
values
This
the
the
content
dissolved
carbonate
separates of
nor
one
on the
gives
mean
dissolution
and
calculated
primary
sediment. In
Fig.
primary
13,
the
sediment
present
rock
reduced
and
amounts
in
underwent
volume,
the
primary
the
sediment
primary the
pore-free
±2.5~,
However, and
a mean
sediment.
(C o ) i s
89.5~;
factor
a mean the thus
of
(see
F = 5.5.
shaded
content
(V- Z,
VZ )
that
the
note in
both
carbonate 2.3.2).
(S)
the
original
Gubbio carbonate
carbonate carbonate
represents
part
zones
did
due
to
the
content variations
equal
sediment
differential
dissolution
and
variation
original
2 sediment content
layers
have
original
of
the
of
not
5% p o r o s i t y
Thus,
the
represents volume
content
assuming
section primary
model
decompacted
changes
in
box
the
Also
mean present the
the
the
calculated
solids
indicating
85.9%. 76.7
carbonate
volume
zones
of
that
The mean original
cementation of
Note in
different
frame whereas
volume.
enriched
compaction.
outer
would of
for are
in
volume be
33.6
Co=83.6
and
both
zones
enhanced
is by
29
2.3.7
Important The Mass
The
dissolution
Definitions Balance and
cementation
c a l c u l a t i o n s do not
exactly layers
limestone
From
Method
marl
and
Resulting
zones
correspond developed
as d e t e r m i n e d by mass balance to
the w e a t h e r l n g - g e n e r a t e d
in the outcrop.
Whether or not
the marl and limestone layers develop depends on the c a r b o n a t e c o n t e n t of
the
weathering
boundary
(Cw;
EINSELE,
1982)
which
usually
PRIMARY WEATHERING CARBONATE CARBONATE PROFILE CURVE CURVE EnCw
b
gi:~i:i:~:~:i::i:i~:>!i:.:.:i.S:i+:....... ):o:.:-~:+>:+>:+:<:
I'CEMENTASO-N.:*I" LIMESTONEI * # ~ *
%~
~I~
MARL BED
======================== :.= .........
~
coco3
coco
MAXIMUM J CARBONATE OSCILLATIONS MEAN CARBONATE OSCILLATIONS BETWEEN D[SSOLUTION AND CEMENTATION ZONES
I
,
,
I-.---I
,-.
Fig. 14 Definitions for describing marl-limestone alternations. The transition between dlssolutlon and c e m e n t a t i o n z o n e s is defined by the c a r b o n a t e neutral value (Cn) , w h i l e the t r a n s i t i o n between marl and l i m e s t o n e layers is d e f i n e d by the c a r b o n a t e content at t h e w e a t h e r i n g b o u n d a r y (Cw). A l s o , t w o w a y s to d e s c r i b e the c a r b o n a t e d i f f e r e n c e s in p r i m a r y sediment a n d d l a g e n e t i c a l l y altered r o c k s are shown, as well as a m e t h o d to e v a l u a t e the factor (F) w h i c h c a l c u l a t e s the d l a g e n e t i c e n h a n c e m e n t b e t w e e n p r i m a r y and p o s t - d l a g e n e t i c CaCO 3 differences. N o t e that in this study c a r b o n a t e f l u c t u a t i o n s are c a l c u l a t e d b e t w e e n the mean carbonate contents of d i s s o l u t i o n and c e m e n t a t i o n zones.
is
30
between
70 a n d 90% C a C O 3 d e p e n d i n g upon the climate and several other
variables
(i.e.,
slope,
length
of e x p o s u r e ) .
Zones
with
a higher
c a r b o n a t e content than the w e a t h e r i n g b o u n d a r y form limestone, whereas zones
with
carbonate content
a lower
carbonate
content
of
the
of
the
neutral
content
weathering
value
(Cn,
weather
to m a r l .
boundary
which
Thus,
the
(C w) and the carbonate
s e p a r a t e s the sequence into
d i s s o l u t i o n and c e m e n t a t i o n zones) are u s u a l l y not exactly equal
(Fig.
14). The
box
layers, and of
model
but
for
present the
the
data
(Fig.
carbonate
carbonate
and
Consequently,
the
but
factor
for
given
not
expressed
present
amplitudes
dissolution
and
marl
and
limestone
Moreover, for
the
instead
contents (Fig.
enhancement carbonate
primary
amplitudes
carbonate
zones
diagenetic
the
for
zones.
mean integrated
and mean
To c a l c u l a t e
the mean d i f f e r e n c e s
are
for of
not
cementation
cementation
between the mean p r i m a r y zones.
are
and
differences
curves,
dissolution
both
13)
dissolution
of
14)
.
is c a l c u l a t e d differences
in
of carbonate oscillations, cementation
zones
must
factor
in
be
m u l t i p l i e d by a factor of 1.5 to 2.
2.4
Onset
of
The
hardening
Lithification
of
calcareous
ooze
is
a decisive
d i a g e n e t i c enhancement of b e d d i n g p h e n o m e n a and r h y t h m i c i t y 4 and
5).
In this study,
lithification compaction rigid
by u s i n g
ceases
framework
compaction
an attempt is made to pinpoint the onset of
rock
compaction
as c e m e n t a t i o n
at t h e
grain
begins
data.
the
Thus,
onset
(KI),
the
mean
minimum
of
which
lithification", is e q u i v a l e n t
or
to the
the m i d d l e of the limestone layers. compaction
smallest
at
of
compaction
in the m i d d l e
the
onset
of
simply amount
to as
of
"compaction
"lithification
all at
compaction"
of m e c h a n i c a l c o m p a c t i o n in
In simple terms,
lithification
usually
small amounts of indicate
early
On the o t h e r
intense c o m p a c t i o n at the onset of l i t h i f i c a t i o n usually implies
the opposite. at
amount
(in terms of o v e r b u r d e n and
c e m e n t a t i o n a c c o m p a n i e d by little m e c h a n i c a l compaction. hand,
mechanical
in the middle of the limestone layers is, at first glance,
limestone layers in a s e q u e n c e is here r e f e r r e d the
Since
(due to the development of a
contacts),
a m e a s u r e of the i n i t i a t i o n of c e m e n t a t i o n time).
the
(sections
the
onset
In order to q u a n t i f y this relationship, of
lithification
will
be
the
transformed
compaction into
its
31 corresponding the
porosity.
This
amount o f o v e r b u r d e n Transformation
(K 1)
into
the
following
of
allows
by u s i n g the
one
compaction
corresponding
to
estimate
the
porosity-overburden
porosity
at
the
(n 1)
is
timing
and
formulas.
onset
of
lithification
accomplished
by u s i n g
the
equation: no-K 1
nl[VOl%]
where
n o is
numerous
the
date
already
been 1983),
cementation
on p o r o s i t y
the
(Ph)
of
section
carbonate
has
1978;
overburden
can be e s t i m a t e d
from the
terms of the found density
in
(see
2.3.5).
developed
and t h e primary gradient
and
the
time
porosity
regression
required at
the
formulae
Project,
amount o f o v e r b u r d e n
have
HAMILTON, 1 9 7 6 ;
SCHMOKER & HALLEY, 1 9 8 2 ;
from the
Deep S e a D r i l l i n g
Since
sequences
(SCHLANGER & DOUGLAS, 1 9 7 4 ;
amount
lithification. H A M I L T O N (1976) sediment
decompaction
reduction
(8)
,
I-0.01K 1
LOCKRIDGE & SCHOLLE,
begins
carbonates
of
collected
SCHOLLE, 1 9 7 7 ; KOPF,
porosity
=
where
(h,
the
i n km) i s
density of sediment (~o) ( d , i n g/cm3m x 1 0 - 4 ) :
until
onset
for p e l a g i c density
of
expressed
in
an d o f an e m p i r i c a l l y
~ h = ~o +dh
where
d = 19.35
In this
study,
of decompaction and
+ 25.5h 2
from primary porosities
(section 2.3.5) using a grain density
a sea w a t e r
with overburden
(9)
- 33.2h
Po can be obtained density
as a result
(Pm) of 2.7g/cm 3
(~w) of 1.05g/cm 3 (HAMILTON,
(n h) results
of
1976).
Porosity
in:
&-& nh[VOl%]
Compaction with
overburden
m u s t be s u b s t i t u t e d The
sedimentation above
were
of
overburden rates
(HAMILTON, 1 9 7 6 , e q u a t i o n 1)
x 100
c a n be o b t a i n e d
from equation
(10)
8 , w h e r e K1
by K a n d n 1 by n .
development
increasing
= ~
for
ascertained
porosity was the
compaction
calculated
studied
with
and
the
as
sections help
of
through
follows: and
for
absolute
time
with
Decompacted the
time
rock tables
column (VAN
32
HINTE, 1 9 7 6 a , b ; were
KENNEDY & ODIN, 1 9 8 2 ) .
calculated
overburden
(eq.
(e.g.,
years).
This
compaction. calculated first
In
9,
a n d 10) f o r
overburden interval the
was
second
a specific,
corresponding shortened loop,
compaction to
small
and
to
be u s e d
of
of
10,000
increasing
compaction
was
plus
again
the
original
shortened
interval.
Then,
were
until
there
equation
9
the
origlnal
due to the new amount of c o m p a c t i o n and
added to the s h o r t e n e d interval of the first run, etc. point,
interval
a period
according
porosity
and porosity
for a new value of o v e r b u r d e n c o n s i s t i n g of the shortened,
interval
interval
8,
Then,
is a p p r o x i m a t e l y
The m e t h o d can
500m of overburden.
After this
yields u n r e a l i s t i c results as a c o n s e q u e n c e of t h e
r e g r e s s i o n m e t h o d used by H A M I L T O N
(1976).
Q U A N T I F I C A T I O N D I A G EN
E S I S
OF
I N
C A R B O N A T E
M A R L-
L I M E S T ON
E
A L T E R N A T I O N S
In
this
section,
the p r e v i o u s l y
described methods
several examples of m a r l - l i m e s t o n e arranged
alternations.
are a p p l i e d
Ten s e c t i o n s
to are
in a loose s u c c e s s i o n from slightly hardened, prediagenetic
sequences
to d i a g e n e t i c a l l y
modified,
well-bedded
alternations.
Decompaction and carbonate mass balance calculations were performed in order to evaluate the cement content, the primary composition, and the timing
of the c a r b o n a t e
the s e c t i o n s
studied,
redistribution.
from laboratory
Data obtained directly from analyses,
and c a l c u l a t i o n s
(Table 2) are compiled in the Appendices II and III in RICKEN (1985b). It is left to the r e a d e r information prefers
on the m e t h o d s
simply
(section
to d e c i d e w h e t h e r
used
and r e s u l t s
to r e a d the c o n c l u s i o n s
3.6).
Readers
he w a n t s
detailed
o b t a i n e d or whether he
at the e n d of t h i s c h a p t e r
w h o would llke a short overview are referred
to the figures illustrating the studied sections - each of which gives special insights into diagenetic bedding: P o r t o Empedocle section (Fig. 15) is a prediagenetic alternation which is
still
in the p h a s e
reduction.
of m e c h a n i c a l
The P l i o c e n e
compaction
foraminlferal
ooze
and p o r e
displays
space
a primary
cyclic bedding with low carbonate oscillations. Rheine
section
(Fig.
18)
clearly
shows
the b e h a v i o r of porosity in
lithifled alternations. Angles
1 section
(Fig.
20)
presents
the
typical
shapes
of the
carbonate curves for clay-rich alternations. Angles
2 section
(Fig.
23)
displays
h o w the carbonate curves change
w h e n the total carbonate content increases; moreover, the behavior of minor elements which are contained in the carbonate fraction is shown. Angles 3 section (Fig. 25) is an exciting section, since it represents a sequence detected addition,
generated
large-scale Angles
from
a primary
fluctuations
3 is a t y p i c a l
in
alternation with carbonate
easily
content.
In
e x a m p l e of how limestone layers
should appear when their carbonate content is very high. LoEis
du Pin
section
(Fig.
28).
This
is the best
section
for the
34
demonstration
of
how
compaction
can be i n d i r e c t l y e v a l u a t e d
from
s e l e c t i v e l y c e m e n t e d burrows• Neuffen
1 section
impact rocks
(Fig.
32).
of w e a t h e r i n g
on
and the d i f f e r e n t
Field and
2:
laboratory
section
shows
both
the
curves
as
reflections
content•
analyses. •
°
o
o ~
0
clearly
of b e d d i n g in c a l c a r e o u s
s h a p e s of c a r b o n a t e
of low and h i g h c a r b o n a t e
Table
This
the development
CD
~,~
Porto Empedocle Pliocene Sicily Rheine Cenomanian Lower Saxony Basin Angles 1 Valanginian Vocontian Basin Angles 2 Hauterivan Vocontian Basin Angles 3 Barremian Vocontian Basin Logis du Pin Hauterivian Vocontian Basin Neuffen 1 Oxfordian S. German Basin Neuffen 2 Oxfordian S. German Basin Gubbio 1 Paleocene Umbrian Apennines Maastrichtian Gubbio 2 Oligocene Umbrian Apennines Gubbio 3" Oligocene Umbrian Apennines Fossombrone** Maastrichtian The Marches Geisingen** Oxfordian S. G e r m a n B a s i n Neuffen** Kimmeridgian S. G e r m a n B a s i n Neuffen Oxfordian S. G e r m a n B a s i n * * * * Total amount of determinations
~
~
,~,.~
~
~
•
0
0
~l Or'-~
0 J,..~
0
~D
"~
I~1 ~ ' , ~
,~
~
~.~
o
~
• ~
--
~l
~D
o
68
--
62
--
66
--
98
20
44
20
75
--
110
7
67
7
36
--
97
29
73
29
85
68
68
17
20
17
15
--
52
35
10
35
26
--
263
--
60
--
39
--
174
--
54
--
36
62, 122"**
127
15
68
15
34
--
144
47
44
47
24
143
33
27
6
27
. . . .
77
3
31
3
60
--
55
.
.
.
.
.
.
.
.
.
.
g3
.
.
.
.
.
.
.
.
.
.
87
.
.
.
.
.
.
.
.
.
.
1546
200
*random spot sample, **event-alternation, a m i n a t i o n of stylolite.
539
200
496
* * * o n l y Mg and Ca,
385
****ex-
35
Neuffen
2 section
behavior
(Fig.
and
limestone
1 section
the
(Fig.
layers
which
are
are
example
of
Tertiary Gubbio
Uncemented
This
section
(Fig.
foraminiferal on
with
sandy gypsum
clay-marl
sequence
which
HEIMANN,
becoming
1975;
Trubi
1973;
DROOGER,
SAITO e t
an
the
-
stylolites
interesting
sediments
1 spans
from
Cretaceous-
of minor
Pliocene, of
an
elements
in
a
called
Sicily.
water
marl-chalk
"Trubi"
(BROLSMA, Trubi
Marls
cyclic This
debris
at
Marls
overlie
a 400m t h i c k , due
Pliocene
(SPROYIERI,
which
Trubi
1976) is
deposits
contains
Marls,
points
entire
flow
fossils
It
T h e 90m t h i c k
the
intensely events.
(PE)
unlithified
sediments
with
Sicily
fluctuations.
chalks of
Above
is
anoxic
with
HSU ( 1 9 8 3 )
of
the
al,
were
that
the
to
the
sequence
and
is
turbidites
1968;
the
CITA,
1973;
BANDY,
deposited 1975;
ooze
BENSON,
1973;
BIJU-DUVAL et
and,
(that
depths
1975). of
is
only
al.,
of
the
again existing
indicates
1000 to
However, 500m ( s e e
1974;
was a
after
evidence
in water depth
Mediterranean
Miocene,
calcareous
a maximum w a t e r
2500m
HEIMANN conference
CATALANO e t
al.,
1975). road
section
True marl not
in
Micropaleontological
intersection The
Marls. are
planktonic
Coastal
Section: ledges)
of
Marls
Location:
Trubi
that
was deposited.
1972,
westward
and
coast
agree
hypothesizes
volumes:
is
primary
carbonate
sequences.
inundated,
the
(1977)
example
which became dessicated
Marl)
(CITA,
limestone
numerous It
abundance
Marl,
weak
marls
shallow
authors
deep basin
that
for
1977).
Most
Trubi
plots
a deep-water
bedding.
Gubbio
shows the
an
interbedded
contain
is
reconstruct
transgressive
incursion
occasionally
element
alternation.
southern
Messinian repeated
40)
as
outcrop
trace
carbonate
and contain
the
addition,
only
Pliocene
the
thin
Foraminiferal
with
of
on
as well.
serves
alternation
shape
section
to
can
In
deep-water
3.1
along
one
boundary
2 section
This
parallel
how
stylolitic,
the
conspicuously
rock.
information
layers.
37).
oriented
compacted
provides
demonstrates
carbonate-rich Gubbio
34)
developed;
between with (Fig.
the 15)
and limestone however,
Porto
Empedocle
"Lldo-Porto is
from
layers slight
and Spoto,
Empedocle" the
(and
upper
road.
part
therefore
carbonate
500m
of
the
weathered
variations
do
36
PORTO EMPEDOCLE[PLIOCENE] Carbonate Compaction Porosity NCdno . 50 55 60 65 50 40 30 35 40 45 20 15 10 K n CoNC
m _
_
1
2
3
4
5
6
Fig. 15 Uncemented foramintferal marl, Pltocene, Porto Empedocle, Sicily (see Fig. 22A,B). Columns: 1) w e a t h e r i n g profile and sample numbers, 2) carbonate content, 3) compaction (K), 4) porosity (n), 5) standardized n o n c a r b o n a t e f r a c t i o n (NCd), 6) c a l c u l a t e d o r i g i n a l s e d i m e n t composition with the primary porosity (n o , s h a d e d a r e a ) , original carbonate content (C o , h a t c h e d a r e a ) , and the s t a n d a r d i z e d n o n c a r b o n a t e f r a c t i o n (NCd, s t r i p e d a r e a ) .
37 cause
a weak
bioturbated 400m o f
major
is
often
have
never
variations o f up t o
compacted
which
the
filled of
upon
10% ( F i g .
(Fig.
22A,B).
and
by 35 t o
an
are
to
although
oscillations of
have
15% CaCO 3 .
smaller
t o 0 . S m an d h a v e
is
(due
chambers of
matrix,
amplitude
oscillations
from 0.2
the
Carbonate
1.5m with
major
and
However,
of
cement.
The s e q u e n c e
Zoophycos,
50%.
compaction
with
1 to
these range
outcrop
Chondrltes,
resisted been
periodicities
Superimposed
in the
Planolttes,
overburden)
foraminifera they
undulation
with
carbonate
fluctuation
i n CaCO 3
15).
n
• • t/.,
-^
'-,,u
O°
3S o
'
~....
•
•
I
,%1r
.,~Wl Z .z
•
I
•
I
=.53 n =.19 C+ 30.09
I I
r
5'o
'
6b
'
7b
COCO3 Fig. 16 porosity.
Relationship Unlithified
Calculations
and r e s u l t s :
redistribution content the
has
(which
inversely
is
not
sediment
can
section
contained
63.4% c a r b o n a t e ,
higher beds,
(Fig.
although (Fig.
in 16).
amount of compaction (Fig.
17).
from be
the
determined On t h e
and
The mean o r i g i n a l
is
to
studied
layers
with
differences
absolute in
Therefore, simply
the
primary
a porosity that
of
porosity of
the
porosity
in the
parts
nature
of
is
the
sediment
64.0%.
The
w as s l i g h t l y
carbonate-rich now l o w e r
by a s t a t i s t i c a l l y
a relatively
clay
most
decompacttng
the
primary
can be e x p l a i n e d
in the
the
2)
by
the
compared
section This
of
eq.
average,
cla~
a m o u n t of c a r b o n a t e
curve
CaCO 3 c u r v e .
36.6% as
a substantial
solving
shows t h a t
beds the
the
15).
calculation
in clay-rich
marl beds
occurred, to
existing
decompactlon
Since
obtained
proportional
original
between carbonate content and foramlntferal marl, Pliocene, Sicily.
in the higher
l o w CaCO 3 c o n t e n t
decompaction
porosity
38 (n o ) were in
only
1.5% b e t w e e n p r i m a r y
carbonate
(for
beds
n o = 63.5%
based
carbonate:
no = 65.0~
on
beds
containing
relatively
more
52 m e a s u r e m e n t s ;
beds
richer
than
and p o o r e r
57.5%
containing
carbonate:
less
than
57.5%
f r o m 26 m e a s u r e m e n t s ) .
100 % C 0 M P A C T I 0 N
80 60 o • ee
q
II
|
40 20
20
z;o'6o
io
1oo
% CARBONATE
Fig. 17 Relationship between carbonate content and compaction. Unl~thified foraminifera1 marl, Pliocene,
Sicily.
3.2
Marl-Chalk
Chalks
Cenomanian,
and m a r l s
in the
have
developed
into
certain
locations
Germany
alternations ERNST e t
at
al.,
correlate
near
FISCHER e t
al.
climatic
Alternation,
1979). salt
Location: Cenomantan,
Lower Saxony Basin
marl-limestone
Although suppose
some
that
or
(SCHNEIDER, 1 9 6 4 ; alternations
domes (ABU MAARUF, 1 9 7 5 ) ,
(1985)
bedding
epicontinental
Lower Saxony Basin
they
northern
clay-marlstone ABU-MAARUF, 1 9 7 5 ; are
ERNST e t
represent
in
difficult al.
to
(1979)
an d
Mllankovitch-like
cycles. Middle
below the
& Co.
quarry,
Red C h a l k
layer.
Rheine,
northwest
Germany,
Upper
39
RHEINE Carbonafe CompactionPorosify N£d [Cenomon.] so 6o 7o 8090~06o 4o 2o 5 101~2010 0
1
2
3
4.
5
FIE. 18 Rheine marl-limestone alternation, Cenomantan, Lower Saxony Basln, Germany. Columns: 1) weathering profile and sample numbers, 2) carbonate content of selectively cemented burrows (x) and of the rock matrix (o), 3) c o m p a c t i o n o f s e l e c t i v e l y cemented burrows (x) and of the rock matrix (o), 4) rock porosity, 5) s t a n d a r d i z e d n o n c a r bonate fraction (NCd).
40
Section: with to
80
to
60% i n
with
cemented
compaction
as
80% i n
the
inversely
by
carbonate
3:
content
lower to
beds. to
high
relatively
from
eq.
(60
carbonate-compaction theoretical
curve clay
22G). matrix,
degree
of
layers. 70
5 a n d 15% a n d i s
(Fig.
bed porosity
this
is
a n d by a d e c r e a s e
19a);
in
Sedimentary
overburden
fraction
(Rheine
10.5
11.2
11.05
10.2
2.5
2.9
2.2
12
The
of
varies
between
(Fig.
23
noncarbonate and
19b),
data
compaction
Since
the
fraction,
15% a n d
conditions.
from the
10.7%).
7.5
section).
2.1
19
absolute
depositional
is
between
80
results:
calculated
bed
limestone
70-80
diagram
content
higher
60-70
8
2,
and
content
upsection.
(Fig.
marl
30% a n d a p p r o x i m a t e l y
varies
50
selectively
section the
neighboring
noncarbonate
of
turbulent
the
approaches
marl
and with bioturbated
have been
than
the
layers
bedding
1900m (THIERMANN, 1 9 7 3 ) .
of m e a s u r e m e n t s
calculated
of
uneven
intensively
burrows
carbonate
and porosity
and
are
content
Porosity the
Mean s t a n d a r d i z e d
Calculations
of
layers
Mean s t a n d a r d i z e d n o n c a r b o n a t e fraction (NCd, v o l %) Standard deviation
absolute
that
limestone
was a p p r o x i m a t e l y
Carbonate content t h e r o c k (%)
Number
carbonate
displays
limestone
These history
a relatively
content
section
micritic
carbonate
compared marl
the
18)
The a l t e r n a t i o n s
diagenetic a
proportional
expressed
Table
the
have
of the
in
(Fig.
Chondrites.
higher
they
Compaction
section
beds.
and in
a
although
the
marl
early
have
Rheine
85% c a r b o n a t e
the
Planolites
They
to
The
points
to
in
the
However, are
scattered law
along
(where
mean a b s o l u t e
clay
the
the mean
content
Fig. 19 D a t a from the C e n o m a n l a n R h e i n e section. a: R e l a t i o n s h i p b e t w e e n p o r o s i t y (n) and c a r b o n a t e c o n t e n t (C). b: Measurements and theoretical curve calculated from the compaction law using a mean absolute clay content of NCd=10.7% a n d t h e f o r m u l a f o r p o r o s i t y used in Fig. 19a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the s e d i m e n t c o l u m n , b a s e d o n DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of lithification with a ±~zone of scatter.
41
n 15:
RHEINE
R °
=~ °,
100 % 90 C 80 0 M 70 P 60 A 50 C T L~0
10. . ," = : 5 6
n =-.14C+20.02
0
/,0
®
60
80 C100
F]
I
~: ~ .~
o
0 N
I
(~ W
~_ I
i I I
I
II ,._J ,
, ,--J
' I
'
'
®
I
I I
I
L--.I
I I
I i t i
I I
r~t..4
'
O, , 10 10 , 20 ZO , BO x 1 0 G Y 00
20
__
..
%
~5 go 55 go 65 7'0 75 so 85 coco 3 200 - ~ ,
52.1
47.9
--
19.9
28.6
63.4
39..8
- -- 2.5~.~&
0-.~8.3-
-
[o :&Be o-126e-" ,:~3.7o= -
1.9
3.6
:,.. k\15.&
60
8o% K n
-
3001 -- _ I
LR
[
40
I
100'
(•)
i
10 20 30 40 50 60 70 80 90 100 % COC03
L-
F- J
,
-
i, .... ?r I 1 "~
{:
I
I I
*o
20 10
r-!;-{-1
r--
,,
30
0
E]
-7;
\30.8~35.7\"
~\\\\\\\\~
II s.611,o.;'lI 13zll 115 ~ I ,04 119.< I
~00 m
®
,5'
42
does 3),
not
vary
significantly
mass balance
clay
content.
neutral
cemented)
is
contains
value
about
an
the
marl
The mass balance 59~ a n d
a primary
carbonate
content
a maximum of differences with
72.6
content
to
in
(62.9
in
31%
cement,
went
80.6%,
is
the m i n i m u m
2.4).
from
the
of
compaction
Now,
the
original
porosity the
zones
of
however,
the
of mean
differed
porosity
the
carbonate
differs
by
minimum
by
porosity
61% p r i m a r y
zones
Thus,
nor
19d).
assumption
cementation
the
layers
Originally,
(56 to
respectively).
by a factor
41% o f
and cementation
19d).
19c), dissolved
limestone
(Fig.
74~.
sediment
and
the
(Table
mean a b s o l u t e
a mean d e c o m p a c t i o n of
resulted
Fig.
compaction
in
neither
whereas
gives
origlnal
the (Fig.
is
solution
dissolution
dissolution
The amount of
into
content
75.5% CaC03,
versus
section
of beds
the
content
using
calculations
carbonate
which
out
carbonate
The
the
5% i n
the
enhancement
these which
calculation
2.8%, of
to
carbonate
carbonate
carried
(at
74~.
average
in
increasing
were
According
carbonate
carbonate
with
calculations
17.7%
diagenetic
6.3. at
the
onset
in the m i d d l e
of
cementation
of the
is
limestone
defined
layers
by (see
It has been calculated at 32.9~ ±15 and corresponds to
a lithiflcatlon porosity
of 38%.
According to the methods described
in section 2.4, the phase of mechanical c o m p a c t i o n of 4 m i l l i o n y e a r s
lasted
an a v e r a g e
( d e c o m p a c t e d sedimentation rates are O.Im/100Oy),
and ended when 280m of overburden had been deposited.
3.3
Pelagic
to
Vocontian
Neritic Basin,
Alternations Lower
of
Cretaceous,
the France
The most conspicuous features of the Lower Cretaceous in the Vocontlan Basin (French Maritime Alps) are the extremely well-bedded, pelagic to hemlpelag!c marl-llmestone
alternations (Fig. 22C) which interfinger
with neritic sediments to the south (COTILLON,
1971;
GEBHARD,
1983).
Rhythmic alternations are interrupted by slumped horizons, and locally even by turbidltes. llmestone
layers
COTILLON et al. can be t r a c e d
(1980)
across
Vocontian Basin over a distance of 130km. located over
2000km
apart
have
the
shown
that
tectonlcally
Even
sites which
several
shortened had b e e n
( A n g l e s - V e r g o n s section, Vocontlan Basin,
and sites in the Central Atlantic and in the Gulf of Mexico, sites 534 and
535/540)
26000
years
Voconttan
should
display
(COTILLION
Basin
contain
a similar
& RIO,
1984).
a significantly
bedding
rhythmicity
Limestone greater
of
layers
amount of
6000 to in
the
radiolarians
43
ANGLES 1 Corbonofe CompctOion n NCd [Valanginien]so 60708090 806040 0 102010 0 12t z s ~ 80- 81
77 - 78~ ~
11"
7,,. 76~-,~ 73 ----~~..e" 72-71~
63-65~2----" 62 1 5 3 - - ~ 152,154.-~-~
9
58-6o~F~__ 52-53-~=~ 54--
8
88 5 1 ~ - L ' ~ 89~ 9O---2 36 -40-~ ~
6
91 35~
29-32<
5 25-~o~------___} 22~ 45-21--
3
?(----~ lzs g-vg---L." 1s-17~..~
2"
13/ I~ 111"f-L~l
1-
,05~
0
loo-loI-~"
729
1
2
3
4,
5
F i g . 20 Angles 1 marl-limestone alternation, Valanginian, Vocontian Basin, French Maritime Alps. Columns: 1) weathering profile a n d s a m p l e n u m b e r s , 2) c a r b o n a t e c o n t e n t , 3) c o m p a c t i o n , 4) p o r o s i t y ( n ) , 5) n o n c a r b o n a t e fraction, expressed as a percentage of the original sediment volume
(NCd).
44 than
the
marl beds
forming
in
circulation hand,
(DARMEDRU e t
nutrient-rich (DARMEDRU,
carbonate
stagnant
3.3.1
water
Marly
Location: Angles, zone,
1982).
masses
They
COTILLION & R I O ,
layers
are
are
interpreted
due t o w e l l - d e v e l o p e d 1984).
interpreted
as
oceanic
On t h e
other
formed
under
de Castillion
and
to
be
conditions.
Alternation, Road
middle
1984;
poor
cut
15km n o r t h
Valanglnian
along
of
the
al.
road
Castellane.
Valanginian,
DARMEDRU e t
al.,
water
see
between
Lac
A 12m s e c t i o n
layer
(1982);
(A1)
numbers
323
illustrated
to
of 330
section
the as
Verrucosum
assigned
by COTILLION e t
by al.
(1980). Section:
The
marl-llmestone between
relatively
The
bloturbated; detected.
(Fig.
20)
is c o m p r i s e d
of one m i c r i t i c
alternation containing variations in carbonate content
50 and 85% w i t h
represent curve.
section
grey,
periodicities
distinct
micritic
therefore,
maxima
marls
single,
of 0.8m.
These
and m i n i m a
and
variations
on the c a r b o n a t e
limestones
are
totally
w e l l - p r e s e r v e d burrows could not be
Thus, compaction was calculated from the living chambers of
straight ammonites of the genus Anahamullna (preserved as stelnkerns). Measurements limestone
indicate relatively high compaction in the middle of the
layers
Sedimentary
(40
to
60%)
overburden was
and
about
approximately
80%
in
1250m
the
marl
beds.
( K E R C K H O V E & ROUX,
1976). Calculations calculated content,
from
and the
compaction,
results: compaction and
porosity,
Absolute law
clay
(eq.
decreases
2)
content, utilizing upsection
which
was
carbonate somewhat
F i g . 21 D a t a f r o m t h e V a l a n g i n i a n A n g l e s 1 s e c t i o n . a: Relationship between porosity an d c a r b o n a t e c o n t e n t . b: Measurements and theoretical curve calculated from the c o m p a c t i o n l a w u s i n g mean a b s o l u t e c l a y c o n t e n t s o f 6 . 0 ~ a n d 7.4% an d t h e f o r m u l a f o r p o r o s i t y used in Fig. 21a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the s e d i m e n t c o l u m n , b a s e d on DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of lithification with a ~zone of scatter.
45
ANGLES D
1
100
15 •~" ¢ "~.'.~ IT"
10 5
I
"
X
r = .92 % n = 7.96 LnHO0-C) -18.79 ~ t i .
%
/,0
T
60 80 100 %CQCO 3
@
I
~.
30'
Ned = t 6.0 I
t
I
i-",, L_
0 ®
10 20 30 ~0 50 60 70 80 90 100 % CoC03
, 10, , 20, , 30x,
©
,106Y "$Kn
~ 5 550 60 6 5 ~757 80 0 85 90 % CaC03 68.1
$3.8
79.0
ii l
31.9
2t667.8 ®
46 because large
the
calculated content
value
original
Table
carbonate
the
measured
the
compaction
dissolution
(Fig. (Table
sediment
4:
21b). 4),
and which
c a n be d e r i v e d
of
Mean s t a n d a r d i z e d noncarbonate fraction ( N e d , v o l %) Standard deviation Number o f m e a s u r e m e n t s
increases.
data
causes
the
theoretical
where
the
mean
law, beds
zones
clearly
small, without
noncarbonate <60
This
around
cementation
The m a r l
from
Mean s t a n d a r d i z e d
Carbonate content t h e r o c k (%)
content
of the
from in
respectively clay
total
scattering
is
7.4
have a higher
primary
differences
significant
error.
fraction
(Angles
75-85
85-90
8.49
6.72
6.26
5.74
1.61
1.95
2.43
1.10
27
28
curves
absolute
60-75
8
relatively clay
and
6.0%,
absolute in
the
1 section).
11
Fig. 22 A: Pliocene foramtnlferal marl, Capo Rosello, southern Sicily. Variations in carbonate content are easily traced through the section, b u t no t r u e b e d d i n g p l a n e s e x i s t (prediagenetic marl-chalk bedding cycles, marl-limestone alternation Type 0 ) . B: Pliocene foraminiferal marls, section of Porto Empedocle, southern Sicily. A g a i n , no t r u e b e d d i n g p l a n e s exist. C: Hauterivian part of the Angles section, Vocontian Basin, French Maritime Alps. Marl and l i m e s t o n e l a y e r s display an equal thickness. Limestone layers have a convex-shaped distribution of their carbonate content (marl-limestone alternation Type I I ) . D: Barremian Angles 3 section, Vocontian Basin, French Maritime Alps. The sequence contains angular-shaped carbonate curves and thin shale layers with a relatively high organic carbon content (marl-limestone alternation Type
III). E: Valanginian Angles 1 section, Vocontian Basin, French Maritime Alps. Weathering points to irregular carbonate distribution with several smaller limestone layers within larger marl beds. Limestone layers have a predominantly sinusotdal carbonate distribution (marl-limestone alternation, Type I). F,G: Selectively early cementation of the burrow system (arthropod burrows), which suffered minor to intermediate amounts of compaction prior to the onset of cementation. F = L o g i s du P i n , H a u t e r i v e , French Maritime Alps; G=Rheine, Cenomanian, Lower Saxony B a s i n , Germany.
47
~ ~ ~'~ 'i ~ ~iil~,ii~i~ ¸~~i~ ~ . . . . . i
C
48
From the d e c o m p a c t i o n (Fig.
21c,d),
statistical
neutral
cementation boundary);
the m e a n
zones thus,
and the c e m e n t
primary
carbonate
is 70% the
mass
balance
calculations
p o r o s i t y was computed as 77.4~. value
(this
cemented
between
is less zones
than
are
The
dissolution
that
and
at the weathering
a little
thicker
than the
in
original
limestone layers. If
one
sediment, and
assumes primary
zones
n o = 77.4+2.5%,
are
low.
from
the
limestone
Only
25% o f
marl
beds.
dissolved
(33~)
zones
are
of
the
carbonate;
thus,
an
using
the the
interval
of
0.17m/1000y
(Hauterivian),
decompacted
sections.
Rhythmic
3.3.2
4.6
Marl-Limestone
Location:
Ikm
Castillion
and A n g l e s
west
of
content the
the
incorporate
the onset
only
about
the
51% w h i c h
diagenetically
the
layers
is
reached
about were
460m
carried
(Valanginian) and
time
and
span
Hauterivian road
in
mobilized
Calculations
along
in
existing
at
thickness
limestone
dissolved
and porosity
Alternation,
Angles,
(see
was
(Fig.
0.16m/1000y
on the
to
1.5.
carbonate
zones
of
years.
of
only
dissolution
mean overburden
million based
was
zones:
Co=76.1%).
of
because
have
(45%)
amount
dissolution
cemented
cement
low, and
process small
rates
and
content
thick
was high
corresponding
sedimentation
factor
relative
small
relatively
relative
a
carbonate
relatively the
to
the
the
no=77.4-2.5%,
dissolved
remarkably
redistribution
with
out
not
compaction
carbonate
agreement within
is
of
Mechanical
original
Nevertheless,
layers carbonate
21d).
the
of
the
13% ( d i s s o l u t i o n
zones:
amounts
amounts
5~
between
a maximum of
cementation
absolute
of
differences
have
enhancement the
cemented
would
Co=63.2%;
diagenetic
Accordingly,
differences
mean carbonate
cementation
Mean
porosity
of
the
(A2)
between
Lac
de
2 to 16 in B U S N A R D O ,
1963). Section:
The s e c t i o n
Hauterivian. thicknesses
Although of about
is nine meters thick and is from the Upper
the m a r l
30cm
and
limestone layers reveal similar
in the w e a t h e r i n g
profile
(Fig.
22C),
carbonate content is asymmetrically distributed with narrow minima and wide maxima (ranging between 50 and 90%) and e x h i b i t i n g 0.6m are
(Fig.
23).
lacking,
Crioceratites
Since burrows
i n t e r v a l s of
s u i t a b l e for compaction measurements
compaction was evaluated from ammonites (Anahamulina and in s t e i n k e r n
preservation).
Measurements
indicate
49
..t:. o
1.1-
•
~o 0 ~
U
z~
--
• °
°" ; "
•
" q" "
oo
oe~
,R~," •
oo
•
ee
•
• eoo o e ° + e e 0 o e o ~ e + °
~t,
t" ° oo,'°
I~
oeebano ee~oeeeeoeoel,
°0 " • ~ ' " t "
00~0
"
,;
I.FI
"~~g %
rn
'
GI
ku i
F i g . 23 Angles 2 marl-limestone alternation, Hauterivian, French Maritime Alps. Columns: 1) w e a t h e r i n g p r o f i l e an d sample numbers, 2) c a r b o n a t e content, 3) c o m p a c t i o n , 4) porosity, 5) noncarbonate fraction, expressed as a percentage of the original sediment volume, 6) minor elements, expressed as a percentage of the total carbonate fraction.
50
compaction
of
marl
Rock p o r o s i t y
beds.
content
30 t o
(Figs.
Minor
23,
(0.03%,
or
depleted
a
(NCd,
eq.
curve,
2)
(Fig. which
absolute Fig.
clay
24a).
affected
Mn).
of
degree to
1.6 to
(further
varies is
the
The
by t h e
is
mean
varying
the
MgCO 3
marl
from
8%.
data
absolute carbonate
In
the
content
(Table
noncarbonate
Carbonate content t h e r o c k (%)
30-70
70-80
80-90
5.32
6.52
6.61
1.24
1.16
1.58
Mean s t a n d a r d i z e d n o n c a r b o n a t e fraction (NCd, v o l %) Standard deviation Number
of m e a s u r e m e n t s
8
in
15
1%,
total
whereas in
the
section
FeCO 3
marl
and
7). fraction
carbonate-compaction the
law
formula
T a b l e 5: Mean s t a n d a r d i z e d (Angles 2 section). of
and
the
S r a n d Mn s h o w n o
compaction content
have
MgCO 3 b e c o m e s
around
porosity
clay
on
noncarbonate
the
scatter
6.4% and the
(0.3%
carbonate
given
23)
a n d l o w MnCO3
beds,
In contrast, are
the
carbonate
(Fig.
compaction.
amount of
4 and
measured
calculated
content
and
The s t a n d a r d i z e d
between the
2.5.
90% i n
the
900ppm S r ) , depending
of
explanations
and results: 24b),
or
2 within
to
to
a f e w a n d 15%.
FeCO 3
1.3
a n d 80 t o
carbonate
behavior
the
relationship layers
Calculations diagram
of
the
(0.15%,
inverse
and
factor
layers
proportional
between in
140ppm
by a f a c t o r
recognizable limestone
and varies
an
content by
limestone
inversely
SrCO 3 c o n t e n t s
show
carbonate enriched
the
is
contained
high
respectively)
is
24a)
elements
comparatively values
50% i n
is
not
theoretical
(where is
that
the
mean
used
significantly
5).
fraction
38
Fig. 24 D a t a from the H a u t e r i v i a n A n g l e s 2 section. a: R e l a t i o n s h i p b e t w e e n p o r o s i t y (n) and c a r b o n a t e c o n t e n t (C). b: Measurements and theoretical curve calculated from the compaction law using a mean absolute clay content of 6.4% and the formula for porosity used in Fig. 24a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the s e d i m e n t c o l u m n , b a s e d o n DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of lithification with a ±ffzone of scatter.
in
51
ANGLES 2 n
100
% 90 C 80
2
15"
lO.
"'".~..
~ 70 P 6O
5
~' so
.~ r =36 n =9.09/n(I00-C)-20.76
I kO
, 60
@
80
T ~0 I 100 0 30
%CaCO3
N 20 10 r]
ih
0
r:i ® (~)
10 20 30 40 50 60 70 80 90 100
% CQCO3
L.,-,tillllL,~rl = I
i 5%
~4 " .....
"---
j
o
~.rl
,
lo,
, 2o,
, 3,0x10 6Y
20 ~,o 60
I
80 % K n I
F--,,,=
I
~oo 30
40
50
58.5
60
70
,/
\
" ,,,'tI
41.5
"L
2~.3 58.4 ~&8
\
80 90 % CaCO3
I
8Q1
!
~--8~I. 8=4.#=== 1
~5.~ t3. o0~_32.7~ i'~5.&l o " = y 2 e ' - S 2 6 o ~ \ \ \ ' , k ~ \ \ \
ii:
m
I i
A2®
52
Decompaction mean
primary
about
76%.
and
porosity in
cementation
order
zones and
difference zones
in
reach
the
the
carbonate
418m,
with
rates
in
an
m per
average
of
172m.
1000
years: 0.14).
3.3.3
Black
Shale-Limestone
Location:
One
km w e s t w a r d
of
Castillion
and
Angles.
section
layers
Section:
The
The
144 to
mean
150
limestone
are e x t r e m e l y well-bedded.
Angles as
76%
described
of
between mechanical 0.04;
(AS)
road
Upper
78
sedimentation
Barremian,
between
Barremian
Lac de consists
b y BUSNARDO ( 1 9 6 3 ) .
layers are between 0.1 and 1 m thick and This bedding is especially pronounced due
to the presence of bituminous m a r l
to c l a y
are o n l y
( C O T I L L I O N & RIO,
22D).
nearly
deviation
was
period
the
the
is
mean
boundary.
Barremian
along
the a 5~
the
standard
0.17;
from
of
cementation
(decompacted
Alternation,
layers).
and of
the
Hauterivian,
the
Assuming
overburden
years
in
2.3.2),
weathering
The
5 million
Albian,
value from
the
limestone
those
4.6.
by
by
enhancement of
section
the
the
of
dissolution
lithification,
of
about
(see
68~ derived
of
0.06;
limestone
diagenetic
carbonate
content
Aptian,
of
carbonate
between
of
onset
lasted
original
porosity
level the
the
carbonate
of
affected
required in
a
content
was
carbonate
total
produce
carbonate sediment
by a factor
neutral
24c,d)
the
the
differences
at
a primary original
a maximum
original
(Fig.
reprecipitated
variations
The
compaction
of
39% o f
4.5~. to
compaction
(45%
created
At a confidence and
and the
mobilized,
carbonate
carbonate
equivalent of
73.2% supply
now comprize
original
calculations
60% o f to
was
The redistribution
primary
of
processes
dissolution
mean
balance
Approximately
dissolution
layers,
mass
a few c e n t i m e t e r s
thick
interbeds,
most
of w h i c h
1984;
see Fig.
In contrast to the limestone layers, the bituminous marl layers
are only slightly bioturbated by Chondrites, thus indicating anoxic or nearly
anoxic
conditions
(BROMLEY et al., 1984).
Flasery marl seams
at the marl-limestone transition and pressure shadow structures around belemnite guards (see Fig. 88) within the marl beds point to intensive carbonate redistribution processes. Compared
to the p r e v i o u s l y
described
layers (when plotted) have e x t r e m e l y 25).
This
is t y p i c a l
for
sections,
angular
limestone
t h e s e limestone
carbonate
layers with
content and a relatively early onset of diagenesis.
curves
a high
(Fig.
carbonate
Carbonate content
53
diminishes very slightly from the middle to the edges of the limestone layers, then decreases suddenly adjacent to the marl Soints. carbonate differences are therefore between 5 and 97~. evaluated
using
Crioceratites)
ammonites
(mainly
and Chondrites.
steinkerns
sediment
overburden was about 900m (KERCKHOVE & ROUX,
thickness, whereas
I
~
volume.
1976).
. I
t
t
I
I
I
f
I
T
1
i
I L IDII s o ~
3'
t
i
~
i
, ;
i
39--
] 3,-33-~'..T~
/~
z~-~o~
Maximum
[ ar bonafe [om-acfionp Ned 20 /.0 60 80 ~100 80 60 ~ 20 0 20100
lldarremlanJo s6
and
The middle of the limestone layers is
c o m p a c t e d by I0 to 40~ of the o r i g i n a l
.3
Compaction was
of B a r r e m i t e s
marl beds lost 80 to 90% of their original s e d i m e n t
..-.ANGLES.
Maximum
I
o.
I
L
±
~
---"
I,~|
'
I
/
%--~t
i
~
I
~
~
~-~,
/
I
1 1
2
3
4
Fig. 25 Angles 3 section, Barremian, Vocontian Basin, French Maritime Alps. Columns: 1) weathering profile and sample numbers, 2) carbonate content, 3) compaction, 4) noncarbonate fraction, expressed as a percentage of the original s e d i m e n t v o l u m e (NCd).
Calculations (eq.
2)
correlates 26). lie
with
In
the
along
(where zones
are
from S to the
The s t a n d a r d i z e d 10% i n t h e m a r l
existing
fluctuations
carbonate-compaction
two
mean
calculations ranging
and r e s u l t s :
increases
separate
absolute
8.5
and result
curves clay
3.4%, in
in
diagram calculated
contents
in
respectively). primary
f r o m 74 t o 91% a n d an
(Fig.
25)
carbonate (Fig. from
dissolution with
porosity
(Fig.
measured
compaction and
data law
cementation
mass
mean c a r b o n a t e of
fraction
and c l e a r l y
content
27b), the
Carbonate
sediment
average
noncarbonate
beds
65% ( F i g .
balance contents 27c,d).
54
%NCd
"
0
NCd'=-:0907C÷!1"863"
20
"
/,0
"
60
I
"
80
100
%COCO3 Fig. 26 Relationship between the standardized noncarbonate content (expressed as a percentage of the original sediment volume, NC d ) a n d t h e c a r b o n a t e content in the existing rock in percent. Angles 3 section.
Primary of
thicknesses
the
dissolution
original is
a
sediment
somewhat
weathering The of
averages cement
About
70% o f
beds,
was
carbonate
existing
column.
higher
carbonate the
Assuming
the
marl
cementation
and
zones)
The carbonate
percentage
than
limestone
were neutral
the
layers
nearly value
carbonate
(areas
equal is
in
the
90%, w h i c h
content
of
the
boundary.
cement
layers,
of and
the
of
42%;
however,
content
original
dissolved primary
fraction
differences
limestone in
increases carbonate,
and
porosity
the
then
middle
to
60% o f
which
was
reprecipitated
variations between
layers
the
the
of
5% ( s e e
cemented
which of
the the
carbonate. in
the
limestone
section and
composed
limestone
total
contained in
is
the
dissolved
marl
layers.
2.3.2), zones
Fig. 27 Data from the Barremian Angles 3 section. a: Relationship between porosity and carbonate content. b: Measurements and theoretical curve calculated from the compaction law using mean absolute clay contents of 8.5 and 3.4% and the formula for porosity used in Fig. 27a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the sediment c o l u m n , b a s e d o n DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of lithification with a ±Gzone of scatter.
mean were
55
ANGLES n 20:
3
100
1,4 3
90 %
c 80
15 ¸
~ 7o P 6O
\.
10
A
c 5O T
~ 3o
=.97 n = 5.191n(I00-C)-4.97 r
20
0
@
~0
80 100 %COCO 3
60
'
2O 10 I
0
10 20 30 40 50 60 70 80 90 100 % CoCO3
®
r]
-I
i i i i
Ei L
0 I
00
©
Y 20 ~0 60 8o%1~,n 10 I
i
20 I
30 x 10 6
J
100
V1
r-L_f-" i
r. . . .
io 20 3o ~o so 6o 7b so 9o
% CoCO 3
44.9
55.1 18.1 ~&.7
,
200300
/-~3
tOO
8ZO
® ' e-I0.I " &184 • -113.0 •
~1.s-t.~z8,,7-.t.=~I~3" ~,\~.~\\Z \ \ ",';7.9\ '
®
I~.0\\3X3_\
5 ~.o"X
114n, I I ~.Sl I I IS2.11 ~l.5.v-M3.4rN-~- 5.9..,
m
56
17.3~ are
(73.6 46.2~
and
90.9~,
(47.9
and
enhancement At 2.4),
of
the
primary
onset
of
27e)
carbonate
variation
70 and
at
onset
mechanical
the
decompacted
0.04;
Aptian,
3.3.4 Location: Pin"
R.N.85
cut
and
to
the
of
rates
in
135m with deviation
average,
years
m/1000
Alternation,
quarry
southeast
hardground-bearing,
years:
that
of
the
marl
2km
south
of
the
condensed
95% i n
the
rock
matrix.
layers
significantly
more
consists
of
towards
as
70
in
Barremlan
of
However,
and
which
carbonates
is c o m p o s e d
of
are o v e r l a i n
by
(GEBHARD,
surrounding
in
the
of
compaction
marl
layers and
(see
section
possible
only
on a few samples.
with
indirectly
(eq.
29a).
They
within
the
are total
2)
the the
marl,
burrows
Calculations
2.1.2). evaluated
was
All
compaction,
burrows
limestones
the
marl
the
traces
of
attained
75 to
these
carbonate,
10% a n d
show of
70%)
not
as
cemented
compaction
close
was
congruence
data.
Standardized
regardless
of in
to
by considering
selectively
were
is
but which
80% c o m p a c t i o n .
evaluated the
(20 it
to
within
layers,
however,
measurement
compaction
varies
equivalent
the
layers;
from
which
is
than of
indirectly
Direct
results: 5 and
marl
carbonate
from section
matrix
which
and between
1983).
selectively
cemented
carbonate
Compaction
of
system,
layers,
selectively
than
middle
the
calculated
du
(Fig. 28) belongs to the
limestone
less
75% CaCO 3 . the
Compaction
the
the
contain
carbonate
to
the
amounts
"Logis
(Fig. 22F); they give the section a nodular
middle
usually
increases high
by
(L)
crossroad
Basin
The carbonate content of the b u r r o w
the
phase
Barremian,
Hauterivian
of the V o c o n t i a n
cemented arthropod burrows 90 to
the
(calculated
The alternation is totally penetrated by bedding-parallel,
from
a for
0.14).
slightly silty marls and limestones,
character.
section
respectively
of
standard
million
2.7.
(see 53~,
On t h e
3.5
This upper Hauterivlan section
zone
micritic,
Albian,
and
diagenetic
and D.21.
Section: neritic
about
a factor
overburden
lithification).
lasted
by
26.4
mean
250m (according of
is
mean differences minimum
redistribution
were a
Marl-Limestone
Road
of
porosity
sedimentation
0.06;
Neritic
variations
from
compaction
present thus,
carbonate
result
between
compaction using
and
which
whereas
respectively);
intense
mean compaction
(Fig.
of
respectively), 94.1~,
clay and
only
changes
one in
contents
porosity major
lithology
data
were (Fig.
variation from
marl
57
to limestone. slightly data
Since the mean a b s o l u t e
for d i f f e r e n t
scatter
around
percentages the
clay
content
fluctuates
only
of carbonate (Table 6), measured
theoretical
curve
representing
relationship between carbonate content and compaction (Fig. 29b).
the The
curve is calculated from the compaction law using a mean absolute clay content
of 7 . 3 ~ and
the c a r b o n a t e
p o r o s i t y regression curve in Fig.
29a.
LOGIS-DU-PINcorbonofe Compaction NCd lHCluterlvlclnJ657o 80 90 100 80 60 40 20 015105 0 ,/. 6 5. 4 3 2 1, O 1
2
3
4
28 L o g i s du P i n m a r l - l i m e s t o n e alternation, Hauterivian, Vocontian Basin, French Maritime Alps. Columns: 1) weathering profile a n d s a m p l e n u m b e r s , 2) c a r b o n a t e c o n t e n t of mainly selectively cemented burrows (x) and rock matrix ( o ) , 3) c o m p a c t i o n o f m a i n l y s e l e c t i v e l y cemented burrows ( x ) a n d r o c k m a t r i x ( o ) , 4) n o n c a r b o n a t e c o n t e n t , expressed as a percentage of the original s e d i m e n t v o l u m e (NCd). Fig.
58
Table 6: section). Carbonate the rock
Mean
standardized
content (%)
of
Mean standardized n o n c a r b o n a t e fraction (Ned, vol ~) Standard deviation
were
carried
out
absolute of
porosity the
reducing
original
carbonate content carbonate that
36% w a s the
cemented
than Fig.
zones
14).
oscillations
6.22
0.95
1.97
1.29
1.91
0.74
i0
mass and
Its
Mean
12.8~ were
the
(79.4% present (74
and
enhanced
only
was
carbonate (or
portions,
which
for
by at
least
and
and
81.9%
differences
a factor
in
lower
than
thus the
the are
outcrop
fluctuated for
by
cementation
between
primary of
total
zones)
ledges
therefore,
the
(85%);
content
then
a cement
of is
a in
primary
Thus,
(81~)
be
role
the
cementation form
dissolution
86.8%);
might
a percentage
carbonate
mean carbonate
of
boundary
alternation
The
dissolved
value
weathering
mean
a critical
layers. as
29c,d)
utilizing
which
plays percent
(expressed
(Fig.
respectively. 62%,
presence
limestone
original
zones
7.2%,
zones
now t h e
5
calculations
Thirty-two
achieved
weathered
the
and
Pin
90
14
cementation low,
silt.
are
6
balance
7.3
The neutral
2.5%
whereas are
7.59
dissolution
of
the
approximately zones),
7.62
marl-limestone
portions
thicker (see
the
content).
for
6.63
relatively
of
in what
of
7.78
porosity.
in
reprecipitated
85-90
of
is
presence
du
80-85
dissolution
contents
(Logis
75-80
carbonate
for
clay
decompaction result
and
fraction
70-75
I0
Number of measurements
Decompaction
noncarbonate
the
carbonate
5.1.
Fig. 29 Data from the Hauterivian Logis du Pin section. a: Relationship between porosity (n) and carbonate content (C). b: Measurements and theoretical curve calculated from the compaction law using a mean absolute clay content of 7.3% and the formula for porosity used in Fig. 29a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the sediment c o l u m n , b a s e d o n DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of lithification with a ±azone of scatter.
two
59
LOGI5 DU PIN
t~ 15
100
L
%
90
C 0 M P A C T
80
1o
k_.
5. n = :26 C+27. 94
80
60
@
''"'
70 60 50
4.0 30 0 N 20 10
100
I
%COCO 3
0
®
© ,,
NCd = 7.3
10 20 30 /.4 50 60 70 80 90 100 % EctCO3
[~
rl
II II l I ~ F'LI ' I
i i
'I , I I' I
!1~1 i,,--'
I
1,o, 2o , I,_
-
h
LF L~
0(
20
z,O
6O
3,ox,lO6y
oo%Kn
I
6"8
72
75 80
84
88
% 92
100
CoCO 3
2001-
@
6&5
36.5
30015.2 4 t 7 &&O
69.3
I I 1~,61I I I z31 i 126.Ol ] i
--1.2--3.2--'.5,.5-
12.~ I 7.2113.2
400 m
L ®
60
61
Compaction
and p o r o s i t y
at the onset
of c e m e n t a t i o n
calculated as 27.9 and 47%, r e s p e c t i v e l y .
According
presented
amount
between
in s e c t i o n
95 and
2.4,
300m w i t h
the
resulting
a mean
of 170m.
have been
to the m e t h o d s
of o v e r b u r d e n
The p h a s e
was
of m e c h a n i c a l
compaction had a long duration - 20 million years - because the Aptian is a p e r i o d
of
(calculated Barremian,
3.4
sediment
0.01; Aptian,
Epicontinental
Since
bypassing
decompacted
SEIBOLD's
well-developed,
1985a)
bedding
indicate
Jurassic (1952)
depositional
Alternations
classic
marl-limestone cycles. that
events.
netto-sedimentation
rates
in
m/1000
0.00; Albian 0.01; Cenomanian,
(Oxfordian and K i m m e r i d g i a n ) climatic
without
sedimentation
the
have
study
0.12).
of
Southern
Germany
(see
section
5.6),
the
alternations
in s o u t h e r n
been
to be the r e s u l t
However, original
However,
years:
thought
recent
facies
bedding
was
analyses partly
the m a r l - l i m e s t o n e
Germany of
(RICKEN,
formed
by
alternations now
appear rather uniform because most of the depositional structures were destroyed
by
development
both
intense
(see section 8).
bioturbation
and
diagenetic
The following
observations
marl
seam
confirm
the
principle of diagenetic bedding: i.
Marl
layers
of the U p p e r
Oxfordian alternation display intensive
flasering of microstylolitic WANLESS,
1979);
dissolution
particularly
in c o r e d
seams
(Fig.
sections.
dissect the bioturbation structures and are p a r t i a l l y with
small-scale
compaction
(RICKEN
slickenslides & HEMLEBEN,
as
1982).
a result
30H,
e.g.,
These
seams
associated
of d i f f e r e n t i a l
In a d d i t i o n ,
calcareous
F i g . 30 A,B,C: D i a g e n e t i c marl seams b e l o w and a b o v e slightly c o m p a c t e d a l g a e - s p o n g e b i o h e r m s (A,B: Gosheim, M i d d l e O x f o r d i a n ) and s k e l e t a l c h a n n e l fill (C: Neuffen, Upper Oxfordian; see Fig. 31). D: Sllckenslides d u e to c o m p a c t i o n a l d i f f e r e n c e s and development of d i a g e n e t i c s t y l o l i t e s v e r t i c a l to b e d d i n g , Neuffen, Upper Oxfordian (see Fig. 9). E: Residual limestone layers w i t h i n marl beds, G e n k i n g e n , Upper Oxfordian. F,G: Typical CaCO 3 pressure shadow structure around a belemnite shell in a marl layer, T a l h e i m , U p p e r O x f o r d i a n (see Fig. 58). Scale is lcm. H: T y p i c a l microstylolitic, flasery marl seams as a result of p r e s s u r e d i s s o l u t i o n . Marl-limestone transition, Talheim, Upper Oxfordian. Scale is lcm.
62
CARBONATE CONTENT 9
0
~
__ --
-
-
--
-
84
.....
BO
84
88 -92 ¸ 9?
:B8 -
~- 80
-
--
-
-
-
.
.
.
.
BL
80
76--76
.
76 76
LJ'80
~76
=~-: ~7~
~
-
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
.
80
80 84
86
~
9
2
_.
'20 cm '
COMPACTION
2O cm I
!
20cm Fig. S1 CaCO 3 c o n t e n t and compaction of a bioclastic channel fill (shaded), Neuffen, Upper Oxfordian (see Fig. 30C). Below the weakly compacted channel fill, carbonate content decreases sharply as compaction increases. Data collected using a grid of points of 93 carbonate determinations. Compaction was calculated using the carbonate compaction law with an absolute clay content of NCd=-0.053C+7.8.
94 96
63
pressure
s h a d o w structures around massive shells are present (see
Figs. 30F,G; 58).
Nevertheless, the weathered marl l a y e r s
appear
to be mostly homogenous. 2.
Diagenetic
marl
layers
little-compacted
rock
coarse-grained marl
beds
for
the
channel
delivered
formed
areas, fills
part,
cementation
as
(Figs.
but
of
above
such not
30A,B,C; all,
slightly
and
below
several of
31).
the
compacted
relatively
biostromes
and
The s u r r o u n d i n g
carbonate
areas.
necessary
Another
source
of cement are the dissolution seams within the biostromes. 3.
Carbonate
content fluctuates slightly when material from the marl
bed was brought into the underlying limestone layer, except for in submarine
channels
and b e d s
composed
variations are more pronounced. original
sediment
had
of
lag d e p o s i t s where the
This can be i n t e r p r e t e d that
smaller
carbonate
variations
than
the the
present, rhythmically bedded rock.
3.4.1
~iddle
Location:
Oxfordian
Quarry
Alternation
(N1)
near Neuffen,
S w a b l a n Alb, see SEIBOLD (1952) and
section
32) c o m p r i s e s the upper part of the
RICKEN (1985a). Section: Middle
The
Oxfordian,
The w e a t h e r e d limestone 36A).
section
layers,
which
(Fig.
is composed of blue-grey mlcrites and marls. shows are
three
is c o m p o s e d
predominantly
carbonate
variations
of n u m e r o u s exhibit
intervals
separated
In contrast to the a p p e a r a n c e
section which
which
Below
an a v e r a g e
carbonate
content
weathering boundary (section 2.3.7), the t o t a l regardless limestone
of
Compaction marl
smaller
layers varies
beds.
(Planolites,
carbonate
develop when between
Compaction
of 5 to
on t h e i r have
of 85%,
32), Small
carbonate
curved, which
rock weathers
variations.
the c a r b o n a t e
(Fig. 8m.
the
wide
is the to m a r l
On the o t h e r hand,
content
is a b o v e
B5~.
20~ in the limestone layers and 80~ in the
was
Chondrites)
profile,
oscillations
cycliclty
sharp maxima
carbonate
spaced
by 2m t h i c k marl zones (Fig.
curves, whereas larger carbonate variations m a i n l y maxima.
closely
of the w e a t h e r i n g
a major
have narrow,
of
evaluated using and
ammonites
Perisphinctes; in steinkern preservation).
several
trace
(Glochlceras,
fossils Oppelia,
64
NEUFFEN 1 m [hi. Oxford~on]
Carbonate Compaction NEd 60 80 100 60 20 0108642
J
...:...:....:.
~!~!~:if~ 19361~, "~"?:':~':":':~
199
~3~~ 196-19B~
3B 2 0 2 - 3 ~
""'~"........ t
S
219"'- 6 5 ~ , q ~ 4 8 - 9 ~ ~^^ ~
[[[[.. ."~.z27~61 ~:! \ , ~.............. :::~::.;~::~:
1
56
26/+
2
3 Cw
L.
5
Fig. 32 Neuffen 1 marl-limestone alternation, Middle Oxfordian, southern Germany. Columns: 1) lithology, for explanation see Fig. 91, 2) weathering profile and s a m p l e numbers, 3) carbonate content and (shaded) the carbonate
65
Calculations normalized (Fig.
and
to
32)
and
lowest
(Table
33c,d)
indicate
carbonate
the tends
to
7).
in
amount
to
zones);
whereas
of
5.4~
in
cement.
(76.5%
for
present
in
the
layers
and
weathering
boundary;
the
of
middle
7:
the
therefore,
marl
content (%)
When
of
measurements
methods
described
1S0m).
began,
years. 0.09;
in
compaction
The p h a s e
and
86.8~, 32~
of
form
carbonate
as
between
than
is
are to
value lower
fraction
at
the
restricted
to
1 section).
75-80
80-85
85-90
90-95
7.09
6.71
7.05
6.67
5.11
1.47
2.08
2.14
1.62
1.26
9
10
mechanlcal
section was
(Neuffen
55-75
2.4,
between
of m e c h a n i c a l
18
12
compaction was 27.4% thereby
the
50 and
33e).
According
overburden S50m
compaction
to the
at the end of
(the a v e r a g e
being
lasted about 1.2 million
Decompacted sedimentation rates in m / 1 0 0 0 Klmmerfdgian,
cementation
released
dissolution
reducing the primary porosity to 55.5~ (Fig. mechanical
is
differences
average,
total
a
5% p o r o s i t y
variations
was
their
79%)
carbonate
11
cementation
for
carbonate
(at
68% a n d
(71.1
On t h e zones
neutral
noncarbonate
Mean standardized noncarbonate fraction (Ned, v o l %) Standard deviation Number of
a
is (Fig.
beds.
Mean standardized
Carbonate the rock
2.9.
37% o f
zones
content of
carbonate
dissolution
the
cementation
81.9% 15.7%
was
varies
calculations
porosity
and
primary
with
carbonate
Assuming
are
of
which
clearly
mean carbonate
differences
by a factor
limestone
80~. original
the
content, 2),
balance
a mean
dissolution
mean
Statistically,
dissolution
Table
sediment,
carbonate
the
with
clay (eq.
total
mass
approximately
enhanced
original
volume
and
Therefore,
diagenetically
absolute
when the
sediment
primary
respectively).
cement
be highest
a primary the
The sediment
Decompaction
content
variation
the
results:
original
years:
Oxfordlan,
0.13.
~content of the weathering boundary between marl and l i m e s t o n e (Cw) , 4) measured compaction (e), interpolated by u s i n g eq. 4 and the m e a n a b s o l u t e c l a y c o n t e n t (a), 5) nonoarbonate f r a c t i o n , e x p r e s s e d as a p e r c e n t a g e of the original sediment volume (NCd).
66
1
NEUFFEN
n 15 % 10:
C 0 M P A C
5 rn =="91:25C+ 26,46
"~o~
~])4~0 6()'8'0'C100 TI 0 N F'-I
80
NCd= ?.0-
I
0
®
I I
Fi
4.?. 9
68 72
76 80 84
73.4
(~ , 1,o , 2,0 , 3,0 x, l O 6 y oo 20 ~,o 6o 8 o % K , n
88 92
CoCO3
I00~
34.8 !1'7.5
50.2
m ®
Ned, = 6.3°f'~,i-,
I
65.2 D-.
• I
10 20 30 40 50 60 70 80 90 100 % Co[0 3
L--iF~-'--:,L_~
j
56 60 64
•
50 40 3020r 10
i
•
70 60
®
67
3.4.2
Upper
Location:
Oxfordian
Quarry
Well-Bedded
near
Neuffen,
Oxfordian-Kimmeridgian
Limestones
Swabian
boundary;
(N2)
Alb,
section
see
SEIBOLD
is
completely
10m b e l o w t h e
(1952)
and
RICKEN
(1985a). Section: represents section 20
to
beds
The
8).
(Fig.
36B).
are
The carbonate stylolltic
middle
of
the
in
marl
elements content the of
the
slight
the
beds
of
2 to
result
layers. in and
varied
theoretical
curves
results:
and
absolute
diagram are
clay
dissolution-affected
and
absolute
tends
(Table
clay
content
7),
other
hand,
carbonate
calculated marl
events
(see
(Fig.
35b), on
contents
cemented to
of
zones,
increase
as
Compaction, only
in
the
it
increases
to
80%
Fe
total
are
minor
carbonate fraction
increased
in
the
marl
4.0
clay 8).
data
only
content
fall
In along
compaction
and
3.2%
respectively). carbonate
by
carbonate
w h i c h may b e t h e
section
carbonate
of
beds.
absolute beds,
measured
the
curves.
low
the
the
in
Fig.
Mn a n d S r u n d e r w e n t
of
individual
97%;
is
carbonate
Mg a n d
based
and
carbonate-bound in
In the
of marl
40% ( s e e
carbonate
concentration
The
within
(which
(section
their
depositional
carbonate-compaction me an
residual
mainly
whereas
zones) to
60
nearly
30%),
on fluctuations
On t h e
the
to
(see
5cm t h i c k
alternations.
compaction.
dissolution
differs of
amount of compared
limestone
2)
dependent
between
Planolites,
(5 to
(or
Calculations (eq.
layers
of
1 to
angular
carbonate-rich
5 as
enrichment
varies
and
cyclothem alternations
and
may d r o p
produce
As s h o w n l a t e r
clearly
and in
it
layers
of
layers
content
deformation
limestone
layers.
are
marl
factors
the
bioturbated
Upper Oxfordian
shows brick-like
seams,
limestone
from
the
limestone
characteristic
calculated the
34) of
profile
micritic
When p l o t t e d ,
These
(Fig.
The weathering
30cm thick
bedding-parallel 9).
section
maximum t r a n s g r e s s i o n
content
the two law
for
the
The
mean
decreases
8).
F i g . 33 D a t a f r o m t h e M i d d l e O x f o r d i a n N e u f f e n 1 s e c t i o n . a: Relationship between porosity (n) and carbonate content (C). b: Measurements and theoretical curve calculated from the c o m p a c t i o n law u s i n g mean a b s o l u t e clay contents of 7.0% and 6.3% and the formula for porosity used in Fig. 33a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the s e d i m e n t c o l u m n , b a s e d on DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of lithification with a ±Gzone of scatter.
68
o
u_~.
(~C O.
- - - -
x~
~2 o .o c~
~o0
o
o
o
o
o
o
o
o
o
o
Fig. $4 Neuffen 2 marl-llmestone alternation, Upper 0xfordian, southern Germany. Columns: i) w e a t h e r i n g profile and sample numbers, 2) c a r b o n a t e c o n t e n t , S) measured compaction (e) interpolated by using eg. 4 and the mean absolute clay content (A), 4) porosity, 8) noncarbonate fraction, expressed as a percentage of the original sediment v o l u m e (NCd), 8) m i n o r elements, expressed as a percentage of the total carbonate fraction.
69
Mean s t a n d a r d i z e d n o n c a r b o n a t e Table 8: (Neuffen 2 section). C a r b o n a t e content of the rock (~)
60-80
80-90
3.95
4.42
3.30
1.29
2.50
1.34
Mean s t a n d a r d i z e d n o n c a r b o n a t e fraction (NCd, vol ~) S t a n d a r d deviation N u m b e r of m e a s u r e m e n t s Assuming
that
Ii
the
(for
dissolution
original
zones)
porosity
differences
were
fluctuations
of
of
and
3.8%
p o r o s i t y varied by 5%, c a r b o n a t e mass
the
carbonate
(for
65%.
and
37
primary
91.4~
about
16.8%
90-100
5
balance c a l c u l a t i o n s yield m e a n original
fraction
cementation
Since present
in d i s s o l u t i o n
contents
87.6%
zones) and mean
mean
primary
rock
has
and
of
carbonate
mean
cementation
carbonate zones,
the
dlagenetlc
enhancement
of c a r b o n a t e v a r i a t i o n s is by a factor of 4.4.
Due
relatively
small
to the
cementation,
amount
of
compaction
at
the
layers was filled with c a r b o n a t e cement
(forming an a v e r a g e
the
layers).
total
this,
carbonate
in the
a considerable
limestone
amount
d i s s o l u t i o n zones was r e l e a s e d marl
beds
onset
of
the large amount of pore space r e m a i n i n g in the limestone
caused
a large
the limestone layers,
(56%) (Fig.
of
the
35d).
decrease
of
39% of
As a c o n s e q u e n c e of
original
C a C O 3 in the
The loss of v o l u m e
in the
in t h e i r t h i c k n e s s as c o m p a r e d to
a l t h o u g h o r i g i n a l l y the beds slightly richer and
poorer in c a r b o n a t e had n e a r l y the same thickness. When
carbonate
compaction
of
redistribution
19.3%
reduced
began,
the
an
original
a c c o r d i n g to the m e t h o d s d e s c r i b e d in s e c t i o n of
80m
can
be c a l c u l a t e d
with
minimum
average
porosity 2.4,
mechanical
to
a mean
and maximum
57%;
thus,
overburden
values of 35 and
160m (this is due to the s t a n d a r d d e v i a t i o n in the m e a s u r e d c o m p a c t i o n at
the
onset
of
lithiflcation).
The
p h a s e of m e c h a n i c a l compaction
had a d u r a t i o n of about 0.8 m i l l i o n years. rates in m / 1 0 0 0 years are:
3.5
Cretaceous Umbrian
A complete, sediments, nearby
to
Tertiary
Apennines, 500m
thick
predominantly
sections
Oxfordian,
near
Deep
Decompacted
sedimentation
0.09; Kimmeridgian,
Water
0.13.
Limestones,
Italy s e q u e n c e of C r e t a c e o u s to T e r t i a r y deep water composed
Gubblo,
of
Italy
limestones, (in
the
is e x p o s e d
Contessa
in two
valley and the
70
NEUFFEN
n 15
100 % C 0 M P A C T
10 5
ot ®
r ==93 n = :25C+2.£34
~;o 6o ' 8o doo
~
90 80
I i
NCd = &O
~..
70 60 50 /+0
I
10 L--
I
i
4.
0 30 N 20
I-'I
NCd = 3.2
"4~
.;.
"..~ I' 10 20 30 40 50 60 70 80 90 100 % CoCO3 !
I Ii
0
@
I r-a
2
i .-J
F-
,
o'
,
55
60 65
70 75
80
85 90 95
20
m
/.4
\'
lOO¸ % 100CAC0 3
10 , 20,
i •
60
3,0x 106 Y
8o%K,n
I I
200
@
53.6
46.4 300 ¸
!t
20.5 44.2
43.6
8Z3
....
6
1.2 . . . . .
9.2 19.9 36.5 ~
•
m
,\\\\..',.\%~) X\?~..5x'31.4~\57.5 \
500
m
N2®
71
Bottacione gorge). terms
of
The sequence was p r e v i o u s l y
its g e o c h e m i s t r y
FISCHER,
1977;
(LUTERBACHER
ALVAREZ
et al.,
and et
1962;
facies
al.,
1980;
PREMOLI
studied
(ARTHUR, 1981),
SILVA,
in d e t a i l
in
1977; 1979; ARTHUR & biostratigraphy
1977), and paleomagnetism
(LOWRIE et al., 1977; ROGGENTHEN et al., 1977). Other
than
the
Albian
shales
and b l a c k
shales,
foramlnlferal
limestones of the Scaglla Bianca (Upper Alblan to Lower T u r o n l a n ) Scaglia
Rossa
Limestones is
estimated
Oligocene, pelagic
(Niddle
Turonian
to
have
been
roughly
(Scaglia
Cinerea),
sequence composed of turbidite al.,
1970).
The b e d d i n g
layers,
dissolution
1000m
the
sequence.
(ARTHUR,
1979).
seams
sandstones
and
silty,
shales
(BORTOLOTTI
et
of the Scaglla resembles solution cleavage:
5 to 2 0 c m thick,
contain
(Fig.
ARTHUR
rhythmicities
In the
which are overlain by a 2.Skm thick
36F,G,H).
first and second order dissolution planes, bedding
dominate
and water depth during deposition
limestones of the Scaglia Rossa grade into s l i g h t l y
marls
Limestone
to E o c e n e )
are free of macrofossils,
and
irregular, (1979)
stylolltic
has distinguished
for which he has identified
of about 100,000 and 20,000 years,
respectively
(see also FISCHER et al., 1985).
3.5.1
Stylolitic Tertiary
Location: sampled
Limestones Boundary
Road
cuts
Cretaceous-
(G1)
near
in the B o t t a c i o n e
from the
Gubbio,
gorge;
Italy.
The M a a s t r l c h t l a n
the P a l e o c e n e
was
sampled
was
in the
Contessa valley. Section: sharp,
and
The
it is w e l l - d e f i n e d
"boundary clay").
Fig.
35
Cretaceous-Tertiary
Data
The
boundary
from the
Upper
boundary at Gubbio (Fig. 37) is
by a I to 2cm t h i c k is also
Oxfordian
clay
characterized
Neuffen
layer
(or
by an abrupt
2 section.
a: Relationship between porosity (n) and c a r b o n a t e c o n t e n t (C). b: M e a s u r e m e n t s and theoretical curve calculated from the compaction law using mean absolute clay contents of 4.0% and 3.2~ and the formula for porosity used in Fig. 35a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), c o m p a c t i o n (K), and time (t) in the sediment column, based on DSDP data (HAMILTON, 1976). Value s h o w n r e p r e s e n t s c o m p a c t i o n at the onset of lithification with a ± G z o n e of scatter.
72
73
change
in the
1962). this
foraminiferal assemblages
(LUTERBACHER & PREMOLI SILVA,
Since high iridium contents are found in the b o u n d a r y and
similar
Cretaceous-Tertiary
sections
stratigraphic
events.
impact
(e.g.,
et
al. ,
clay
1980)
,
of the
boundary is one of the most discussed and disputed
extraterrestrial O'KEEFE
(ALVAREZ
Explanations
(e.g.,
& AHRENS, 1 9 8 2 )
of
ALVAREZ e t
and volcanic
and
this
al.,
event
1980;
include
1982;
environmental
1984;
processes
KENT, 1 9 8 1 ; KEITH, 1 9 8 2 ; McLEAN, 1 9 8 2 ; RAMPINO, 1 9 8 2 ;
EKDALE &
BROMLEY, 1 9 8 4 ) . The
two
meter
bedding-parallel (approximately 20 t o
90% i n t h e
70% ( F i g .
compaction Planolites stylolitic
37).
reduced whereas
in
limestones)
limestone
have
numerous
carbonate
to values
layers
(5 to
content
ranging 10cm
from
thick),
the deformation
of
compaction measurements in the
were i m p o s s i b l e . completely
cemented
and
beds
porosity in
the
marl
limestones
uppermost Cretaceous
r e m a i n s more o r l e s s
38a,b).
data
Porosity
contains the
by m e a s u r i n g
However,
usually
porosity
which
decreases
evaluated
and Teichichnus. rocks
studied
planes,
In the
bedding planes
strongly
porosities;
interval
c o u l d be d i r e c t l y
Lower Tertiary with
thick
stylolitic
provide
with
much
and marls
constant
no evidence
limestone
for
at
3.5% early
layers higher
from the
(Figs.
37;
hardground
F i g . 36 A: Thick marl bed in the Neuffen 1 marl-limestone alternation, Middle Oxfordian. The m a r l b e d c o n t a i n s small carbonate variations. However, t h e c a r b o n a t e c o n t e n t of t h e variations is below the critical carbonate value of the marl-limestone weathering boundary, therefore the variations weather entirely to marl. B: Marl-limestone alternation with high mean carbonate content, angular carbonate curves, and thin marl layers (Type I I I ) . Upper O x f o r d i a n , P f u l l i n g e n , South Germany. C: Compactional deformation of the bioturbation structure in a m a r l l a y e r . Upper Oxfordian, Neuffen, southern Germany. D: W e a k c o m p a c t i o n in limestone layers. Slightly deformed ammonite oriented v e r t i c a l to b e d d i n g . Middle Oxfordian, Schlatt, South Germany. E: Marl-limestone a l t e r n a t l o n in an a n c i e n t s u b m a r i n e channel system which shift laterally to the northeast. Oxfordian-Kimmeridgian boundary zone, Neuffen, South Germany. F: Cretaceous-Tertiary boundary, Scaglia Rossa, Contessa valley, Gubbio, Italy. A b l e a c h e d z o n e 30cm t h i c k d e v e l o p e d below the boundary clay. Note frequency of stylolitic bedding planes. G,H: M a r l - l i m e s t o n e alternation at the transition between the Scaglia Rossa/Scaglia Cinerea showing frequent stylolitic bedding planes. Eocene and Oligocene, Contessa valley, Gubbio, Italy.
74
o
~
~
~
~
|
r~r ~
~D
o
C °
"O U •
Z
}
~D O
LJ7
Oo C O
O O
(D o
O
(D
O
O
O
v--
v--
O
EO
Fig. 37 G u b b i o 1 m a r l - l i m e s t o n e a l t e r n a t i o n spanning the Cretaceous-Tertlary boundary, Scaglia Rossa, Umbria, Italy. Columns: 1) reddish rock (black), light grey rock (white), 2) weathering profile and sample numbers ( M a a s t r l c h t l a n was s a m p l e d in the B o t t a c c l o n e gorge, Paleocene was sampled in the C o n t e s s a valley, 3) c a r b o n a t e c o n t e n t of s e l e c t l v e l y c e m e n t e d b u r r o w s (x) and rock matrix (o), 4) compaction of
75 cementation
at
infers
the
30 t o
50cm t h i c k
Bleaching
of the
red
from
clay.
depletion
the
during
(eq.
iron
deposition
Calculations fraction
Cretaceous-Tertiary pigment
of the
and r e s u l t s :
2)
decreases
boundary,
bleached could
boundary
The
zone
ARTHUR ( 1 9 7 9 ) the
be e x p l a i n e d
boundary by o x y g e n
clay.
average
upsection
as below
normalized
from
6 to
5~
noncarbonate towards
the
Cretaceous-Tertlary boundary and then increases to more than 8% in the Tertiary which
section
(Fig.
is the r e s u l t
noncarbonate
37).
Contrary
of d i f f e r e n t i a l
fraction
remains
to the b e h a v i o r
cementation,
unchanged
directly
Unfortunately, compaction measurements could not
the
of p o r o s i t y standardized
at the boundary.
be c o m p u t e d
for the
boundary clay because individual burrows could not be detected.
Since
compaction was evaluated predominantly for the limestone layers, it is difficult
to d e t e r m i n e
the e x i s t i n g marl could
the
and
absolute
the primary compositional differences between limestone
clay
content
layers.
be c a l c u l a t e d
varying carbonate content (Table 9). content
Only within
Because
in s u b s e c t i o n D is nearly constant,
absolute slightly.
clay c o n t e n t
in s u b s e c t i o n s
Cretaceous
(subsections C,D) w e r e
then
absolute
C fluctuates and
Tertiary
and b a l a n c e d
(Figs.
only rocks 38d,e;
39a,b) .
T a b l e 9: Mean s t a n d a r d i z e d noncarbonate (Gubbio 1 section, subsection D). Carbonate content t h e r o c k (%)
of
fraction
20-80
80-100
Mean s t a n d a r d i z e d noncarbonate fraction (Ned, v o l ~)
8.20
8.30
Number of measurements
8
9
of
clay
it was presumed that the
A,B)
decompacted
lithologles
the m e a n
A through
(subsections
for
subsection D
selectively cemented burrows (x) and rock matrix (e), interpolated values of compaction using eq. 4 and mean absolute clay contents (~), 5) p o r o s i t y , 6) noncarbonate fraction, expressed as a percentage of the primary or d e c o m p a c t e d s e d i m e n t v o l u m e (NCd) , 7) mean o r i g i n a l sediment composition with the primary porosity (no) , and absolute values of the original carbonate content (Cod) and noncarbonate content (NCd) , 8) p r i m a r y relative carbonate content (Co).
76
GUBBIO
1
n 100
Gled
10t
%
90
C 0 M P A C T I 0 N
80 ?0
n '~'- ~o ' a) ' 8b c1~
ax
- -' = ---~
"'T'~-Fq-7.~'4.,. 5. !
_~ ,.--'
Nc,j = 6.,, f
60 50
E-I--,
i •
4.0 30
"r"I
q
20
b*
OW
® ~o 6'o'Bo E lOO
10-
a,b. c,d
0
©
;
l
10 20 30 40 50 60 70 80 90 100 % CaCO 3
7 If
[J
i
'H! I
(~)
US~
[7 I
I
'~
50
I
5%
r I
,
I--J
L ~ - ~~-'J I
70
/
1"--1 I I p-~ I I I I I I L-J , /_
% CaCO 3
I
1 I
,,'---'
90
L- 7 ~_J
I I
rI 7 I ~-J I I I
30
I
"-7
30
50
I I , I
,
I L-~I
I I I.
J - -
70
I
L-7
~ 1 I ~ ' '~ -
% 90
CaCO 3
77 The
results
porosities
of
are
subsections
these
67%
with
respectively.
the
(Fig.
mean
lasted
deposition reached
similar
original layers
limestone
section
mean
later
2.3.7) mean
were
thus,
8.0
for
Maastrichtian
the
limestone of
derived
from
carbonate
46
is
the at
the
(Maastrichtian)
is
by
5% i n
zones
3.9%
by
the the (see
(Paleocene).
a factor
a n d 31.1% of
respectively.
10.3
and
Consequently,
quantities
of cement
fraction).
where
the
already
between
large
seams
for
has
differences and
carbonate
marl
onset
lasted
of in
the
(an
The c e m e n t i s
64% o f
cementation
the
the
at
the
a n d 120m ( P a l e o c e n e ) , and
from
an
average
and Tertiary using
the
(according
to
compacted
65
to of
in m/lO00 years:
220m 22
subsections,
following
and
section onset
ranging 16
primary
from
rates
39c,d).
lO0
to
years
450m
for
the
Calculations
sedimentation from
of
Mechanical
million
Eocene,
33.5% i n
of cementation
respectively.
0.01;
is
(Fig.
(Paleocene).
decompacted
sedimentation Paleocene,
processes
Paleocene
a mean overburden
performed 1977)
relatively total
needed
varied
of
stylolitic
25.8% ( M a a s t r i c h t i a n )
enhancement
28.2%
to
200m ( M a a s t r i c h t i a n )
Cretaceous
are
cementation
deposition
present, time
77%,
cementation
(Maastrichtian)
stylolitic
and
corresponds
compaction
and
and
carbonate
dissolved.
Maastrichtian
This
carbonate
and P a l e o c e n e ,
contain
of
the
ARTHUR ( 1 9 7 9 )
porosity
dissolution
t o 48% o f t h e
Compaction the
primary
diagenetic
layers
average
Given that
83
in the
by t h e
amount
Tertiary
column,
reprecipitated
the
the of
sediment
sediment.
variations
(Paleocene); the
than
2.5%
mean d e c o m p a c t i o n in
contents
original
represented
layer
become
carbonate
71%
one must assume that
is
conclusions.
sediment, which
Present
which
somewhat l o n g e r
of the
that
and
carbonate
and t h e n
Therefore,
sediment,
indicate
Cretaceous
primary
released
39a,b).
primary
seams,
the
I n 57 t o 60% o f t h e
was diagenetically zones
calculations
in
were rates
ARTHUR & FISCHER,
0.02;
and
Oligocene,
0.03. Discussion: carbonate
mass
The balance
following
summary
calculations
results
from
independent
for the four subsections
(A,B,C
Fig. 38 D a t a from the Gubblo I section with subsections A through C. a,b: Relationship between porosity (n) and c a r b o n a t e content (C); sections A,B (b), section C,D (a). c: M e a s u r e m e n t s and t h e o r e t i c a l curve calculated from the compaction law u s i n g m e a n a b s o l u t e clay c o n t e n t s of 5 . 5 % ( s e c t i o n s A,B) and 6 . 4 % (sections C,D) and the formula for porosity used in Fig. 38a,b. d,e: Carbonate mass balance, sections A,B (d), sections C,D
(e).
78
43.3
56.7 8.2
0
.19.8
4-20
Z
~_,..o.9.=.=.~.o- - -~.[L: lO.g z3.o, 41.~ ~ 3 _ _ , _'_0~6_'_ _ _ :~>~1 _- 1 1 . g \ \
z.9.9
@
']_111
0 I
I I~.~
10
,
I
O0 10 20
20
,
..o.-4..._~..-L--%:
2 2 5 \ " %'.i ,,
12_/+I | I ~ I
I I 1.~<611
83.9
I
\9.1\\ 22.6\ 45.0
~\\\\\\\\\
30 I
12_61 ] I 6_/. I I?_£1
;i;linnlllllillllll
1 9~.I
I
10
0
i
I
I
30 40 50 60 70 80 90
\
20 > 106Y t
i
I
I
10 20 30 ~
i
#
t
# # I \
/'("
I
50 60 70 k D
',,
100
4.8.9
.y :x.2,.,~ .::~..?-
• "% ~,, s 6 \ \ \ x 9.9.~\ +~>.~\ k\\\\\\\\\\ I
4o.5
,59,,~
_
"".,,,/
I
I
I
"\\ \/ I-'\i
/ ,\.t I I
-- .'¢9
300
I
© ~ m ola,
~.oo
and
D;
Fig.
calcareous
37).
ooze,
mean decompaction deposition
content
I
years
\.
31
%%.
\ \
@
'.:,' ~
Glc,'d from
Gubbio
1 section
with
subsections
A
mass balance showing box models; sections C,D ( b ) . (n), compaction (K), and time (t) in the b a s e d on DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value compaction at the onset of lithification of scatter; sections A,B (c), sections C,D
First,
during
the
uppermost
with an average carbonate porosity
of the b o u n d a r y
mean porosity i00,000
,t
I
V -~ iM
Fig. 39 Data t h r o u g h D. a,b: Carbonate A,B ( a ) , s e c t i o n s c,d: Porosity sediment column, shown represents with a ±Gzone (d).
'.@,
\-
of 67 to 68~, clay
(that
was
decreased
dropped suddenly by 6~.
to 64~,
The
deposited.
After
the
is, after the iridium event),
increased to 78% for an interval and then
Maastrichtian,
content of 82 to 85% and a
high
ranging
while
from
the m e a n
porosity
in the
I0,000
to
carbonate lowermost
79
Paleocene the
presumably
results
event.
Moreover,
iridium
greater
proportion
Mg-calcite), years the of
of
because
earlier
and
Therefore,
Cinerea
in
the
Section: are
15cm
Smaller
and
carbonate
cycles
dissolution 90 a n d 95% i n
both
beds
directly
marl in
beds.
the
5 times
(1800ppm)
marl
greater are
epicontinental 2
(section
carbonate Scaglia
is
directly
and the times
For
the
these
reflect
the
the
most part,
the
degree
of
by maximum f a c t o r s
Calculations
and
the
clay
than
beds
results: content,
no significant
80% (Table 10).
the
the o r i g i n a l
to
and
80% i n
the
be ascertained
the
to
the
The
normalized
eq.
2)
changes
range when
Nevertheless,
sediment
trapped
in
the
of
the
of
1.2
minor
Sr,
and a n d Mn
contained
in
and 2.
noncarbonate from 4 to the
the
content
Mg, F e ,
amounts
between
Mg and
environment
carbonate
compaction.
and
is
and of Neuffen
concentration
the
relative
(660ppm)
(390ppm)
elements
fraction
8% ( F i g s .
carbonate
40,
content
the absolute clay content
decreases slightly with lower carbonate content; that
is been
hemipelagic
3.3.2)
deep-water
to
marl
is m o r e
not
to
80% i n
Planolites
of Fe
in
minor
40)
layers
exhibits
to
(having
fraction
2 (section
proportional to
carbonate than
in the
It
40). due
content
50
layers
could
which
rhythm
from
using
concentration less
the
41b).
Scaglia
(Fig.
Compaction
usually
of Angles
Therefore, (Fig.
proportional
absolute
most
limestones beds
major
limestone
were enriched
(or
and
The c a r b o n a t e
planes.
the
to
marl
ranges
evaluated
30% i n
o f Mn i n
6
inversely
limestone
Rossa
on this
and it
bedding
alternations
limestones.
lost
joints.
to
3.4.2).
narrow
36G,H).
compaction
than
2
fraction
elements
(Fig.
indirectly
T h e mean c o n c e n t r a t i o n 4 to
Scaglia
weather
by
limestones,
from
Unfortunately,
stylolitic
the
superimposed
planes
varies
have
to
(G2)
oscillations
are
the
and
Oligocene
separated
and stylolitic
Teichichnus)
6 million compared
valley.
are
between
limestones
a
aragonite,
began
w a s 80m l e s s
Paleocene
had
cementation.
between
Major carbonate thick
marl
zone
Contessa
pressure the
the
during
after
have
(e.g.,
sediments
overburden
rate
must
phases
of these
Alternatioa,
Transition
sedimentation
sediments
carbonate
average
porosity
Stylolitic
Location:
unstable
their
original
3.5.2
Paleocene
lithification
Maastrichtian. their
from a greater
this m i g h t
indicate
which is now represented by the marl beds
80
~ Z\j...',.
~
LP)
....
~
,-<
c.~"l'L ,
jt r v
vK4_i-"
,l "t, ~ ]
"V~'~ ,.- . i . ~ ,
.-iv"
r
v -~
t~t~lf~'t--t--tX'Ttt~
",',
'"'7
.... ~""
"i-
""
i- t -
6o /
(~
EO
~n
O
an
O
Ufrl
C~4
N
v =-
v=-
an
Fig. 40 Gubbio 2 marl-llmestone a l t e r n a t i o n , Eocene, Contessa valley, Italy. Columns: 1) weathering profile and sample numbers, 2) carbonate content in selectively cemented burrows (x) and in the rock matrix (o), 3) c o m p a c t i o n in selectively c e m e n t e d b u r r o w s ( x ) an d i n t h e r o c k m a t r i x ( $ ) , 4) n o n c a r b o n a t e f r a c t i o n , expressed as a percentage of the original s e d i m e n t v o l u m e ( N C d ) , 5) t r a c e an d m i n o r e l e m e n t s , expressed as a percentage of the total carbonate fraction.
81
had
a slightly
llmestone
higher
primary
porosity
layers (see section 2.3.4).
balance c a l c u l a t l o n s
(Fig.
41c,d)
than
that
of
the
present
D e c o m p a c t l o n and c a r b o n a t e mass
yield
a mean
primary
porosity
of
6 6 . 4 % and an original c a r b o n a t e content of 85%.
Table 10:
Mean s t a n d a r d i z e d n o n c a r b o n a t e 75
C a r b o n a t e content of the rock (~) Mean s t a n d a r d i z e d n o n c a r b o n a t e fraction (Ned, vol ~) Standard deviation
An a v e r a g e layers of
the
5%
in
was
of
carbonate the
41% o f
dissolved in
the
primary
80-85
85-90
90-95
4.73
4.49
5.21
5.26
5.21
-
0.93
0.55
1.57
1.06
the
to
are
cementation
zones).
2.3~
13
I0
primary
produce
limestone
sediment
differences
(83.6%
layers.
If
mean
fluctuations
were
a porosity
enhanced
to
zones
for 5.5
in
the
marl
comprises
34~
variation
of
mean and
carbonate
12.8% (76.7% for d i s s o l u t i o n zones and 8 9 . 5 % carbonate
which
original
dissolution
present
24
content
cement
assumed,
for
32
carbonate
carbonate
is
Since
(Gubbio 2 section).
75-80
9
N u m b e r of m e a s u r e m e n t s
fraction
carbonate 85.9%
for
differences
cementation times
their
are
zones), original
value. Compaction
at the onset of l i t h l f i c a t i o n had an average amount of
2 7 . 3 % (Fig. 41d).
According
to eq.
8 and
the m e t h o d s
presented
in
s e c t i o n 2.4, porosity at the b e g i n n i n g of c e m e n t a t i o n was 54% and mean o v e r b u r d e n was 138m (the s t a n d a r d d e v i a t i o n of K I values indicate that o v e r b u r d e n was b e t w e e n about
6.3
million
70 a n d
years
270m).
Mechanical
(decompacted
compaction
sedimentation
c a l c u l a t e d u s i n g c o m p a c t e d s e d i m e n t a t i o n rates from A R T H U R 1977):
3.5.3
Ollgocene,
0.03; Miocene,
Marly to Silty
Location:
0.21;
Alternation,
lasted
rates
were
& FISCHER,
in m / 1 0 0 0 years).
Oltgocene
(G3)
R o a d cut in the C o n t e s s a valley near e n t r a n c e of the upper
quarry. Section: in
an
A r a n d o m spot s a m p l i n g c o n s i s t i n g of 32 samples was made
interval
of
30
meters;
the
a l t e r n a t l o n of the Scaglia Cinerea.
section
Compaction
is was
a marly mostly
to
silty
evaluated
82
GUBB/O 2 n
100
10,
,! 0
@
% 90
60
80
C
C 80 0 M 70 P 60 100 A
q [
C 50T I+0I 0 30. N 20.
10. , _J
t-- 1
®
I I
10 20 30 40 50 60 70 80 90 100 % Carbonafe
r_i
(D
"-'
0 I
,.--~ _~'
10 I
I
oo~2o
106y 40 60 B o % g n 20
I
I
i
30 x I
~;'-~--
~0 .~5 60 os 70 is 80 s'5 90 9s c°/~c% 100 55s
~s
200--t'-.4ckK-,/nt--- ~-
I ,[",,\[ ! // "
~,2.9
723
"~"-~"~'~'~~~"
®
500
m
83
from selectively
early
cemented
introduced in section 2.1.2. spot
sampling
truly
burrows
using
the
indirect
Assuming that the samples
represent
the b e d d i n g
variations,
sediment had a mean porosity of 66%, an a v e r a g e
method
in the r a n d o m
carbonate
the p r i m a r y content
of
75~, and an absolute clay content of 8.4%. Discussion:
Although Upper ~aastrlchtlan and Paleocene limestones
f r o m the G u b b l o section have various primary carbonate contents of 75 to 85~, the decompactlon porosities are i n d e p e n d e n t content
and range
from
approximately
lowermost Paleocene seems to be an exception; increased
to 78~.
sedimentation
Therefore,
rates
of the c a r b o n a t e
64 to 68% (Fig. 42).
Only the
where primary porosities
this provides documentation of the hlgh
directly
following
the
Cretaceous-Tertlary
boundary event (see section 3.5.2).
MEAN DEEOMPAETION POROSITY 60
65
70
75
MEAN PRIMARY CARBONATE CONTENT B0 75
80
B5
UPPER OLIGOEENE(G3°)
LOWER OLIGOCENE(G2)
!
<
LOWERMOST PALEOEENE (GI)
>
UPPERMOSTMAASTRIEHTIAN(GI)CTB *) r a n d o m s p o t
sampling
Fig. 42 Mean a m o u n t s o f d e c o m p a c t i o n p o r o s i t y an d p r i m a r y carbonate at several sites in the Gubblo section (Italy). Note the relatively high value of the decompactton porosity directly above the Cretaceous-Tertiary b o u n d a r y (CTB).
F i g . 41 D a t a f r o m t h e G u b b i o 2 s e c t i o n . a: Relationship between porosity (n) and c a r b o n a t e c o n t e n t (C). b: Measurements and theoretical curve calculated from the c o m p a c t i o n l a w u s i n g mean a b s o l u t e c l a y c o n t e n t of 5.1% and the formula for porosity used in Fig. 41a. c,d: Carbonate mass balance showing histogram and box model. e: Porosity (n), compaction (K), and time (t) in the s e d i m e n t c o l u m n , b a s e d on DSDP d a t a (HAMILTON, 1 9 7 6 ) . Value shown represents compaction at the onset of ltthificatton with a ±~zone of scatter.
84
Table 11: studied.
of
Compilation
Section T y p e of alternation Maximum sedimentary overburden
data
in
the
marl-limestone
PE
R
A1
A2
A3
L
0
I
I
II
III
II
950
900 1 5 0 0
500 1900 1250
N1 I
N2 III
alternations
GIA,B GIC,D IIIII
IIIIl
G2 II
>400 >400 >2500 >2500 >2500
(m) Mean overb u r d e n at the onset of lithification (m)
>500
Mean c o m p a c tion at the onset of lithification (Kl,~)
276
460
172
135
169
130
80
200
120
138
32.9
54.1
36.0
26.4
27.9
27.4
19.3
33.5
28.2
27.3
38.2
50.8
58.1
52.9
47.4
55.5
57.0
50.4
59.6
53.8
58.5
77.4
73.2
65.3
62.1
67.7
65.3
67.0
71.0
66.4
10.7
6.0 7.4
6.4
3.4 8.5
7.3 7.2
6.3 7.0
3.2 4.0
5.5
6,4
5.1
--
72.6 75.4
63.2 76.1
73.7 78.2
73.6 90.9
79.4 81.9
76.5 81.9
87.6 91.4
82.0 84.5
75.8 79.7
83.6 85.9
--
2.8
12.9
4.5
17.3
2.5
5.4
3.8
2.5
3.9
2.3
--
62.9 80.6
60.5 80.4
63.4 83.9
47.9 94.1
74.0 86.8
71.1 86.8
77.2 94.0
64.4 90.2
56.1 87.2
76.7 89.5
--
17.7
19.9
20.5
46.2
12.8
15.7
16.8
25.8
31.1
12.8
36.2
Mean p o r o s i t y at the onset -o f lithific a t i o n (nl,%) Mean d e c o m paction porosity
64
(no,%) M e a n standardized non-13.2 carboante fraction
(Ned, vol %) Mean p r i m a r y carbonate content in dissolution and c e m e n t a tion zones
(Co,%)
*)
difference
Mean e x i s t i n g carbonate c o n t e n t in dissolution and cementat i o n zones
(c,%) difference
85
PE
R
AI
A2
A3
L
N1
N2
--
6.3
1.5
4.6
2.7
5.1
2.9
4.4
10.3
8.0
5.5
Mean relative cement content (Zc,%) of the cementation zones
--
30.8
32.6
38.9
41.9
35.9
36.6
38.8
45.6
48.4
34.1
Volume of the p r i m a r y sediment w h i c h underwent cementation
--
47.9
31.9
41.5
44.9
36.5
34.8
46.4
43.3
40.5
44.5
--
73.8
70
76
90
81
79
89
83
78
7277
72
7482
8090
85
85
90
80
85-
82-
90
88
Section Factor of dtagenetic enhancement (F) * )
GIA,B GIC,D
G2
(Vz,~) Carbonate content of the neutral value
85
(Cn,~) C a r b o n a t e con60 tent at the weathering boundary
(Cw,%) PE = P o r t o Empedocle; R = Rheine; Al-3 - Angles 1 to 3; L = Logis Pin; N1-2 = Neuffen 1 and 2; G1A,B and G1C,D = Gubbio 1, subsections t o D; G2 = G u b b i o 2 . *)assuming a variation in the primary porosity o f 5%.
3.6 1.
Results As
and Bedding
already
the
porosities
ranging
the
of
onset
Mechanical
a lower
Primary
sediments contents
bioturbation
dissolution average
gives
under was
carbonate
were between
5.8%.
an
diagenetic
carbonate
system,
Fig.
mean
I0).
must
because primary
However,
redistribution
until
sediments
of
greater
when
the
primary
see
Fig.
60a).
content
(Table
oozes
60 and 90~.
After
carbonate
zones w e r e According
11,
with
50
to
were
overburden
usually
mean
bedding
realistic
calcareous
primary
of
(see
carbonate
and cementation value
2.3.1,
closed
from 59 to 78%
compacted
had
an
or nearly
compaction
carbonate
section
calculation
diagenetic
sediment
to
in
a closed
decompaction
mechanically
2.
Types
discussed
occur w i t h i n
du A
original
sediment
mixing
differences
between
450m.
mean due
between
2.3 and 17.3~ with
to section
2.3.7
(Fig.
14),
86
these
values
2 when the
the
have
to be m u l t i p l i e d
average
carbonate
variations
fluctuation
curve
after
is
between
factors
of 1.5
Diagenetlc
to
10.3
were
(average
bedding
ranging
the m a x i m a
calculated.
bioturbation
5.1).
by a factor
The
from 1.5
to
and m i n i m a
on
primary
carbonate
diagenetically
enhancement
formed
was
parallel
by
to
enhanced
by
a factor
of
the
original
stratification. S.
In
the
and
primary
those
thickness. became they
4.
Only
appear
whereas
80%
their
of
limestone
layers
the t h i c k n e s s
as
Therefore,
variations
but also b e d d i n g
carbonate are
content
of
the
primary
become
c o n v e x to angular
beds.
minimum In
alternations
porosity
and
clearly
demonstrates In l i t h i f i e d carbonate
unlithified
alternations
As
introduced
already
zones
do not c o r r e s p o n d
weathered
section.
high mean c a r b o n a t e cementation limestone the
in Fig.
layers
cemented
weathered
zones
contents
portions
43). of
ledges
no
and only
the
case
for
carbonate
changes
in
carbonate
curves
and n a r r o w
in t h e
in the m i d d l e
of the
than
does the
close
relationship
Nevertheless,
rock
(see
porosity
Fig.
62).
Whereas
beds
clay values
(about
alternations
in the outcrop.
are
in
the
3~) or
dissolution
of the w e a t h e r e d clay-rich
in
cementation
and l i m e s t o n e
in
on
increases
opposite.
and
of
the
depends
porosity
dissolution
thickness
the
not
total
is the direct
to marl
However,
is
variations
do the t h i c k n e s s
the
by 60 to
layers.
at low a b s o l u t e
equal
(Fig.
limestone
exactly
Only
14,
the
layers
content
that
content
rock
marl-limestone
different
alternations,
the b e h a v i o r
as
the
affects
processes,
studied,
content.
decreasing
the
overburden.
carbonate
of
of m e c h a n i c a l
as on
smaller
in the marl
evidence
with
and
carbonate
exhibits
content
lithified between
the
volume
alternations
lithified
in the l i m e s t o n e
always
carbonate
the
exists
layers
of
redistribution
Moreover,
limestone
sediment
same
rhythmicity.
Depending
sediment
due to c a r b o n a t e
the
is r e d u c e d
a result
sinusoidal
alternations.
volume
marl
not
beds
dissolution
have
most
diagenesis
curves
usually
comprise
of the marl
thickness
compaction.
plotted,
not
in c a r b o n a t e - r i c h
carbonate When
underwent
did
of 41~ of the p r i m a r y
chemical
alternations
6.
an average
original
beds w h i c h
cementation
Nevertheless,
today,
column,
column,
underwent
cemented.
prediagenetic
5.
sediment
which
marl
and and
alternations,
thicker
than the
87
%CeCO3 100
Cw=-1.493 NCd + 91.252 n=-2.128 NCd + 93.282
80 60
•
|w
•
•
0 Fig.
43
(Cw,
x,
According of
to
types
of
these
is
lithified
show
commonly the
marl-limestone
only
I to
Table
are
%NCd
"
"
°
"
with
sediments,
which
law
cycles.
the
carbonate
can
while
curves,
four
be distinguished. the
remaining
are
carbonate carbonate
the
low
Examples:
and the P o r t o
mechanical
sinusoidal
differences
on the
follow
the
or
depositional They
decreasing
for
in
theoretical
porosities
alternations display only m o d e r a t e and compaction.
of
boundary @, ) in (NCd).
One three
are
12):
moderate
mean carbonate
decreases
3.2 to 3.5)
!
10
0),
still
stochastic
and minima
compaction
"
alternations
III;
to
to
bedding
have
maxima
"
Alternations
weak due
and
"
forms
(Type
alternations
oscillations events,
different
unlithified
Unlithified
Unlithified They
the
(Types
Type 0
•
The carbonate content at the weathering ---) and the neutral carbonate value (Cn, to the standardized noncarbonate fraction
relation
basic
I
5
compaction complex
carbonate
processes,
usually
deposltional
bioturbated,
below curve;
and
15% ( c a l c u l a t e d see
Fig.
content.
(see
differences
of
Fig.
the
7),
they
between
14). Unlike
curves
phase.
Porosity llthified carbonate
unlithified
in c a r b o n a t e
content
the calculated original sediments
(section
Empedocle
foraminifera1 ooze (section 3.i).
section
describing
uncemented
88
Table 12: Carbonate predtagenetic; Types
curves I, II,
of marl-limestone alternations. and III are ltthified.
Type
0 is
I
TYPE 0 ITYPE I TYPE I} TYPE III I
~.-
dso-
i onqulor ,
C::I00
80' t~ 60"
%7
0
~'~0
~zo o~O
SHAPE OF THE CARBONATE CURVES
/%
20 (,0 60 80
20 ~0 60 80
MEASURED CARBONATE COMPACTION DATA 20 ~0 60 80
20 ~ 60 80
% CaCO3
% caco3
15- 25
25- 35
35- 55
6 -10
STANDARDIZED NONCARBONATE FRACTION
3-4
t+-6
COMPACTION AT THE ONSET OF LITHIFICAT/ON IN %
/N%
Type
I
35-/+0
/.,0 - 48
1-6
/+-10
3-5
FACTOR OF ENHANCEMENT OF PRIMARY CARB DIFFERENCES
60- 80
75 - 90
85 - 91
MEAN PRIMARY CoCO3 CONTENT W%
Lithified
Alternations
Characterized These
are
contents 80%.
Mechanical
was
high
(35
considerably degree
zones data
55%),
and
rich
to
pore
space
the
enhancement
the
around
marl
to
the
35% o f
in
carbonate
prior
Therefore,
(30
Curves
Maxima
original
compaction
scatter
representing
Carbonate
Sinusoidal
10% a n d
reduced.
of d i a g e n e t i c
measured curve
to
with
relatively
6 and
and
cementation
by
alternations between
% CEMENT (CEMENTATION ZONE} RELATIVE TO THE TOTAL CARB CONTENT
30-35
both total
the
relationship
onset to
the
carbonate
a small
of
clay
between
cemented content For that the
carbonate
60
lithiflcation
content)
low.
part
between
absolute of
be
cement
are r e l a t i v e l y
only
with contents
was in
the
and
the
reason,
theoretical content
and
89 compaction plots
(Table
Carbonate
sinusoidally
with
carbonate
value
neutral
dissolution layers.
Examples:
II
(that
I
is
the
limestone
contents
o f 80 t o
carbonate still
with
Carbonate
85~.
The
between
the weathered
(section
3.4.1).
layers
content
within
from Rheine
by Convex
type of m a r l - l i m e s t o n e
in
(section
Alternations
Lithified
the
sections
and N e u f f e n
Characterized This
is,
zones)
studied
3.3.1),
content
maximum c a r b o n a t e
and cementation
1 (section
Type
12).
3.2),
marl
Angles
Curves
Maxima
rhythm is characterized by broad, convex
carbonate peaks w i t h m a x i m u m
carbonate
values
of 85 to 95%,
medium
absolute clay contents of 4 to 6%, medium amounts of cement (35 to 40% of the total carbonate in the l i m e s t o n e diagenetic
enhancement
variations). than
i0
Type
at the w e a t h e r i n g
Gubbio I and 2 ( s e c t i o n s
Alternations
Lithified
Characterized The
limestone
3.3.2),
by Angular of
layers
with
the
boundary. Logis
3.5.1
than
95%.
content
the contact with the marl beds.
(section
an d 3 . 5 . 2 ) .
Carbonate
Curves
Maxima conspicuous type o f
this h i g h l y
Carbonate
Examples:
du Pin
have broad, angular carbonate curves; m a x i m u m c a r b o n a t e more
l e v e l s of
lower
and p a r t l y
III
high
CaCO 3
studied sections of Angles 2 ( s e c t i o n
3.3.4),
times
but
Commonly, the neutral carbonate value is s l i g h t l y content
4 to
layers),
original
the c a r b o n a t e
(from
alternation
values
reach
d i m i n i s h e s abruptly just prior to
Usually, the marl beds are only a few
centimeters thick; thus, limestone layers predominate in the weathered section, resulting in a brick appearance where the l i m e s t o n e s bricks and the marl represent the grout between them. sediment, carbonate content increased to more than 85%. the
reduction
compaction, limestone
of
was
the
low;
pore
therefore,
space, the
caused
cement
Due
to this,
by m e c h a n i c a l
content
in
the
l a y e r s is high (40 to 48~ of the total carbonate content in
the limestone layers). were
original and,
are the
In the original
Nevertheless,
original
e n h a n c e d by a factor from only 3 to 5.
relatively expressing
well
to
the
branch
of
variations
the
theoretical
curve
the r e l a t i o n s h i p between carbonate content and compaction
(see Fig. 7 and Table 12). dissolution
right
carbonate
Measured data correspond
and
The carbonate n e u t r a l
cementation
zones)
is
value
usually
(between
higher
than
the the
90 carbonate are
layers
marl
Neuffen
than
of the weathering the weathered
boundary;
limestone
always have a flasery-stylolitic
structures the
content
thinner
around massive joints. 2 (section
shells
Examples: 3.4.2).
(see section
thus,
layers. outer
Fig.
58)
Angles
cementation Therefore,
edge. are
Pressure frequently
3 (section
zones
limestone shadow found in
3.3.3)
and
4
D I A G ENE AND
T I C
L E D G E
B E D D I N G
In the p r e v i o u s quantified sections,
through
rhythmicity
MA
T I ON
R H Y T H M I C I T Y
section,
the p r o d u c t i o n
the use
the o r i g i n
FOR
of v a r i o u s
of d i f f e r e n t
as e x p r e s s e d
in
of d i a g e n e t i c
examples.
carbonate
calcareous
b e d d i n g was
In the
curves
bedding
and
following dlagenetlc
alternatlons
is
studied.
4.1
Carbonate
As c a n
be
seen
carbonate degree
Profiles in
Table
curve of
is
12,
mechanical shape
compaction
maxima
marl
when
(in
beds)
mechanical
the
This
hypothetical
a particular clay
carbonate
clay
layers)
content and
clay
and
curve
Conversely,
absolute
type
content
displays
and the
the
a
degree
CaCO 3 c u r v e
pointed,
content
of
on the
sharp and
the
of
shows
minima
(in
degree
of
low.
can for
sediment
equal thickness.
absolute high.
of
absolute The
the
are
phenomenon models
development
are the
Layers
on the
limestone
when
compaction
compaction
the
compaction.
sinusoldal
the
Limestone
dependent
mechanical angular
in
be
explained
limestone
in
a
simple
layers.
column which
Fig.
is d i v i d e d
In the model one assumes that
manner 44
using
presents
a
i n t o s u b s e c t i o n s of compaction,
which
is
lowest in the middle of what later becomes the cementation zone of the limestone
layer,
Therefore,
the
progresses
thicknesses
increasing compaction. pattern
found
in this
outwards
during
diagenesls.
of the s u b s e c t i o n s
steadily
become
s m a l l e r with
This model study.
produces
the t y p i c a l
Compaction increases markedly from the
middle of the limestone layer (the center of cementation) marl
beds.
The d i s t r i b u t i o n
compaction towards
the
of c o m p a c t i o n explains why layers with
different absolute clay content have varying shapes of their carbonate curves,
since
compaction can be transformed into carbonate content by
using the compaction law and various mean absolute clay contents. Fig.
44a,b present
carbonate neglected.
curves When
simple
for l i m e s t o n e the a b s o l u t e
constructions layers. clay
of the above-mentloned
Mechanical
content
is h i g h
compaction
is
( N C d = I O % , Fig.
92
EARBONATE DISTRIBUTION IN LIHESTONE LAYERS % Compaction 100'
80"
-iiii iiiiiiiiiiiiiii i -~!!!!!!!!!!i~
-F
NEd = ~
60"
;liiiiiiili;iiiiiii!iii~~
40" 20"
@o
li i i:i i i !i i i i il 2o L,O 6"0 8o 1oo
l~i~i~;~;I~i~i~ o 2o ~o 6o
%CaCO3
o
c-
._E
% Compaction 100-
'100
% CaCO3
~D
0
o cr
O0
80
liii,liii:iiiiiiil 60 NC d - 10 0% --~i!':!~'~!~!~!~!l
!:!!!!!!!!!!!!!!!I
4020
®o 20 4o 60 80 100
0 2'O
% CaC03
FIE.
44
Schematic
models
% COCO3
which
explain
the
different
Ibo
,~
types
of carbonate curves in limestone layers. The models use the carbonate compaction law with absolute clay contents of NCd=2.5 and 10%. The porosity in the existing limestone layers is assumed to be negligible. a,b: The mechanical compaction p r i o r to the o n s e t of c e m e n t a t i o n in the middle of the limestone l a y e r is a s s u m e d to be zero. c,d: Mechanical compaction in the middle of the limestone layer is supposed t o b e MK=35%.
44a),
the c o m p a c t i o n law (eq. 4) simply p r o d u c e s a curved r e l a t i o n s h i p
between
carbonate
relationship,
one
content
and
obtains
slnusoidal
compaction.
According
carbonate
curves
to
this
for
the
93
% Compaction 100. o
80. NCd
--:::::::::::::::::::::::::::::::
!iiiiii}iiiiiiiil; iiij
60
4iiiiiiiiiii;,iiiiiiir----
/.020.
,I;iiiiili~i~i~?i~:!:!]
l
~:
0 20 gO 6'0
MK= 35%
©o
°
%CaC03
'100
o
2'0 4'0 6'0 80 100 % CaCO3
% Compaction 100'
0
8060" 40-
2'0
20-
®o
20 40 60 80 100 % CaCO3
limestone the of
layers
absolute
in
clay
carbonate
first
marl-rich content
content
negligible.
dependency
compaction For
alternations
the
that
have
until
the
model
that
curves
in
onset
On t h e
low
Fig.
at
law
high
of
the
to
their are
with
(Fig. become
in
the
44c,d). causes
It the
narrower
is
does
the
shape
(see
carbonate-rich curves.
modified
by
limestone
layer
is
evident
shapes and
at
this
contents,
an angular
carbonate of
when
dependence
compaction
clay
further
hand,
the
compaction
layers
middle
compaction layers
of
of
absolute
a curve
models in
cementation
mechanical limestone
values low
other
44b),
degree
limestone
shapes
compaction of
at
displays
reason,
angular
(NCd=2.5%,
increasing
The previously-described mechanical
alternations.
Therefore,
carbonate 7).
on
is
Only
exist.
Fig.
that
160
of
more
the
assuming from
is
35% this
carbonate
curved.
The
94
greater
the
amount
of m e c h a n i c a l
compaction,
the more the carbonate
distribution in the limestone layer is determined by the left p o r t i o n of the
theoretical
compaction limestone begin
affects
layers with
to l i t h i f y
carbonate
carbonate-compactlon
greatly
high
later)
curves with
the
mechanical
should have
lower
This
relationship
narrower
7), where
Therefore,
and m o r e
slnusoidal
contents than layers with low
early
is p a r t i c u l a r l y
(see Fig.
content.
compaction (or which commonly
carbonate
mechanical compaction and u s u a l l y
curve
carbonate
beginning
obvious
of l i t h i f l c a t i o n .
in the Neuffen i section
(see Fig. 32), in which the carbonate maxima plot more a n g u l a r l y w h e n the carbonate content increases. In
the
quantified. the
following
pages,
the
previous
models
First, it shall be t e s t e d w h e t h e r
limestone
Angles
or not
further
compaction
in
layers increased evenly at every step of llthlficatlon.
In order to detect this, compaction in s e v e r a l the
become
and
Neuffen
sections
was
limestone
calculated
detailed carbonate curves and mean absolute clay
(eq.
layers
form
4) by u s i n g
contents
from those
sections.
T h e n the thickness of each limestone layer was decompacted
according
to
eq.
7
(Fig.
45a).
If
the
amount
of
compaction
continuously increased throughout the primary sediment, the compaction curve
calculated
straight.
curve.
for
However,
Compaction
the
decompacted
limestone
(Fig.
45a)
layers
decreases
cm
sediment
column
would
do not conform exactly to this
only
slightly
in the
middle
CITI
0-
10"I"~i"~:: ::>':'''-_ 2030" z+O. 50 60 100 6'o' o % COMPACTION
~~:'~ .....=.......... @
be
10
20 30z+050 60 /!11// o loo so 6o % COMPACTION
2'0
Fig. 45 I n c r e a s i n g degree of compaction from the middle of some l i m e s t o n e l a y e r s t o w a r d s t h e i r m a r l b e d s v e r s u s the thickness of the decompacted sediment column. a: L i m e s t o n e l a y e r s of A n g l e s I (-.-), A n g l e s 2 (. ), Angles 3 (---), and Neuffen 2 (.... ). b: S i m u l a t e d c o m p a c t i o n c u r v e s s h o w n for a b s o l u t e c l a y c o n t e n t s of 2 . 5 ~ (---) and 7.5~ ( ), as expressed in eq. 11, w i t h v a l u e s f o r t h e c o m p a c t i o n at t h e o n s e t of lithificatlon, K1=12.5% , d0%, and 70~.
of
95
the
limestone
layers;
this
may
be e x p l a i n e d by the
intensity
of
cementation processes during the beginning of lithification. The
different
compaction
curves in Fig. 45a were simulated using
the empirical equation
1 1/3
K_KI h * = (100_--~_NCd /
which
fits
original
the
curves
sediment
the
amount
and
NC d
of
is
well
thickness,
compaction
the
(Fig.
clay
45b);
where
K a n d K1 a r e
at
the
content
onset
of
the
(11)
,
x 25
h* is
the
amount
of
compaction
lithification,
normalized
to
the
decompacted, and
respectively,
decompacted
sediment
volume. The
different
follows:
Primary
compacted
(eq.
t y p e s of c a r b o n a t e sediment
II).
curves ( ~ h*)
can be c a l c u l a t e d must
as
be c o n t i n u o u s l y
Thereby, the process begins in the middle of the
later limestone layer. the s p e c i f i c
intervals
amount
The intervals have to be compressed reflecting of t h e i r
compaction
limestone
layer
and then
thickness.
added to give the
compacted
(half)
For
calculated
for compaction the c a r b o n a t e content is then determined by
every
value
using eq. S wlth a constant mean absolute clay content. The
resulting
plots
describing
carbonate
curves
in l i m e s t o n e
layers for the Angles and Neuffen sections are p r e s e n t e d where
the
parameters
degree of c o m p a c t i o n opinion
that
are
the
(K).
limestone
absolute
Fig.
clay
46 c o n f i r m s
content
in Fig.
46,
(NC d) and the
the p r e v i o u s l y - s t a t e d
layers have angular carbonate curves when the
absolute clay content is low and have sinusoldal carbonate curves w h e n the
absolute
clay
content
is high.
carbonate curves and t h e i r m a x i m u m degree
of m e c h a n i c a l
smaller,
narrower,
compaction,
and
Moreover,
carbonate since
less p r o n o u n c e d
the
shapes
of the
content
depend
on the
peaks
become
the c a r b o n a t e as
mechanical
compaction
increases. In the
alternations
studied,
the
content on the shapes of the c a r b o n a t e manner
that
the
degree
of
i n f l u e n c e of the absolute clay curves
mechanical
is e n h a n c e d
compaction
in such a
increases with
increasing absolute clay content in the primary sediment (see Table 12 and
Fig.
60).
In
primary carbonate undergo
slight
simpler
content
to
terms,
sediments which
and a low a b s o l u t e
moderate
degrees
clay
of m e c h a n i c a l
contain content
a high usually
compaction
and
96
% 0
20
/+0
CalZO 3 80 100 0
60
% 20
/+0
CoCO 3 80 100
60
. . . . . . . .
NC d
1.2s
NEd
l,t NEd
2.5
~
~ 1 I i ~ i i i i '-~%11
~ NEd
....
,
,
" :
~
'
~,,
,,,,,
,
I ,...4~~ 9,o ' 80 '~o~'oK ~::~>; ~ )
;
i
~
) I)l
NEd 15
l ~
6o
'
'&'aK
~ . ~
N[ d
1 Fig. 46 Simulated carbonate curves for l i m e s t o n e l a y e r s in s o m e J u r a s s i c and C r e t a c e o u s s e c t i o n s from s o u t h e a s t e r n France and southern Germany. The carbonate curves depend on the n o r m a l i z e d n o n c a r b o n a t e fraction (NCd=1.25 to 20%) and on t h e a m o u n t of c o m p a c t i o n (K, s m a l l n u m b e r s at t h e nonlinear scales). It Is a s s u m e d that p o r o s i t y in the limestone layers is negliglble. Example: C a r b o n a t e c u r v e for a l i m e s t o n e layer w l t h a standardized noncarbonate f r a c t i o n of 1 0 % , a m a x i m u m carbonate content of 83%, and a mechanical compaction at the onset of lithlflcatlon of 409.
commonly peaks
begin
with
sediments,
to l i t h i f y
angular the onset
early;
shapes. of
thus,
However,
lithlficatlon
diagenesls in
initially,
Therefore,
carbonate clay-rich
is c o m p a r a t i v e l y
occurs when mechanlcal compaction Is greater. sequences,
forms
later
and
in clay-rich
carbonate diagenesis only generates peaks with sinusoidal,
narrow shapes.
97
4.2
Thickness
of
the
Limestone
Layers
Since the absolute clay content is approximately constant in sequences with
diagenetlc
carbonate
bedding
peaks,
which
(section 3), the somewhat variable shapes of can be
found within
single
sections,
must
primarily be a result of a fluctuating degree of mechanical compaction (that the
is,
the
middle
mechanical
amount
of
the
with
compaction
at
the
limestone
layers,
see
in
middle
of
compaction
from about ~15 but
of
the
to ±20%,
different
onset
of
section the
2.4).
layers
the
varies
causing carbonate curves with similar shapes
widths
the v a r i a t i o n
in m e c h a n i c a l
sediment
therefore,
those layers.
in
Commonly,
limestone
in
their
carbonate
fluctuating maximum carbonate contents (see Fig.
and,
lithification
compaction
changes
affects
the m a x i m u m
peaks
46).
and
with
Nevertheless,
o n l y carbonate-poor
carbonate
content
in
As the compaction law shows (see Fig. 7), the influence
of compaction on carbonate content is relatively high at high absolute clay
c o n t e n t s when compaction is between 0 and 60~.
equivalent to the different amounts of m e c h a n i c a l
This interval is
compaction
seen
in
numerous alternations studied. The
different
manners
in w h i c h
the
fluctuating
degree
of
mechanical compaction acts upon the maximum carbonate content explains the
observations
described
in
the
literature
concerning
relationship between carbonate content and the thickness of layers. with
These
carbonate
between
data appeared contradictory, contents
increasing
less t h a n
35% s h o w
since
the
limestone
limestone layers
a direct
relationship
c a r b o n a t e content and increasing layer thickness.
However, such a relationship is not or only weakly found in l i m e s t o n e layers
containing
more
than
90~
C a C O 3 (SEIBOLD,
1952;
FLUGEL &
FENNINGER, 1966; FLUGEL, 1968). As a r e s u l t
of the various carbonate curves presented in Fig. 46,
the theoretical relationship between the thickness of limestone layers and m a x i m u m
carbonate
shown in Fig. 47. between
c o n t e n t for the Angles and Neuffen sections is
When c o m p a c t i o n at the o n s e t
0 and 60%,
a clear
of
llthiflcatlon
maximum carbonate content exists only when the a b s o l u t e is m o r e
than
5~.
In a c c o r d a n c e w i t h
Neuffen section ( S E I B O L D ,
1952)
curves (Fig. 48). B a s e d on the c o m p a c t i o n
is
r e l a t i o n s h i p between layer thickness and
that,
measured
correspond well
law and the
clay data
content from the
to the t h e o r e t i c a l
simplified
assumption that
compaction steadily increases per interval of l i t h i f i c a t i o n
( f r o m the
m i d d l e of the limestone layer), the different types of carbonate peaks
98
%COCO3 Inn VV
~o /~o
~
o
~
,,25
!
.I
V" L~.(,~.~,~...--//s.o
I
I
20
I
I~ ' 2 1 ~
90
'~'
' 7
I
I
~o-
i
/
/15
I
0 10 20 3'0 4;0 50 60
[cml
THICKNESS OF LIMESTONE LAYERS Fig. 47 Theoretical relationship between the carbonate c o n t e n t in t h e m i d d l e of t h e l i m e s t o n e layers and their thickness found in J u r a s s i c and Cretaceous s e c t i o n s in southeastern France and southern Germany. The values are calculated from the carbonate c u r v e s p r e s e n t e d in Fig. 46 and the formula for the c a r b o n a t e content at t h e w e a t h e r i n g b o u n d a r y c a l c u l a t e d in Fig. 43.
CctCO3
loo
I
90
".~-'~~:'~/TSNCd
CaCO3 100 : . . -- :. C. ,...=__ ~ - ~ 5
NCd
ee
90 @
80
-... •
7°0
80
: " J71OX.
I0 20 30
70
so cm
U.OX.
0 lb 2o 30
so cm
THICKNESS OF LIMESTONE LAYERS FIE. 48 Thickness of limestone layers and amount of carbonate i n t h e N e u f f e n Q u a r r y ( f r o m SEIBOLD, 1 9 5 2 ) . Data fit the theoretical curves from Fig. 47 w i t h a b s o l u t e clay contents of 7.5% (Middle Oxfordian) a n d 5% ( U p p e r Oxfor dian ).
in m a r l - l i m e s t o n e
alternations
Primary
differences
only
so
far
as
of
the
carbonate
in
shapes
diagenetic
histories
degree
of
the
layers
with
product
can
in composition they
trigger
be
satisfactorily
produce
curves
are
angular
carbonate
o f an a b r u p t ,
violent
change
a result
absolute
mechanical
extremely
existing
bedding.
mainly
w h i c h d e p e n d on t h e
prediagenetic,
the
diagenetic
clay
compaction.
curves
in the
explained.
are
primary
not
stratification The
different
of
different
content
and t h e
Even l i m e s t o n e necessarily
composition.
a
99
4.3
Development Related
Event
beds
to
may
(see
the
Fig.
several
special
zone
centimeters layer.
part,
due
to
the
upper
bedding Most
extends
Consequently,
"upperbeds".
most
composition,
(MEISCHNER,
cemented of
the
principle,
because
post-event
the
EDER,
beyond
the
top
of
bioturbation
1971; base column to
event
bed
form
event
bed
event
bed
become
a
the
often
of
the
which
and
single
existence
recognize,
is
often
are
the
assume
to
dimlnuation
1982) of
or
they
these
the
also difficult
the and
of
sediment has
turbidites
because
diagenesis
one are
as
phenomena
1964;
underlying they
such
conspicuous
during
In
However,
as
Events
cementation.
49).
limestone of
cause
"underbeds"
because
Layers
an allochthonous
preferred
so-called
Limestone
Depositional
with
tempestites, undergo
of
for
the
poorly
defined
size
towards
grain
contact.
CoCOs-->
b1
normal Fig. 49 lithified
The
Plots event
"underbeds"
diagenesis. phenomenon
of
been
have
(e.g.,
developmenf of " underbeds"
very
described early
they
in
this
are
not
dlagenetic
secondarily
skeletal
c
developmenf of "upperbeds"
of carbonate variations typical deposits. Center of cementation
Therefore,
which
b2
in
be
are
the
and
products
confused
cementation
burrowed
tempestites
study to
for various (e).
zones
postdate
below
early
German Muschelkalk;
of
with
burial
similar event
beds
cementation AIGNER,
1982;
1985). The f o l l o w i n g t y p e s o f c a r b o n a t e c u r v e s a r e formed by p r e f e r r e d cementation in depositional
e v e n t beds ( F i g .
49).
The c u r v e s a r e
d e t e r m i n e d somewhat by the location of the center of cementation, is the site of the highest c a r b o n a t e content and the l o w e s t compaction
which
is u s u a l l y
layer (see section 2.4).
located
in the
middle
that
amount
of
of the limestone
100
1.
The
center
lower
of
cementation
and upper
proportions
edges of
is
of
the
in
this
the
bed
middle
of
the
correspond
CaCO 3 c u r v e
(Fig.
event
to
49a).
the
No
bed;
the
decreasing
"underbed"
is
formed. 2.
The
center
part
of
partly
of c e m e n t a t i o n event
bed
able
to
withstand
grain-supported promote low,
the
reason, of
the
formed.
bed
and
in
the
beds and 3.
and
located
in for
relatively
which
the bed
of
carbonate
is
can
of
merge
EDER
displaying
to
For
base
and
the
carbonate "underbed"
in
the
a single
described
carbonate
of
event
center
several
curves
is
high.
an
form
which
is
cementation
(1971)
is the
bed
than
Consequently,
center
of
phases
event
higher
layer
compaction
cemented,
the
lower
the
because
mechanical
at
usually
49b2).
the
The
bleached,
form
fine-grained,
instance,
b are
Section:
1983).
the
if
of
two
the
upper
a certain
onset
following,
Calciturbidite
Italy.
supposedly
early
a and
the
of
event
types
b1
center
portion
mineral
of of
cementation the
composition
event might
is bed.
cause
a
cementation.
examples
of
the
origin
of
carbonate
curves
presented:
of
the
Quarries Red
Scaglia are
Scaglia
Rossa,
located Rossa
Italy near
Fossombrone,
limestones
are
The
Marches,
interbedded
with
almost totally cemented turbidites about 30cm thick (LABUDE, One of those
"underbed" possible is
layers
was
in detail studied which exhibits an
locally and is sometimes separated from the underlying rock
by one or s e v e r a l layer
is
part
b2 .
There,
In
if
boundary.
underlying
"underbeds"
"Upperbeds"
types
below
(Fig.
unstable
content
some cases,
lithification
to
space,
weathering In
due
coarse-grained,
lower
compaction
However,
carbonate
centimeters
content
or
the
The
mechanical
pore
the
towards
49bl).
cementation.
remaining
several
(Fig.
matrix
early
that
is
shifts
the
stylolitic
to d e t e r m i n e slightly
the
bedding
degree
affected
by
planes
(Figs. 50, 51).
of c o m p a c t i o n post-event
because
It was
the e n t i r e
bioturbation
(mainly
Chondrites). Calculations highest
carbonate
and
results:
content
The (97~)
in
turbidite the
middle
layer of
the
displays
its
event
bed,
101
Fig. 50 Bedding phenomena due to deposition and diagenesis of a calcareous turbidite bed (light colored layer). The length of the strata s h o w n i s 15m. Notethe appearance of a b l e a c h e d " u n d e r b e d " (U) a t s e v e r a l sites below the turbidite bed (T). For sections A and B see Fig. 52. Maastrichtian Scaglia Rossa, Fossombrone, Italy.
102
TB~. U't3,
T
b
TB." £
103
although
its
upwards
original
as
the
to
3-4%.
After
to
20~),
lithification
compaction due
to
of
and
the
shallow
onset of
porosity
was 1976),
sea
Fig.
Later,
the
another,
at
Mg-calcite), into
deep-sea
the
the
between
phases
favored
pelagic was
at
in
carbonate
Rossa
the
began
an overburden
which
lies
of
cementation
in the u p p e r
(which part
of
smaller center of c e m e n t a t i o n
of the turbidite.
recent
turbidite
lithification
unstable
Scaglia
that
from
an
early
Scaglia
mainly
Rossa
composed
ooze. center
minimum)
whereas
transported
surrounding non-existent
from
the
(10
mechanical
Assuming
known
much later
The pelagic
calcite
52A,
compaction
were
1980).
the
practically
of
diagenetically aragonite,
to
1-2%
compaction since
layer.
that
80m,
began
mechanical
became
slightly
approximately
turbidite,
event to
to
decreased
from
compared
space the
of the
lithification
layers
cementation,
foraminiferal In
pore
40
(i.e.,
SCHLAGER,
in
similar
between Probably,
phase
30% l e s s in
(HAMILTON,
300m.
of
(see
the
limestone
150
to
probably
increased
early
cementation
overburden
neighboring
short
10
additionally,
carbonates
content content
began
about
complete
behavior an
clay
a relatively
was
sediment;
carbonate
absolute
is
identical
the
to
turbidite
the bed.
formed in the lower part
Its c a r b o n a t e curve g r e a t l y
decreases
towards
t u r b i d i t e base where a d i a g e n e t i c marl joint developed.
the
An "underbed"
did not form. In
contrast,
slightly
in
downward
in
secondary
center
in
underlying
limestone
This
formed
center much
in later
second
under
the
the
turbidite
bed
combined
the
of
clay
bed (see
and the
the
content
form
a
overburden
the
as
compaction
in
is
very
low
(2 to
5%).
(see
Fig.
7).
For
underbed
are
in
Fig.
high
carbonate
law curve
compared between
because
within
a
the in
to
the first
and
increased
to (65%)
because
evident
reason,
single
main began
compaction is
the
center.
the
content
This that
reason, center
lithification
turbidite
decrease
that
shifted
secondary
However,
compaction carbonate
for
single
comparatively
contained
cementation
cementation
cementation
an appreciable
absolute
of
the
Nevertheless,
did
carbonate
to
of
Probably
and
turbidite.
bases
65%.
cause
center
bed.
50m more the
approximately not
the
turbidite
of
around
52B
the
about
middle
center
Fig.
the
the
from
the
turbidite
limestone
52B).
Fig. 51 The base (TB) of the turbidite layer which is represented in Fig. 50. a,b: Sharp, jointless contact with the lower limestone layer forms the "underbed" (U). c: The turbidite bed is separated from the lower limestone layer by a stylolitic marl joint. Scale shown uses cm. Scaglia Rossa, Fossombrone, Italy.
layer
104
Q3
ii!ililiiii!iiii!iiiiiiiiiiiiiii!!iAiiiiiiiiiiii
- ~ Z
i!!!!ii!iiiDi!i!ii iiiiiii iii!
~t-o~ o o
t..
a°o c- o o
co
tJo 0_~o
Eo 0 g
co o o
~ o
t~
r- o o ~o _D o
~q
t~o
g
c,~
•
.a.
~
E
i
•
........ ~;ii~
T
M
E
F i g . 52 D e t a i l e d s t u d y o f t h e t u r b i d i t e bed presented in F i g . 50 ( s h a d e d ) both without (A) a n d w i t h a n " u n d e r b e d " (B). Columns: 1) w e a t h e r i n g p r o f i l e and sample n u m b e r s , 2) carbonate content of selectively cemented burrows (x) and of t h e r o c k m a t r i x ( o ) , 3) c o m p a c t i o n o f s e l e c t i v e l y cemented burrows (x) and of the rock matrix (o), compaction is interpolated by u s i n g e q . 4 a n d mean a b s o l u t e c l a y c o n t e n t s (O), 4) porosity, 5) n o n c a r b o n a t e f r a c t i o n , standardized as a percentage of the original sediment volume.
105
Turbtdite
to Tempestite
Sequence
Upper Jurassic,
Southern
Another
concerning
example
bedding
is
the
southern cementation, carbonate other of
the
primary
various
boundary,
90~.
that
several
beds
to
see
within
curve
the
because
and a r e
not the
event
in
reach at
sequence
in
Centers
of
they
turbidlte
form bed,
now m o s t l y
a carbonate
are
in the
content
at
7o
8o
I
90
lOO
ROCK
.
i.
m r
@
% coco3
0
the
contain
beds).
SEDIHENT
the
approximately usually
WEATHERING BOUNDARY [Cw]
5o
an d
of the
between content
of
ledges
on t h e
independent
middle
content
carbonate
limestone
maxima
"underbed,"
of cementation
below the
event
8.2.3).
carbonate
existing
of primary
tempestite
section
every
decrease
which is
reason,
(mostly
turbidite
53,
The c e n t e r s
does
weathering
alteration
recognizable
carbonate beds
diagenetic
Oxfordian
developed
Often,
event For
the
of limestones.
layers.
Calctlutite,
Germany
(Fig.
which are
curve,
types
event
Upper
Germany
Composed of
%cac03
Fig. 53 Upper Oxfordian marl-limestone alternation, Geisingen Quarry, southern Germany. a: Plot of variation in carbonate content with the carbonate content of the weathering boundary (Cw). The lithology column displays graded, partly laminated calcilutite beds which show post-event bioturbation (see Fig. 93). b: Interpretation of the alternation a s an d i a g e n e t i c a l l y overprinted turbidite to tempestite sequence.
106
4.4
Diagenetic
Diagenesis
Enhancement
modifies
original
carbonate
form in which the to
moderately
considerably sections of
compacted,
while
with
cycles,
to
decrease
in
primary every
limestone
the
carbonate
of
the
is
marl
the of
becomes
The
following
the
rhythmicity
number
between
slightly
layers
which affect
the
alternations
only
compaction. of
of
of
primary
maximum c a r b o n a t e
the
dissolution
and
oscillations.
as
In
oscillation
compared
certain
oscillations
Primary
carbonate
is
diagenetically
oscillation
Therefore,
layers
of p r i m a r y
rhythmic
layers
variations
Number of
enhanced
ledge.
limestone
the
frequency
zones).
Oscillations
not
that
compaction
Carbonate every
cycle
diagenesls,
diminution
differential
in
and
and
processes
(e.g.,
Rhythm
limestone
intense
various
Reduction
Not
diagenesis to
the
usually
number
circumstances,
can a m o u n t
to
of
to
The
form
generates
primary
the r e d u c t i o n
40%.
enhanced,
weathers
a
fewer
carbonate of the number
following
processes
observed: Centers
of
cementation
one another I).
Such
smaller
can result layers
carbonate
cementation. mainly are 37, 2.
due
the
bedding
and
I.
During of the
contents,
4.4.1
curves.
Bedding
shape,
thickness
carbonate cementation
the
amplitude,
reduced
deal
diagenetic
were
the
of
located
maxima. 40,
Smaller
It at
are
which
in close p r o x i m i t y
usually
thicker
slightly
than
assumed
those
Examples
situated
carbonate
peaks is
are
in a single m a j o r
those
that
sites
with
the
in Figs.
and
only
centers
on the p r i m a r y
are shown
peak
20,
(see
have
one
to
Fig.
several
center
of
of c e m e n t a t i o n
are
CaCO 3 23,
curve
25,
which
28,
32,
34,
and 53. carbonate
the m a r l - l l m e s t o n e completely
to
alternations
(Type
variations
with
weathering
marl.
This
carbonate
boundary occurs
I, see T a b l e
12).
contents
(EINSELE,
especially Examples
in are
below 1982) the
shown
that of weather
marl-rlch in F i g s .
20 and 32. Primary wher e
carbonate
oscillations
the p o s t - d i a g e n e t i c
carbonate
can curve
be
detected
has m a x i m a
at and
those
sites
minima
(both
107
for of
larger
and
primary
and
smaller
variations
III)
is
processes
between
just
CaCO 3 f l u c t u a t i o n s ) . for
5 and
described
cycles
in
40%,
to
processes
the
well-developed oscillations
marly
be
I 2 1 2
4.4.2
The
13),
more
in
than
during
the
carbonate limestone carbonate
layers
sections
in
a result
in
is
the
one
explain
this,
marl-rlch
larger
one has
(e.g.,
the
number
of
absolute
carbonate
clay
Flg. 7 and section 4.2).
20 to only
carbonate
carbonate
c as percentage of a
percentage of a
84.8 75.0 83.3 86.7 90.0 61.7 89.3 91.3 95.7
51.5 37.5 83.3 80.0 90.0 36.7 78.6 78.3 47.8
3.2 to 3.5) provide clear have
a nearly
content
constant
of the
limestone
layers,
whereas
sections
display
larger
maximum
compare
the
that
to ~20%.
alternations (Types II and III), and the
of
primary
b as
(sections
to c o n s i d e r
are c o m m o n l y ± 1 5
diagenetic
the
and weathering.
carbonate
sections Angles 1 and 3, 3.3.1 and 3.3.3, respectively).
compaction
of
considers
primary
II
amount
approximately
If the
alternations
in the m i d d l e
variations
as
number
(Types
Content
carbonate-rich
content
the
Variations
Carbonate
llthifled
of
17 9 15 12 9 22 22 36 22
in
that
I) 2.
Amount of limestone layers with well developed ledges
28 18 15 13 9 37 25 42 44
of
studied
in
c
Diminution
evidence
(Type 1 and 60%
in
b
Amount of limestone layers with well and weakly developed ledges
Maximum
primarily reduction
diagenesis
diminuation
33 24 18 15 10 60 28 46 46
Reduction alternations
However,
described
Diagenetic
a
1 2 3
(Table
1.
alternations
lost
Amount of primary carbonate oscillations in the studied sections (for symbols see Table 11) R A A A L N N G G
20~
ledges, can
Table 13: oscillations.
carbonate-rich
in
primary due
the
fluctuations
of the
In o r d e r to in m e c h a n i c a l
These variations cannot cause
d i f f e r e n c e s when, mechanical is low
curves
(<6~,
On the o t h e r hand,
in c a r b o n a t e - r i c h
compaction see
is 15 to 35%
the compaction law,
marl-rlch
alternations
108
wlth
high
(30
to
absolute
55%)
compaction result
in
The
law,
clay 54
gives
the
in each
have
small
degree
carbonate
of
between by t h e of
higher
compaction
according
mechanical
to
compaction
in both
variations
law) The
limestone
is
layers
with
the
of
more
content
compaction than
20%,
an d m a r l
as compared law,
marl
although
60
20
10
also
sections
80
5
and
presented
diagram
carbonate-rich
maximum c a r b o n a t e
In accordance
content
%CQEO3 100
0
the
compaction
carbonate
compaction.
As e x p e c t e d ,
in their
hence,
variations.
degrees
studied.
sections.
exhibit
the
o f CaCO 3 v a r i a t i o n
section
differences
to marl-rich beds
(described
different
amount
beds
in
10%) u n d e r g o in;
relationship
content
for
(6 t o sets
maximum c a r b o n a t e
theoretical
In
contents
dtagenesis variations
larger
absolute Fig.
clay
until
15 % NEd
F i g . 54 T h e o r e t i c a l relationship between carbonate content, the standardized n o n c a r b o n a t e c o n t e n t ( N C d ) , an d c o m p a c t i o n (K=O t o 90%), c a l c u l a t e d by u s i n g t h e c o m p a c t i o n law. It was assumed that the porosity In ltthifted marl limestone alternations i s 5%. Measured carbonate fluctuations in the various lithified alternations studied is shown for the middle of limestone layers 0 ,) a n d m a r l b e d s ( ~ - ~ ) .
109 compaction than as
in
the
70 to
4.4.3
varies
to
limestone
90% ( s e e
compacted
limestone beds
thickness
changes
to
low.
is
high
composition. (see
It
Table Fig.
dissolution
12 and 55
and
compacted
the
detriment
compaction is
low
Fig.
compaction
amount
is
as
much
when
zones)
zones)
is
of
marl
the
the
in
and
that
compaction
depends
between
original
the
the
the
on the carbonate
slightly strongly
original
beds.
in
turn
the
bed
Differential limestone primary content
layers sediment is
high
62). the
variability
cementation
studied. rock
a lesser
Dissolution
(cementation
(dissolution
displays
alternations
even
compaction
when mechanical
Mechanical
to
total
Between
differential
layers
marl
the
or
Zones of
compacted
as
however,
Compaction
result
compaction
degree
7).
Cementation
An i m p o r t a n t
same
layers;
Fig.
Differential and
is
the
zones
The
volumes
in
thickness
calculated
reduction
(100-K)
in
is the
from
expressed
reduction the as
dissolution
between
marl-limestone the
ratio
and
cementation
of
IO0-K_z lO0-Kz .'7.1 .6 @@
k .2" w
0
,
w
|
5
•
,
,
,
|
,
,
lO%NEd
Fig. 55 Ratio of the thickness of dissolution zones to the thickness of cementation zones in various lithified marl-limestone alternations (vertical axis) versus the normalized noncarbonate fraction (NCd, horizontal axis). The relative thickness of both zones is expressed as the difference between original thickness (100%) and the degree of compaction (%K).
the
110
zones
by
using
average
compaction
values.
Dissolution
zones
c a r b o n a t e - r l c h a l t e r n a t i o n s are reduced from one third to o n e of
the
thickness
zones,
whereas
in m a r l - r l c h
a l t e r n a t i o n s the t h i c k n e s s of d i s s o l u t i o n z o n e s
is o n l y
one
thickness
of
calculatlon thickness
of
the
it
the
cementation
in
quarter
cementation
is a s s u m e d
zones.
that
the
For
half
simplification,
original
sediment
had
the
in t h i s the
same
for both zones.
Differential diagenetic
compaction
bedding.
markedly
Alternatlons
affects
with
the
rhythmicity
low m e c h a n i c a l
of
compaction
(Types II and Ill; Table 12) have s t r o n g l y r e d u c e d marl layers and are d o m i n a t e d by limestone layers which have a p p r o x i m a t e l y carbonate 4.4.2).
contents Therefore,
to be m o r e
and
the
same
thickness
these a l t e r n a t i o n s now
rhythmical
original sediment.
nearly
appear
equal
maximum
(sections 4.2 and
(after
diagenesis)
or c y c l i c a l than as they w e r e e x p r e s s e d in the
However,
even
marl-rich
alternations
display
an
enhancement
of their o r i g l n a l b e d d i n g r h y t h m i c i t y due to d i f f e r e n t i a l
compaction,
although
enhancement
is l e s s
than
for
carbonate-rich
alternations.
4.4.4
Relative
Enrichment
Differential
Marl
beds
often
detritus,
1951; this
are
contain
a greater
to the
agglutinated
marl
beds
one
al.,
highly The
in
foraminiferas,
1953;
the
marl
compaction. relative
assumes
sediment,
amount
neighboring
1959;
to
of p a r t i c l e s
limestone
with
layers.
low
to
that
a mainly soluble
can
considerably of
the
constant particles
effects,
be
limestone be
the
easily
reduces
particle must
compacted volume of the marl amount
also
layers
relatively
fossil
Although particle
explained
the
content
volume (section in
the
enriched
by
of
the
4.4.3). primary in the
beds.
of p a r t i c l e s with low s o l u b i l i t y
(N) in a given volume
of rock or sediment depends on the initial p a r t i c l e c o n c e n t r a t i o n and the degree of c o m p a c t i o n
low
These
(e.g. , W E B E R ,
EDER, 1 9 8 2 ) .
due t o p r i m a r y
beds It
and p a l y n o m o r p h s
HALLAM, 1 9 6 4 ;
p h e n o m e n o n m i g h t be i n p a r t
differential
due
c o m p o s e d of s i l i c l a s t i c and c a l c a r e n i t i c grains,
SEIBOLD e t
enrichment
If
Particles
Compaction
s o l u b i l i t y as c o m p a r e d particles
of
(N o )
(K).
No
N
(1-0.01K)
(12)
111
If
the
enrichment
in
neighboring
is
marl
expressed
and
limestone
~
~
compaction
KL),
beds
of
(e),
particle
one
then
concentration
gets
from eq.
12:
(13)
,
IO0-K M
s u b s c r i p t s M and L indicate c o m p a c t i o n in the m i d d l e of the
marl and limestone beds, of
ratio
-
NL
the
the
100-K L
NM e
where
as
respectively.
in the m i d d l e
of
If one uses the average a m o u n t
several
limestone layers (instead of
this c a l c u l a t l o n w o u l d a p p r o x i m a t e the c o m p a c t i o n at the onset of
lithification The
(KI).
theoretical,
mean factors of enrichment,
which are c a l c u l a t e d
from the l i t h l f i c a t i o n c o m p a c t i o n and the mean c o m p a c t i o n
of t h e m a r l
layers,
increases if
the
are
between
lithification
enrichment should
The
affect
their
f a c t o r of e n r i c h m e n t
decreases
dlfferentlal
m u d s t o n e s or w a c k e s t o n e s packstones
5.
compaction
factors,
also
2 and
(Table 14).
compaction
petrographical
in the
A c c o r d i n g to the
in s k e l e t a l pattern.
limestone
layers
limestones
For
should
instance, convert
to
in the marl beds as a result of the i n c r e a s i n g compaction.
This can be o b s e r v e d in several bedded J u r a s s i c reef talus d e p o s i t s s o u t h e a s t e r n Germany
(B. LANG, Erlangen;
Table 14: Theoretical enrichment of beds relative to the limestone layer. Section*
R
A1
Compaction at the onset of lithific. (%)
33
55
Mean c o m p a c tion in the m a r l b e d s (%)
69
81
Mean f a c t o r enrichment *for
of (e)
symbols
see
2.2
A2
nonsoluble
the
26
28
27
19
33
28
27
81.2
82
73.2
71.8
82.1
85.6
85.2
78.7
2.7
2.6
4.5
4.7
4.9
3.4
11.
G1A,B G1C,D
marl
36
4.1
N2
in
L
3.4
N1
particles
A3
2.4
Table
in
oral communication).
G2
112
4.5
Simulation
In t h e
previous
rhythms into
were
three
Diagenetic
sections
In t h e s e
composition
Bedding
(4.1
quantified
such
models could
sequences. initial
of
through that
simulate simulation
of
4.4),
the
the
Rhythms bedding
input
of
cyclicity
models,
72~ CaCO 3 and
and
diagenetic
theoretical seen
parameters
in marl-limestone
a calcareous
ooze
c o r r e s p o n d s to an absolute clay content of 7~.
The c a r b o n a t e
v a l u e between d i s s o l u t i o n and c e m e n t a t i o n
(Cn=72%)
to the p r i m a r y c a r b o n a t e system
was
assumed
to
the
distance
3),
follows:
First,
content,
to be
the
zones
because
closed.
between
with
75~ p o r o s i t y was assumed;
the
an
this
neutral
is e q u i v a l e n t
diagenetic
carbonate
In the three m o d e l s given b e l o w (I
two
carbonate
carbonate
curve
peaks
of
a
was
evaluated
limestone
evaluated
(eqs. 5, II) and then the cement content of the
zone was
determined
(eq. 17, section 5.3).
Thereafter,
as
layer
was
cementation the t h i c k n e s s
of the d i s s o l u t i o n zone was chosen so that the d i s s o l v e d c a r b o n a t e w a s equivalent layers. I.
to half the cement content of the two n e i g h b o r i n g limestone
Rock p o r o s i t y was n e g l e c t e d in the calculations.
In the
first
model,
it is assumed that c o m p a c t i o n at the onset of
l i t h i f i c a t l o n and c o m p a c t i o n in the m a r l constant
at
55
and
85~,
layers
respectively.
The
data
result
of
constant
carbonate
content
in the m i d d l e of the l i m e s t o n e layers
The
resulting
oscillating
alternation
carbonate
has
curve
beds
a perfectly
which
and
in a
content
84.4%.
the m a r l
be
carbonate
of
in
always
constant
periodic
53.5%
should
in
a
regular,
is not d o c u m e n t e d in
the rock record and is t h e r e f o r e not p r e s e n t e d here. 2.
However,
in
the
second
model
(Fig.
c o m p a c t i o n at the onset of l i t h i f i c a t i o n according standard poorly
it
is a s s u m e d
that
(K I) should vary randomly
to a n o r m a l d i s t r i b u t i o n w i t h a m e a n of K I = 5 5 % and a deviation of 15%. T h i s t y p e of a l t e r n a t i o n is a l s o
documented
content
56a)
in the
rock
record,
because
in the marl beds remains constant,
the
carbonate
and c a r b o n a t e peaks do
not have several maxima. 3.
The
third
model
(Fig.
56b)
is a v a r i a t i o n
c o m p a c t i o n at the onset of l i t h i f i c a t i o n the
same
distance randomly reveal
way
as
between
in m o d e l two
distributed that
for
this
2.
given
In a d d i t i o n , centers
within model
an
of
of m o d e l
should
vary
however,
cementation
interval
comparatively
of
2m. large
2 w h e r e the randomly
in
the original should
be
Calculations carbonate
113
® 93
90 8S ,80 ~ 0 Compocfion ~ 0 20 4.0 COCO3
93
9,0 85,80 .500 Compaction 0 20 40 60 80 10( C
L[,
®
.
00, i"
.
®
7210
R
.
'v111
.
J"f7j
,2'62 I "I
].7o
'185.~,
(D •
'1658
l
"t76.e
lll i,l Ii :t, ,i , ,
®
111,,,5.,,11 rLL.I I
®
®a t t I J I 1 7T">Z,..oa II
1971,
M
'I0¢
®
.h"
7
l
Kt
Cn I
16~.s
( ~ lI
7 g t;
®
!! ,;~: n:
~Cn KL
Flg. 56 Simulation models of marl-limestone alternations with the carbonate content curve (left) and the weathering profile (right, hatched). Scale is in meters. Values shown represent the interval ( i n cm) b e t w e e n t h e a d j a c e n t centers of lithtftcation (~h*), and the compaction at the onset of cementation (K1). Cn=CaCO 3 n e u t r a l value. a: Compaction at the onset of lithiftcatton scatters randomly around a mean of K1=55% by using a normal distribution curve with~=15%. Compaction in the marl layers is constantly 85%. b: Compaction at the onset of ltthification as in Fig. 56a but with a random variation o f 0 t o 2m b e t w e e n the adjacent centers of litbificatlon.
variations
in t h e m a r l
beds
are
produced.
layers contain several c a r b o n a t e peaks, record.
In
the
weathered
Neuffen
I section
dlagenetic rhythmicity depends
on
a
typical
is c o m p a r a b l e
(see Fig.
32). the
limestone
as is the case in the r o c k
section,
limestone layers is c a u s e d w h i c h the
Moreover,
Model
absolute
"bundling"
of
to s o m e
parts
3 shows
that
the
content
(or
clay
in
114
the
primary
compaction, The
sites
sediment
composition),
the
degree
and the distance between the c e n t e r s
of
mechanical
of c e m e n t a t i o n .
w h e r e cementation sets in are triggered by the (slight)
compositional differences in the primary stratification
(see Fig.
1).
4.6
Conclusions:
Diagenetlc
Beddlng
The rhythmicity in m a r l - l i m e s t o n e primary
bedding
many authors, FISCHER
cycles
e.g.,
(1982);
(e.g.,
FISCHER
COTILLON
Rhythms
alternations
Mllankovltch
(1980); & RIO
EINSELE
(1984);
may
indeed
be due to
cycles),
as described by
(1982),
SCHWARZACHER
DE B O E R & W O N D E R S
FISCHER et al. (1985), BOTTJER & ARTHUR (1988); DEAN & GRADNER BARRON et al. (1985). The r e s u l t s
obtained
However, show
that
as w e l l
randomly,
as s e q u e n c e s
the d l a g e n e t l c
with
event
the b e d d i n g
pattern
which
stratification
or
Therefore,
with
a
rhythmic
in the present rock offer little information on (cyclic
Cw
I I I Fig. 57
overprinting,
affects primary bedding
slightly oscillating carbonate content.
carbonate oscillations
(1985);
this is not necessarily a requirement.
considerably enhances the bedding rhythmicity, cycles
&
(1984);
or not
cyclic)
Cw
in the primary sediment.
Cw
Ill
T y p e s of l i t h i f i e d m a r l - l l m e s t o n e alternations, carbonate curves, and weathering profiles (black). Cw=carbonate c o n t e n t of t h e m a r l - l i m e s t o n e weathering boundary, C=CaCO 3 content in weight percent.
115
Also,
the
(higher)
determined
with
Assuming
that
constant,
the
depends
solely
the
centers
at
on
of
of
the
is
primary
sediment
their
from
Types
of
Type
Marly
According
carbonate
the
content
carbonate
the
curves
content.
of is
clay
the
the
mechanical
greater
when
its
primary
absolute
clay
Compaction
compaction the
clay
concerning history
rhythms
in the
absolute
results
diagenetic
bedding
between
the
the
can
and t h e
be
shapes
of
Fine-Grained,
curve appear
content
of
with
10%).
layers
because
half
the
the
compaction Moreover,
(35
the
compaction of
the
because
affect
the
thickness
small
produces
of t h e
to
maximum
relatively
bedding
reduction
weakened
have
must vary widely
diagenetic
of
alternations
only
dissolution
of the c e m e n t a t i o n
because
CaCO 3 weathering
lower
maxima
boundary;
on
hence,
in the outcrop.
Medium to
Content
compaction
have
mechanical
thickness
beds
the
mechanical
and
below
as marl
Carbonate
clay
limestone
is f u r t h e r
are
Alternations
mechanical
one
law,
(6 t o
compaction,
apprOximately
Both
content
The m a x i m u m
The r h y t h m i c i t y
High
due t o h i g h
degree
differential
carbonate
compaction
Therefore,
rhythmicity.
II
in
in several
in
these m a x i m a
Type
distance by
of lithification.
qualitative
and
carbonate
absolute
fluctuations
zones.
the
is
bedding
57).
Rhythms
carbonate
55%) an d h i g h
zones
(Fig.
are
controlled
is
is
boundary
of diagenetic
Alternations
to
sinusoidal
amount
layers)
weathering
be
layers.
Carbonates
I
weak
onset
cannot
limestone
parameters,
post-diagenetic
peaks
is
(that
composition
Bedding
Lithtfied
the
Consequently,
the
carbonate
at
the types
These
which
lithification
higher.
at
interrelated
limestone
content obtained
two
oscillations
number o f
different
parameters.
compaction
of
present
content
of the
three
and
onset
middle
carbonate
lithification,
an d t h e
the
the
carbonate
from the
development
stratification, content
number of initial
certainty
in
intermediate
the
limestone values
(25
layers to
an d t h e
35%
and
absolute 4 to
6%,
116
respectively).
Therefore,
the
c o n v e x - s h a p e d c a r b o n a t e curves, of s e v e r a l
limestone
compaction
between
thickness
of the
layers
carbonate
varies
dissolution
dissolution
llttle.
and
of
dlagenetic
Moreover,
cementation
zones
law
gives
differential
zones
reduces
the
(marl beds) to about one half or
one third the t h i c k n e s s of the c e m e n t a t i o n Reduction
compaction
in w h i c h the m a x i m u m c a r b o n a t e c o n t e n t
carbonate
zones
cycles
(limestone
due
to the
layers).
influence
of
w e a t h e r i n g is m e d i u m to low.
Type
III
Mechanical (less
than
compaction more
Calcareous
compaction 25~ is
and
as less
intense.
one
third
the
rhythmicity
brick-like
alternations,
a relative
limestone carbonate
content
must is
well
as
than
4%,
the
constant
layers
Alternations the
absolute of
thickness is as
thickness.
constant
of
great.
the
the
of
beds
the
the
low
reduced
layers;
sections
where to
are
differential is
limestone
carbonate middle
content Thus,
marl
above,
According
angular in
the
Weathered
described
have
clay
respectively).
The thicknesses
therefore, have
than
Highly
to and,
display
limestone
ledges
compaction
curves, limestone
while layers.
law, the
5
D I A G E N E T I C AND
5.1
B E D D
S I M U L A T I O N
Causes
and
Carbonate
In the
Processes
I N G
M O D E L S
of
Burial
studied,
d i a g e n e t i c bedding, w h i c h p r e d o m i n a n t l y is a
stratiform carbonate redistribution thicknesses
carbonate between
which
primary
beds
indicates
5.8%).
and
that
of
the
30F,G;
around
massive
beds
to
when
chemical
overburden
mean
only
reprecipitation
form
typical
which
are
composition,
differences small
(on
between
an
average
occurs even in the pore
pressure
lithostatic
in c a r b o n a t e
original
carbonate
were
Presumably,
peculiarities
differences
calculated
zones
the
fossils
begins
by
slight
the
primary
58) w h e n
caused
had
from
carbonate
marl
(Figs.
is not
cementation
Moreover,
process,
80 and 4 6 0 m (see Table 12).
which
This is evident
dissolution
space
between
redistribution
content.
C A U S E S
Redistribution
sections
reaches
:
stress
shadow is
difficult
structures
l a t e r a l l y reduced
to
compact
(e.g.,
belemnites). Pressure
shadow s t r u c t u r e s clearly have a higher c a r b o n a t e content
as c o m p a r e d to the content
is
Probably, greater
not
marl
as t h a t
beds,
in the
although
adjacent
this is caused by p r i m a r y c o m p o s i t i o n a l pre-diagenetic
as c o m p a r e d shadow
surrounding
as h i g h
to t h a t
structures
carbonate layers.
d i f f e r e n c e s and by a
c o m p a c t i o n of the pore space in the marl beds
in the
are
their
limestone
limestone
especially
layers
well
(Table
developed
15).
Pressure
in c a r b o n a t e - r i c h
a l t e r n a t i o n s w h i c h u n d e r w e n t low levels of m e c h a n i c a l
compaction
w h i c h w e r e a c c o m p a n i e d by a r e l a t i v e l y early onset of d i a g e n e s i s III).
On
the
other
hand,
in
alternations
with
high
levels
m e c h a n i c a l c o m p a c t i o n and u s u a l l y a late b e g i n n i n g of d i a g e n e s l s I),
the
pore
space
adjacent
to
r e s t r i c t e d to receive s i g n i f i c a n t The o c c u r r e n c e presented
in Fig.
& HEMLEBEN, bed
is
that
the
in s t r e s s
(e.g.,
already
flasery
marl
seams
1979; T R U R N I T & AMSTUTZ,
carbonate
1978; E N G E L D E R et al., 1981).
of
(Type too
amounts of c a r b o n a t e cement.
stylolitic,
30H (WANLESS,
fossils
1982) and p r e s s u r e shadow s t r u c t u r e s w i t h i n
indicates
differences
of b o t h
massive
and (Type
redistribution
WEYL,
1959;
In the marl
it is
1979; R I C K E N
the
same
marl
m u s t be related to
NEUGEBAUER, bed,
as
pressure
1974;
ROBIN,
dissolution
118
of
CaCO 3 i s
uncemented in
the
presumably grain
marl
locally (i.e.,
caused
contacts.
beds
at
those
in
response
to
heavy
shells,
Fig.
by
The sites the
lithostatic
stress
dissolved
carbonate
where
lithostatic
the
presence
of
solid
which
is
acts
upon
reprecipitated stress
pressure
decreases conductors
58).
PRESSURE SHADOW STRUCTURES dissolution of outer shell layer iii!~iii~:~::-::.::::.:.::.:.::.:..:.-,
cement
1 cm I
brochiopod shell
I
Fig. 58 In calcareous pressure shadow structures, carbonate precipitation occurs laterally of slightly compacted to uncompacted fossils in response to the diminution of the lithostatic stress. Calcareous pressure shadow structures are frequently found in the marl layers of the marllimestone alternation Type III.
The
formation
of
c a l c a r e o u s pressure shadow structures may serve
as a model for the carbonate cementation in limestones. layers
In l i m e s t o n e
and pressure shadow structures, the original carbonate content
is greatly enhanced due to cementation; however, only p r e s s u r e structures
p r o v i d e a clear insight into the hypothesis that carbonate
cementation during b u r i a l
diagenesis
may
be c a u s e d by d i f f e r e n t i a l
stress between the layers of a bedded sequence. the marl beds s h o u l d h a v e contacts
shadow
than
the
a higher
limestone
lithostatic
layers.
During llthlflcation, stress
As C O R R E N S
at the
grain
(1949), NEUGEBAUER
(1973; 1974) and WALTER & MORSE (1984) demonstrated, the i n t e n s i t y the
pressure
dlssolution-repreclpitation
process
depends
specific llthostatic pressure, the mode and n u m b e r of g r a i n
of
on the
contacts
119
Table 15: Carbonate content and the degree shadow structures (PSS) lateral of belemnite Type PSS
of
Mean carbonate content i n PSS
A3 .<~
N2 "~
Carbonate content in the adjacent marl bed
Standardized noncarbonate content in the marl bed
of compaction guards.
in
Compaction Compaction i n t h e PSS i n t h e adjacent marl bed*
pressure
Mean compaction at onset lithif, in limestone layers
82.2
44.3
8.5
48.9
81.8
26.4
86.2
42.5
8.5
35.2
26.4
88.4
7.8
8.5
23.3
82.4 75-83** 88.7
86.7***
24.8
8.5
32.8
86.3
26.4
83.8
77.2
4.0
74.0
81.2
19.3
84.8
74.8
4.0
72.6
82.9
19.3
26.4
*calculated by using eq. 4 and the regression curves between porosity and carbonate content as described in Figs. 27 a and 35 a. **measurement. ***carbonate reprecipitation within the belemnite phragmocone.
and
grain
the
pore
size,
One can obviously
of
phase
grain
expect
seems
structure the
the
mineral
phases
involved,
and
the
composition
of
solution.
of
be
the
contacts
dissolution-reprecipitation
triggered
and
by
limestone
mechanical
stress
layers,
compaction,
should
when diagenetic developed
to
marl
that
be
carbonate
relatively
homogeneous
At the
in
which
the
self-perpetuating.
lithostatic
redistribution
in the s e d i m e n t .
differences is
the
process,
begins, grain
pressure at
first.
at
the
However,
differential
contacts
grain During
stress
in the limestone
layers, the stress continuously decreases due to the welding of grains by carbonate precipitation. affects
the
unwelded
dissolution.
Whereas, in the marl layers, the pressure
grain
contacts,
In a n a l o g y w i t h
resulting
the a b o v e - m e n t i o n e d
in
carbonate
CaCO 3 pressure
shadow structures, the dissoloved carbonate is reprecipltated at sites with
low
limestone
lithostatic layers.
reprecipitated grain
process
carbonate
structure,
self-perpetuating,
which
causes in
(WEYL, is
1959),
a further
turn
i.e.,
in the
self-perpetuating
favors
later
since
the
p r e s s u r e decrease in the cementation.
The
dissolution-reprecipitation process probably comes
to a s t a n d s t i l l w h e n dissolution
pressure
This
an e q u i l i b r i u m
in the m a r l
is
reached
between
pressure
beds and opposing factors such as decreasing
120
permeability,
the
increasing
increasing
density
of
amount
packing
dissolution-reprecipitation limestone
layer
is
of
in
ceases
totally
filled
insoluble
the
before
(the
residue,
marl the
porosity
and
layers. pore in
the
Usually, space
in
limestone
the
layers
is
b e t w e e n 0 an d 5%). Obviously, marl
and
stress
limestone
qementation explained 1.
The
in as
the
higher
relatively
primary
for
the
different
determine
sediment
of clay
calcareous
increasing
tbe
in
several
consisting
can
the
(The
(see
be
in the
to
more of
Both
original hand,
the
between the formation
elements
is
which
hampered
by
an
beds relatively diagenetic
bedding.
of compaction 61).
as compared
Given
oscillations,
a
the
reduced
to
carbonate-rich
layers large
than
coccoliths
the
and
primary
porosity
due
comparatively stress
richer
(see
Fig.
carbonate
smaller
clay
in
higher
clay
minerals
are
respectively.) differential
Drilling
Project.
sections
some
of
the
an
other
trace
Sr)
somewhat
beds
to
(MARSCHNER, 1 9 6 8 ;
of
60,
carbonate
that
phases.
reaction
trigger
degree
to
the
sequence
an d t o h a m p e r t h e
primary
could
is
diagenetic
sequences
of
layers
is
process
7.2).
Figs.
diameters
5 an d 1 - 2 # m ,
On t h e the
(e.g.,
a higher
marl
that
greater
of
cementation
section
content
from
alternations
stress
bedding In layers
(SCHLANGER & DOUGLAS, 1 9 7 4 ; calcareous
This
carbonate
exchange
fraction
subjected
triggers
the
slight
relative
are
during
undergo
containing
The a s s u m p t i o n Sea
slight
a primary
potential"
1980)
compaction
carbonate-poor Thus,
al.,
(see
carbonates
minerals.
Deep
content
in carbonate
compaction
the
of
seems to hinder
carbonate
clays
pelagic
layers
beds
"diagenetic
crystals
in
an d p o o r e r Usually,
grains
between
first,
beds.
amounts of unstable
Moreover,
clay
Differences
sediment
the
content,
various
(BAKER e t
calcite in the
roughly
carbonate
minerals
BAUSCH, 1 9 6 8 ) . contain
structure
by
carbonate-rich
the
the
phases
of larger
15).
grain
(SCHLANGER & DOUGLAS, 1 9 7 4 ) .
presence
the
the
CaCO 3 d i s s o l u t i o n - r e p r e c i p i t a t i o n
Moreover,
contain
factors
to
triggered
the
be i n i t i a t e d .
2.
within
are
follows:
probability can
differences layers
the
the
is
between marl
supported
ooze/chalk
harden
while
GARRISON, 1 9 8 1 ) . Arabian ranging
Sea
(60,
from soft
an d l i m e s t o n e
by r e s u l t s transition others
remain
MATTER ( 1 9 7 4 ) 70,
and
from the zone
of
soft
examined
200m t h i c k )
an d s e m i l i t h i f i e d
ooze
12t
and
chalk
layers
cementation
in
(sites these
primary
composition.
study,
the
onset
60% an d a t
sequences
subjected
to
to
with
to
at
200m.
degrees
differences
results a porosity
of
in
obtained
in
the this
of approximately
Presumably,
trigger
greater
different
slight the
occurs
of 100
arise
The
reflect
of cementation
could
sequences are
223).
In agreement
an o v e r b u r d e n
differences
and
220
diagenetic
larger
stress
bedding
if
these
overburden.
A1 R A2 GlcdNl L OlobG2 A3 N2
0 2O
I-..
4O
P
16o 8O (,o
100 Fig. 59 Compaction in marl-limestone alternations. Shown are means and areas of scatter for compaction. White: compaction in the middle of the limestone layers (that is, compaction at the onset of lithifieation), hatched: compaction of selectively cemented burrows, black: compaction in the middle of the marl layers, PSS: compaction in calcareous pressure shadow structures.
In
this
study,
to
differences
related
diagenetic
compaction
between
mechanical
compaction
This the
is
because
same ( a b o u t
sequences (Fig.
is
59).
DOUGLAS
marl
compaction 80~),
in the
carbonate
content
of the
and marly
sediments
of the marl
reported
the
is
lower
an a v e r a g e
According
to
layers
are
limestone is
always
primary
the
(Fig.
of
in when
lower.
approximately
in and
the
various content
SCHLANGER &
when
60a).
mechanical behavior
is
carbonate
higher
always
greater
layers
compaction
is
are
differences
b y MATTER ( 1 9 7 4 )
compaction
sediment
undergo
on
stated,
layers
mechanical
depending
mechanical
oscillations
Simply
limestone
middle
whereas
As a l r e a d y
40%, r e s p e c t i v e l y .
and
in the
different
(1974),
carbonate
in compaction.
the
primary
Carbonate-rich
compaction porosity
o f 20 an d in
recent
122
tO tJ
"<
L
% C 20 0
0
tO
lJL
G
IN2
200
M p L,O A C T 60 I J 0 N 80 ,'f
,00
z
l
j
600
J
/
0
800
1000
20
6)
40
r,., tO tO
100C 80 100 5-- ~ %CaC03[~]
60
20
40
60
80 100 % CaCO3 Ir-ol
Fig. 60 Compaction and meters of overburden at the onset of lithification. a: Compaction at the onset of lithification (or mechanical compaction) v e r s u s t h e mean p r i m a r y c a r b o n a t e content in the original sediment of the cementation zones. b: O v e r b u r d e n ( i n m e t e r s ) v e r s u s t h e mean p r i m a r y c a r b o n a t e content in the original sediment of the cementation zones.
pelagic
carbonates
of overburden In
the
burrow have
(Fig.
the
and
edges
of
carbonate burrow
the
to
mechanical the
marl
sediment
(for
carbonate higher
porosity.
the
to
1 0 0 a n d 400m
at
in
both
examples
in
59, time of
burrow Figs.
18, and
because the
the
degree
of
the
same towards
the
Fig.
28). fossils
Despite
they
interstitial
the layers
the
often
in is
this,
onset
of
towards
surrounding
Obviously, is
of
earlier
for in
outer
sediment
4c).
limestone and
the
precipitation
occurs
required the
system
burrows
pH i n
of
in
neighboring
see
the
supposedly
a higher
onset
often
the
middle
see
the
about
It
(Fig.
thus the
environment
during
the
usually
simultaneously
layers,
whereas
layer,
cementation)
proceeds
selective.
from the
limestone
Therefore,
limestone
compaction and
the (after
predominantly
fossils,
cementation, content,
equivalent
becomes sediment
matrix
quite
increase
microchemical organic
is
compaction layers
is
when lithification
and
further
lithification
occurs
later
cement
subjected
later
sediment
are
systems
this
content.
process
However, what
what
surrounding
carbonate
the
compaction.
of
and the
same
cementation,
2.4),
60b).
middle
system
burrows
(section
the
suitable have
solutions,
for
a higher and
a
123
The
transportation
must occur fluid.
with
In
of
and against
the
Upper
dissolution-affected and
downsection
section
2.3.1).
studied
mainly
migration
more
of
southern
in
the
two
neighboring
In
addition,
limestone
is
symmetrical above
than
from the
of
and below.
transport
the
Germany,
repreeipitated in
Thus,
1980;
from
upsection
(see
during
Fig.
9,
alternations
indicating
carbonate
burial
due to u p w a r d l y
1979; BATHURST,
carbonate
the
PlNGITORE,
beds pore
layers
layers
marl
expelled both
limestone
CaCO 3 c u r v e s ,
(BERNER,
1977; WEDEPOHL,
released
direction
planes
by d i f f u s i o n
(EINSELE,
flow
Jurassic
have
effective
carbonate
the
bedding
from both
transport
the
diagenesis
1982) must be much
moving
pore
waters
1980b).
Further evidence for this is the u n r e a l i s t i c a l l y
large
amount
of
time needed for the cementation of limestone layers if their carbonate cement was exclusively t r a n s p o r t e d order
to c e m e n t
a typical,
of which 40% is cement), pure
CaCO 3 cement.
equivalent
to
one
needs
A column
30g
that
in
BATHURST, 1 9 7 6 ) 1000
years.
0.05m/1000 water
of
15
years
These
and
million
years
in
pore
example, the
with
order
5.2
Burial
During
the
display
a
stages
500m o f
of only
is
decreases
Reduction deposition different
and of
In
is not
precipitation
begins
is
at
an
found
in
of
the
would be 1.gmg/cm 2 as
high
o f Ca i n
the
as pore
1975;
minimum time
an unrealistic, to
order
of
with
solely
since
sedimentation
"Inversion"
overburden, reduction
of clay
cement
million the
increasing of
GIESKES, of
the
waters.
100
velocity
is
realistic;
SALES & MANHEIM,
the
the
very
rates
concentrations
diagenesis,
of
rate.
in
the
rapidly
an
of
layer
in the p o r e w a t e r
sedimentation
necessary
in
porosity
composed
this
is c o m m o n l y
by upmoving pore
overburden,
one tenth
(which
however,
1974;
layer
intervals
layer
from
cementation
carbonate
found
result
which
later
fluid
on
commonly
limestone
Minimum time rising
based
(NEUGEBAUER,
thick
Icm 2
about half the s e d i m e n t a t i o n
(which,
calculations
above-mentioned necessary
is
pore waters.
the v e l o c i t y of the rising pore water
maximum c a r b o n a t e
This
0.5g/1
1984).
If
all of the d i s s o l v e d
consumed during cementation see
by
at 6 0 % p o r o s i t y
alternations),
would be, as EINSELE (1977) shows, Assuming
expelled
an 1 1 c m
11cm
CaCO 3 cement.
overburden of 200m and marl-limestone
by the
30cm thick limestone layer (with 90% CaCO 3
years
velocity
are of
the
overburden. the
rate
pore
For
water
(EINSELE,
is
on
1977).
Porosity and
behavior
calcareous (Fig.
ooze 61,
data
124
compiled
f r o m BALDWIN, 1 9 7 1 ;
& SCHOLLE, relatively
1978;
ooze has
BALDWIN & BUTLER,
large
overburden,
reduction
porosity
decrease
At
certain
CaCO 3 v a r i a t i o n s
must
a nd c a r b o n a t e
SCHOLLE, 1 9 7 7 ;
1985).
in porosity,
reduction
a more linear
intersect.
HAMILTON, 1 9 7 6 ;
Originally,
but with
becomes low. in porosity;
amounts
of
clays
have a
500 t o 1000 m e t e r s
In contrast, therefore,
overburden,
show a different
LOCKRIDGE of
calcareous
the
two c u r v e s
sequences
containing
relationship
between porosity
content.
0
20
40
60
80 n
CLAY ... ""'" ......
1000
~ C~HALK
2000
t
i 3000' m
J
Tlg. 61 Porosity versus overburden in f i n e - g r a i n e d c a r b o n a t e s and clays. IPl 2:" " i n v e r s i o n s " of porosity; arrow: p o r o s i t y r e d u c t i o n 'in c h a l k s due to c e m e n t a t i o n . Curves compiled from BALDWIN, 1971; HAMILTON, 1976; SCHOLLE, 1977; LOCKRIDGE & SCHOLLE, 1978; BALDWIN & BUTLER, 1985.
The
first
mechanical
"inversion"
compaction
of p o r o s i t y
with
occurs
during
the
10 to 1 0 0 m of o v e r b u r d e n .
stage
of
Although the
porosity is orlginally somewhat higher in carbonate-poor beds (section 2.3.2), amount
porosity
is r e d u c e d
of m e c h a n i c a l
compaction.
increasing carbonate content The or
second
1000's
"inversion"
m of
calcareous fills
their
beds. pore
Thus,
by a r e l a t i v e l y
porosity
increases
higher wlth
of porosity takes place with several 100's
curves
Cementation space,
beds
(see Flg. 17).
overburden,
poroslty-overburden
in t h o s e
due
to
(Fig.
of the
whereas
the
61,
intersection P2)
or the
carbonate-rich
the p o r o s i t y
of the two
cementation layers
of
nearly
of the carbonate-poor
125
layers
must progressively
clay
due
to
when
carbonate
observed
the
decreasing
ceases,
the
porosities
curve
for
of
500 t o
to
the
clay
content
in
porosity
of
of
25%.
15 t o
amount of
porosity
manner
beds
According
(BALDWIN, 1 9 7 1 ; necessary
same
marl
to to
curve
carbonate.
alternations
the
the
in
the
marl-limestone
1500m i s
observed
porosity-overburden
redistribution
carbonate
yields
the
impoverishment
litbified
extrapolates
follow
increasing
in
62).
the
overburden
in
(see
n
its
Table
all with If
carbonate-free
one
rock,
it
porosity-overburden
BALDWIN & BUTLER, 1 9 8 5 ) ,
corresponding
nearly
~ncreases (Fig.
for
Therefore,
an overburden
order
of
magnitude
11).
n
t
1
®
20
"
;
cac03
cec03
Fig. 62 Relationship between porosity (n) a n d c a r b o n a t e content (C) in l i t h i f i e d m a r l - l i m e s t o n e alternations. a: Regression curves of various marl-limestone alternations. b: C o m b i n e d plot of all p o r o s i t y and c a r b o n a t e data.
5.3
Calculation Primary
One
of
the
exchange
is
of
Cement
Carbonate most the
cement.
In
content
serves
this
of
study, as
an
and
Content
promising use
Content
means
formulas the
for
numerical
instrument
quantifying
which
in
calculate
the d i a g e n e t i c the amount
determination calculating
and
of
the
mass
of CaCO 3 cement
simulating
the
126
process
of
somewhat sample
1.
the
negative
In the
amount
different
total
of
diagenetically the
the
cement primary
"relative
is
cement
here in
used
of
(Z)
sediment
(Z d) volume
content"
fraction.
percent.
is
carbonate. expressed
which
normalized
(expressed
(Z c)
which
It is m o s t
However,
is
the
in
the s p e c i f i c
fractions 3.
The
are
"cement
absolute
is
normalized
accurately
relative
The the
cement
must
(see
primary
added are
to
the
expressed
as
content
is
cement
percent,
similar.
this
is
(Z d)
and
a dimensionless the
to
ratio
primary,
expressed
in
porosity
(no),
porosity
(nd,
in
a basic
is
not
between
absolute
sufficient
because
cemented (n o ) or
four
no
amount
the
carbonate
the
primary related
in
content,
C;
fraction, 63,
as
compaction expressed
(K), as
is
Therefore,
the
made
content
(C o )
compaction
law
porosity,
n;
and
the
NCd).
the
equation
determine
CaCO 3 .
carbonate
carbonate
Fig.
to
distinction
of
parameters K;
noncarbonate
displayed
2.2)
the
porosity the
law alone
section
and
compaction,
standardized As
(z);
amount
primary
the be
very
compaction
content
the
(these
the
(Cod).
carbonate
between either
number"
to
d e n s i t i e s of the carbonate and noncarbonate
commonly
cement
content
in
vol.%).
practically equivalent to the amount expressed as w e i g h t because
a
rock
carbonate,
dissolved
content
in
a given
precipitated
amount
cement
content"
cement
carbonate
volume
of
"cement"
forms:
"absolute
The
term values
indicate
discussion,
decompacted 2.
The
Positive
values
following
The
bedding.
sense.
indicate
whereas three
diagenetic broad
absolute the and
cement
difference the
a percentage
content between
absolute of
the
amount primary
(Z d)
is
original of
rock
sediment
volume ) : Zd[vOl~]
The
absolute
porosity
(nd)
(14)
= no-K-n d
is
related
to
the
rock
porosity
(n)
as
follows:
nd[VOl% ] = n(1-0.01K)
(15)
127
:::::::::::::::::::::::::::::::::::::: :.:<+:+:+:.:.:<+:+:.:+:. .:+:.:.:+:.:+:.:<+:1:.:.:1:.: :::::::::::::::::::::::::::::::::::::: :.:.:+:.:.:+:.:+x.:<.:.:+:. :.:.:.:.:.:.:+:.:<.:.:+:.:.:+:, :.:+:.:.:.:.:.:+:.:.:+:.:+:.:, :.:+:.:.:+:.:.:<.:.:+:.:+:.:,
I
I
I
I
ilililililili iiiiiiiiii .......::..¢..,,:,.....1..,...... ::::::::::::::::::::::::::::::::::::: +:+:,:-:.:-:-:+:-:.:-:+:-x.: ::::::::::::::::::::::::::::::::::::: :::::::::::::::::::::::::::::::::::::: .:.:.:.:.:.:.:.:.:.:.:,:.:.:.:.:<.:,: .............................,.., ::::::::::::::::::::::::::::::::::::: ::::::::::::::::::::::::::::::::::::: .:.:.:.:.:.:.:.:.:.x<<.:<Xs:,
;iiiiiiiiii:iiiiiii :!Iiii
NEd
Ill@fill
Fig. 63 Scheme for the c a l c u l a t i o n of the c e m e n t c o n t e n t (Z). Left: primary s e d i m e n t with o r i g i n a l pore space (no) , o r i g i n a l c a r b o n a t e content (Co) , and n o r m a l i z e d n o n c a r b o n a t e fraction (NCd). Right: transformation into rock. The p r i m a r y p o r o s i t y (n o ) is greatly reduced by c o m p a c t i o n (K) and p r e c i p i t a t i o n of c a r b o n a t e cement (Z). Due to this, the c a r b o n a t e content of the rock (C) is e n h a n c e d as c o m p a r e d to the primary c a r b o n a t e content (Co).
If
n d in
15,
the
eq.
14 is
following
substituted
for
equation
for
by its the
equivalent absolute
expression cement
in
content
eq. is
obtained:
Zd[vOl~]
Moreover,
the
= no-n+K(0.01n-1
absolute
cement
primary
porosity
content
(C) if c o m p a c t i o n
content
(no) , a b s o l u t e
(16)
)
clay
can
be e x p r e s s e d
content
in terms of
(NCd) , and
carbonate
(K) in eq. 16 is r e p l a c e d by eq. 4: NC d
Zd[vOl%]
In
order
carbonate
to
express
fraction,
primary
sediment
relative
cement
= no-100
the
cement
the
carbonate
volume) content
is
(17)
1-0.01C
content
as
volume
must (Z c)
+
a percentage (which
correspond written
as
to
is
of
the
existing
100-K-nd-NC d of
100%.
Therefore,
the the
follows:
100Z d
Zc[vol%] The
terms
n d and
Zd have
=
(18)
100-K-nd-NC d to
be
substituted
for
by
eqs.
15
and
16,
128
100
,9,0 . 80. 70 . .60 50 L.o 30 20 10 0
C 80:
1.252_.5_
........
60
i
'
,
....
1-°
I,,
bU
20~/,/{~o
! lO ~" 0 LI / 0
Ei/
~
Zd
011 ' 0 ' I' -10003050 2 ; 0 3 8 ' 0 5 9080"/060
100 il l ' J ~
40
,
20
0 Z25 " -
..~~ 7 5.
,,
z.~
'685 ' 7 8
,n
[Yl'/4~>-'4 " , - ~ - _ " - ~ ~
l°z~1d21Cod I
--
.....
I.~/*" " ~ L w _ f/1J /i " .',., / ' " . . . . . .- ~ 50 (/!VI / -, ~ 5 o rl/ 'I/, ix//
?0
_
20
_
~ "~
,,,
" 6o
no = 7o % 0 ,,>,"7o - ' 6 ' i .21 -1000305070 90 7060
.____
40
20
0
3
2, 80
5 ~6 85
#
8
9 90
Z25
Zd I0 1'1112C,.,a Z 92 "" C
rJuuI ~ ~ Z ' 7 . , II /5 L, ,' . .~.. 4
1
/
~
401~I'// ~., I~',/F/ ~
2oI /
=
I -
~
/~o
o,' ~o _i '0' i I~I ~ qO003050 70
J- . . . . . . . . . . . . . . . . . .
~,
^^^.
n.. =
GO%
o¼ 5 16 80 85
~
Zd
8
~ I0 I'I I 90 Z c 92
Fig. 64 The diagram shows the ratio between the absolute values of cement and primary carbonate (Zd/Cod) and the relative cement content (Zc). The t w o v a l u e s a r e c a l c u l a t e d for various contents of post-diagenetJc carbonate (C), of standardized noncarbonate (NCd,~), of compaction (K, ), and of primary porosity (no). It is assumed that the porosity of the existing rock is small enough to be negligible.
Cod
129
respectively;
the r e l a t i v e cement content
(Z c) is then:
lO0no-100n+K(n-100) Zc[vol% ]
(19)
=
100-NCd-n+K(0.01n-1) However,
during
application
commonly
more
content.
For that reason,
4 to
give
porosity content
difficult
the
relative
the
than
determination the
determination
c o m p a c t i o n in eq. cement
content
(no) , absolute clay content
of
compaction
of the
is
carbonate
19 can be r e p l a c e d by eq.
in r e l a t i o n
to the
primary
(NCd) , and the e x i s t i n g c a r b o n a t e
(C): NCd+no-lO0+C(l-0.01n o ) Zc[vol~]
=
x 10 4
(20)
NCdC
The relative
cement
content
(Z c)
is
Zd
related
to
the
cement
number
(z):
Zc
z
, Cod
(21)
100-Z c
and 100z Zc[vol%]
where
z > (-1).
content Fig. 64. existing
(Z c)
For
a quick
=
,
l+z
(22)
estimation,
and the cement number
both
the
relative
cement
(z) are g r a p h i c a l l y r e p r e s e n t e d in
The curves are a p p l i c a b l e only to
dense
rocks,
because
the
(post-diagenetic) p o r o s i t y was assumed to be negligible.
In a d d i t i o n to the cement content, of the sediment
the p r i m a r y
carbonate
content
(C o ) can be determined:
Cod Co[vol% ]
1-O.Oln o
,
Example: A given sample of lithified rock with a carbonate content o f 80% c o n t a i n s as much cement as primary carbonate (Zd/Cod=l) or has a relative cement content of Zc=50% of the total carbonate. This is, if the primary porosity is no=70% , and when the standardized clay content (NC d ) o r t h e degree of compaction ( K ) i s 1 0 a n d 50%, r e s p e c t i v e l y .
(23)
130
where eq.
the n o r m a l i z e d p r i m a r y carbonate content (Cod) is derived from
21: IOOZ d Cod[VOl% ] -
Zd = lO0-NCd-n o
(24)
Zc
By r e p l a c i n g (C o )
is
Cod
original
only
porosity
23 by eq. 24, t h e
in eq.
dependent
on
the
absolute
original
clay
carbonate
content
content
(NC d )
and
the
(no): 100-NCd-n o
Co[vol%] Additional
methods
-
(25)
1-0.01n o
concerning
the o r i g i n a l
carbonate
content
are
presented in section 6.6.
5.4
Simulation
of
The simulation o f
Dtagenetic
Separation
the diagenetic separation of the o r i g i n a l
into c a r b o n a t e - r i c h
and c l a y - r i c h
compaction
on
law
compaction
law
and (eq.
the
sediment
(Fig. 65). content
is b a s e d on the carbonate
formulas.
4) can be r e p r e s e n t e d
diagram comparing c a r b o n a t e given
layers
cement
or r o c k
content,
sample with
compaction
all p o s s i b l e
stages
(which
is
of d i a g e n e s i s
sample may be subjected. transformations
porosity,
valid
and c o m p a c t i o n
carbonate contents.
in a
for
carbonate
limestones with segment
low
representing
to which a given sediment or rock
can be d e s c r i b e d w i t h
porosities,
the
Therefore, different types of s e d i m e n t - r o c k
On the diagram, sediments are l o c a t e d high
principle,
a constant absolute clay content
porosities, see Fig. 7) changes to a s p h e r o i d a l
have
In
as a t h r e e - d i m e n s i o n a l
By doing this, the curved r e l a t i o n s h i p b e t w e e n
and
sediment
low
the carbonate compaction law.
at the
degrees
of
lower
edge,
compaction,
since
they
and d i f f e r e n t
Rocks, however, are located at the u p p e r
edge of
the spheroidal diagram since they display low porosities and both high and low amounts of compaction and carbonate (Fig. 65). Carbonate compaction, BATHURST,
diagenesls
cementation, 1980a,b;
simulated using compaction law.
follows
three
and c h e m i c a l
HARRIS
et
al.,
the t h r e e - d i m e n s i o n a l
b a s i c processes: compaction
1985).
(SCHOLLE,
All
diagram
mechanical
of
of
these
the
1977; can be
carbonate
131
COMPACTION d = consfonf
CARBONATE CONTENT
J POROSITY
MK
F i g . 65 Three-dimensional diagram of t h e c o m p a c t i o n l a w . Mathematical relationship between all possible values of carbonate content, compaction, and porosity for a given sediment or rock sample with a constant absolute noncarbonate fraction (NC d ) d u r i n g i t s d i a g e n e t i c history. M e c h a n i c a l c o m p a c t i o n (MK) f o l l o w s a curve parallel to the plane between the porosity and compaction axis, while cementation (Z) follows a curve parallel to the plane between the carbonate content and porosity axis.
Mechanical porosity
Compaction
is r e d u c e d ,
while
(MK):
During
the
carbonate
Curves of m e c h a n i c a l c o m p a c t i o n
(e.g., Fig.
mechanical content
compaction,
only
r e m a i n s constant.
65 curve MK)
are
parallel
to a plane between the n and K axes of the diagram. Cementation strengthening
(Z):
Compaction
and w e l d i n g
w h e r e a s c a r b o n a t e content cementation
process
usually remains constant due to the
grain
increases.
(e.g.,
between the n and C axes.
of
Fig.
contacts; Therefore,
porosity
decreases,
curves s i m u l a t i n g the
65 c u r v e Z) are parallel
to a plane
132
Chemical
Compaction
dissolution, further
causes
decrease
compaction (for
law,
example,
In t h e are the in
see Fig.
66a
Thus,
compaction
66 a c u r v e
discussion,
to simulate
diagenetic Fig.
Chemical
a diminution
in porosity. chemical
following
applied
(-Z):
both
on t h e
therefore,
porosity
and
(MK, F i g .
66a).
alternating
dissolution.
Hence,
represent
the
the
zones
carbonate
branches
sites
model,
a
of the curves
As t h e
a phase
compaction
follow
Thereafter,
of
example
the
curve
of sets
cementation
porosity,
and
an d c o m p a c t i o n
Z an d - Z ( F i g . and
in
of mechanical
lithification
carbonate
cementation
curves
an d c o m p a c t i o n
with
two c u r v e s
of m a x i m u m
diagenetic
must
66a).
dissolution
They (in the
respectively).
In
all other c a r b o n a t e and c o m p a c t i o n values w h i c h o s c i l l a t e
in an a l t e r n a t i o n porosity
and
diagram
alternations.
content,
of the
basic
middle of what are later limestone and marl layers, this
pressure
left-trending
porosity,
initiates
compaction
change along
three
of marl-limestone
compaction; producing
in
content,
mechanical in
or
CaCO 3 c o n t e n t
spheroidal
results
these
diagenesis
the
-Z).
carbonate
history shows,
compaction,
of
lie,
connecting
for
the
simplification,
branches
Z and
-Z
on
lines
(this
with
constant
is r e p r e s e n t e d
by
o u t l i n e d arrows or "tie lines" for two d i a g e n e t l c stages in Fig. 66a). W h e n the process of l i t h l f i c a t i o n ends,
and p o r o s i t y is e x t r e m e l y low;
the r e l a t i o n s h i p between c a r b o n a t e content to that o b t a i n e d from m e a s u r e m e n t s
and
compaction
is s i m i l a r
in m a r l - l l m e s t o n e a l t e r n a t i o n s
(see
the s u m m a r i z i n g graphs in Table 12). The
paths
of
the
MK
and
c o m p a c t i o n and cementation, the
compaction
degree
of
law w i t h
compaction,
determination
of c u r v e
Z curves
respectively)
a constant
respectively -Z
(representing
mechanical
are easily c a l c u l a t e d
using
carbonate
content and a constant
(section
2.2).
(chemical compaction)
However,
is based on the fact
that the d i s s o l u t i o n zones are the only source of the c a r b o n a t e is
repreclpitated
limestone
layers
bedding
occurs
2.3.1).
This
in
the
pore
(convincing
predominantly implies
that
space
evidence
of was
in a c l o s e d in e v e r y
the
cementation
found
that
carbonate
diagenetic
the
or
dlagenetic
system,
stage
which
zones
with
section a given
Fig. 66 Formation of diagenetic carbonate oscillations explained by using the carbonate compaction law with normalized noncarbonate fractions o f NCd=5% ( a ) an d 30% ( b ) . MK=mechanlcal compaction, Z=cementation, -Z=chemtcal compaction or pressure dissolution, 0 to 4=successive diagenetic stages. The two blank tie lines in Fig. 66a represent fluctuations i n c a r b o n a t e c o n t e n t an d c o m p a c t i o n f o r an e a r l y a n d a l a t e d i a g e n e t t c stage.
133
10C % C 8C 0 M P 6C A C T 4C I 0 N 20 @0
u
zu
40
60
80
100 % CaCO3
% C 0 M P A C T I 0 N
® u -~u zu Ju 4u 50 60 70 80 90 100 % CoCO3
134
constant must
porosity
be
However,
since
compaction
curves
to
considered
and c e m e n t e d
Z and
-Z have
consider
the
relatively
absolute
richer
ratio
c a n be e a s i l y
simulated,
observations
(Fig.
to ascertain 66b). it
for
very
whether
is
the
interpolated of
mechanical
compaction
diagram
the
60).
of
cementation
began
diagenetic directly
by
carbonate
open,
early
because sets
intense
in
should
likewise
sequences, bedding, should
pore
sediment,
be
occur
primary
essentially
In occurs
the in
following fine-grained
to
preserved. cycles the
sediments
represented by t h r e e models the following assumptions:
For in
must
formation with
(Figs.
system would
30~) presumably Thus,
usually
67a,b
in primary be
low and
to carbonate-rich of
diagenetic alternations
SCHNEIDER Cretaceous
of diagenetic
different
However,
redistribution
processes
Lower
carbonate
an d 6 8 ) .
the
alternations
carbonate-poor instance,
early
provided
intervals.
Contrary
the
of
be
if
early
because
marly
be cemented.
of
of
carbonate in
carbonate
by t h e
rhythm
in Fig. high,
case
layers,
of
spheroidal
not
CaCO 3 b e l o w
system.
affected
bedding
the
the
can
shale
redistribution
heavily
pages,
layers
before
left
of
in
marl
(with
a long curve
formation
cement
large
(Fig. because
c a n be v e r y
the
also
there
of lithificatlon
The d i a g e n e t i c
in a closed
described such bedding northern Germany.
of
agrees
can
alternations.
follows
However,
have
occur
edge
onset
cemented
is
one
(NCd=30%) i n o r d e r
also
left
during
compaction
carbonate
which are the
the the
sediments space
sediments
adjacent
low.
mechanical
little
clay-rich
one
are
sediments
hand,
cement content
the
should
other
carbonate-rich
amount
closed,
carbonate-poor
undergo
the
which
model predominantly
presumably
(e.g.,
in
diagenesis
of
In addition,
thickness
somewhat speculative
law (see
only
if
17.
can
concretions).
is
or,
eq.
and
amounts
branches
bedding
to
necessary
dissolution
content
be e i t h e r with
the
carbonate
model is
relative
early
carbonate
cementation,
two
layer
the
studied,
parallel
the
the
On t h e
sediments
compaction
Theoretically,
of
the a b s o l u t e
carbonate-rich
carbonate-poor
the
clay-rich
the
since
66a).
latter
from
Diagenesis
values
using
of
diagenetic
Unfortunately,
all
fine-grained
(NCd=5~)
a model
(-Z d) (Zd).
in carbonate. in
with
develop
carbonate carbonate
between
to be i n t e g r a t e d
bedding
dissolved of c e m e n t e d
an alternation,
carbonate
original
of
amount
models
within
or poorer
Diagenetic the
amount
to the a b s o l u t e
in the s i m u l a t i o n
are
of d i s s o l v e d
has
the
equivalent
(1964)
shales
bedding,
which
contents,
They a r e
of
based
is on
135
1.
Primary
porosities
should
vary
section 2.
The
onset
of
the
those
should
dissolution
sediment
relatively
the
present
column, poorer
the
differences
between
of simplicity,
stage
there
is
layers
Although
the
data
three
a somewhat
into
the
shows d i a g e n e t i c
clay
contents
cementation
curves
Z and -Z. It
three
displays
simply
The s e c o n d
mechanical
compaction
and c a r b o n a t e
more
abstract
which schematically curves
for
primary
several
(slight)
in
Fig.
displays
the
diagenetic carbonate
In
67a,b
occurs
and
from
for
zone
of
cementation
(Fig.
68),
into
dtagenetic
the
a graph
carbonate
of simplicity,
shown
the Fig.
porosity
transformed
are
of
after
diagenetic
compiled
three
of
manner
layers
which connect
For reason
oscillations
-Z)
(Fig.
absolute
of carbonate
development stages.
are from
insights
two d i m e n s i o n a l
model
are
68
model
into
(curve
compaction,
two a r e a s
(-Z).
first
Successive
predominantly
(ME) a n d t h e
and
in a similar
is
and
5.2).
different
separation
67b,
pore
marl
important
by t i e - l i n e s
Fig.
are every
of
section 67a,b
The with
MK).
at
extrapolation
give
represented
content, the
see
on
compaction
model,
to
layers
that
developing
Figs.
bedding.
(curve
the
richer
reduction
and
Diagenetlc
dissolution
diagrams
in
diagrams
expressed
carbonate
zones of diagenesis:
assumed
the
in sediments
compaction
In
relatively
true,
input
the
Z) a n d c h e m i c a l
67a a r e
not
15%), w h i c h i s 66.
zones.
limestone
is in
is
diagenetic
in Fig.
of mechanlcal in Fig.
curve
have been thicker
progressively
data
separation
(curve
stages 67a.
of
and
portrayed
sediments,
(NCd=I t o
described
a phase
see
assumed t o be 1 : 2 .
it
porosity
models
development
as those
the
arbitrary
on c a r b o n a t e - r i c h
of beds is
marl
(which actually
67a)
(Z )
(during
a constant
limestone
on
included)
0% CaCO 3,
regression
originally
ratio
For reasons
space)
the
cementation
in carbonate
ignored. diagenetlc
follow
zones should
of
Porosity
based
are
60a.
precursor
original
4.
sediments
100~ CaCO 3) an d 80% ( a t
lithification
in Fig.
The existing than
fine-grained
65% ( a t
2.3.2).
portrayed 3.
(only
between
in
the
no
three
diagrams. Results:
1.
Carbonate-rich phase
primary
of mechanical
sediments
compaction
are
subjected
and u s u a l l y
undergo
to
only
an
early
a short onset
136
sITY oR 0 40 %
I
P~ 607
'+~+. . . .
~;.-........
80J
I
"-..
I 1
%
-.
,,,.
"""~...':.-_ ......... ..-\
•
", ,-....~.,.,, -Z':i .............. / ""..: ",.
"".-.
%
.."
I
"-,. k
: :
C 0 M P A C T+ I 0 N
"".
......%" '
V'. ........... " ~ I
/
I
z l
"
!
' ,
MKi
t
-
:
l ] s"
.~Lmm
s
S
® 0
"
20
m
mmmlml
40
mmm
mm m
; ,
NCd 7 ~
~
'
/
m
." "
s
O
mm;m
t
70
60
BO
100 % CoCO 3
Fig. 67 a: Model for the production of dlagenetic bedding in fine-grained, calcareous sediment based on the c a r b o n a t e c o m p a c t i o n law w i t h s t a n d a r d i z e d noncarbonate fractions of NCd=I to 15~. Shown are the main diagenetic curves (MK=mechanical compaction, Z=cementation, -Z=chemical compaction or pressure dissolution). Thin tie lines between the Z and -Z curves represent the oscillations of c a r b o n a t e content and compaction in successive stages of diagenesis. b: Block diagram for fine-grained, calcareous s e d i m e n t s as presented in F i g . 67a. S t r i p e d p l a n e is t h e z o n e of mechanical compaction (MK), and, a f t e r t h e o n s e t of lithification, the striped plane is the neutral zone between the areas of cementation (Z) and c h e m i c a l c o m p a c t i o n (-Z), Small n u m b e r s indicate various successive diagenetic stages
(0 to 5). of
diagenetic
precipitation triggers greatly
carbonate of large
intense enhances
carbonate the
redistribution.
amounts of cement primary
dissolution bedding
This in the in
rhythm
enables
limestone the
(see
marl
the
layers, beds,
sections
and 4.4.3
137
%
C 0 M
F C T I 0 N
®0 and
20 4.6).
40
However,
redistribution fact
that total
amount Hence,
alter
the
by
an
of
cement
onset
carbonate
or
an
the
values
content
(expressed
of
the
onset Table
12),
number of dissolution-reprecipitation
space
fs in
dissolution
in the
enhances
the
already
very
CaCO 3 a r e
high
thin,
low
primary
of
carbonate
percent
(Figs. marl
content
and
high
after
a when
Dtagenettc by
whereas only
low.
carbonate
68).
caused
of
very
episodes,
67a, beds,
of
amount is
diagenesis
predominantly
stylolittc
in
i n an y s u b s t a n t i a l
diagenetic
considerable pore
stages
not
due t o t h e
ltthlfication
form
differences
is
content
oscillations the
late
does
absolute
clay
of
carbonate
but
This
be c h a n g e d
absolute
(see at
lithtfication,
compaction
content.
cannot
early
only
of
decrease
that
100 % Ca£03
affects
solids)
increase
spite
absolute
the
carbonate
of
provided
in
the
relative
amount
carbonate,
after
80
predominantly
significantly the
60
very
carbonate cementation slightly
in
138
the 2.
limestone
Sediments
layers.
with
intermediate
have
a relatively
late
beginning
space
is
the
decrease amount
in
the
the
content
absolute
cement the
reduced
low,
(Fig.
of
which
contents
and
the
often
primary
However,
high,
the
does
to
a
pore since
increase
or
significantly
Although results
begin
clay
67).
carbonate content.
diagenesis
12),
when
comparatively
amount
of
absolute compaction
separation, is
Table
onset
and
mechanical
carbonate is
(see
with
of
diagenetic
(relative)
of
carbonate
phase
substantially
clay
oscillations neously
of
already
absolute
affect
long
in generate
the
absolute
large
CaCO 3
simulta-
lithification.
80 70 60 50 40 30 20 10 0 MEAN poROSITY
r, u
_
, 1.1
~- -
ll~.,
IU.J
X MECHANICAL\ COMPACTION I
68
71
"
COMPACTION, CEMENTATION
Fig. 68 Formation of diagenetic carbonate oscillations in flne-grained, calcareous sediments with standardized noncarbonate fractions of NCd~I to 15~, which is presented in relation to the mean porosity and the amount of compaction (K). Shown are schematic carbonate curves, which are representations of how d I a g e n e t i c carbonate curves successively fluctuate around centers of lithification (e). Data is based on the models in Fig. 67.
139
3.
As a l r e a d y
discussed,
the
very
clay-rlch
s e d i m e n t s , which this
study does not deal with, should be little affected by d l a g e n e t i c bedding because
of h i g h
reduction
in porosity due to mechanical
compaction (Fig. 66b).
of
diagenetic
carbonate
redistribution in some sediments, significant
In
spite
carbonate
oscillations
are o n l y
of
the
formed
early
during
beginning
late stages of dlagenesis when the pore space
is considerably reduced (below porosities of 30 to 40%); regardless of whether
or
supported pelagic
not
the p r i m a r y
by data o b t a i n e d
carbonates,
begins when
the
porosity
sediment
was
carbonate-rich.
f r o m the D e e p
formation
This
Sea D r i l l i n g Project.
of b e d d l n g - p a r a l l e l
is In
stylolites
is between 5 and 40% and overburden ranges from
600 to 1000m (Table 16).
T a b l e 16: Onset of the development of bedding-parallel p e l a g i c c a r b o n a t e s e q u e n c e s (DSDP). Site
Meters of overburden
367 463 516
Carbonate content (%)
1050 632 875 The
Porosity (%)
60-90 90 75-90
effect
of
carbonate content
G A R D N E Re t a l . , 1977 THIEDE e t a l . , 1981 BARKER e t a l . , 1984
b e d d i n g on s e d i m e n t s w i t h
is s u m m a r i z e d
in
Reference
5-20 20-40 30
diagenetic
stylolites
in Fig.
69.
different
The c l a y - r i c h
bedding
types are extrapolated from the studied alternations containing medium to high
carbonate
weather
to
distinct
alternations because
contents. marl
Only
and
limestone
in c a r b o n a t e - p o o r
their
carbonate
weathering
boundary
relatively
high.
predominantly within
is
layers,
rocks weather
content
(Cw).
This
the c a r b o n a t e - r i c h
alternations
whereas
completely
the C a C O 3 to
In all cases, because
the t o t a l
carbonate
is
compaction
compaction in lithifled alternations must be on the same o r d e r
amount
as the
Hence, in spite of large compactional
in a l t e r n a t i o n s w i t h
of c o m p a c t i o n
is
redistributed
a c l o s e d system; therefore, the amount of total
amount of original pore volume. differences
marl,
is b e l o w that of the marl-limestone
diagenetic
bedding,
their
total
s h o u l d be essentially the same as that observed
in neighboring shales. Rhythmicity, differential compaction, the constancy of the maximum carbonate content, and the ability to develop a n g u l a r - s h a p e d m a x i m u m s on the c a r b o n a t e content.
curves
increase with
i n c r e a s i n g primary carbonate
However, the largest diagenetic c a r b o n a t e
oscillations
are
140
20
18.5 NEd
NCd
Co
~o Cw
,], Cw ,,',
',',,
15 NCd
Co 4, Cw
10
NCd
co $
5 NCd
~
I NEd
n
Co Cw,I,
:~
|
II
II i
J
|
,~1
o 5'o[Ioo o 5OciOO 6 50 CI00 0 50 CI00 0 50 CI00 0 5o [ioo mart-[imesfone fransifion: g r ad u a [ disfincf fraser
¢
0-olcm 0 olcm
o , lcm
141
found
in
alternations
The types
position
of
the
transition
the
carbonate between
part).
increasing
Moreover,
curves
cementation Fig.
middle
within
of
the
hence,
in
marl
For
still
magnitude
weathering
boundary.
the
transition
between
flasery,
stylolitic
nonsutured-seam transition contact the
neutral
contents The
both
a sharp carbonate
preservation
beds
that
of
depends the
on than
are
value.
the This
by
is
of
delicate
calcareous
the the
carbonate
(Fig.
Since
dissolution
zones,
the of
alternations
the or
displays
"sutured-
and
1979).
The
WANLESS,
at
is
content
zones
to
ledge,
less
distinct
corresponds
medium
to
to
high
mean
69). fossils
content
boundary.
highly neutral
which
carbonate
curve
usually
clay
in the
limestone
a more
carbonate
absolute
between
However,
carbonate-rich
of
occurs
CaCO 3 c o n t e n t ;
curves,
equivalent
is
towards
transition
the
described
in
low
(see
value
rapidly
cementation
consists
and
content
CaCO 3 c o n t e n t ,
in
angular.
transition
gradual.
and
weathering
thicker
types zones
decrease
carbonate
of
marl
usually
solution"
the
relatively
and
change
to
neutral
reason,
than
Therefore, (these
the decreases
(weathered)
greater
the
lower
dissolution
curve
a high
dissolution
seams
between when
even
at
of 69,
maxima
carbonate
carbonate the
occurs
or
the
is
(Fig.
sinusoidal
between
macroscopic
angular inside
value
a
the zones
with
is
neutral of
at
alternations
value
same order
that
bed
cementation
from
different
appearance
carbonate
alternations,
the
on the
zones
increasing
clay-rich
marl
the
the
value
with
bed.
of
content
carbonate
and
the
shapes
sinusoidal
alternations
carbonate because
in
(C n )
cementation
the
marl-rich
calcareous
the
content.
value
influences
and
increases
(weathered)
dissolution
greatly
carbonate
Therefore, where
carbonate
carbonate
carbonate
neutral zones
43).
located
above,
mean
the
intermediate neutral
dissolution
As mentioned
with
the
with of
of the the
the
in
weathered marl
the
neutral
weathered zone
marl
beds
can
delicate fossils which are unaffected by pressure dissolution. flasery marl joints of highly calcareous alternations,
beds
and are
contain In the
dissolution
Fig. 69 A summary of the effects of diagenetic bedding for fine-grained, calcareous sediments with standardized noncarbonate fractions of NCd=I to 20~. Shown are the original volume of sediment (---) and the post-diagenetic compacted rock volume ( ) with its typical carbonate curve (C) and the mean primary composition (C O ) of the original sediment. Also represented is the carbonate content at the weathering boundary (Cw, d a s h e d d o u b l e l i n e ) , the weathering profile (black, left) and the extent of dissolution (blank) and the cementation zones (starred, shaded) in the sections. Marl-limestone transitions from KB6, Strassberg, southern Germany (Upper Oxfordian).
is
142
often
intense.
areas
However,
of carbonate
between certain
5.5
Bedding:
Stratiform
Process
low
diagenetic 1985), This
dissolution
Diagenetic
Although
angles
bedding
results
in
several
disparity
bedding
o f km,
limestone
layers
bentonite
beds
process
of
of
when
the
the
(BATHURST, Fig.
90),
beds
stress
only
bedding
plane
cuts
be
concretions. overburden limestones al.,
shear part, space
shall 1978;
planes the
fills
cut
long distances
beds
at by
and
stratiformal the
primary
limestone
in
layers
an a n g l e
to the
at from
Perhaps,
the
laminae
is
primary
low angles
by
intervals layers
briefly
al., a high
carbonate between the
(MIMRAN, 1 9 7 7 ) .
(e.g.,
1981). angle is
not
slate
the
joints the
near in the
traceable The p r i m a r y
are
of
chert
due
to
cleavage
in
PLESSMANN,
chalks
1964;
bedding. is
For within
and
ALVAREZ
wavy dissolution
but
an
Pleistocene.
reprecipitated planes,
but
"bands"
Usually, to
Klint
bedding
40cm.
containing
dissolution
bedding. of secondary
Stevens
delicate,
marl
of
type
at
(see
an d p o i n t - b a r
diagenetic
of about
during
sediment
in Neuffen
biostromal
secondary
be m e n t i o n e d at
the
2000m o f i c e
phenomenon GEISER e t
by
direction
of
observed
"copied"
in the
isochronous
overburden
be
1985)
concretionary
a mainly
marl
stratification
regular
inferred
develop
are
often
HATTIN ( 1 9 7 1 ,
Creek Limestone
for
can
bedding
an d p a r t l y
knows w h e r e a s p e c i a l
ThereD at
dissolved
in the
caused
author
of approximately
tectonic
deposited
primary
is
joints, can
The
the
chalk
stylolitic bedding
this
Denmark.
Maastrichtian
bedding.
certain
was
phenomenon
channel
location
Copenhagen,
et
This
SIMPSON,
original
700km u s i n g
evidence
are
and
to the
Bridge
that
original
and A n g l e s w h e r e c r u m b l y slump l a y e r s
in submarine
The
or
b e d s which can be t r a c e d
over
diagenetic
the
diagenetic
individual
is
by
beds which
1984). Gubbio,
in small fossils
(WALTHER, 1 9 8 3 ;
For instance,
America
bedding
primary
major
that
individual
Other
"copied"
between
scale
Upper Cretaceous North
diagenetic are
dip
fact
traced
as controls.
stratification even
of
around massive
parallel
the
cemented
of the
Interior
mainly
i n some c a s e s .
a n d ELDER & KIRELAND ( 1 9 8 5 ) Western
in
on a s m a l l
is
however,
selectively
100's
m i g h t be p r e s e r v e d
A Predominantly
of
exclude,
fauna
which occur
seams.
may o c c u r
diagenetic
does not
delicate
precipitation
the the
transported
an d most pore over
143
5.6
Discussion
In
a
of
classic to
of
the
develop
alternations. (e.g.,
Seibold
SEIBOLD
Upper
Jurassic
a quantitative
This
HILLER,
so-called
1964;
the
results
of this
(1952)
in
"Seibold
deposition
model"
the
al.,
has
rhythmic
and
was
the
in marl-limestone become
1966;
1982).
Seibold
the
Germany
& FENNINGER,
BAUSCH e t
study,
studied
southern
model of
FLUGEL
FUCHTBAUER & MULLER, 1 9 7 7 , to
Iodel
investigation,
alternations first
the
widely
used
FLUGEL,
However,
model should
1968;
according
be considerably
modified. SEIBOLD affected
(1952)
by
assumed
diagenetic
differential
that
marl-limestone
carbonate
compaction.
a l t e r n a t i o n s are not
redistribution
Further,
he
processes
or
assumed that the same time is
r e q u i r e d for the d e p o s i t i o n of the e x i s t i n g marl and limestone layers. Based per
on
these
bed"
limestone
clay is
(NC d )
remained
rhythmic
in
background
(see
therefore,
remain must
Upper per
absolute
on
clay
volume. Oxfordian
bed thickness
SEIBOLD
was negligible,
the
had
Fig.
carbonate
assumed
that
he inferred
that
a constant
developed
rate
of
in
each
show p r o n o u n c e d have
large
in
from
the
slightly same
after the
layer,
variations.
compactional
must this
Upper
thickness
(Fig. with
of
and
in
in
poorer
the
primary
compaction
absolute
content
while
the
Since differences,
the
absolute studied the
a
Oxfordian
differential clay
be
study,
sediment
richer
in
now
redistribution
data
Moreover, the
bed thickness
from an original
redistribution,
constant
carbonate
originally Hence,
per
constant
compaction
nearly
35).
content
often
diagenetic
the
layers
clay
is
of
to
carbonate
alternations
that
composition.
content
sediment
normalized
the
Since
absolute
sediment
the
or
SEIBOLD's
or
content
was superimposed
alternations
Germany,
carbonate
in
that
70a).
that
the
clay
marl
sedimentation.
as a result
uniform
southern
stressed
original
clay
amount of a given
normalized
that
redistribution
According
marl-limestone
the
but
(Fig.
deposition
be
of
Here,
of
absolute
alternations
reinterpreted
must
study.
constant,
conclusion
marl-limestone 70b).
this
the
"absolute
from the
demonstrated
carbonate carbonate
It
a percentage
considerably
SEIBOLD's
content
as
alternation
varied
diagenetic
must
used
the
cm t h i c k n e s s
different
predominantly
content
fairly
is
calculations
marl-limestone
in
respectively.
expressed
SEIBOLD's
he evaluated
expressed
content"
content
content
clay
he
layer,
"absolute clay
assumptions,
which
mainly
per
and, bed
carbonate lithified constant
144
SEIBOLD MODEL BED THICKNESS'-'~"
BED THICKNESS~
N[ mean primary (~) carbonate content (Co)
NC
(~)
mean primary porosity (n o )
70 a: S e i b o l d Model f o r m a r l - l i m e s t o n e alternations. I n many a l t e r n a t i o n s , the total amount of noncarbonate per bed (NC, striped) is predominantly constant while the carbonate content (C, shaded) varies considerably. I f no diagenetic redistribution of carbonate occurred, this phenomenon i s due t o a l t e r n a t i n g periods with and without CaCO 3 d i l u t i o n of a constant clay background sedimentation. The dilution w o u l d be c a u s e d by t h e r a p i d deposition of calcareous sediment. b: Interpretation in terms of diagenetlc carbonate redistribution. Layers, which were originally slightly richer and poor in carbonate content underwent differential compaction. In t h e s l i g h t l y compacted layers, the remaining pore space was filled with carbonate cement which was p r o v i d e d by t h e h i g h l y compacted marl beds as a result of pressure dissolution. Assumed mean primary sediment c o m p o s i t i o n shows t h e amounts o f n o n c a r b o n a t e (NC), o r i g i n a l carbonate ( C o ) , and o r i g i n a l porosity (no). Note, that the noncarbonate content per bed remains unchanged during the diagenetic redistribution of carbonate. Fig.
absolute
clay
marl-limestone bedding primary be
rather
content than
sediment.
implemented,
per
alternations the In because
bed
assumed the its
found
now c o n f i r m s high
future,
the
by the
several concept
authors
carbonate
oscillations
Seibold
model should
sedimentological
validity
in
of diagenetic
is
in
the
no l o n g e r severely
145
restricted.
If
thickness
or
one
volume
expresses
of
the
marl
the and
clay
content
relative
layers,
several
limestone
to
the
problems
arise: 1.
The
absolute
primary
2.
beds
hand,
the
clay
used
in
clearly
interpreted
in of
zones
only
thicker
in h i g h l y
than
a
of
of
the
the and
marl
the
and
can
be
layers
cementation
(see Fig. 43).
are
usually
In
somewhat
a d d i t i o n a l l y sites c o n t a i n i n g
small carbonate m a x i m a can w e a t h e r totally to marl 3.
sediment
which
limestone
alternations
the d i s s o l u t i o n zones;
and
On t h e
diagenesis.
and
layers
marl
primary
dissolution
marl
to
compaction.
parameter
deposition
related
existing
of
to
valid
weathered
clearly
the
degrees
calcareous
alternations,
not
because
is
terms
the
is
normalized
study
c o r r e s p o n d s to the t h i c k n e s s marl-rlch
bed
different
content
this
thickness
per
parameters,
underwent
volume
The
content
depositional
limestone other
clay
(see Fig.
32).
In the original sediment the p r e c u r s o r s of the present d i s s o l u t i o n and c e m e n t a t i o n zones did not thickness
of w h a t
are
the
have
equivalent
thicknesses.
The
later c e m e n t a t i o n zones was between 34
and 50~ of the p r i m a r y sediment column. The
objections
raised
absolute clay content of
carbonate-poor
limestone layers.
in
problems
2 and
(per bed thickness)
alternations This
effect
As
relative
to t h a t
contained
visible
in the
the
existence
in the
marl-rich
(1952).
of
calcareous
pressure
poorer
exchange
of
in
carbonate
carbonate
predominantly
framework of beds s l i g h t l y
content.
between
between
porosities
have
50 and been
The
adjacent
governed by diffusion.
once an o v e r b u r d e n original
shadow structures show, the
d i s s o l u t i o n - r e p r e c i p i t a t i o n process of CaCO S is t r i g g e r e d
by d i f f e r e n t i a l stress in the grain
diagenetic
marl
and
is
evident
from
simulation
richer
transport
limestone
beds
and is
A p p r e c i a b l e c e m e n t a t i o n sets in
400m
reduced
has
been
deposited
models
and w h e n
to values between 50 and 60%,
d e p e n d i n g on the carbonate content of the p r i m a r y s e d i m e n t . it
the beds
Conclusions
stratiformal
and
that
in the m a r l
is c l e a r l y
p o r t i o n s of the a l t e r n a t i o n s studied by S E I B O L D
5.7
3 indicate
increases
that
significant
However, diagenetic
146
changes
in
diagenesis carbonate-rich layers, whereas
15~).
the
relative
when
the and
cementation the
porosity
CaCO 3 c o n t e n t
porosity
becomes
carbonate-poor considerably in
the
marl
form less
only than
alternations. reduces layers
the
in
late
30~, In
pore
remains
stages
of
especially
space
relatively
the to
in
limestone 0 high
--
5%, (5 to
A P P L I C A T I O N S FOR D
THE
AND
R A P I D
M E T H O D S
Q U A N T I F I C A T I O N
I A G EN
E T
I C
0 F
C A R B O N A T E
R E D I S T R I B U T I O N
The
applications
only
of
an analysis
of
other
natural
the
easily
and
applied
to
content. field
mass
new,
more
fields
Although
application
of
are
and
The
in
of
the
amount
of
compaction
to
subsidence
is
of
the
However,
one
the
2 and
somewhat
which
Fraction
(NC d )
fraction,
which
sediment
If no s u i t a b l e
fraction
section
the
applied
and
sections and
of
rely
5)
is
imprecise on
only
a
samples.
Noncarbonate
original
in
oil
compaction.
be
parameters. rapid
following
of
also
from in
composition
to
analyses
be
cement
result
compaction
presented
for the a p p l i c a t i o n
formulas.
carbonate
ignored,
Therefore,
the
should
basin
diagenetic
noncarbonate
the
basic p a r a m e t e r
in
be
then
taken
isotopic
related
compaction
(as
tedious. number
standardized
cement
methods
small
Standardized
percentage
and
developed
comparatively
6.1
precise
of
logs
a
can
can
new tools
as
closely
instance
frequently
geological
lengthy
methods
view
cement
and
one
carbonate its
valuable,
chemical
is
if
compaction
determine
interpreted
be
common c a r b o n a t e s
instance,
can
and
can
fundamental
compaction
to
become
the
which for
rock
be
of
a
parameters:
of
not but
This
is
a sequence,
determinable
include
well.
For
compaction
should
geology,
of
could
Moreover,
inclusive
important
often
future,
study
alternations,
law
diagenesis
calcareous
exchange,
in
the
measurement
holes
carbonates
calculations. most
the drill
exploration.
diagenetic other
in
as
exchanges.
readily
of
rocks
compaction
content
This
sequence and
existing
This
the
in t h i s
marl-llmestone
and
mass
clay
from
Thus,
gas
of
porosity.
sections
in
enables
terms
absolute
a
developed
carbonate
which in
calculated
content
and
the
relationship
evaluate
methods diagenesis
sediments
since
be understood
of
the the
calcareous
accomplished to
of
and
volume
of both
structures to
(or the a b s o l u t e
expressed
(see section the c o m p a c t i o n are a v a i l a b l e
calculate clay
is
the
content)
2.2),
as
a
is the
law and t h e to d e t e r m i n e
standardized
by s o l v i n g
eq.
non2,
an
148
estimation
of
following The
if
history
(for
original
clay
instance, is
prior
to
absolute
content
if
of is
Therefore, fraction
assumed the
content
is
carried
in
o u t by u s i n g
if
on
the
in
containing
the
the
absolute
middle
lowest
clay
up
carbonate
the
the
the
to
50%
However,
relative
(Type III), layers
the the
relative low ( s e e the
(that
gives
clay to
compaction,
(or is
the
by m e c h a n i c a l 7).
According
content
limestone
in the
than
clay
diagenetic
because
Fig.
content
clay
amount o f c o m p a c t i o n )
content
the
reduced
(see
less
alternations
of
relative
in
compaction. with
absolute
in carbonate-rich
slightly
always
interval
the
early
concretions),
of cementation is
to
very
diagenettc
underwent
an
equivalent
t o be o n l y
content
compaction small
is
occurred
onset
sediment
law,
influence
content in early
clay the
compaction content)
clay
CaCO 3 c e m e n t a t i o n
volume
compaction
the
absolute
absolute
content
the
the
methods.
clay Fig.
7).
noncarbonate is,
the
site
an a p p r o x i m a t i o n
of
sequence.
K/
0
KI= -1.69 EL + 184.'/8
20 40 60 0
Y80
9'0
100
CaCO3 F i g . 71 Relationship between compaction at the lithification (K 1) a n d t h e m e a n p o s t - d i a g e n e t i c content in the middle of the limestone layers. In o r d e r alternations,
to d e t e r m i n e
the
the c o m p a c t i o n
be ascertained by u s i n g
the
absolute
clay
content
onset of carbonate
in m o r e
at the onset of lithification
carbonate
content
marly
(K l) must
in the m i d d l e
of the
limestone layers (C L, Fig. 71): K1 = _ 1 . 6 9 C L + 1 8 4 . 7 8
(26)
149
The
author
content
in
alternation using eq.
26.
eq.
3.
2 or
suggests
the
middle
and
then
Then, Eq.
with
a porosity
6.2
Porosity
Errors in
which
30% ( s e e
the
is
the
the
carbonate
degree
law,
content
the c a r b o n a t e
layers
mechanical
in
using
alternations
(n)
so
Fig.
long
in as
7).
If
porosity
be
carbonate
expression,
n is
Fig.
are
total
necessary,
can
decreasing (see
porosity
the
the
is
in
because
content
(see
measured
below
porosity
estimated
the
negligible
If
Compaction it
is
and C
62b).
(27)
(K)
impossible
to d e t e r m i n e
compaction
previously
discussed
(see s e c t i o n
2.1.2),
using
4 and
eq.
the
curves
in Fig.
then be e s t i m a t e d
according
and rock p o r o s i t y
can be a s c e r t a i n e d
6.4 An
Primary
Porosity
approximation
quantitative presented determined form
an
porosity
of
the
must
be
porosity
due
to
apparent
primary
the
the
sections
individual
normalized
directly
or i n d i r e c t l y
compaction
7.
The
to the m e t h o d s with
can he c a l c u l a t e d
absolute
clay content
presented eq.
as
in
section
can 6.1,
27.
(n o )
decompaction in in
it
section
porosity
n = 5.56 ln(100-C)-9.46
6.3
an
compaction
can be d e t e r m i n e d
to s e m i l i t h i f i e d
differences
alternations with
of
clay content applied
methods,
following
determine
limestone
Alternations
from small
rapid
first
ten
30%.
Lithified
regularly In
to
the
be
than
micrictic
increases 5.2).
cannot
compaction
lithified,
five
estimate
of more
result
the
of
the a b s o l u t e
26
in
utilizing
that one should
middle
primary of
ten
6.2 of
either porosity porosity
samples.
and five
sequence. determined
porosity 6.3,
marl For
According
and five every does
dissolution
or
(nd,
from the eq.
be
compaction
which
results
can
15).
to and
cementation If
the of
of
are which
primary original
CaCO 3 .
compaction
diagenetic
a
methods
layers
an apparent
represent
addition
the
by
porosity
limestone
sample, not
obtained
The to
carbonate
150
redistribution apparent
occurred
porosity
in a c l o s e d
in
the
marl
system,
and
e q u i v a l e n t to the mean d e c o m p a c t l o n p o r o s i t y However,
in the original sediment,
the mean
limestone
value
samples
in the
of t h e
should
studied
be
section.
the p r e c u r s o r of the e x i s t i n g marl
beds was on an average one and a half times thicker than the p r e c u r s o r of
the
present
limestone
layers
apparent p o r o s i t y of the marl factor error
of of
1.5 b e f o r e this
(see
layer
Table
samples
ii).
must
Therefore,
the
be m u l t i p l i e d
by
a m e a n primary p o r o s i t y can be calculated.
a
The
m e t h o d is about ± I 0 ~ of the p r i m a r y p o r o s i t y w h e n it is
d e t e r m i n e d u s i n g the more d e t a i l e d d e c o m p a c t i o n c a l c u l a t i o n in section
2.3.5.
6.5
Cement
Content
(Zc,
Zd )
The relative
and a b s o l u t e
cement content
be e s t i m a t e d
by u s i n g
diagrams
16 a n d two
17,
or
other
eqs. such
standardized
porosity
6.6
19 and 2 0 .
parameters
calculations: the
the
known
carbonate
porosity
in
fraction
at
Content
6.4)
the
compaction
(section
6.3),
6.1),
an d t h e
existing
(C o )
sediment
of m a r l - l l m e s t o n e a l t e r n a t i o n s by
boundary,
They
because
have
to be
between
the
dissolution
and
c o n s i d e r a b l e error results f r o m u s i n g content
at
quite
the w e a t h e r i n g equal
(see
boundary
Fig.
43).
change w i t h i n the rock column 46,
69).
sampling
For
differences mean
only
of up
primary
weathering
example,
sites
method,
if the
composition
in the
centimeter Therefore, by
should
using only
neutral
However,
a
carbonate
a n d that at the neutral zone are the most p r o n o u n c e d CaC03 neutral
zone
in c a r b o n a t e - r l c h a l t e r n a t i o n s one
to 40%!
boundary
c e m e n t a t i o n zones. this
Moreover,
occurs
carried
in some cases the c a r b o n a t e
content at the w e a t h e r i n g b o u n d a r y c o r r e s p o n d s to that at t h e
not
and
perform
it is p o s s i b l e to a s c e r t a i n the average c a r b o n a t e amount
in the p r i m a r y
the w e a t h e r i n g
boundary
can eqs.
to
(section
p e r f o r m i n g a few c a r b o n a t e d e t e r m i n a t i o n s . out
(section
order
content,
respectively)
o r by c a l c u l a t i n g
6.2).
Carbonate
In principle, contained
as
64,
The p r i m a r y be
noncarbonate
(section
Primary
must
(Z c an d Zd,
in Fig.
the
apart the
can
direct
carbonate
be p e r f o r m e d
(see
Figs.
(Type III), two
have
carbonate
e s t i m a t i o n of the content
in T y p e
at
the
I, m a r l - r l c h
151
alternations, 4.1).
which
In
all
proposed.
This
absolute
display
other can
clay
sinusoidal
cases, be
an
carbonate
indirect
accomplished
content
(section
by 6.1)
oscillations
(section
determination applying
and
eq.
primary
method
25,
which
porosity
is uses
(section
6.4). A graphic in
method
fine-grained
process
of
rich
and
66a,
but
here the
Fig.
72a
the
degree
The
diagenetic
clay-rich
between
is
of
represented
part
is
Fig.
if
72b
is
but
primary
a
length
the
of on
of
this
(see
is
the
hence
diagram. involves
is
defined
is
7).
the
all
equivalent
However, curve
is
the is
evident
curve
low or
At a
closed, is
compaction It
by a
mechanical
content.
which
Fig.
The
of
space
12).
72a. (with
porosity
carbonate
of and
in
not that
Fig.
primary
curve
which
is
represented
of
mechanical
use
a
graphic
shows
80~)
described
amount
sediment
It
varying
72a
is
carbonate
how the
amounts
by
on the
by the
the
measured
estimation
of
carbonate
and
find
corresponding
post-
vertical
compaction
law.
data
which
This the
absolute
the
compaction,
composition.
different
of
determine
compaction
the
primary
to
Fig.
curve to
the
one
of
sediment
theoretical
related
enables
pore
compaction
compaction
constant
amounts of
turn
of
66a,
first
on a curve
Table
carbonate
extension
the
with
position
in
an
of
diagenetlc
directly
the
(see
Fig.
amount
carbonate
data
mechanical
in
carbonate
the
low porosities
stretches
high.
compositions clay
of lie
Fig.
redistribution.
primary
when most
in
Additionally,
bottom
the
the
theoretical
of
to
the
carbonateas
which
process
describing
measured
into
plane
position
top
case,
manner
the
carbonate
compaction
for
the
by the
complete
content
law
sediment
alternations
to
this
compaction.
its
from
CaCO 3 c o n t e n t
In
similar
redistribution
relation and
of
to
then
60a)
original
72a.
onto and
relative
diagenesis,
vertical
more
in
a
projected
and
carbonate
length
in
increases
the
Fig.
a primary
content
carbonate
compaction
of
marl-limestone
Fig.
(K 1 )
of
the
The
the in
stage
entire the
of
of
compaction
to
180 °
compaction
(given
later
are
of in
expressed
carbonate
compaction
beginning
values
is
curves
of
rotated of
estimation derived
separation
the
axes
mechanical
the is
beds
diagenesis
curve
for
carbonates
is
depends
relationship
primary
carbonate
content. If
one
knows
fine-grained
of
then
amounts
sample,
compaction 72b;
the
curve one
mechanical
one
given
follows
this
compaction
for
of can a
curve
certain until
(arrows).
the
compaction
absolute one
reaches
Thereafter,
in
any
given
carbonate
clay
content
in
Fig.
the
specific
amount
one
proceeds
to
the
152
CoCO
SEDIIVlEN T 0
0 % 20 C 0 M z~0 P A C 60 T I 0 80 N 100 ®
0
20
40
60
80
I00
CoCO 3 R O C K
Fig. 72 a: O r i g i n of d i a g e n e t i c c a r b o n a t e o s c i l l a t i o n s similar to that presented in Fig. 66. P r o j e c t i o n of c u r v e s is o n t o the plane between the axes of carbonate content and compaction. MK=mechanical compaction, Kl=compaction at the onset of lithi~icatlon as c a l c u l a t e d in Fig. 60a, curves: theoretical relationship b e t w e e n c a r b o n a t e c o n t e n t and compaction after the compaction law c a l c u l a t e d for v a r i o u s porosities (n=0 to 70%). Example: S e d i m e n t w i t h 83~ CaCO3, a p r i m a r y p o r o s i t y of 70~, and with a normalized noncarbonate content of NCd=5%. b: D i a g r a m for the e s t i m a t i o n of the p r i m a r y c a r b o n a t e content (C o ) or p r i m a r y n o n c a r b o n a t e content (NCo), respectively, in f i n e - g r a i n e d , c a l c a r e o u s s e d i m e n t s w i t h s t a n d a r d i z e d noncarbonate fractions of NCd=I to 15~, and an assumed primary porosity of 80%. Kl=Compactlon at the onset of cementation, MK=area of mechanical compaction, Z = a r e a of cementation, -Z=area of chemical compaction. Example: Rock sample with a standardized noncarbonate fraction of 10% (arrows).
153
SEDIMENT
% NCo 100 O
% Co 100
50
MK
% 20 C 0 I'I P 60 A C T 6(] I 0 N 8(]
Z
-Z 10C 100 ® %NC ( x-axis primary content
to
the
regression
carbonate on the
upper
50
100
ROCK curve
content scale.
correlating and
then
%c >
mechanical reads
the
compaction
original
with
carbonate
B UR
I A L
D I A G EN
E L E M E N T S
carbonate
elements
VEIZER,
occur
BAKER e t
diagenetic
system
In this
carbonate
for
During closed
Reaction
Time
Carbonate
The
Ca
the
the
an
time
reaction
1979;
governing
these
is
supposed
the
t o be s t i l l
of minor elements
was of the
(GIESKES,
while
affected 100
to
carbonate
during 400m
was
s y s t e m was
and 3 . 6 ) .
of
Incongruent
Disintegration
were
residue
and time
lengths
Most o f t h e
considerably
(KINSMAN,
1982)
behavior
overburden
2.3.1
undergo
low o v e r b u r d e n
content
Problem
of
the
reaction
of
of
the
in
occurred
by
three
to
fraction,
individual
were
the
acid hours;
Therefore,
investigated same
solution thereafter,
first.
sample
for
(Fig.
73).
leaching
was l o w . However, acid
if
solution
different
acid
one gradually (during
enhances
disintegration
concentrations),
the
a
1975).
leaching
a 10% a c e t i c
and,
resldue-free
disproportionately.
dissolution
within
Mn,
diluted,
calcareous
determined time
from
(HERRMANN,
may d i s s o l v e
incongruent was
dilute acetic acid with
the amounts of Mg, Sr, Fe, determined
dissolution
of the
differing
are
processes
of diagenesis,
s o l u t i o n s u s i n g atomic a b s o r p t i o n
reaction
The
diagenetic
sections
Thereafter,
extent,
During
a n d Mn
fraction was d i s s o l v e d in warm,
a pH of 4 to 5.
components
Fe,
and minor
fraction
impoverished
element
stage
During
of t r a c e
carbonate
Fraction
carbonate
certain
late after
and
Mg,
become
1980).
minor
(see
the
and minor e l e m e n t s
the
this
concentrations
ELDERFIELD & G I E S K E S ,
redistribution
Dissolution
The
Na
major
section,
predominantly
I N OR THE
with a relatively
1982;
This
deposited.
IN
in
a rule,
and
partly
aI.,
discussed.
7.1
As Sr
1977; BRAND & VEIZER,
open. is
the
contained
whereas
fluctuations
1981;
are
changes.
enriched,
M
F R A C T I O N
dlagenesls
which
significant
OF
C O N T A I N E D
C A R B O N A T E
During
E S I S
concentration
of
the
evidence
of
same
of the
sample
incongruent
by
acetic using
dissolution
155
G2140 % IN SOLUTION .07 .06 .05 .0/.,
+
sr
+
....
• " ._.
.03 ;
1
zMn
FeCq,, 1000
.02
•
.01
"MgxlO
10 20
30
~0
50
60 70 HOURS
Fig. 73 Leaching of the noncarbonate residue from Gubbio 2 s a m p l e 40 (59% CaCO3). The s a m p l e c o n s i s t e d o f 100mg w h i c h was t h e n p l a c e d i n 5ml o f 10% a c e t i c a c i d s o l u t i o n .
G2157
G2140
% IN SOLUTION
% IN SOLUTION
o7E---_~__SZSZ,...~ ~ Fe.j~,l o , ] j ~ ~ " - ~ l
:1osJ__Mn.
% IN SOLUTION
o7t
"
• I
~l
o4~,/
o3~
• L
G2175
I .o~i,~.~
o)
•=^
~-;
1
J
+-Sr~l
I o3~f"c'a"1000 °I
.caca~1000 o]
11
I
MqxlOJ
02~-/--vv-~..~ :1 o2i/ 0 I0 2'0 30 ~
50
0
•° T.
' 100 " 200 " 300
I~
0
'.1
200 x10"3mo[
EH3EOOH F i g . 74 Incongruent mobilization o f Fe a f t e r d i s s o l u t i o n the easily soluble carbonate fraction. Samples 40, 57, 75 (200mg e a c h ) f r o m G u b b i o 2. appears acid
(Fig.
74).
concentrations),
to dissolution high
During
acid
increase dissolved
the
of the
easily
concentrations), is
more o r fraction.
less
the
early
element soluble Ca,
St,
proportional In
contrast,
phase
of
disintegration
concentration carbonate
quickly
phases.
Mg, a n d Mn i n c r e a s e to
their
the
of and
Fe
total content
(at
low
increase
After
slowly. amounts rises
due
that
(at Their
in
the
over-
156
Table 17: Ratio between the slope coefficient of the regression curve (describing the dissolution of the fraction of low solubility) and the mean minor element concentration Numbers contained in the carbonate fraction. are standardized o n t h e Ca v a l u e . Sample Total carbonate content (%) Ca Sr Mg Mn Fe proportionally.
The
75). is
is
soluble
hundred
was
this,
caused
in the
section
for
±100ppm;
and
the
in
which
the
total
so contact
the
increase
in
concentration
of
amount
the
of
in
of
the
each
residue
case first
and
dissolved
2 and
Neuffen
same acid
so Two
2 sections However,
sample
amount
in
substance of
solution.
determined
Fe
chosen
dissolved.
solution. of
the
of residue.
was
be
the
pure
96% i n
mobilization
amount
less
dissolved
94 to
would
10% a c e t i c
was
of
and
solution
acid
a certain
(E) is
carbonate-free
acid
Gubbio
acetic
5ml of
amount
phase
acetic
the
2 section that
the
portion
5~
soluble carbonate
incongruent
leaching of
of
with
easily types
soluble the
from
20ml
Angles
the
both
soluble
samples
residue For
this
b y NaOH t i t r a t i o n
2.1.1). measurements with
of
different
Ca ±4000ppm; for
the
same analytical
for
Mg, ± 1 0 0 p p m ;
~g, If
conditions~ for
St,
of
±10ppm;
Minor
the
Carbonate
Fraction
three
sections
(Gubblo
several
samples
standard
for
Mn, ± 1 0 p p m .
Concentrations
the
to
Ca v a l u e s ,
the
easily
with
disintegrations accuracy
by
the
concentration the
Numerous
In
17,
in
Despite
the
was
In
Table related of
that
easily
disintegrated
7.2
in is
the
99% i n
phase.
from
purpose, (see
shows
milligram
(50mg)
shown
to
leached
samples
is
solution
to
mainly
were
1 0.9 1.7 1.5 14.0
According
supposedly
that
1 1.7 2.4 3.5 15.1
composition
phases
98
Therefore,
1 1.8 1.8 2.8 10.8
the
relative
(Fig.
G2 7 5 65.37
elements.
(L)
CaC03 less
in
measured
soluble
G2 57 94.00
This
concentration the
G2 4 0 59.08
one the for
compares accuracy
Elements
2,
solutions)
±100ppm;
Fe,
Angles
(recording
for
furnished Sr,
±20ppm;
measurements is
improved:
±70ppm;
multiple
and
for
an
for
taken
Fe,
under
Ca ± 1 5 0 0 p p m ; Mn, ± 5 p p m .
Contained
2,
and
Neuffen
2)
in
which
157
[[I
•1]
~
[[[
[[[
_ III
~ Io.1% IO%[MgC03 [FeC03
II1
JMnCe3
L
C2140
L Ca Hg Sr Fe Hn
R ~ ~o~E Ca Hg Sr Fe Hn
C2175
L [o Hg Sr Fe Mn
F i g . 75 Proportions of t h e r e a d i l y s o l u b l e c a r b o n a t e fraction (E) to that of low s o l u b i l i t y (L), and the amount of r e s i d u e (R) in three s a m p l e s f r o m the Gubbio 2 section (left column, acetic acid solution). Relative composition of the easily soluble carbonate fraction (E) and that of low solubility (L, right).
minor elements were studied the carbonate fraction contains 0.3 to 1.5 weight exhibit to
both
% of m i n o r large
and t r a c e
fluctuations
paleogeographlc
diagenesis.
For
instance,
elements
(Fig.
76).
The three sections
in their minor element concentrations position the
and
the
foramlnlferal
manner
limestones
lO00m
comparatively
and very low Fe and Mg contents
also RENARD, Neuffen
1979).
(which w e r e
Mn contents,
ARTHUR,
due of
from Gubbio
(deposited in water approximately high
deep;
specific
1976)
display (see
On the other hand, the alternations of Angles and deposited
in relatively shallow water) have very
158
13UBBIO AN6LES NEUFFEN ETE[%].34
.37
.55 61
Mn
650
675
145
SF
~660 720
~900 895
~ 530 550
Fe
3,0
,700 woo
2350
M g
1740 1840
2700 3720
5900
4,0
.90 1./-..9
150
-
155 -
215
10770
Fig. 76 Mean amounts of minor elements (TE) which are contained within the carbonate fraction ( i n ppm o f t h e t o t a l carbonate content). Concentrations are given for limestone l a y e r s ( s h a d e d ) and m a r l b e d s ( h a t c h e d ) , respectively. high
Fe an d Mg c o n c e n t r a t i o n s . T h e mean a m o u n t s o f S r f r o m N e u f f e n ,
a n d 900ppm,
respectively)
for
pre-Tertiary
the
amount
content
of
Sr
(which
observations sediments from the
is
relatively
proportional
89.5,
84.8,
and
76.1%,
shown
that
high
clay
partially 3970;
high
hamper phases
an d A n g l e s
compared
(WEDEPOHL, 1 9 7 9 ) .
inversely
is
have
carbonate
WEDEPOHL,
are
limestones
Gubbio,
the
to
the
exchange
690, given
sections carbonate
respectively).
diagenetic 1974;
data
three
total
contents
(KNOBLAUCH, 1 9 6 3 ;
VEIZER & DEMOVIC,
to
In the
(540,
Various
in
calcareous
and r e m o v a l
of Sr
FLUGEL & WEDEPOHL,
1967;
KRANZ,
1976;
VEIZER, 1 9 7 7 ;
BAUSCH & POLL, 1 9 8 4 ) . The
concentrations
somewhat limestone in
the
Plotted
lesser layers;
marl
beds
against
concentration
of
degree, but of the
Mg,
are the
the
and
higher
also
of
in
the
a m o u n t o f Fe i s
three
total
of minor elements
Sr
either
investigated carbonate exhibits
and
marl
Mn, beds
although than
lowered
sections
in
to
a
the
or elevated (Fig.
content
(Figs.
77,
a fairly
wide scatter.
78),
76). the This
159
GUBBIO 2
Cn
!, Mg
18o0 o°o
I
•8".2200.
.
-200
7
Cn .
.
.
;18oo
. ,:
"..
. .~;~.
:1600 ,-:._,2
I'°"
°
-6
O~-0 ~'~
°oj:i oo
.1o--
-~oo
"'" °
.15-
IL
"°': ""
°'
Fe
°
.05 . . . . ~" 50 60
;~;~o
i0
•55o ~o 7'0 8o 9o lOO .17
80on cJ0
IooM
c
CD ,I S / -
1000
.15-
I
.16-
-750
C
° ol ° °°° trio7
.15"
o
8 0 ~ o ~ oo° , :~~ . ~,o._ _ -4 :° ~%~-~. .10- .600
.14" .6so
I
400
100
I
°
.13"
I
.05 ,=:~s
so ~0 7b 8'0 9'o I00C so 60 70 80 90 I00C
ANGLES
2
co
Mg
1.75.5ooo %o 15° -~ooo 1.25 3 0 ; 0 o " 1.00-
".~. °
°
°
°~ "
"201I0()0
I.-2 !. I?.-
.
.25| ~_~",
" %
75- 2000 r=-.83
cn
.~oi2ooo F e 35-I
,:°o;!] °°
°r =59
I
30 ~o sb 6"0 /o SOc9O 30 40 5"0 6"0 iO 80090 Cn
Cn
.165-
jI
Sc
.160"-950 155~ 900
]50
I
.035
~ .030 o
145
": °
850
r =.07
.
"
:l®
o
"~
"."
l
18o Mn 170 160 150 I~0
130
°:i .® -
. r :.25
o
. . .o.
i
o
o
:'~ I w.
"o
I
~°~o ~o so 6o io 8Oc9O°2S3o ~0 so 60 io 80C90 Fig. 77, 78 R e l a t i o n s h i p between minor e l e m e n t s (TE) w h i c h are c o n t a i n e d in the c a r b o n a t e f r a c t i o n a n d the c a r b o n a t e c o n t e n t of the rock (C). Vertical axis: c o n c e n t r a t i o n s of t h e m i n o r e l e m e n t s e x p r e s s e d as p e r c e n t a g e T E C O 3 of the total c a r b o n a t e fraction (numbers to the left) and e x p r e s s e d as p p m T E of the t o t a l c a r b o n a t e f r a c t i o n (numbers to the right). D a s h e d llne: c a r b o n a t e neutral value (Cn).
160
NEUFFEN 2 12 10. 8
°:° : : IMg
~30O~ \ -25000
~
o°
o
2oooo
6. t+.
1.0' .sooo
I--
I o /
, °o
o [Fe
I
.8 ooo
.6'
°i
°
2000
15000 ° ~ °o0' °°l' " "~.o °o 01 o -I0000 o0 ~ . o 04~0~;
2'
o
° :o
[:~1
lOOO ~-~...i
.2:
.1
~1
I
I,,
40 so 60 70 80 90 100c,
5ooo0 °0 :° . ° : ' ~
s'o 6o 7b oo 90 looC
.06--300
°
Mn
"° o
.101600
.o o
i~lc r
.o5-
°°:;I
i15o .o3-' 100~°-.57
o6J-L,oo •
17-I~,
o
-200
is
due
78
to
40).
trends
According
a nd t h e element poor
For explanation
analytical
concentration
are
as
curves
between
follows:
77.
to
studied
carbonate,
concentration
layers
and
the
to regression
amount o f t o t a l
°° ~
~o ~o 6o io 8o 90 16oC
see Fig.
errors within
°
.02"
~,0 50 6o 70 80 90 I00C Fig.
,
between
or (see
the
Fe,
23,
minor element
carbonate-rich
25000ppm;
decreasing
Figs.
maximum d i f f e r e n c e s the
Mg,
increasing sections
in
an d t h e
2500ppm;
34,
content
the
minor
carbonate-
Sr,
200ppm;
and Mn, 100ppm.
7.3
Interpretation
7.3.1
Minor
of
Minor
Mass Balance
Element
In m a r l - l i m e s t o n e alternations, to be distinguished. in t h e
dissolution minor
Behavior
Calculation
four d i f f e r e n t types of c a r b o n a t e have
These are d i s s o l v e d zones,
(P) in the c e m e n t a t i o n various
Element
(-Z) and relic c a r b o n a t e
and the c e m e n t e d
zones.
From
the
(R)
(Z) and p r i m a r y c a r b o n a t e
bulk
of
the
e l e m e n t s c o n t a i n e d in the total c a r b o n a t e fraction,
concentrations
the
161
minor element content in the four c a r b o n a t e types can be using
a mass
balance
calculation.
This
depends
on
evaluated the
by
following
preconditions: 1.
9..
One
has
to
for
a given
One
also
know
the
mass
proportions
of
the
four
carbonate
types
alternation.
has
to k n o w
the
minor
element
content of the "primary"
c a r b o n a t e in the c e m e n t a t i o n zones. The
quantities
of
and
proportions
between
the
c a r b o n a t e fractions can be d e t e r m i n e d by p e r f o r m i n g balance
calculation
(see
above-mentioned a carbonate
mass
s e c t i o n 9.3), or by u s i n g the cement number
(z, eq. 21) which is defined as the ratio between the absolute a m o u n t s of
cemented
section
5.3).
"primary"
For
element
carbonate
Additionally,
carbonate
evaluated. minor
(or d i s s o l v e d )
fraction
reasons
of
and
the
minor
within
the
"primary" element
was
not
content
cementation
simplification,
concentration
carbonate
it
is a s s u m e d
affected
by
element
to be
equivalent
(TEn).
The
that
its
dissolution
and
be
to t h e m i n o r
carbonate
stressed,
neutral
value
diagenetic trace
neutral
amount
not
the
element
content
that
usually
and
the m i n o r
cementation element
correspond
elements
in the
calculation
concentrations
of the neutral value
value r e p r e s e n t s the c a r b o n a t e content
dissolution
of m i n o r
balance
post-diagenetic
The
the
however,
does
element
carbonate
Therefore,
content of the "primary" c a r b o n a t e fraction is s u p p o s e d
at the b o u n d a r y b e t w e e n must
the
zone has to be
c e m e n t a t i o n p r o c e s s e s during c a r b o n a t e redistribution. minor
of
(see
It
of the
to the
original,
pre-
primary
sediment.
The
gives
of m i n o r
zones.
content
and
only trace
the
present,
elements
in the
fractions w i t h i n the e x i s t i n g rock. minor
element
content
of t h e
carbonate
cement
(TE z)
is a
function of the ratio between the absolute values of primary c a r b o n a t e and
cement
tration
(l/z,
eq.
21),
the measured
(TE, in ppm) and the m i n o r
carbonate,
which
is a s s u m e d
bulk
element
to be
trace
content
equivalent
element of the
to the
concen-
"primary"
trace
element
content of the c a r b o n a t e neutral value (TEn): 1 TEz[ ppm] = --(TE-TE n )+TE z Eq.
28 h a s
content
of
to be m a n i p u l a t e d the
dissolved
( 28 )
in order to d e t e r m i n e the minor element
carbonate
(TE- z) in the d i s s o l u t i o n zones.
The ratio between the p r i m a r y c a r b o n a t e content and the cement content
162
(l/z)
as u s e d
for
the
cementation
zones now c o r r e s p o n d s to the ratio
between the rellc c a r b o n a t e and the d i s s o l v e d c a r b o n a t e the cement number
(z) is n e g a t i v e in the d i s s o l u t i o n zones: 1 =(-- + I ) ( T E n - T E ) - T E n z
TE-z[ppm]
Using
eqs.
28
dissolved
and
and
(E/-Z=(1/~+I);
29,
the
cemented
minor
element
carbonate
(29)
concentrations
were
determined
of
before
the being
compared. A schematic the
Fe
regression Fig.
(z)
is
between
histograms
calculation
minor
the
and shows the
as
neutral
from
curve
77),
given
presentation
content
(see
value
calculated element
41c). is
for
the
of the
result
different in
28 and 29.
the
carbonate-bounded
Fe
They are
content
four
types.
carbonate
carbonate the
79 u s i n g
displays
carbonate
the Fe
in Fig.
figure
of
and the
mass the
For example,
balance
carbonate
cement
classes. carbonate
(from
number
Then, fractions
the Fe m a s s
the is
balance
a s s u m e s that the "original" c a r b o n a t e c o n t a i n e d 370ppm Fe
redistribution). carbonate
reprecipitated Thus,
given
(Fen=370ppm);
t h r o u g h o u t the c a r b o n a t e f r a c t i o n
of t h e
four
the
is The
form
First,
evaluated the
method
section.
CaCO 3 v e r s u s
concentration
d e t e r m i n e d by u s i n g eqs. calculation
total amounts
which
Fig. (C n )
of
Gubbio
However, contained in the
(prior
to t h e
onset
of
diagenetic
only 2 7 0 p p m Fe was d i s s o l v e d from a portion in
the m a r l
carbonate
layers;
cement
of
the
270ppm
Fe w a s
cementation
this
zones.
1 0 0 p p m Fe r e m a i n e d in the d i s s o l u t i o n zones and was i n c o r p o r a t e d
i n t o the relic c a r b o n a t e of those zones. the relic c a r b o n a t e
increased
from
370
Therefore, to 4 4 0 p p m
the Fe content in (according
to the
r a t i o of 0.71 between the amounts of the d i s s o l v e d and relic c a r b o n a t e in the d i s s o l u t i o n zones).
Fig. 79 S c h e m a t i c r e p r e s e n t a t i o n of a m i n o r e l e m e n t m a s s balance c a l c u l a t i o n u s i n g the Fe c o n c e n t r a t i o n f r o m the Gubbio 2 section. Above: regression curve of the Fe content versus t o t a l c a r b o n a t e c o n t e n t ( f r o m Fig. 77). Fen=Fe content of t h e c a r b o n a t e neutral value. Upper histogram: dissolved (circles), cemented (crosses), residual and "primary" c a r b o n a t e ( h a t c h e d ) for v a r i o u s l e v e l s of C a C O 3. C a l c u l a t l o n of the "cement number" (z). Lower histogram: c o m p u t e d Fe c o n t e n t a n d m e a n s f o r t h e d i s s o l v e d (-Z), c e m e n t e d (Z), r e s i d u a l (R), and "primary" (P) c a r b o n a t e fractions.
163
MINOR ELEMENT MASS BALANCE % FeCO3 ppm Fe .20 0_7 . .1580 J'~ .10
Fen 692
610
528
4.69 4,19 3 7 7 ~ 3/,1
311
6004.00
-05200~ oCO3
Z =
Zd/E 0 d ".81 .2.s .sl.,z3z3~.~z6( [ i t i i c I (.6 .'?9:77"75.72:69:65:61 "56-50:43"34:23:08.12 ~0.861.67225
i,
i
87480614.5692544510563528
-Z
-159/-,1.7 + 59 = -270 ppm
R
367.37.2 - 83= 4.4.3ppm
970
15928.8 +59 = +270 ppm
Z
42177.2 +114.= 370 ppm P
164
Results 1.
In
(Fig. spite
total
80): of
the
carbonate
element
to
in
the
the
carbonate. in
(Figs.
calculated
the
cement
the
marl well
the
of
marl
the
limestone
as
the
possibility,
the
layers
minor
amount
minor
the
elements
This
during
in
or
was
the
is
cemented from
the
redeposited late
system
does
early
elements
minor
released
during
a closed
and
essentially
content
Thus,
formed
element
calculated
be completely
elements. trace
minor
fraction
element
layers.
that
of
78),
seem to
layers
however,
total
77,
several
carbonate
minor
limestone
and
between
dissolved
Consequently,
carbonate
the
amounts
content
equivalent
as
low correlations
very
diagenesis, for
not
in
carbonate
exclude
late
affected
the
diagenesis
by
diagenetic
changes. 2.
In
the
residual
section)
carbonate
the
various
impoverished
to
carbonate
has
contrast to
to
the
the
of
1.1
to
and
are
just
slightly
the
marl
beds.
In
principle,
elements
in
particles, purpose, the
the
rock
to
this
section,
addition enriched
basic
the
particles
in marl
this or
bed
of
in
0.8
due
the
is
Fe
is 1.8,
in
the
sharp
compared
Mg i n c r e a s e s
three
to
or
cemented in
example,
cement,
diminished
Elements
For
any one
enriched the
which
the
fraction,
calculate
beds
are
if
the
one
enriched
equation
amount
the
Accordingly,
carbonate.
by a factor
Minor
can
marl
a certain of
In
the
(within are
in
sections
both
by a
considerably
whereas relic
Sr
a n d Mn
carbonate
in
to
Compaction
one the
which
existing
of
zones
elements
distribution
residual
enriched
Differential
trace
concentration
2.5.
of
dissolution
and
degrees.
the
enriched
Enrichment
the
element
carbonate
reduced
7.3.2
of
element
residual
factor
varying
a minor
that
minor
in
minor
of
degree
(~N).
by
of
section
primary
4.4.4
(N)
compaction amount
of
enrichment
those
elements
differential
particles
existing number
in
diagenetic
considers
of
particles
particles
of
(eq.
12),
has
in to (N)
be is
(N O ) a n d
For
which
a given
minor
insoluble
compaction.
contained (E),
as
this
relates volume
rewritten. expressed of
the
of In
as
number
the of
165
GUBBIO-2 [ = 76.7
89.5
ANGLES-2 [ = 63.4
M° Sr Fe Mn
1B&l 717 &~ 67&
83.9
M° 17~3 Sr 658 Fe 336 Mn 6~8
NEUFFEN-2 [ = 77 2
94.0
Mg 3722 Sr 895 Fe 1309 Mn I~.~,
Mg Sr Fe Mn
10767 551 337& 215
M 9 2708 Sr 900 Fe 1707 Mn 149
M° 589B Sr 52g Fe 2355 Hn 165
Fig. 80 Minor element mass balance calculation for the Gubbio, Angles, and Neuffen sections, respectively. Diagrams show the concentrations of minor elements (in ppm) which are removed from the carbonate in the dissolution zones (left side of the diagrams) and are reprecipitated in the cementation zones (right side). The diagrams also represent the amount of minor elements which are enriched in or depleted from the relic carbonate in the dissolution zones. Symbols are the same as in Fig. 79. C=mean post-diagenetic carbonate content of dissolution and cementation zones. Values below: mean post-diagenetic minor element concentrations (in ppm) measured in the carbonate fraction of both zones.
166
(3o)
N -- No+AN If
one
substitutes
(AN) t h e n
eq.
12
for
N,
the
increasing
amount
of
particles
becomes NoK AN = N-N o
Accordingly,
the
number
of
=
particles
(31)
IO0-K (N) within
a certain
rock
volume
is NoK (32)
N = No + 1 0 0 - K
On
the
following
pages,
enrichment
due
to
calculates
the
compactional
the
maximum enrichment
they
are
perfectly
elements the
are
total
sediment as
"100"
carbonate
or
the
compaction
cementation
minor
only
at
the as
into
minor
because
In
neutral
the
to this
value
not
of
32
Kn i s
minor within
particle which
is
amount
of
absolute
term,
that
32,
for
eq.
between
enrichment
eq.
and
in the
only
assuming
assumed
volume
which
First,
to
fraction
now equivalent
carbonate
elements.
was previously
particle
equation
described
carbonate
it
the
an
Contrary
initial
is
describes
is
(100-Kn-nd-NCd).
the
zones,
of
elements
the
percent
which
substances.
in
volume,
term
32,
transformed
enrichment
of
Therefore,
expressed of
is
insoluble
enriched
enrichment.
eq.
compaction,
the
degree
dissolution
minor
and
elements
expressed relative to the minor element content of that value. replaces
the
absolute
porosity
(n d) by eq.
15
(section
is
If one
5.3),
the
starting carbonate volume for the maximum enrichment of minor elements is given by: (100-Kn-NCd+n(0.01Kn-1))
Now, minor of 32)
eq.
elements
the
can and
correspond
to zone
carbonate
calculations
be
contained
existing
dissolution the
32
within
the
grain
to
the
original
value
deal
to
the
the
The
primary is
The
of
amounts
respectively,
element
concentration (which
enrichment
fraction.
(N a n d N o ,
minor
(TEn).
enrichment
with
carbonate
particles
measured
(TE- Z) and
neutral of
transformed
(33)
content of
minor volume
expressed
by
eq. of
elements used the
in
the at the
number
167
"100"
in
(K) i s
expressed
the
eq.
32)
compaction
enrichment value
at
is
by
neutral
Hence, as
maximum
term
amount occurs
the
the
33.
of
value
beds only
expressed
the
replaced
increasing
the
exceeded.
(TE_Zmax) of
be
in the marl
is
and
must as the
Moreover,
compaction
(K-Kn).
This
when c o m p a c t i o n
maximum m i n o r
addition
enriched
of the
compaction
relative is
at
initial
concentration
of
because
the
element
to
neutral
enrichment concentration
minor
elements
(TE-Zmax=TEn+ATEmax): TEn(K-K n ) TE-Zmax[ppm] = TE n +
In
naturally
enrichment minor
occurring
particle
are
not
enrichment
completeness
of
introduced, (ATE)
alternations,
of minor elements
elements
and
the
defined
however,
largely
In
maximum p o s s i b l e
ratio
the
is
of
the
studied
required
to
term
actual
minor
for
quantify
"closure"
between the
increase
compactional
since as
order
processes,
as the
the
incomplete, insoluble,
4.4.4).
enrichment
which is
compaction
is
completely
(section
the
(34)
100-NCd-K+n(0.01Kn-1)
the (X) i s
increase
elements
during
(aTEmax): 100aTE X[%]
-
(35)
aTEmax
For
example,
and
minor
increase causes X=0%, at
if
marl
elements would
equal
a complete
to eq.
the
35 t h e
the
actual
(aTEma
has
be
to
system the
hence chemical
initial
minor element
aTE=aTEmaxX/100. to
closed particles,
of minor elements.
expression x)
a completely insoluble
maximum i n c r e a s e ;
relative
X values
According
the
are like
enrichment
no e n r i c h m e n t
negative
layers
behave
In
substituted
(ATE) i s
equation, by
its in
compactional
within
addition increase
of
the
of minor elements
intitial
concentration
contrary,
equivalent
the
eq.
to the
maximum i n c r e a s e expression
34. the
at while
impoverished.
similar
(TEn(K-Kn))/(100-NCd-K+n(0.01Kn-1)) enrichment
is
actual
compaction
(TE n ) o c c u r s ,
concentration
increase this
On t h e
value
(X=100%)
Finally, marl
(TE n ) a n d
of
the
bed
is
the
the
actual
(ATE) : TEn(K-K n ) TE-Z[ppm]
= TE n +
0.01X 100-NCd-K+n(0.01Kn-l)
(36)
168
GUBBIO .8
Mg
2200
1.7 -2000
×=7ol "
~ :
Kn
2 Kn
•
.
.Is.
":". "'_I---_.-_.-_.-_.-_~-:~
.16oo
-
.
.
. ..
-.-- .'~
.10"
" 60 " 8o I~K
5r
800
.10
"*
i.
•
750
. •
-700
.
"" i •
,
0
,
,
,
.
20 40
"" -. ",.~."
I .
60
ANGLES
2
,
,
80 10OK
6 " 2b 4 0
Kn
3~3
I
.4. -2000
. ~ •
1.5-. 40OO 1.0. 3000
. ~
I
" "'-'.:':i-
.24 •1000F e
I 1
' 2"0 4'0
i •
.3
2000
6
~
-..
÷
.
' 60 " 8b ' 100K
Kn
Mg
2.0-
"~ix
.--I, .'/"
I .
oK
60Kn80
.13
I I
•
.5
40
.14
4.00
05
.15
X-~o.
" "
•'"
20
Mn
.16
.
OUV
~:-,-'v,~C~.
I •
I
100o
.-."
0
Kn .'15"
400
.05
I
O " zo 4b
,.z~"
,," .-
:.: ~ ¢ ~ :
.5" •1400
!x:38~l
600
""~
..6° "1800_:_t. ": ---'=~-~-~•
8OOFe
.
6 2o'go
"6'0 " 80 " look
x !I .'~1361 6'0 80 lOOK
Fig. 81, 82 Enrichment of minor elements, which are c o n t a i n e d w i t h i n the c a r b o n a t e fraction, via c o m p a c t i o n (K). V e r t i c a l axis: m i n o r e l e m e n t c o n c e n t r a t i o n (TE) e x p r e s s e d as p e r c e n t a g e TECO 3 of the total c a r b o n a t e fraction (numbers to the left), and as p p m TE of the total c a r b o n a t e f r a c t i o n ( n u m b e r s to the right)• Curves: t h e o r e t i c a l e n r i c h m e n t due to c o m p a c t i o n as c a l c u l a t e d by eq. 36 with values of c l o s u r e (X) Jn the s y s t e m of the d i s s o l u t i o n zones e q u i v a l e n t to the influx or outflux of minor elements as displayed in Table 18• Kn=compaction at the carbonate neutral value. The beds
is
element
amount
of
inclusion
determined mass
balance
by
using
of
the
eq.
calculation
various 35
and
(section
minor the
elements
results
7.3.1).
of
in the
the
marl minor
The determination
169
NEUFFEN
2
~ooooMg i~;
10.
1.4-7000Fe
25000
8
Kn 1.6"
1.2" 6000 1.0, 5000
20000
Q
°
isooo
8 ,,ooo
I )
4- 10000 . j~..., . i~2~_.~T.,'
I/
•/+
•
• I ..
.2 ,lOOb'."
I
4I
•
I ,
i
0 20 /.4 60 80 100
k;
0
~
•
20
1
i
40
60
I
.101
"
•
~oo,~
05 shows each
18)
the
PINGITORE minor
the
marl
The from
x-98
In
beds
is
Table
of
and
the
is
show
carbonate
neutral increases about
a n d Mn i n
a
the as
value. from described
For 5000
eq.
as to
% MgCO 3 o r
of
trace
to
element of
in
30,000ppm about
Neuffen
(with
22 weight
dolomitization
element
content
the
and
carbonate that
section
90~ compaction); % dolomite. of
the
curves to
of
closure
between
in
relative
the
of
calculated
content
times
fraction
amount
minor
Both
element six
carbonate the
correspondence
82).
example,
burial
the
36 a n d
correlating
minor
much
for
According
38%.
clear
and
different
minimum and maximum closure
Fe,
by using
81
that
10 weight
already
the
Sr, is
is
section.
phenomenon
to
measurements
enhanced
a single
-14
Mg,
(Figs.
impoverishment
typical
sections,
.......... 0 20 ~0 60 8o#00
from
There
compaction
or within
a
calculated
18.
data
authors
three
enrichment
fraction content
enrichment
varies
"t .M~..'."
.02-1-100" ". . . . . .o2
elements
the
.
04}200. ,. ~
"
is
-~
,
. V ~1"
ll"
.... 00, 60 80100 K
this
elements
measured
equals
I
that
(1982),
calculations with
•
various
diagenesis. the
eea
I
~ 0 20,0
(Table of
:04
soo_:~:..._.-_. • I
w
r~
o8.1-~oo Mn
.10
i
80/100
Kn
Kn
15
,
i
stylolittc
at the
the Mg this
Several seams
170
Table 18: Mean a m o u n t s o f c l o s u r e i n t h e s y s t e m ( i n p e r c e n t ) for the different minor elements contained in the carbonate fraction of the dissolution zones. Section
Gubbio 2
Ratio between the amounts of dissolved ( - Z ) an d r e l i c carbonate (R)
Neuffen
0.71
Mg Sr Fe Mn
and w a v y
pressure
MATTES
0.81
30.8 1.5 14.5 9.8
dissolution
& MOUNTJOY,
Angels 2
1.26
7.0 10.5 38.1 5.1
1979;
2
seams
33.3 -0.5 -13.6 -2.5
(BERGER
1980; J~RGENSEN,
& RAD,
1983).
1972;
WANLESS,
In principle,
there
are two possibilities to explain this phenomenon. 1.
Accumulation
of pre-existing
dissolution
dolomite
crystals
o f CaCO 3 (BERGER & RAD, 1 9 7 2 ;
by t h e
preferential
MATTES & MOUNTJOY, 1 9 8 0 ;
J~RGENSEN, 1 9 8 3 ) . 2.
New
formation
1980).
of d o l o m i t e
For instance,
could
increase
the M g / C a
beds which favors 1975).
(WANLESS,
1979;
the p r e d o m i n a n t ratio
MATTES
& MOUNTJOY,
of M g - c a l c i t e
in the pore solution of the marl
dolomitization
Moreover,
MATTES
dissolution
(LIPPMANN,
&
MOUNTJOY
1973; (1980)
F O L K & LAND, explain
dolomitization of pressure dissolution seams as Ca/Mg
the
exchange
at
the strained surface of the calcite crystals. Unlike exhibits
the
behavior
enrichment
or
results
from the
presumably processes.
If
sulfate
c o n s u m e d by s u l f i d e Then,
after
increases
1980;
begins extend
carbonate relatively mechanical cementation
is
pore
or
The
closely
several
cements
of
and if,
as
set
in;
thus
leaves is
content,
of sulfate
in
the the
sulfate,
the
usually
pore
which sections,
reduction water,
carbonate
Fe i s
system.
F e 2+ c o n t e n t the
case,
again
reducing
(FOCHTBAUER & MOLLER, 1 9 7 7 ;
CURTIS, 1 9 7 7 ;
zone
which
of
below
sulfate
the
meters
and
reduction,
sediment-water downward
Gubbio
l o w Fe c o n c e n t r a t i o n s . compaction
Fe
cement of various
present
of
100 the
the
the
or existence
already
waters
1984).
few to
in
absence
maintained
within a
elements,
depletion
consumption
the
are
other
precipitation
the in
conditions BERNER,
of
and
low
Neuffen
overburden
cementation
interface,
(GIESKES,
The l i m e s t o n e s presumably
often
sections had (80
may
1981).
display
relatively and
The low
140m)
occurred
when
during
171
sulfate
reduction.
cementation
On
began
reduction
was
with
the
other
a higher
supposedly
hand,
in
overburden
completed
since
the
Angles
(170m),
the
section
and
cements
are
sulfate
enriched
in
Fe.
7.3.3
Composition
The
of
concentration
carbonate enables
of
(e.g., one to
different
(pore)
of The
a minor
and
the
elements
in
cemented
carbonate;
composition
sedimentary
and
relative
the
of the
calcium
the
precipitating
composition
(mol
types
section
pore waters
TE/mol
Ca)
for
between
calcite
of the
of
7.3.1)
using distribution cc KTE d e f i n e s the molar
coefficient
and
various
ancient
overburden
distribution
(s)
the
Solution
minor
element
solution
Accordingly,
the
estimate
values
for
Pore
"primary"
coefficients. ratio
the
pore
phase
solution
the (cc).
is:
molTEcc/molCacc molTEs/molCa s =
The
distribution
determined
coefficient
experimentally,
New d e t e r m i n a t i o n s from 0.035 BAKER e t
to
1980).
In
1982)
this
three 1.
Early
(eq.
Stage: by of
"primary"
the
concentration one value
is
must
in
the
assume
was
assumptions,
in
that
If
no
to
to the
the
and
of
using
Sr/Ca
(Table
the
content
19): Sr/Ca)
is
neutral
minor element that
of
the
element
occurred,
diagenetic
cementation.
in
following
minor
fraction early
ratios
the
(Mg/Ca,
to
of
MUCCI &
carbonate the
surrounding
may n o t b e v a l i d .
1980;
values
molar for
ratio
of
element the
S r a n d Mg v a r y
Mg (BRAND & VEIZER,
7.3.1),
carbonate
onset
with
for
of the
alteration
minor
for
BRAND & V E I Z E R ,
equivalent
a relatively
usually
(MICHARD, 1 9 7 1 ;
molar
is
is
uncertainties.
calculated
(section
"primary"
which
made
content
value
Mn,
diagenesis
pore water
discussed
equilibrium however,
Mg/Ca
element
corresponds
equivalent
were k~=0.02
tentatively
neutral
carbonate.
concentration
an d 0 . 0 6
and the
and
considerable 1972;
increasing
minor
As p r e v i o u s l y
content
which
of
The h i g h e s t the
0.02
1982) is
Fe
coefficient
al.,
calculations
al.,
which represent
described value.
distribution
and b e t w e e n
37)
for displays
(KATZ e t
An e s t i m a t i o n
water
stages
Sr
study,
MORSE, 1 9 8 3 ) . pore
for
(BAKER e t
kSr_0.035cc_ the
of the
0.05
al.,
still
(37)
cc kTE
its stage
Additionally, of
the
neutral
pore water.
Both
172
2.
Intermediate Stage: using
The pore water element ratios were calculated
the a v e r a g e m i n o r
element
c o n t e n t of the carbonate cement
precipitated in the cementation zones.
The minor e l e m e n t
was
mass
obtained
from
the m i n o r
element
balance
content
calculatlon
(section 7.3.1). 3.
Late
Stage:
the
carbonate
layers; in
This
this
stage
carbonate
the
limestone
Table 19: carbonate calculated
Trace fraction by using
Ca **) Mg Sr Fe Mn
i
during was
the the
minor
element
greatest
subsequently
composition
compaction
in
reprecipitated
the
as
in marl
cement
layers.
and minor elements (in ppm) and the relative composition eq. 37.
Gubbio Stages of diagenesis*)
describes
released
2
Neuffen
2
3
1
contained in the of the pore fluid
2
Angles
2
3
1
2
2
396645 1779 681 370 658
396947 1673 613 270 628
396905 1696 639 253 635
388157 6880 535 2665 178
392325 4365 518 1853 193
393309 3407 528 2296 162
394276 394842 3028 2210 898 904 1475 2156 147 152
395410 Z162 900 1557 149
0.37
0.35
0.35
1.46
0.92
0.71
0.63
0.48
0.45
2.24
2.02
2.10
1.80
1.73
1.75
2.98
3.13
2.97
mol Mg s mol Ca s mol Sr s mol C a s x
10 -2
* ) s t a g e s of d i a g e n e s l s 1 to 3 c o r r e s p o n d late diagenetlc stage, respectlvely. **)calculated. The
calculated
to an early, medium, and
c o m p o s i t i o n of the pore solution (Fig. 83b) shows
only a moderate correlation with the actual curves of M g / C a molar
ratios
(Fig.
83a),
which
carbonates (NEUGEBAUER, 1974; 1981;
BAKER
et al.,
1982)
are k n o w n
f r o m b o t h marine, pelaglc
SALES & MANHEIM,
and
1975;
formation waters
(ENGELHARD, 1972).
This indicates that the m o l a r
pore
result
water
which
conditions found d u r i n g
the
and
GIESKES,
1975;
in calcareous rocks proportions
calculations
late diagenesls
thicknesses of overburden. in s i m u l a t i o n m o d e l s
from
and S r / C a
mostly
of the
represent
in s e c t i o n s w i t h
large
Therefore, as has already been establlshed
(section
5.2.2),
the
formation
of d i a g e n e t l c
bedding occurs malnly during the late stages of diagenesis.
173
mMglmEo 0 o 123/+56
[mSrlmEa]xlO
0123~567 ,~
Y
500,
1000 ._.~m 0', , , , , , I
-2
a
l
i
I
=
I
i
I
J
a
a
•
J
|
.~
f
,|1
I
3
®
P2
~, ~3
F i g . 83 a: Molar proportions (Mg/Ca; Sr/Ca) of the pore water during increasing overburden of carbonates from the Deep Sea Drilling Project. D a t a f r o m NEUGEBAUER, 1 9 7 4 ; SALES & MANHEIM, 1 9 7 5 ; G I E S K E S , 1 9 7 5 ; 1 9 8 1 ; a n d BAKER e t al., 1982. b: Calculated relative composition of the ancient pore water in the Gubbio 2 (I), Neuffen 2 (4), a n d A n g l e s 2 (@) sections, respectively. The increased overburden in the diagenetic s t a g e s (1 t o 3) i s n o t s h o w n t o s c a l e . Primary molar proportions o f t h e s e a w a t e r i s M g / C a = 5 . 2 , an d S r / C a = 0 . 8 6 x 1 0 - z (KINSMAN, 1 9 6 9 ) .
7.4
Conclusions
The processes primary
of diagenetic
carbonate
concentration of
marl
of
and
calculations cemented
and is
elements chemical were
layers. is
this
in the relic the the
various
to
closed
Mg a n d marl
layers
pore water
bedding
the
composition
forms mainly
during
mass
balance
of the
dtagenetic
other zones)
from the
cementation provides
of
in
(dissolution
late
in
especially several
released
of
fractions
concentrations
important of
amplitude
differences
element
fractions, that
the
carbonate
different
The m i n o r e l e m e n t s in
only cause
in the
minor
the
The most of
not also
contained
reprecipitated
relative
they
carbonate
carbonate.
partly
increase
As
due
enrichment
compaction.
diagenetic
elements
show,
completely
calculated that
in
minor
but
limestone
minor elements processes
bedding
oscillations,
marl zones.
further
dlagenesis.
the
minor due t o layers The
evidence
P R I M A R Y
D E P O S I T I O N
L I M E S T O N E FROM
J U R A S S I C ,
In
lithified
to
infer
that
often
the
sediment
Fig.
The well-bedded,
Germany
provide
alternations evidenced
development
a
striking
were by t h e i r
thought
WEILER, 1 9 5 7 ;
KOHLER,
GWINNER, 1 9 7 6 ;
However,
new
results
stratification
was
description
of
therefore,
this
84a)
were
stretched north. but and,
the
presently towards
northwestern
Fig.
on
the
to west
facies
zone
mostly the
eroded basin,
outcrop
area
some
history only
1982;
to the
probably
the
primary
by RICKEN ( 1 9 8 5 a ) ;
overview. of
alternations the
Tethys
a major
facies
ancient
shoreline
reef
belt
(Fig. Ocean.
zone which in
of
Alb,
the
the
an e x t e n d e d ,
(GWINNER,
alternations.
Swabian
1982).
A detailed
marl-limestone the
(e.g.,
EINSELE,
composed of both
algae-sponge
as
FREYBERG, 1 9 6 6 ; of
given
shelf to
The
cycles,
events.
a short
belonged parallel
in southern
rhythmicity
portions is
to (see
problems.
marl-limestone
northern
was
al.,
due
seams
climatic
GYGI, 1 9 6 6 ;
depositional
Kimmeridgian
alternations
from east This
presents
and
deposited
Presumably,
that
depositional
section
The Oxfordian
by
these by
Second,
destroyed
enhanced
BAUSCH e t
show
caused
the
of
HILLER, 1 9 6 4 ;
diagenesis
limestones
generated
diagenetically
SEIBOLD, 1 9 5 2 ; 1971;
be
of
possible bedding
4.5).
dissolution
Jurassic
mode not
because
section
mostly
example to
present,
are
is
rhythmic
cyclic (see
of diagenetic Upper
it
present
actually
structures
an d t h e
original
First,
of
rhythmicity
bioturbation 30H).
existence
was
the
depositional
the
to determine.
from the
enhances
G E R M A N Y
alternations,
difficult
primary
considerably
U P P E R
S O U T H E R N
conclusively
primary
THE
marl-limestone is
M A R L -
A L T E R N A T I O N S :
E X A M P L E
deposition
OF
1976) In
alternations
84 a: Outcrop of the Oxfordian and K t m m e r t d g i a n i n the Swabian Alb (southern Germany) with the locations of measured sections shown i n F i g . 8 5 . Current roses: bipolar measurements of belemnite shells (white) and foreset orientation of ripple laminations in turbidite to tempestite sequences (black). I n s e t map s h o w s t h e p a l e o g e o g r a p h y and the supposed flow regime. b: Cross section through the Swabian Alb (parallel to strike). Crosshatched: biostrome complexes,stippled: marl-limestone alternations i n b i o s t r o m e t a l u s and e r o s i o n faces, shaded: micritic marl-limestone alternations.
the
175
marl-limestone alternation algae-sponge bioherms
n46 U. OX. n 223 U.OX. LKI.
n 72 U.OX.
t
A
U U.OX.n36 n "/k M.OX.
n 50
U.0X
o,~ NEUFF/EIV
n 146 M.OX.
o.ox.
ISIN
20 km
,
I 100k~ ~ ,
SW
50 m
,
-[
.
e
6e~,.~,
y
. - - - -
b
Y
NE GEISINGEN LOCHEN BASIN SWELL
®
j
BASIN
.
®
RIES IMPACT CRATER
9 3X. L.KI.
,50 km
NEUFFEN BASIN
FRANCONIAN PLATFORM
176
interfinger
with
higher
the
than
striking
algae-sponge adjacent
reef-swell
reefs w h i c h
sea-floor
(Lochen
(Fig.
Swell)
divided
(i.e., Geisingen and Neuffen Basin).
at least
30 to 50m
A prominent,
the
N-S
sea into two basins
Since m a j o r
in the basins were in an N-S direction indicators,
were 84b).
facies
differences
(see the orientation of current
Fig. 84a), the alternations
look very monotonous
along the
NE-SW striking outcrop of the Swabian Alb. During
transgressive
movements
of the total
phases South
(caused
German
by e u s t a s y
Platform),
calcareous turbidites to tempestites and h e m i p e l a g l c deposited. decreased basins
However, (EINSELE,
of
the
boundaries
d u r i n g regressive phases,
fine-grained,
carbonates
Alb.
Regressive
the M i d d l e
and U p p e r
were
the carbonate content
1985) and bloclastic detritus was s p r e a d
Swabian
between
or by t e c t o n i c
very
phases
over
occurred
Oxfordian
the
at the
and b e t w e e n
the
Upper Oxfordian and Kimmeridgian.
8.1 In
The Bedding outcrops,
the b e d d i n g
diagenetic bedding: alternate
with
exhibits
typical
characteristics
of
Equally thick limestone layers (15 to 30cm thick)
differently
thick marl beds.
content ranges from 75 to 80% Lower Kimmeridgian),
the
(i.e.,
Lower
When the mean carbonate
and M i d d l e
Oxfordian
and
the marl beds are 0.1 to 5m thick (see Fig. 36A).
Only when the average carbonate content is high (approximately 90%) do brlck-like
alternations
only
marl
small
by-bed
joints
correlation
appear. (Upper
between
Then,
the marl beds are reduced to
Oxfordian,
the v a r i o u s
see Fig. larger
36B).
The bed-
outcrops
along
the
Swabian Alb (Fig. 86) provides the following results: 1.
The U p p e r
Oxfordian
limestones
(composed
of
the marl-limestone
alternation Type III) show a clear relationship between thickness 85).
of the s e c t i o n
The number of bedding planes
constantly
with
the total
and the n u m b e r of bedding planes
increasing
(or limestone layers)
thickness
base and the top of the Upper Oxfordlan
of the total section. alternation
(Fig.
increases
are
The
actually
isochronous boundaries because near the boundaries contemporaneous event layers can be traced (Fig.
86).
Therefore,
laterally
new
same thickness are inserted w h e n Thus,
the U p p e r
Oxfordian
throughout
limestone the
the S w a b l a n
Alb
layers of more or less the
total
marl-limestone
thickness
increases.
alternation is regarded
177
predominantly 2.
The
two
as a non-cyclic
basins
of
rhythmicities,
and the are
also
Every basin
shows i t s
According
to the
be traced
for
sequences
own b e d d i n g
in
distances. the
tens
more
constant
areas.
Marl-rich
bedding
can
traced
be
is
Alb
display
have
both
10 t o
of
100km
thickness.
of the
distinct, Basin,
individual to
Alb.
regressive
phases,
originally
the
layers
other
the
in channel
by l a g
base
pinch
hand,
except
caused at
beds can
tempestite
individual On t h e
(especially
Similar
Franconian
turbidite
kilometers. in
facies
(FREYBERG, 1 9 6 6 ) .
In the
planes
bedding
parallel
layer
rhythm
Geisingen
distinct
a
subbasins
mode o f d e p o s i t i o n ,
a few to
bedding
found in the
varying
found
after
they
same mean l i m e s t o n e
conditions
out
Swablan
although
development
3.
the
alternation.
deposits
of the
Upper
Oxfordian).
Thickness[m]
100 1
80' ~
40'
f
Xf
•
~'~"
20
0
~?'
~AN .--~/~
Number 200 250 300 350 .ooOr aeaa,ng planes J~
so
L
J J ~
__
Fig. 85 Thickness of the Upper Oxfordian marl-limestone alternation and number of bedding planes. Swabian Alb, southern Germany. Major bedding plans (x), major and minor bedding planes (o). Bordered data points: number of bedding planes is interpolated by s t u d y i n g a p p r o x i m a t e l y o n e half of the total section and using the entire strata thickness f r o m ZIEGLER, 1 9 7 7 . At pinch Mass
the out
as
Oxfordian-Kimmeridgian towards
a result
the
Franconian
of
erosion
boundary, Platform
the
and
(FREYBERG, 1 9 6 6 ) .
the
layers
systematically
Middle On t h e
German
other
Land
hand,
in
178
TURBIDI -TEMPE
NORMAL ALTERNATION /
GRADING
LAG DE
ox./ki,
o"
s
\WHITE: POST EVENT \ TRACES, BLACK: INF1LLED BY LAG DETRITUS
BIOSTR[ DETRITI
~
:csl
!
Ul
- - PLANOLITES j [HONDRITES
RELATIV AMOUNT BIOCLA.~ DETRITI,
A Be Br C
BIOSTROME 7.1km
2.5
.
klTI
= = = =
ammonites belemnites brachiopods crinoid fragments S = sponges TI, 2 = s u b m a r i n e fan deposit Roses: orientation of belemnite guards (white) and ripples in turbidites to mbers ,asure-
C (Br~S: ::!i S~ [~ [ [
U.lff
179
Fig. 86 Bed by bed correlation and sedimentological observations in sections from the Swabian Alb, southern Germany. For location of sections see Fig. 84a.
_~
.~
.8 km
ki. ~,
~
ox
'~
~m ~1.~m
6.6kin
13.6 km
• ~
__Bei 6.2 km ~ ~J
~
II I1-10m
@~
I
L
: ~~
i
: ...... -
,
5m u./m.
180
U. OX, m.ox.
7.I km
2.Skm
9.8km
13.6km
A, Be.~
C
C Q
C O
QO
the
Lower
remains
and M i d d l e constant
for
0xfordian more
in the
than
Neuffen
150km.
The
Basin layers
the can
through the Neuffen Basin over the Ries M e t e o r i t e C r a t e r (SCHMIDT-KALER,
1962).
traced
to F r a n c o n i a
The cause of this p h e n o m e n o n remains unclear,
because there is little e v i d e n c e i n d i c a t i n g the nature of d e p o s i t i o n a l mode.
bedding be
the
primary
181
31.8km
18.8km
6.6km
6.2km J ~
:i~iii::¸i:i~
i
8.2 Relic
Processes
of
sedimentary
percent
of
the
identification
Deposition structures present
sequence.
However,
they
of three major types of event deposition:
lags, submarine c h a n n e l s turbidites.
in the alternations comprise only a few
Due
and
fans,
to the p r e s e n c e
and
fine-grained
of two
allow
the
sedimentary
tempestites
to
transgresslve-regresslve
182
cycles
in the M i d d l e
alternations
and U p p e r
Oxfordian
(at the boundary between the M i d d l e the Oxfordian and Kimmeridgian, structures
sequence,
the
micritic
have two horizons of bioclastic channel and lag deposits and U p p e r
Oxfordian
see Fig. 84b).
(Fig. 85) suggests that event d e p o s i t i o n
in the o r i g i n a l
sediment.
and b e t w e e n
The existence of relic was
quite
common
The deposition of pelagic and hemipelagic
carbonates remains unclear.
8.2.1
Lag Deposits
Bioclastic
marl
laterally
into
intraclasts, is
into
parautochthonal
belemnites.
to
dissolution.
One for
the
dilution
in the
1.3
clay can
use
of
dilution
would
and 1 . 4
be
for
and
zones 2.0
average
about
(see
for
content 3.4) of
primary one
clay
uses
higher
than
14),
factor
of
Middle
the and
Upper
to
sediment
two t i m e s
Fig.
the
carbonate
section
If
of
caused
factor
beds of the
(Upper Oxfordian).
which are
both
1.7
The
of
phases
carbonate (see
(Fig.
which
of diagenetic
zones
poor
sediment
fragment~
short
basin,
pass
consists
stem
during the
primary
dilution.
lag
lags
crinoid
sites
mean
carbonate
variations
values
preferred the
clay
relatively
maximum c a r b o n a t e
articulated into
they
detritus,
by b i o t u r b a t i o n
bioclastic
and c e m e n t a t i o n
(Middle Oxfordian)
mean p r i m a r y
the
since
erosional
some o f t h i s
Apparently,
dissolution
amount
deposits,
layers the
was t r a n s p o r t e d
become one of
estimate
limestone e.g.,
and
lag
contain
Usually,
assemblages,
the
is
87).
channels,
erosion,
calculated
(Fig.
as
often
in submarine
submarine lags
and
the underlying
Except
ammonites,
interpreted
fills
and s h e l l s
brought
88A,B).
beds are
channel
the the clay
Oxfordian,
respectively.
8.2.2
Shelf
Channel
Most o f t h e
eroded
the
the
south;
deeper which
shelf were
and
sediment
sediment
the lO's
Fan
eroded of
was t r a n s p o r t e d
was thereby material
km w i d e
channels
vertical
dimension;
(Fig.
90).
The c h a n n e l
shift
Large fill
thereby
consists
89).
causing
channels
remained
submarine into
redeposited
o f 50m.
relatively
in
brought
was
(Fig.
5m d e e p a n d h a d a maximum w i d t h outcrop,
Systems
slightly
in the
active
for
crinoid
is
point
fans
w e r e up t o
unknown.
lateral
several
to
On t h e
submarine
channels
length
prograding
of ammonites,
in
The s h e l f Their
channels
suspension.
bar
In
and i n t h e structures
million
years.
stem fragments,
partly
183
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i E o
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~
i.~
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D..
oo
184
5cm
5cm
32 km II
5 cm
.... II
185
$£
F i g . 89 Sedimentation processes during regressive phases. The s t o r m w a v e b a s e (SWB) t o u c h e s bottom, thereby causing lag deposits (LD) on the reef swells and in the basin. Suspension clouds (SC) of fine-grained material are transported in presumably sinusoidal channels below the storm wave base. The eroded sediment is redeposited in submarine fans.
~Flg, 88 Petrographic pattern of erosional lags, channel fills, and calclluttte layers in submarine fans. Upper Jurassic, southern Germany. A: Erosion typically o c c u r s i n t h e m a r l b e d an d a t t h e t o p of the underlaying limestone layer. Detritus is brought into the limestone layer via bioturbation. Neuffen Quarry, Middle Oxfordian. B: Section f r o m F i g . 88A s h o w s i r r e g u l a r marl intraclasts and f o s s i l remains (e.g., broken belemnttes). C: channel fill consisting of crinoid fragments (often articulated). Arrows indicate sponge fragments. Neuffen Quarry, Upper Oxfordlan. D-G: Graded lutite bed with Bouma-Piper intervals D t o E2 (see Figs. 8 5 , 91 f o r T 1 ) . The b e d b e l o n g s t o a s u b m a r i n e fan and can be traced f o r 32km. Post-event bioturbation o c c u r s i n two p h a s e s ( T h a l a s s t n o l d e s f o l l o w e d by C h o n d r i t e s ; D,E). Weak g r a d i n g a n d t h i c k e n i n g o f t h e bed i n t h e c h a n n e l areas (E); lnterchannel deposits are characterized by grading, lamination, and mtcrochannellng (F,G). Neuffen Quarry (E,F); Hausen Landslide (D,G). Lowermost Kimmerldgian.
186
broken
(!)
88C).
Most
belemnite
breccias"
which
Germany In event
are
the
Neuffen
layers
can
parallel
to
carried sediment showing
with
be a portion T1)
in
the in
channels
a submarine
can
was
during
be traced
form
in
within
southern
much of
the
composed T2)
these
and
are
over
The
calcilutites
These
lutite
Basin
lag was
clouds.
E 2.
beds
are
interpreted
layers
(Figs.
a distance
30km (RICKEN, 1985a).
NE
the
channel
sediment
of
of
always in
little
eroded
suspension
Neuffen
channels beds
of
and
areas
marl
beds
T1 and
erosional
erosion,
the
One of the
in
into
the
slight,
El,
91,
fan.
(Fig.
"ammonite
distinct
channels
intense
D, (Fig.
Jurassic
"normal"
Thus,
graded
intervals,
the of
or
channels.
redeposited
Bouma-Piper
91,
the
presumably
was
associated
whereas
in
Upper
the
events
erosion
fragments
so-called
3.4.1),
from
deposits
sponge the
1966).
section
Erosive lag
When
left
away
(see
91).
remained;
was
the
FREYBERG,
laterally
marly
to
throughout
Quarry
(Fig.
occasional
equivalent
1962;
alternation.
sediment
material
88E,F,G;
found
either
and
are
be traced
bedding
correspond
to
fills
(SCHMIDT-KALER,
parallel
lag
guards,
channel
SW
m
lOm Fig. 90 Lower part of a 35m thick channel system which existed for several million years at the OxfordianKimmeridgian boundary. Limestone layers are shown in black, while marl beds are presented in white. During deposition channel shifting occurs in the lateral and vertical direction. Individual stages of shifting are marked with white circles. Lateral shifting t o t h e NE c a u s e s presumably oversteepening of the northeastern channel wall and slumping. Note that erosion occurred predominantly in the marl layers (see Figs. 36E and 91). Neuffen Quarry, southern Germany.
of
187
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I
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I
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(',,I
7
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,
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2 (D
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o
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0
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%
C
o
E
-6
%
7-
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o
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5 o
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,~.o
o_,,,-._
~:
o
I
!
o
A
E ~,, .'.:
~
=~
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~ o ~ . ~ o~ "-" ~ co --,I"
188
8.2.3
Graded
Particularly
Calcilutites in
the
Lochen Reef Swell, which
are
especially 92),
and
turbidite partly
not are
clearly
near
an d t e m p e s t i t e . lutite
amounts of clastic
the
as
with base
being
They
and at
contain
associated
interpreted
---. t g " . ~
Basin
alternations
recognizable
laminated
of minor
Geisingen
the
of
the
submarine
consist
silicates.
channels.
in the
The
of the beds
They a r e
cycles spectrum
predominantly carbonates
slope
calcllutite
transgressive
somewhere
and silt-sized
western
graded
of
(Fig. between
graded
(reef-derived)
turbidite
to
and and
tempestite
DIRECTION OF THE DIP OF LOW_._AND H(6H....
I~::t NL~F, R TALU%,,MAINLY M. OXE DIP, PREDOMINANTLYPALEORELIEF
Fig. 92 Upper Oxfordian marl-limestone alternation fills the interreef areas (hatched) of predominantly Middle Oxfordian algae-sponge biostromes (shaded). During deposition of the alternation, the differences in relief between reef and interreef areas became successively diminished. Arrows: direction of low and high angle lamination in some calcilutites in the Oxfordian marl-limestone alternation. Western slope of the Lochen Swell, Plettenberg Quarry, southern Germany.
189
beds
represent
BOUMA-PIPER intervals B to E 3.
Proximal types consist
of equal intervals where rippled calcareous silt is overlain by graded and l a m i n a t e d
calcilutite
(Fig.
93A).
Distal
composed entirely of graded calcilutite w h i c h lamination.
The
deposition
types,
often
however,
lack
of those beds from suspension clouds can
be supposed from post-event b i o t u r b a t l o n
(Fig.
93D).
Several
beds
layer
(Fig.
93A,B,C).
usually
form
are
significant
a single
limestone
original CaCO 3 content was largely redistributed
event The
(see Fig. 53).
Sites
of preferential diagenetic carbonate dissolution were the base and the top of the turbidite to tempestite beds. In the Middle and Upper Oxfordian, structures are fairly frequent
of graded layers was much g r e a t e r calcilutite distal
sedimentation
lutite Later,
modes
sediment
to t e m p e s t i t e
than
it is now.
The
dominance
of
but
beds
(PIPER,
even w h e n
diagenetic
resulted
there
the
delicate
1978;
ARTHUR
was
from
a lack
of
little
sedimentary & KELTS,
structures
1981)
bioturbation
were
(Fig.
in
easily
93E,F,G).
marl seam formation and oxidation of iron compounds
during weathering,
largely
thus,
limestones
most
instead
because algae and sponges were the main reef
After deposition,
event
destroyed
turbidite
deposition during the events was presumably not caused by
coarse-grained builders.
relic
(see Fig. 85), thus the original number
of the
The origin of the g r a d e d
obliterates
the b l o t u r b a t i o n
now a p p e a r
calcilutite
structure;
to be totally homogeneous.
beds
can be e x p l a i n e d
by both
facies
the
lag
of
the
erosion during storms and slope instability: 1.
During
transgressions,
deposits; basin,
section
suspension
1983;
WALKER,
(DOTT,
found
transported
2.
in
to the
Their
overprinted
in their
Suspension
clouds
debris
flows,
clouds 1985;
the
parts
formed
events
of the
GWINNER
(1962)
communication)
that
slump
proximal
basins.
types
Similar below the
lutite
beds
storms to
clouds
the were
storm wave
which were not
by w a v e a c t i o n .
frequently
T.
BRACHERT
deposits
overlain by graded bioclastic beds. the
during
by slumping and during the formation of
which and
is,
margins
suspension
basins
Jurassic reef-tall of southern Germany. by
the
1985).
phases,
graded
parts
(that
to
be generated
AIGNER,
caused upper
shifted
could
regressive
deeper
settling
erosion
presumably
where
processes base.
the
8.2.1)
of some
of the
occurred
in
the
Upper
It has already been shown (Erlangen,
in the reef
personal
talus are often
Those beds can be regarded as graded
calcilutites
in the
190
,z
5
I-,,
191
8.3 The
Conclusions
rhythmic
marl-limestone
Oxfordian
in
southern
composed
of
two
deposits,
channel
However,
primary
bioturbation
remains
change
much
and
fan
systems
sedimentary nearly
through
layers
of
overprint
are
S w a b i a n A l b show t h e i r
the
graded
because
diagenetic
facies
own b e d d i n g
lateral
changes.
Upper
sequence
containing
calcilutite
thickness
However, to
and
complex
were largely
The a v e r a g e
time. related
Middle
cycles
and
structures same,
the
a rather
transgression-regression
and d i a g e n e s i s .
layers
limestone
alternations
Germany
destroyed of
the
lag beds. due t o
limestone
conditions variations
Both subbasins
did not in
the
of the
rhythm.
F i g . 93 Sedimentary structures of fine-grained, calcareous turbidites to tempestites which are contained in Upper Jurassic marl-limestone alternations in southern Germany. A-D: Graded calcilutites with increasing distance from the source. Letters indicate Bouma-Piper intervals (B t o E 3 ) . Note, that limestone layers often contain several event beds (see Fig. 53a). E-G: Progradational destruction of graded calcilutites due to increasing post-event bioturbation (E,F). Common bioturbation pattern i n an u n w e a t h e r e d limestone layer in the transgressive sequence (G). Geisingen Quarry, Upper Oxfordian (A,B,C); Plettenberg Quarry, Upper Oxfordian (E); Schlatt Landslide, Middle Oxfordian (F).
9
C ON
C LU
S I
ON
S
:
D I
A G EN
E T I
C
B E D D I N G
Diagenetic of
carbonate
calcareous
oscillations
ooze
Alternating
zones
parallel
to
the
stratification processes
formed
an
overburden
of
CaCO 3 d i s s o l u t i o n
primary
in
were
at
a
of
bedding,
closed
during
lithification
100
and
cementation
which
carbonate
the
several
m of
produced
system.
developed
a
The
sediment. diagenetic
following
major
occurred:
The
amplitudes
considerably Extremely number
rhythmic of
the
primary
alternations
carbonate
sediment. maxima
of
carbonate
variations
were
enhanced.
oscillations
Diagenetically with
an
originated as
enhanced
angular
to
containing
compared
to
carbonate
convex
shape
and
the
curves with
a smaller primary
tend
to
have
narrow,
sharp
enriched
within
minima. Minor the The
elements,
relic
carbonate
following The
especially
methods
law,
with
are
which
carbonate
in
carbonate numerical The
and
mass
decompaction
carbonate
was in
balance
evaluated
of
the
minor
evaluated
from
total
the
the
by
using
compaction diagenettc
the
sediment They
to
be
degree
of
tubes.
computed
bulk
and These
calculations
were
elements the
of
original
existing
carbonate
carbonate
bioturbation
calculations.
of
the
mass
carbonate
balance
concentration
contained
in
compaction content.
explanation
cylindrical
cemented
rock
carbonate in
layers.
processes:
measure
related
was
marl
these
e.g.,
numerical
enables
differences and
to
data;
the
originally
Compositional dissolved
quantify
is
chemical
Compaction
deformation
to
mathematically
curves
performed.
of
used
provides
considerably
dissolution-affected
principle
along
parameters
the
were
underlying
porosity
of
Mg, w e r e
are
and by
the
amount
performing
based
on
the
rock. in the minor fraction
different
element and
types
of
concentration the
degree
of
193
compaction
by
enrichment beds
of
was
due
to
explained
Diagenetic
calculations,
the
are
mean
later of
pressure
of
set
structures arose
from
early
the
30%.
onset not
After
the
carbonate
than
of
the
original
factor
of
predominantly of
sections
from
the
minor
degree the
hand,
cement
amount
of
lithification
the
reduction
pore cement
the
space
found
which
the
content
in
marl
beds in
the
at
occurred of
the
the
had
to
of
the
onset in
be derived
pore layer from
to
to
of
which
are
was
same
in
some
marl
beds
respectively.
were
dissolved
reprecipitated
as
layers. (about
rhythm
low,
30 t o curves, were
If diagenetic and
45% o f and
the the
controlled the
by onset
history,
therefore,
significant
carbonate
a
the
on the
the 2,
which
carbonate
received
in of
Mg a n d
of
completely
the
higher
carbonates.
of
sediment's
volume
end,
times occurred
6 and
to
enhancement
lithification.
the
reduced
decompaction
of
in (when
an
10.3
diagenetic
layers
the
was
came
limestone
the
that, carbonate
fine-grained
bedding
early
original
were the
primary
limestone
space
1.5
elements
limestone
shapes the
pore
carbonate
minor
a
redistribution
enrichment
relic
cement
the of
of
here
diagenetic
porosities
by maximum factors
the
slightly
indicates
redistribution
recent,
the form
in the
This
numerical
the
of the
process.
were
in
5 . 8 % CaCO 3 . in
presented
(mean
primary
the the
the
carbonate
were
between
process
because
caused
compaction
of
before
oscillations
amount
in
models
60%),
that
cementation
beds.
larger
The
of
enhancement
of
marl
the
14)
differences
carbonate
within
fraction), of
the
in
between
precipitation
contacts
in in
Fig.
a mean of
that
grain
(see
55%),
and
those
Fe
carbonate
carbonate
suggests
oscillations
contents
constituents
The
Carbonate
the
system
as
of
their
other
to
diagenetic
compaction
also
On t h e
in.
(15
of
displays
magnitude
Chemical augmenting
17.3% with
formed
variations inherent
zones
50
5.1).
closed
sections
order
and
lithification
the
various
2.3
generated
of
a
marl
enrichment
generally
moderate
differences
cementation
simulation
amplitude by
The the
of
uncertainties
carbonate
and
between
were
those
were to
and
at
layers
were
oscillations
is
of
principle
CaCO 3 d i s s o l u t i o n - r e p r e c i p i t a t i o n
the
than
calculation.
carbonate
the
small
compaction
stress
evident
porosities less
between
shadow
self-perpetuating spite
of
account
primary
mechanical
limestone is
into
sediment
lithostatic
It
use
with
dissolution
bioturbation) a phase
cemented
relic
alternations
oozes Taking
limestone-layer of
balance
the
the
marl-limestone
content.
(after
element in
through
calcareous
carbonate
After
a minor elements
compaction.
bioturbated
which
using minor
dissolution
the
amounts in
of the
194 adjacent
marl
chemical of
the
to
that
thicknesses the
of
more the the
models
and
was
so
marl
compacted
analyses
in
that
beds
DEPOSITION
::i:
show t h a t
the more
due to
layers to
this
"noise"
oceanic
diagenetic original
sediment
(Fig.
that,
more,
of
lithified
on t h e
is
but
carbonate
Type I
systems
number of
of
the
the
one
was
stratification
94).
The
primary
WEATHERING
mechanical
(30
to
and
event cyclic
of
Therefore,
was low and m a r l - l i m e s t o n e
was
of
the
in
turn
types
depending related the
to
primary
compaction,
ranged pore
carbonate
alternations
produced
Three
and
process.
primary
diagenetic
constructed
bedding
mechanical
content
of
(e.g., (e.g.,
and Milankovitch
The higher
redistribution
carbonate
bedding
distinguished,
sediment
degree
compaction
were
German
(where only
bedding
oscillations. which
cyclic
south
curves
diagenetic
carbonate
primary
1985;
carbonate
sediment,
and
(the bedding
preserved),
compaction the
noncyclic
stochastic
detailed
ltthtfied
of marl-limestone
example
DINER & EICHER,
beginning
primary
the
55%).
section
Simulation
rhythmicity
types
between in
alternations
lower
the
When t h e
see
primary
of mechanical content
the
cyclic
produce
various
was
from the
the
a fewer
earlier
the
and tempestites),
evident
content the
in
which
in principle
cycles, to
factors
solely
marl-limestone
degree
carbonate
usually
complex
compared
not
are
turbidites It
as
the
compaction,
rhythmic.
or not
a spectrum
studied
production
cycles).
found
these
of
fine-grained
intense
as
more
I
represents Although
Upper Jurassic),
the
dominate
be
of
curves
angular-shaped
BIOTURBATION D I A G E N E S I S
pattern
alternations bedding.
degree
carbonate
However,
:::. :. ::::
stratification
the
become
appear
Fig. 94 Summary of the marl-limestone alternations.
the
they
sediment.
limestone
primary
a considerable
and changed
were reduced
of whether
the
produced
beds
primary
the
independent
present
turn
alternations
facies
generated
marl
layers the
the
in
the
in
weakly
more
This in
limestone
compared
and
beds.
compaction
f r o m 60 t o space
80%,
was h i g h
redistribution
formed only
moderate
195
rhythmicity with
slnusoidal
maximum carbonate
carbonate
contents.
curves
Weathering
of
and varying the
outcrop
f u r t h e r w e a k e n e d the CaCO 3 rhythm because smaller carbonate
maxima w e a t h e r e d Type I I
Rhythmic
completely
to marl.
marl-limestone
alternations
originated
sediments with primary carbonate c o n t e n t s reductions
in
the
original
mechanical
compaction.
volume
The
from
of 75 to 90% and by
25
carbonate
to
35%
via
in
the
curves
limestone layers display convex shapes and the t h i c k n e s s
of
the marl beds is approximately equivalent to one half of the thickness of the limestone layers.
Type I I I
When 85%), than
the and 25%)
original therefore, highly
showing thin, carbonate carbonate nearly
carbonate
mechanical
rhythmic,
flasery curves
content
constant.
content
marl in
(in
the the
of the
(more
was
low
alternations
an d a n g u l a r
limestone middle
high
compaction
brick-like joints
was
limestone
(less
formed,
shapes
layer.
than
of
the
T h e m ax i m u m layers)
is
10
R E F E R E N C E S
A B U - M A A R U F , M. ( 1 9 7 5 ) : Feingliederung und Korrelation der Mergelkalkfazies des U n t e r c a m p a n s yon M i s b u r g , HSver und Wunstorf im ostnieders~chsischen Becken.Berichte Naturhistorische Gesellschaft Hannover 119, 127-204. AIGNER, T. (1982): Calcareous Tempestites: Storm-dominated stratification in Upper Muschelkalk limestones.i n : E I N S E L E , G. & S E I L A C H E R , A. ( e d s . ) : Cyclic and event stratification, 180-198 (Springer, Berlin). -- (1985): Storm depositional systems - dynamic stratigraphy in modern and ancient shallow marine sequences.Lecture Notes in Earth S c i e n c e 3 , 174 p . ( S p r i n g e r , Berlin). ALVAREZ, L.W.; A L V A R E Z , W . ; ASARO, F . & M I C H E L , H . V . (1980): Extraterrestrial cause for the Cretaceous-Tertiary extinction.S c i e n c e 208 (No. 4 4 4 8 ) , 1 0 9 5 - 1 1 0 8 . ALVAREZ, W. ; ENGELDER, T . & G E I S E R , P . A . ( 1 9 7 8 ) : Classification of solution cleavage in pelagic limestones.Geology 6, 263-266. - - & LOWRIE, W. ( 1 9 8 1 ) : U p p e r C r e t a c e o u s t o E o c e n e p e l a g i c l i m e s t o n e s of the Scaglia Rossa are not Miocene turbidites.Nature 294, 246-294. --; KAUFFMAN, E . G . ; SURLYK, F . ; ALVAREZ, L . W . ; ASARO, F. & MICHEL, H.V. ( 1 9 8 4 ) : I m p a c t t h e o r y o f m a s s e x t i n c t i o n s an d t h e i n v e r t e b r a t e fossil record.Science 223, 1135-1141. ARTHUR, M.A. ( 1 9 7 6 ) : S e d i m e n t o l o g y o f G u b b i o s e q u e n c e an d i t s b e a r i n g on p a l e o m a g n e t i s m . Memorie Societa Geologica Italiana 15, 9 - 2 0 . -- (1979): Sedimentology and geochemical studies o f C r e t a c e o u s and P a l e o g e n e s e d i m e n t a r y r o c k s : The G u b b i o s e q u e n c e , Part I. Thesis, P r i n c e t o n U n i v . , 193 p . - - ; DEAN, W . E . ; BOTTJER, D. & SCHOLLE, P . A . ( 1 9 8 4 ) : R h y t h m i c b e d d i n g in Mesozoic-Cenozoic pelagic carbonate sequences: The primary and diagenetic origin of Milancovitch-like cycles.i n : BERGER, A . L . e t al. (eds.): Milancovitch and c l i m a t e , P a r t 1, 1 9 1 - 2 2 2 . -- & FISCHER, A.G. (1977): Upper Cretaceous-Paleocene magnetic stratigraphy at Gubbio, Italy. I Lithostratigraphy and sedimentology.G e o l . S o c . Am. B u l l . 8 8 , 3 6 7 - 3 7 1 . BALDWIN, B. ( 1 9 7 1 ) : Ways o f d e c i p h e r i n g compacted sediments.Jour. Sed. Petrol. 41, 293-301. - - & BUTLER, C . O . ( 1 9 8 5 ) : Compaction curves.Am. A s s o c . P e t r o l e u m Bull. 69, 622-262. BAKER, P . A . ; G I E S K E S , J .M. & E L D E R F IELD , H. ( 1 9 8 2 ) : D i a g e n e s i s o f carbonates in deep-sea sediments - evidence from Sr/Ca ratios and interstitial dissolved Sr data.Jour. Sed. Petrol. 52, 7 1 - 8 2 . - - ; KASTNER, M . ; BEYERLEE, J . D . & LOCKNER, D . A . ( 1 9 8 0 ) : Pressure solution an d h y d r o t h e r m a l r e c r y s t a l l i z a t i o n of carbonate sediments an e x p e r i m e n t a l study.- Marine Geology 38, 185-203. BANDY, O . L . ( 1 9 7 5 ) : Messinian evaporite deposition and t h e M i o c e n e / Pliocene boundary, Pasquasia-Capodarso sections, Sicily.in: S A I T O , T . & BURCKLE, L . H . ( e d s . ) : Late Neogene epoch boundaries, 49-63 (Micropaleontology P r e s s , New Y o r k ) . BARKER, P . F . ; CARLSON, R . L . e t a l . (1984): Site 516: Rio Grande Rise.Init. R e p t s . DSDP 7 2 , 1 5 5 - 3 3 8 . BARRET, P . J . ( 1 9 6 4 ) : R e s i d u a l s e a m s a n d c e m e n t a t i o n i n O l i g o c e n e s h e l l calcarenites, Te K u i t i G r o u p . - J o u r . S e d . P e t r o l . 34, 5 2 4 - 5 3 1 . BARRON, E . J . ; ARTHUR, M . A . & KAUFFMAN, E . G . ( 1 9 8 5 ) : Cretaceous rhythmic bedding sequences: a plausible link between orbital variations and climate.Earth and Planetary Sci. Lett. 72, 327-340. -
197
BATHURST, B . G . C . ( 1 9 7 6 ) : Carbonate s e d i m e n t s an d t h e i r d i a g e n e s i s . D e v e l o p . S e d i m e n t o l o g y 1 2 , 658 p . ( E l s e v i e r , Amsterdam). -- (1980a): Lithification of carbonate sediments.Sci. Prog., Oxf. 66, 451-471. -- (1980b): Deep crustal diagenesis in limestones.Revista Inst. Investigaciones Geol., Barcelona 34, 89-100. - - ( 1 9 8 3 ) : N e o m o r p h i c s p a r v e r s u s c e m e n t i n some J u r a s s i c grainstones: significance for evaluation of porosity evolution and compaction.J o u r . G e o l . S o c . London 1 4 0 , 2 2 9 - 2 3 7 . -- (1984): Origin of bedding planes defined by p r e s s u r e - d i s s o l u t i o n seams in Phanerozoic platform limestones (abstr.).7th Meeting Carbon. Sedimentologists, Liverpool. BAUSCH, W.M. ( 1 9 6 8 ) : Clay content and calcite crystal size of limestones.Sedimentology 10, 71-75. -- (1982): Tonmineralprovinzen im M a l m k a l k e n . - E r l a n g e r F o r s c h u n g e n B8, 78 p . - - ; FATSCHEL, J . & HOFMANN, D. ( 1 9 8 2 ) : Observations on w e l l - b e d d e d Upper Jurassic limestones.i n : EINSELE, G. & SEILACHER, A. ( e d s . ) : C y c l i c an d e v e n t s t r a t i f i c a t i o n , 54-62 (Springer, Berlin). - - & POLL, E . G . ( 1 9 8 4 ) : Das Profil Loser/Altaussee - Bindeglied zwischen alpinem und sOddeutschem Malm.- Geol. Hundschau 73, 351-369. BEACH, D . K . & SCHUMACHER, A . L . ( 1 9 8 2 ) : Stanley field, North Dakota, e c o n o m i c and q u a n t i t a t i v e significance of mechanically compacted shallow water limestone.Am. A s s o c . P e t r o l e u m B u l l . 6 6 , 5 4 7 - 5 4 8 . BENSON, R . H . ( 1 9 7 5 ) : Ostracods and Neogene h i s t o r y . i n : SAITO, T. & BURCKLE, L . H . (eds.): Late Neogene epoch boundaries, 41-48 (Micropaleonotology P r e s s , New Y o r k ) . BERGER, A . L . ; IMBRIE, J . ; HAYS, J . ; KUKLA, G. & SALTZMAN, B. ( 1 9 8 4 , e d s . ) : M i l a n k o v i t c h and c l i m a t e . (The Hague, R e i d e l ) . BERGER, W . H . ; EKDALE, A.A. & BRYANT, P . P . ( 1 9 7 9 ) : Selective preservation of burrows in deep-sea carbonates.Marine Geology 32, 204-230. - - & RAD, U . V . ( 1 9 7 2 ) : Cretaceous and Cenozoic sediments from the Atlantic Ocean.- Init. Rep. Deep Sea D r i l l i n g Project 14, 787-954. BE R NER , R . A . ( 1 9 8 0 ) : Early diagenesis, 241 p. ( U n i v e r s i t y Press, Princeton). -(1984): Sedimentary pyrite formation: an update.Geochim. Cosmochim. Acta 48, 605-615. BHATTACHARYYA, A. & F R I E D M A N , G . M . ( 1 9 8 3 ) : Mineralogical and paramorphic textural changes generated in modern colds by heat and compaction.Geology, 11, 596-598. -(1984): Experimental compaction of ooids under deep-burial diagenetic temperatures and pressures.Jour. Sed. Petrol. 54, 362-372. BIJU-DUVAL, B. & MONTADERT, L. ( 1 9 7 6 , e d s . ) : Structural history of the Mediterranean b a s i n , 448 p . ( E d i t i o n s T e c h n i q u e , P a r i s ) . BOLES, J.H. & FRANKS, S . G . (1979): Clay diagenesis in Wilcox sandstones of southwest Texas: Implications of smectite diagenesis on s a n d s t o n e c e m e n t a t i o n . Jour. Sed. Petrol. 49, 55-70.
BORTOLOTTI, V.; PASSERINI, P.; SAGRI, M. & SESTINI, G. (1970): The miogeosynclinal sequences.- Sedimentary Geol. 4, 341-444. BOTTJER, D.J.; ARTHUR, M.A. & DEAN, W.E. (1985): Rhythmic bedding in Upper Cretaceous chalks.- Cycles and p e r i o d i c i t y in g e o l o g i c events, evolution and stratigraphy, Research Symp. Princeton, p. 4 (abstract). BOUMA, A . H . ( 1 9 6 2 ) : Sedimentology of some flysch deposits, 168 p. (Elsevier, Amsterdam). BRAND, U. & VEIZEB, J . ( 1 9 8 0 ) : C h e m i c a l d i a g e n e s i s of a multicomponent carbonate system - I. Trace elements.Jour. Sed. Petrol. 50, 1219-1236.
198
BROLSMA, M . J . (1976): Discussion of the arguments concerning the paleo-environmental interpretation of the arenazzolo in Capo Rosello and Eraclea Minora (s. Sicily, Italy).Mem. S o c . G e o l . Italiana 16, 153-157. BROMLEY, R . G . & E K D A L E , A . A . ( 1 9 8 4 ) : Chondrites: a trace fossil indicator of anoxia in sediments.Science 224, 872-874. BURGER, G. ( 1 9 8 2 ) : Tonmineralogische und sedimentpetrographische Untersuchungen in der untersten Kreide des Gstlichen Helvetikums.Schweiz. mineral, petrogr. Mitt. 62, 369-414. BUSNARDO, R. ( 1 9 6 3 ) : Le s t r a t o t y p e du B a r r @ m i e n . I. Lithologie et macrofaune.Co11. C r @ t a c @ i n 1 . L y o n , M~m. B . R . G . M . P a r i s 34 (1965), 99-128. BUXTON, T . J . & SIBLEY, D.F. (1981): Pressure solution features in a shallow buried limestone. Jour. Sed. Petrol. 51, 19-26. CAMPOS, H . S . & HALLAM, A. ( 1 9 7 9 ) : D i a g e n e s i s o f E n g l i s h L o w e r J u r a s s i c limestones as inferred from oxygen and carbon isotope analysis.E a r t h an d P l a n e t . S c i . L e t t . 45, 2 3 - 3 1 . CATALANO, R , ; R U G G I E R I , G. & S P R O V I E R I , R. ( 1 9 7 5 , e d s . ) : Messinian evaporites in the Mediterranean.Memorie Societ~ Geologica Italiana 14 ( 1 9 7 6 ) , 385 p . CHANDA, S . K . ; BHATTACHARYYA, A . & SARKAR, S. ( 1 9 7 7 ) : D e f o r m a t i o n o f o o i d s by c o m p a c t i o n i n t h e P r e c a m b r i a n Bhander Limestone, India: implications for lithification.Geol. Soc. Am. B u l l . 88, 1577-1585. C I T A , M.B. ( 1 9 7 2 ) : I1 s i g n i f i c a t o della transgressione Pliocenica alla luce delle nuove scoperte he1Mediterraneo.Riv. Ital. Paleont. 78, 5 2 7 - 5 9 4 . -- (1973): Mediterranean evaporite: Paleontological arguments for a deep-basin desiccation m o d e l . - i n : DROOGER, C.W. ( e d . ) : Messinian events in the Mediterranean, 206-223 (North Holland Publishing Comp., Amsterdam). COOGAN, A . H . ( 1 9 7 0 ) : Measurements of compaction in oolitic grainstones.Jour. Sed. Petrol. 40, 9 2 1 - 9 3 9 . CORRENS, C.W. ( 1 9 4 9 ) : G r o w t h a n d d i s s o l u t i o n of crystals under linear pressure.Discussions Faraday Soc. 5, 267-271. COTILLON, P. (1971): Le Cr@tac@ inf@rieur de 1'arc subalpin de Castellane entre l'Asse et le Var. Stratigraphie et
[email protected] ~ m o i r e s du B . R . G . M . 6 8 , 313 p . - - ; FERRY, S . ; GAILLARD, C . ; J A U T E E , E . ; L A T R E I L L E , G. & R I O , M. (1980): Fluctuation de p a r a m @ t r e s du m i l i e u marin darts le domaine vocontien (France S E ) a u Cr@tac@ i n f @ r i e u r : m i s e en @vidence p a r l'~tude des formations marno-calcaires alternates.Bull. Soc. G@ol. F r a n c e 2 2 , 7 3 5 - 7 4 4 . - - & RIO ( 1 9 8 4 ) : Cyclic sedimentation i n t h e C r e t a c e o u s o f Deep Sea Drilling Project sites 535 and 540 ( G u l f o f M e x i c o ) , 534 ( C e n t r a l Atlantic), an d i n t h e V o c o n t i a n B a s i n ( F r a n c e ) . i n : BUFFLER, R . T . ; SCHLAGER, W. e t a l . ( e d s . ) : Init. R e p t s . DSDP 7 7 . 3 3 9 - 3 7 6 . CRIMES, T.P. (1975): The stratigraphical significance of trace fossils.i n : FREY, R.W. ( e d . ) : The s t u d y o f t r a c e f o s s i l s , 109-130 (Springer, New Y o r k ) . CZERNIAKOWSKI, L . A . ; LOHMANN, E . C . & WILSON, J . L . (1984): Closedsystem marine burial diagenesls: isotopic data from the Austin C h a l k and its c o m p o n e n t s . - S e d l m e n t o l o g y 3_!1, 863-877. DARMEDRUo C. ( 1 9 8 4 ) : Variations au t a u x de s ~ d i m e n t a t i o n et oscillations climatiques lors du d~pSts des alternances marne-calcaire p~lagiques. E x e m p l e du V a l a n g i n i e n sup~rieur V o c o n t i e n (SE de l a F r a n c e ) . Bull. Soc. G~ol. France 26, 63-70. - - ; COTILLON, P. & RIO, M. ( 1 9 8 2 ) : R h y t h m e s c l i m a t i q u e s et biologiques en m i l i e u m a r i n p ~ l a g i q u e . Leurs relations dans les dbpSts cr~tac~s alternants du b a s s i n vocontien (SE F r a n c e ) . Bull. Soc. Geol. F r a n c e Z, 6 2 7 - 6 4 0 .
199
DEAN, W.E. & GRADNER, J . V . ( 1 9 8 5 ) : M i l a n k o v i t c h cycles in Neogene deep-sea sediments.Cycles and periodicity in geologic events, evolution and stratigraphy, Research Symp. Princeton, p. 7 (abstract). D E B O E R , P.L. & W O N D E R S , A.A.H. (1984): Astronomically induced r h y t h m i c b e d d i n g in C r e t a c e o u s pelagic sediments near Morla (Italy).i n : BERGER, A . ; IMBRIE, J . e t a l . ( e d s ) : M i l a n k o v i t c h a n d c l i m a t e , 1 7 7 - 1 9 0 (The H a g u e , R e i d e l ) . DOTT, R . H . ( 1 9 8 3 ) : E p i s o d i c sedimentation - how n o r m a l i s a v e r a g e ? How r a r e i s r a r e ? Does i t m a t t e r ? - J o u r . S e d . P e t r o l . 53, 5 - 2 3 . DROOGER, C.W. ( 1 9 7 3 , e d . ) : M e s s i n i a n e v e n t s i n t h e M e d i t e r r a n e a n , 272 p. ( N o r t h - H o l l a n d P u b l i s h i n g Comp., A m s t e r d a m ) . EDER, F.W. (1971): Riff-nabe detritische Kalke bei Balve im Rheinischen Schiefergebirge.G ~ t t i n g e r Arb. Geol. P a l R o n t o l . 10, 66 p . -- (1982): Diagenetic redistribution of carbonate, a process in forming limestone-marl alternations (Devonian and Carboniferous, Rheinisches Schiefergebirge, W. G e r m a n y ) . i n : E I N S E L E , G. & SEILACHER, A. ( e d s . ) : Cyclic and event stratification, 98-112 (Springer, Berlin). EICHER, D . L . & DINER, R. ( 1 9 8 5 ) : F o r a m i n i f e r a a s i n d i c a t o r s of water mass i n t h e C r e t a c e o u s G r e e n h o r n s e a , W e s t e r n I n t e r i o r . Soc. Econ. Paleont. Mineral. field trip guidebook ~, 60-71. E I N S E L E , G. ( 1 9 7 7 ) : R a n g e ~ v e l o c i t y and material flux of compaction flow i n growing s e d i m e n t a r y s e q u e n c e s . - S e d i m e n t o l o g y 24, 639-655. -(1982): Limestone-marl cycles (Periodites): Diagnosis, significance, causes - a review.- in: E I N S E L E , G. & S E I L A C H E R , A. (eds.): Cyclic and event stratification, 8-53 (Springer, Berlin). -- (1985): Response of s e d i m e n t s to s e a - l e v e l c h a n g e s in d i f f e r i n g s u b s i d i n g storm-dominated marginal and epeiric basins.- in: BAYER, U. & SEILACHERp A. (eds.): S e d i m e n t a r y and e v o l u t i o n a r y c y c l e s . Lecture Notes in Earth Sciences !, 127-162. -- & M O S E B A C H , R. ( 1 9 5 5 ) : Zur P e t r o g r a p h i e , F o s s i l e r h a l t u n g u n d Entstehung der G e s t e i n e des P o s i d o n i e n s c h i e f e r s im S c h w ~ b i s c h e n Jura.- Neues Jahrb. Geol. PalRontol. Abh. 101, 319-430. -- & S E I L A C H E R , A. (1982, eds.): Cyclic and event stratification, 536 p. (Springer, Berlin). EKDALE, A.A. & B R O M L E Y , R.G. (1984): Sedimentology and ichnology of the Cretaceous-Tertlary boundary in Denmark: i m p l i c a t i o n s for the c a u s e s of the t e r m i n a l Cretaceous extinction.- Jour. Sed. Petrol. 54, 681-703. --; M U L L E R , L.N. & NOVAK, M.T. (1984): Q u a n t i t a t i v e I c h n o l o g y of m o d e r n p e l a g i c d e p o s i t s in the a b y s s a l A t l a n t i c . - P a l e o g e o g r . , Paleocllm., Paleoec. 45, 189-223. ELDER, W.P. & K I R K L A N D , J.I. (1985): S t r a t i g r a p h y and depositional environments of the Bridge Creek limestone member of the G r e e n h o r n L i m e s t o n e at R o c k C a n y o n A n t i c l i n e n e a r Pueblo, Colorado.- Soc. Econ. Paleont. Mineral. field trip guidebook 4, 122-134. ELDERFIELD, H. & G I E S K E S , J . M . ( 1 9 8 2 ) : Sr isotopes in interstitial w a t e r s o f m a r i n e s e d i m e n t s f r o m Deep S e a D r i l l i n g Project cores.N a t u r e 300, 4 9 3 - 4 9 6 . ENGELDER, T . ; G E I S E R , P . A . & ALVAREZ, K. ( 1 9 8 1 ) : R o l e o f p r e s s u r e solution and dissolution in geology.- Geology 9, 44-45. ENGELHARD, W. ( 1 9 7 7 ) : T h e o r i g i n o f s e d i m e n t s a n d s e d i m e n t a r y r o c k s . 359 p . (E. S c h w e i z e r b a r t , Stuttgart). ERNST, G . ; SCHMID, F . & K L I S C H I E S , G. ( 1 9 7 9 ) : M u l t i s t r a t i g r a p h i s c h e U n t e r s u c h u n g e n i n d e r O b e r k r e i d e d e s Raumes B r a u n s c h w e i g - H a n n o v e r . i n : WIEDMANN, J . ( e d . ) : Aspekte der Kreide Europas.I.U.G.S. Series A 6, 11-46. FISCHER, A . G . ( 1 9 8 0 ) : G i l b e r t - bedding rhythms and geochronology.i n : YOCHELSON, E . L . ( e d . ) : The s c i e n t i f i c ideas of G.K. Gilbert.G e o l . S o c . Am. S p e c . P a p e r 1 8 3 , 9 3 - 1 0 4 .
200
-- & ARTHUR, M.A. (1977): S e c u l a r v a r i a t i o n s in the pelagic realm.in: C O O K , H.E. & ENOS, P. ( e d s . ) : Deep-water carbonate environments.- Soc. Econ. Paleont. Mineral. Spec. Pub1. 255, 19-50. --; H E R B E R T , T. & P R E M O L I SILVA, J. (1985): Carbonate bedding cycles in C r e t a c e o u s p e l a g i c and h e m l p e l a g l c sequences.Soc. E c o n . Paleont. Mineral. fleld trip guidebook 4, 1-10. FLOGEL, H. (1968): D i e L i t h o g e n e s e der O b e r a l m e r Schlcbten und der mlkrltlschen Plassen-Kalke (Tithonium, N6rdllche Kalkalpen).- Neues Jahrb. Geol. Pal~ontol. Abh. 123, 249-280. FLUGEL, H . W . ( 1 9 6 8 ) : S o m e n o t e s on t h e i n s o l u b l e residues in l i m e s t o n e s . - in: M U L L E R , G. & F R I E D M A N , G.M. (eds.): Recent d e v e l o p m e n t s in c a r b o n a t e s e d l m e n t o l o g y in central Europe, 46-54 (Springer, Berlin). -- & W E D E P O H L , K.H. (1967): Die Verteilung des Strontiums in o b e r j u r a s s l s c h e n K a r b o n a t g e s t e l n e n der n ~ r d l i c h e n K a l k a l p e n . Contr. Mineral. Petrol. 14, 229-249. FOLK, R.L. & LAND, L.S. (1975): Mg/Ca ratio and salinity: two controls over crystallization of dolomite.- Am. Assoc. Petroleum Geol. Bull.
5_99, 6 0 - 6 8 . F U C H T B A U E R , H. & MULLER, G. (1977): S e d i m e n t e u n d Sedimentgestelne (Sediment-Petrologic Tell II), 784 p. (Schweizerbart, Stuttgart). F R E Y B E R G , B.V. (1966): D e r F a z l e s v e r b a n d im unteren Malm Frankens.Erlanger Geol. Abh. 6_~2, 3-92. GARDNER, J.V.; DEAN, W.G. & JANSA, L. (1977): Sediments recovered from the n o r t h w e s t A f r i c a n c o n t i n e n t a l m a r g i n . - Init. Repts. DSDP 4_!1 1121-1134. G A R R I S O N , R.E.: (1981): Diagenesis of oceanic carbonate sediments: A review of the DSDP perspective.- Soc. Econ. Paleont. Mineral. Spec. Publ. 32, 181-207. -- & K E N N E D Y , W.J. ( 1 9 7 7 ) : O r i g i n of s o l u t i o n seams and flaser structures in the U p p e r C r e t a c e o u s c h a l k s of s o u t h e r n E n g l a n d . Sedimentary Geology 19, 107-137. GEBHARD, G. ( 1 9 8 3 ) : S t r a t l g r a p h i s c h e Kondensatlon am B e l s p i e l mlttelkretazlscher Vorkommen im p e r l a l p l n e n R a u m . - Thesis, Univ. T~bingen, 145 p. GEISER, P.A. & SANSONE, S. (1981): Joints, microfractures, and the formation of solution cleavage in limestones.- Geology ~, 280-285. G I E S K E S , J.M. (1981): D e e p - s e a d r i l l i n g interstitial water studies: implications for chemical alteration of the oceanic crust, layers I and If.- 8oc. Econ. Paleont. Mineral. Spec. Publ. 32, 149-167. -- (1965): Chemistry of interstitial waters of marine sediments.- An. Rev. Earth and Planet. Sci. 3, 433-453. GILBERT, G.K. (1895): Sedimentary measurement of geologic time.- Jour. Geology 3, 121-127. GLUYAS, J.G. (1984): E a r l y c a r b o n a t e d i a g e n e s l s within Phanerozoic s h a l e s and sandstones of the NW European shelf.- Clay Minerals 19, 309-321. GWINNER, M.P. (1962): S u b a q u a t l s c h e G l e i t u n g e n und r e s e d i m e n t K r e B r e c c l e n im W e i ~ e n J u r a der S c h w R b l s c h e n Alb (W~rttemberg).Zeitschr. deutsche geol. Gesell. 113, 571-590. -- (1976): O r i g i n of U p p e r J u r a s s i c l i m e s t o n e s of the S w a b l a n Alb (southwest Germany).- Contributions to Sedimentology 5, 75 p. GYGI, R. (1969): Zur S t r a t i g r a p b i e der Oxford-Stufe der Nordschweiz und des sQddeutschen Grenzgebietes.- B e l t r ~ g e geol. K a r t e S c b w e l z N.F. 136, 123 p. HALLAM, A. (1964): O r i g i n of the llmestone-shale rhythms in the Blue Lias of England: A composite theory.- Jour. of Geol. 7__22,157-168. H A M I L T O N , E.L. (1974): P r e d i c t i o n of d e e p - s e a sediment properties: state of a r t . - in: I N D E R B I T Z E N , A.L. (ed.): D e e p Sea S e d i m e n t s : Physical and Mechanical Properties, 1-44 (Plenum Press, New York). -- (1976): Variations of density and porosity w i t h d e p t h in d e e p - s e a sediments.- Jour. Sed. Petrol. 46, 280-300.
201
H~NTZSCHEL, W. ( 1 9 7 5 ) : T r a c e f o s s i l s and p r o b l e m a t i c a . i n : MOORE, R. & TEICHERT, C. ( e d s . ) : Treatise on i n v e r t e b r a t e paleontology, Part W, 269 p . ( U n i v . K a n s a s P r i n t . Serv.). HARMS, J . C . & CHOQUETTE, P.W. ( 1 9 6 5 ) : G e o l o g i c e v a l u a t i o n of a gammaray porosity device.i n : 6 t h Ann. SPWLA L o g g i n g S y m p o s i u m , v o ] . 2 , C1-C37. HATTIN, D . E . ( 1 9 7 1 ) : Widespread, synchronously deposited, burrowmottled limestone beds in Greenhorn Limestone (Upper Cretaceous) of Kansas and southern Colorado.Am. A s s o c . Petrol. Bull. 55, 412-431. -- (1985): Distribution and s i g n i f i c a n c e of widespread, time-parallel pelagic limestone beds in Greenhorn Limestone (Upper Cretaceous) of the Central G r e a t P l a i n s and s o u t h e r n Rocky M o u n t a i n s . - S o c . Econ. Paleont. Mineral. field trip guidebook ~, 28-37. HEIMANN, K . O . ( 1 9 7 7 ) : Die Fazies d e s M e s s i n s und u n t e r s t e n Pliozans auf den Ionischen Inseln (Zakynthos, Kephallinia, Korfu/Griechenland) und auf Sizilien.Thesis, Techn. Univ. M ~ n c h e n , 158 p. HENNINGSMOEN, G. ( 1 9 7 4 ) : A c o m m e n t . O r i g i n o f l i m e s t o n e n o d u l e s i n t h e Lower Paleozoic of the Oslo region.Norsk Geologisk Tidsskrift 54, 401-412. HERRMANN, A . G . ( 1 9 7 5 ) : P r a k t i k u m d e r G e s t e i n s a n a l y s e , 204. (Springer, Berlin). H I L L E R , K. ( 1 9 6 4 ) : O b e r d i e B a n k - und Schwammfazies des Wei~en J u r a der Schw~bischen Alb (WGrttemberg).- Arbeiten Geol. Pal&ont. Inst. TH S t u t t g a r t NF 4 0 , 190 p . HINTE, J.E. van (1976a): A Jurassic time scale.Am. A s s o c . P e t r o l e u m B u l l . 6_00, 4 8 9 - 4 9 7 . -- (1976b): A Cretaceous time scale.Am. A s s o c . P e t r o l e u m B u l l . 6 0 , 498-516. HOLLER, H. & W A L I T Z I , E . M . ( 1 9 6 5 ) : Mineralogische U n t e r s u c h u n g e n an den Oberalmer Schichten und an den m i k r i t i s c h e n Plassenkalken, NOrdliche Kalkalpen.N e u e s J a h r b . G e o l . P a l ~ o n t . Mh. 1 2 3 , 5 5 2 - 5 5 5 . HSU, K. ( 1 9 8 3 ) : The M e d i t e r r a n e a n was a d e s e r t . A voyage of the Glomar Challenger, 197 p . ( P r i n c e t o n U n i v . P r e s s ) . HUDSON, J . D . ( 1 9 7 5 ) : C a r b o n i s o t o p e s a n d l i m e s t o n e c e m e n t . - G e o l o g y 3 , 19-20. JANOWSKY, W. ( 1 9 7 0 ) : E m p i r i c a l i n v e s t i g a t i o n o f some f a c t o r s affecting elastic wave velocities in carbonate rocks.Geophys. Prosp. 18, 103-118. JEANS, C . V . ( 1 9 8 0 ) : E a r l y s u b m a r i n e l i t h i f i c a t i o n i n t h e Red C h a l k and Lo wer C h a l k o f e a s t e r n E n g l a n d : A b a c t e r i a l control model and its implications.Proc. Yorkshire Geol. Soc. 43 (Part 2, No. 6 ) , 81-157. J~RGENSEN, N . O . ( 1 9 8 3 ) : Dolomitization in chalk from the North Sea Central Graben.- Jour. Sed. Petrol. 53, 557-564. KAHLE, C . F . ( 1 9 6 6 ) : Some o b s e r v a t i o n s on c o m p a c t i o n and c o n s o l i d a t i o n in ancient oolites.Compass 4 4 , 1 9 - 2 9 . KATZ, A . ; S A S S , E . ; STARINSKY, A. & HOLLAND, H.D. ( 1 9 7 2 ) : S t r o n t i u m behavior in the aragonite-calcite transformation: An e x p e r i m e n t a l study at 40-90°C. - Geochim. Cosmochim. Acta 36, 481-496. KEITH, M.L. (1982): Violent volcanism, stagnant oceans and some inferences regarding petroleum, strata-bound ores and mass extinctions.Geochim. Cosmochim. Acta 46, 2621-2637. KELLER, G . H . & BENNETT, R . H . ( 1 9 7 0 ) : V a r i a t i o n s in the mass physical properties of selected submarine sediments.Marine Geology 9, 215-223. - - ; LAMBERT, D.N. & BENNETT, R . H . ( 1 9 7 9 ) : G e o t e c h n i c a l properties of continental slop deposits - Cape H a t t e r a s to Hydrographer Canyon.Soc. Econ. Paleont. Mineral. Spec. Pub1. 27, 131-151. KENNEDY, W . J . ( 1 9 7 5 ) : Trace fossils in carbonate rocks.i n : FREY, R.W. ( e d . ) : The s t u d y o f t r a c e f o s s i l s , 377-397 (Springer, Berlin).
202
--
& ODIN, G . S . ( 1 9 8 2 ) : T h e J u r a s s i c and Cretaceous time scale in 1 9 8 1 . - i n : ODIN, G . S . ( e d . ) : Numerical dating in stratigraphy, 557-592 (John Wiley, Chichester). KENT, D . V . ( 1 9 8 1 ) : A s t e r o i d extinction hypothesis.Science 214, 648-650. KERCKHOVE, C. & ROUX, M. ( 1 9 7 6 ) : C a r t e g @ o l o g i q u e de l a F r a n c e , 1 : 5 0 0 0 0 , XXXV-42, C a s t e l l a n e . B u r e a u de r e c h e r c h e s g @ o l o g i q u e s e t mini@res, 39 p. K E T T E N B R I N K , E.C. & MANGER, W.L. (1971): A deformed marine pisolite from the P l a t t s b u r g L i m e s t o n e (Upper P e n n s y l v a n l a n ) of s o u t h e r n Kansas.- Jour. Sed. Petrol. ~_~, 435-443. KINSMAN, D.J.J. (1969): I n t e r p r e t a t i o n of Sr 2+ c o n c e n t r a t i o n s in carbonate minerals and rocks.- Jour. Sed. Petrol. 39, 486-508. KNOBLAUCH, G. ( 1 9 6 3 ) : S e d i m e n t p e t r o g r a p h i s c h e und g e o c h e m i s c h e Untersuchungen an Wei~jurakalken der geschichteten Fazies im Gebiet von Urach und Neuffen.- Thesis, Univ. Tfibingen, 106 p. KOEPNICK, R.B. (1985): D i s t r i b u t i o n and p e r m e a b i l i t y of s t y l o l i t e b e a r i n g h o r i z o n s w i t h i n a Lower Cretaceous carbonate reservoir in the Middle East.- 60th An. Tech. Conf. of Soc. Petroleum Engineers, Las Vegas, NV, 7 p. KOHLER, K.E. (1971): Zur Sedimentologie der Grenzschichten Dogger/Malm in S Q d w e s t w f i r t t e m b e r g . Arbeiten Geol. Pal~ontol. Inst. TH Stuttgart NF 64, 90 p. KOPF, M. (1983): ~ber die Kreidekalkdiagenese.- Zeitschr. geol. Wiss. 11, 1443-1451. KRANZ, J.R. (1976): S t r o n t i u m - ein F a z i e s - D i a g e n e s e - I n d i k a t o r im oberen Wettersteinkalk (Mittel-Trias) der Ostalpen.Geol. Rundschau 65, 593-165. L A B U D E , C. (1983): S e d i m e n t o l o g i e , S u b s l d e n z und die V e r b r e i t u n g sandschaliger und planktonischer F o r a m i n i f e r e n im M a a s t r i c h t des zentralen Apennin Italien~.- Thesis Univ. Tfibingen, 95 p. LIPPMANN, F. (1973): Sedimentary carbonate minerals, 228 p. ( S p r i n g e r Verlag, Berlin). LOCKRIDGE, I . P . & SCHOLLE, P . A . ( 1 9 7 8 ) : N i o b r a r a g a s in e a s t e r n C o l o r a d o a n d n o r t h w e s t e r n K a n s a s . - Rocky M o u n t . A s s o c . G e o l . Symp. 1978, 35-49. LOWRIE, W. & ALVAREZ, W. ( 1 9 7 7 ) : U p p e r C r e t a c e o u s - P a l e o c e n e magnetic stratigraphy at Gubbio, Italy. III Upper Cretaceous magnetic stratigraphy.G e o l . S o c . Am. B u l l . 8 8 , 3 7 4 - 3 7 7 . LUTERBACHER, H . P . & PREMOLI SILVA, I . ( 1 9 6 2 ) : N o t e p r @ l i m i n a i r e s u r une revision du profile de Gubbio, Italie.Riv. Italiana Paleontologia e Stratigrafia 68, 2 5 3 - 2 8 8 . MANUS, R . W . & COOGAN, A . H . ( 1 9 7 4 ) : Bulk volume reduction and pressure-solution derived cement.- Jour. Sed. Petrol. 44, 466-471. MARSCHNER, H. ( 1 9 6 8 ) : R e l a t i o n s h i p between carbonate grain size and noncarbonate content in carbonate sedimentary rocks.i n : MULLER, G. & F R I E D M A N , G . M . ( e d s . ) : R e c e n t d e v e l o p m e n t s in c a r b o n a t e sedimentology in central Europe, 55-57 (Springer, Berlin). MATTER, A. (1974): Burial diagenesis of pelitic and carbonate deep-sea sediments from the Arabian Sea.- Init. Rep. DSDP 23, 421-470. MATTES, B.W. & MOUNTJOY, E.W. (1980): B u r i a l dolomitization of the Upper Devonian Miette buildup, Jasper National Park, Alberta.- Soc. Econ. Paleont. Mineral. Spec. Publ. 28, 259-297. MAYER, L.A. (1980): Deep-sea carbonates: Physical property relationships and the origin of high-frequency acoustic reflectors.- Marine Geology 38, 165-183. MC LEAN, D.M. ( 1 9 8 2 ) : D e c c a n v o l c a n i s m and the Cretaceous-Tertiary transition scenario: A unifying causal mechanism.i n : RUSSELL, D . A . & R I C E , G. ( e d s . ) : Cretaceous-Tertiary extinctions and possible terrestrial and extraterrestrial c a u s e s . N a t . Mus. C a n a d a Syllog. 39, 143-144.
203
MEISCHNER, K . D . ( 1 9 6 4 ) : Allodapische Kalke; Turbidite in Riff-nahen Sedimentationsbecken.Develop. Sedimentology 3, 156-191. MERINO, E.; ORTOLEVA, P . & STRICKHOLM, P . ( 1 9 8 3 ) : Generation of evenly-spaced pressure-solution seams during (late) diagenesis: a kinetic theory.Contrib. Mineral. Petrol. 82, 360-370. MEYERS, W . J . & HILL B . E . ( 1 9 8 3 ) : Q u a n t i t a t i v e studies of compaction in Mississippian skeletal limestones, New M e x i c o . - J o u r . S e d . P e t r o l . 53, 321-242. MICHARD, G. ( 1 9 7 1 ) : Contribution ~ l'@tude de l'entrafnement des @l@ments t r a c e s darts l e c a l c i t e lors de s a p r @ c i p i t a t i o n . Chem. Geol. 8, 311-327. MILANKOVITCH, M. ( 1 9 3 0 ) : Mathematische K l i m a l e h r e und a s t r o n o m i s c h e T h e o r i e d e r K l l m a s c h w a n k u n g e n . - i n : E0PPEN, W. & GEIGER, R. ( e d s . ) : Handbuch d e r K l i m a t o l o g i e , v o l . 1, 176 p . ( B o r n t r a e g e r , Berlin). MIMRAN, Y. ( 1 9 7 7 ) : Chalk deformation and large-scale migration of calcium carbonate.S e d i m e n t o l o g y 24, 3 3 3 - 3 6 0 . M I T R A , S . & BEARD, W . D . ( 1 9 8 0 ) : Theoretical models of porosity reduction by p r e s s u r e solution for well-sorted sandstones.Jour. Sed. Petrol. 50, 1347-1360. MORROW, D.W. & MAYERS, J . R . ( 1 9 7 7 ) : S i m u l a t i o n o f l i m e s t o n e d i a g e n e s i s - a m o d e l b a s e d on s t r o n t i u m d e p l e t i o n . Canadian Jour. Earth Sci. 15, 376-396. MUCCI, A. & MORSE, J . W . ( 1 9 8 3 ) : The incorporation o f Mg2+ a n d S r 2+ into calcite overgrowths: influences of growth rate and solution composition.Geochim. Cosmochim. Acta 47, 217-233. NEUGEBAUER, J . ( 1 9 7 3 ) : The d i a g e n e t i c problem of chalk.- Neues Jahrb. Geol. Pal~ontol. Abh. 1 4 3 , 1 3 6 - 1 5 6 . -- (1974): Some a s p e c t s of cementation in chalk.in: HS0, K.J. & JENKYNS, C. ( e d s . ) : P e l a g i c s e d i m e n t s : on l a n d an d u n d e r t h e s e a . Int. Assoc. Sedim. Spec. Publ. !, 149-176. O'KEEFE, J.D. & AHRENS, T . J . (1982): Impact mechanics of the Cretaceous-Tertiary extinction bolide.Nature 298, 123-127. OSMOND, J . K . (1981): Quarternary deep-sea sediments: Accumulation rates and geochronolgy.in: Emilianl, C. ( e d . ) : The oceanic lithosphere, 1329-1371. P L E S S M A N N , W. ( 1 9 6 4 ) : Gesteinsl~sung, ein Hauptfaktor beim Schieferungsprozess.Geol. Mitt. 4, 69-82. -- (1966): Diagenetische und k o m p r e s s i v e V e r f o r m u n g i n d e r O b e r k r e i d e des Harz-Nordrandes s o w i e im F l y s c h yon San Remo.- Neues Jahrb. Geol. Pal~ontol. Mh. 8 , 4 8 0 - 4 9 3 . P E R R I E R , R. & Q U I B L I E R , J . ( 1 9 7 4 ) : Thickness changes in sedimentary layers during compaction history; methods for quantitative evaluation.Am. A s s o c . P e t r o l e u m G e o l . B u l l . 3 8 , 5 0 7 - 5 2 0 . PINGITORE, N.E. (1976): Vadose and phreatic diagenesis: Processes, products, and their recognition in corals.Jour. Sed. Petrol. 46, 985-1006. -- (1982): The rule of diffusion during carbonate diagenesis.Jour. Sed. Petrol. 52, 2 7 - 3 9 . PIPER, D.J.W. (1978): Turbidite muds and s i l t s on d e e p - s e a f a n s an d abyssal plains.in: STANLEY, D.J. & KELLING, G. (eds.): Sedimentation in submarine canyons, fans and trenches, 163-176 (Hutchinson & Ross, Stoudsburg). POLLASTRO, R.M. & MARTINEZ, G.J. (1985): Whole-rock, insoluble residue, an d c l a y m i n e r a l o g i e o f m a r l , c h a l k , and b e n t o n i t e ; Smoky Hill shale member, Niobrara Formation near Pueblo, Colorado depositional and diagenetic implications.Soc. Econ. Paleont. Mineral. field trip guidebook 4, 215-222. PRAY, L . C . ( 1 9 6 0 ) : Compaction in calcilutites.G e o l . S o c . Am. B u l l . 7 1 , p . 1946 ( a b s t r a c t ) . -- (1966): Informal c o m m e n t s on c a l c i u m c a r b o n a t e c e m e n t a t i o n . Soc. Econ. Paleont. Mineral. Techn. Session on Lithification and Diagenesis, St. Louis Meetings.
204
PREMOLI S I L V A , I . ( 1 9 7 7 ) : Upper Cretaceous-Paleocene stratigraphy at Gubbio, Italy. II Blostratigraphy.G e o l . S o c . Am. B u l l . 88, 371-374. RAMPINO, M . R . ( 1 9 8 2 ) : A n o n - c a t a s t r o p h i s t explanation for the iridium anomaly at the Cretaceous-Tertiary b o u n d a r y . - G e o l . S o c . Am. S p e c . Paper 190, 455-460. RAMSAY, J . G . & HUBER, M . I . ( 1 9 8 3 ) : The t e c h n i q u e s of modern structural g e o l o g y , v o l . 1: s t r a i n analysis, 307 p . ( A c a d e m i c P r e s s , L o n d o n ) . RENARD, M. ( 1 9 7 9 ) : A s p e c t g e o c h i m i q u e de l a d i a g e n e s e d e s c a r b o n a t e s . B u l l du B . R . G . M . ( 2 ) I V , 1 3 3 - 1 5 2 . RICKEN, W. ( 1 9 8 5 a ) : E p i c o n t i n e n t a l marl-limestone alternations: Event deposition and diagenetic bedding (Upper Jurassic, Southwest Germany).i n : BAYER, U. & S E I L A C H E R , A. ( e d s . ) : S e d i m e n t a r y an d evolutionary cycles.Lecture Notes in Earth Sciences !, 127-162. -- (1985b): Diagenetische Bankung: Zementbllanz, Geochemie und F a z i e s von Kalk-Mergel-Wechselfolgen.Dissertation U n i v . T f i b i n g e n , 242 p . - - & HEMLEBEN, C. ( 1 9 8 2 ) : Orig~n of marl-limestone alternations (Oxford 2) i n Southwest Germany.- in: EINSEI,E, G. & SEILACHER, A.
(eds.): Cyclic and event stratification, 63-71 (Springer, Berlin). RIEKE, H.H. & CHILINGARIAN, G.V. (1974): Compaction of argillaceous sediments.Develop. S e d l m e n t o l o g y 16, 424 p. ( E l s e v l e r , Amsterdam). R I T T E N H O U S E , G. (1971a): P o r e - s p a c e r e d u c t i o n by solution and cementation.- Am. Assoc. Petroleum Geol. Bull. 55, 80-91. --
(1971b): Mechanical compaction of sands containing different percentages of ductile grains: a znenretical approach.Am. A s s o c . Petroleum Geol. Bull. 55, 92-96. ROBIN, P . Y . F . (1978): Pressure solution at grain to grain contacts.Geochim. Cosmochim. A c t a 42, 1382-1389. R O L L , A. ( 1 9 7 4 ) : LangfrIstige Reduktion der M~chtigkeit yon Sedimentgesteinen und ihre Auswirkung - eine 0bersicht.Geol. J a h r b . A14, 76 p . ROGGENTHEN, W.M. & NAPOLEONE, G. ( 1 9 7 7 ) : U p p e r C r e t a c e o u s - P a l e o c e n e magnetic stratigraphy at Gubbio, Italy. IV U p p e r M a a s t r i c h t i a n Paleocene magnetic stratigraphy.G e o l . S o c . Am. B u l l . 8 8 , 3 7 8 - 3 8 2 . SAITO, T. & BURCKLE, L . H . ( 1 9 7 5 , e d s . ) : Late Neogen epoch boundaries.Micropaleontology P r e s s , New Y o r k ) . SAYLES, F.L. & MANHEIM, F . T . ( 1 9 7 5 ) : Interstitial solutions and diagenesis in deeply buried marine sediments: results from the DSDP.- Geochim. Cosmochim. A c t a 39, 1 0 3 - 1 2 7 . SCHLAGER, W. ( 1 9 8 0 ) : Mesozoic calciturbidites in deep sea drilling project h o l e 416A. R e c o g n i t i o n of a drowned carbonate platform.Init. R e p . DSDP 5 0 , 7 3 3 - 7 4 9 . SCHLANGER, S . O . & DOUGLAS, R . G . ( 1 9 7 4 ) : P e l a g i c o o z e - c h a l k - l i m e s t o n e transition an d i t s i m p l i c a t i o n s for marine stratigraphy.in: HS0, K . J . & JENKINS, C. ( e d s . ) : Pelaglc sediments: on l a n d and u n d e r t h e sea.Intern. Assoc. Sedim. Spec. Publ. !, 117-148. SCHMIDT-KALER, H. ( 1 9 6 2 ) : Stratigraphische und tektonische U n t e r s u c h u n g e n im Malm d e s n o r d 0 s t l i c h e n Ries-Rahmens.Erlanger g e o l . Abh. 4 4 , 51 p . SCHMOKER, J . W . & HALLEY, R . B . ( 1 9 8 2 ) : C a r b o n a t e p o r o s i t y versus depth: a predictable relation for South Florida.Am. A s s o c . P e t r o l e u m G e o l . B u l l . 66, 2561-2570. SCHNEIDER, F.K. (1964): Erscheinungsbild und Entstehung der r h y t h m i s c h e n Bankung d e r a l t k r e t a z i s c h e n Tongesteine Nordwestfalens und der Braunschweiger Bucht.Fortschr. Geol. Rhefnland u. W e s t f a l e n Z, 3 5 3 - 3 8 2 . SCHOLLE, P . A . ( 1 9 7 7 ) : Chalk diagenesis an d i t s r e l a t i o n to petroleum exploration: Oil from chalks, a modern miracle?Am. A s s o c . Petroleum Geol. Bull. 61, 982-1009.
205
--
; ARTHUR, M.A. & EKDALE, A . A . ( 1 9 8 3 ) : Pelagic sediments.in: SCHOLLE, P . A . ; BEBOUT, D . G . & MOORE, C . H . (eds.): Carbonate depositional environments.Am. A s s o c . P e t r o l e u m G e o l . Mem. 3 3 , 620-691. SCHWARZACHER, W. & F I S C H E R , A . G . ( 1 9 8 2 ) : L i m e s t o n e - s h a l e b e d d i n g an d perturbations of the earth's orbit.i n : E I N S E L E , G. & SEILACHER, A. ( e d s . ) : Cyclic and event stratiIlcation, 72-95 (Springer, Berlin). S E I B O L D , E. ( 1 9 5 2 ) : Chemische Untersuchungen z u r B a n k u n g im u n t e r e n Malm S c h w a b e n s . - N e u e s J a h r b . G e o l . P a l ~ o n t o l . Abh. 9 5 , 3 3 7 - 3 7 0 . -- & SEIBOLD, I. (1953): Foraminiferenfauna und Kalkgehalt eines Profils im g e b a n k t e n u n t e r e n Malm S c h w a b e n s . Neues Jahrb. Geol. Pal~ontol. Abh. 9 8 , 2 8 - 8 6 . - - & - - ( 1 9 5 9 ) : K a l k b a n k u n g und F o r a m i n i f e r e n . Eclog. geol. Helv. 51. SEILACHER, A.; ANDALIB, F.; DIETEL, G. & GOCHT, H. ( 1 9 7 6 ) : Preservational history of compressed Jurassic ammonites from southern Germany.- Neues Jahrb. Geol. Pal~ontol. Abh. 1 5 2 , 3 0 7 - 3 5 6 . SHINN, E.A.; HALLEY, R.B.; HUDSON, J.H. & LIDZ, B.H. (1977): Limestone compaction - an enigma.- Geology 5, 21-24. SIMPSON, J. (1985): S t y l o l i t e c o n t r o l l e d l a y e r i n g in an homogenous limestone: pseudo-bedding produced by b u r i a l d i a g e n e s i s . Sedimentology 3-3, 495-505. SPROVIERI, R. (1968): La serie P l i o - P l e i s t o c e n l c a di A g r i g e n t o . Giornale di Geologia 35, 295-301. STEINEN, R.P. (1978): On the diagenesis of lime mud: scanning electron m i c r o s c o p i c o b s e r v a t l o n s on s u b s u r f a c e m a t e r l a l from B a r b a d o s , W.I.- Jour. Sed. Petrol. 4-8, 1139-1147. S U J K O W S K I , Z.L. (1958): Diagenesis.- Am. Assoc. Petroleum Geol. Bull. 42, 2692-2717. T H I E D E , J.; V A L L I E R , T . L . et al. (1981): Site 463: W e s t e r n MidPacific Mountains.- Init. Repts. DSDP 62, 33-156. THIERMANN, A. (1973): Erl~uterungen zu Blatt 3710 Rheine.- Geol. Karte 1:2500 yon Nordrhein-Westfalen, 174 p. T R U R N I T , P. & AMSTUTZ, G.C. (1979): Die Bedeutung des R~ckstandes yon Druck-L~sungsvorg~ngen fur stratlgraphische Abfolgen, Wechsellagerung und L a g e r s t ~ t t e n b i l d u n g . - Geol. R u n d s c h a u 6-8, 1107-1124. V I N O P A L , R.J. & COOGAN, A.H. (1978): Effect of particle shape on the p a c k i n g of c a r b o n a t e s a n d s and g r a v e l s . - Jour. Sed. Petrol. 48, 7-24. V E I Z E R , J. ( 1 9 7 7 a ) : D i a g e n e s i s of p r e - Q u a r t e r n a r y c a r b o n a t e s as indicated by tracer studies.- Jour. Sed. Petrol. 47, 565-581. -- (1977b): Geochemistry of lithographic limestones an d d a r k m a r l s from the Jurassic of southern Germany.Neues Jahrb. Geol. Palaontol. Abh. 1 5 3 , 1 2 9 - 1 4 6 . -(1978): Simulation of limestone diagenesis - a m o d e l b a s e d on strontium depletion: Discussion.Canadian Jour. Earth Sci. 15, 1683-1685. - - & DEMOVIC, R. ( 1 9 7 4 ) : Strontium as a tool in facies analysis.Jour. Sed. Petrol. 44, 93-115. WALKER, R . G . ( 1 9 8 4 ) : S h e l f a n d s h a l l o w m a r i n e s a n d s . - i n : WALKER, R.G. (ed.): Facies models (second edition), 141-170 (Geol. Assoc. Canada, Reprint Series 1). WALTER, L.M. & MORSE, J.W. (1984): Reactive surface area of skeletal carbonates during dissolution: e f f e c t of g r a i n s i z e . - Jour. Sed. Petrol. 54, 1081-1090. WALTHER, M. (1983): D i a g e n e s e g e b a n k t e r K a r b o n a t e im U n t e r k a r b o n nordwest Irlands.- Thesis Univ. G6ttingen, 76 p. W A N L E S S , H.R. (1979): Limestone response to stress: pressure solution and dolomitization.- Jour. Sed. Petrol. 49, 437-462.
206
WEBER, R. (1951): Die Verbreltung yon Pollen und Sporen in bltuminSsen Mergeln des Lias Alpha, Lias Epsilon und im Opalinuston W~rttemberglscher Fundorte.- Thesis Univ. Stuttgart, 85 p. WEDEPOHL, K.H. (1970): Geochemische Daten yon sedlment~ren K a r b o n a t e n und Karbonatgesteinen in i h r e m f a z l e l l e n u n d p e t r o g r a p h i s c h e n Aussagewert.- Verh. Geol. Bundesanstalt Wien 1970,4, 692-705. -- (1979): G e o c h e m i s c h e A s p e k t e der D i a g e n e s e yon marinen Ton- und Karbonatsedimenten.- Geol. Rundschau 68(3), 833-847. WEILER, H. ( 1 9 5 7 ) : U n t e r s u c h u n g e n zur Frage der Kalk-MergelSedimentation im Jura Schwabens.- Thesis Univ. T~bingen, 57 p. WEPFER, E. (1926): Die Auslaugungsdiagenese, ihre Wirkung auf Gestein und Fossilinhalt.- Neues Jahrb. Mineral. Beilagen Bd. 5 4 B, 17-94. WETZEL, A. (1981): Okologische und stratigraphische Bedeutung biogener Gef~ge in quartRren Sedimenten am NW-afrikanischen Kontinentalrand.- "Meteor" Forsch.- Ergebnisse C34, 1-47. WEYL, P.K. (1959): Pressure solution and the force of crystallization - a phenomenological theory.Jour. Geophys. Research 64, 2001-2025. WOLFE, M.J. (1968): L i t h i f i c a t i o n of a carbonate mud: Senonian chalk in Northern Ireland.- Sedimentary Geology 2, 263-290. ZANKL, H. (1969): Structural textural evidence of early lithification in flne-gralned carbonate rocks.- Sedimentology I_22, 241-256. ZIEGLER, B. (1977): The "White" (Upper) Jurassic in southern Germany.Stuttgarter BeitrRge Naturkunde B26, 79 p.
SUBJECT
INDEX
absolute clay content, see standardized noncarbonate fraction absolute clay content per bed, 143-145; 7O algae sponge reef, Figs. 30,92
Fig.
bed by bed correlation, 176-181; Figs. 85-86 bedding rhythm, dlagenetic enhancement, 106-111; Fig. 54-55 differential c o m p a c t i o n , 1 0 9 - 1 1 0 ; F i g . 55 d i m i n u a t i o n of v a r i a t i o n s in c a r b o n a t e maxima, 107-109; F i g . 54 i n c l a y r i c h s e d i m e n t , 134 in l i t h i f i e d alternations, 40; F i g . 18; 44; F i g s . 2 0 , 4 9 ; 5 2 - 5 3 ; F i g . 25; 63; Figs. 28,34,37,40 in unlithified alternations, 37; F i g . 15 primary control, 115,142,176-181; Figs. 85-86 r e d u c t i o n in primary c a r b o n a t e oscillations, 1 0 6 - 1 0 7 ; T a b l e 13 s i m u l a t i o n m o d e l s , 1 1 2 - 1 1 4 ; F i g . 56 t y p e s , 1 1 4 - 1 1 6 ; F i g . 57; 139-142 bioturbation, 9-10,37 m i x i n g , 189; F i g . 93 s e l e c t i v e c e m e n t a t i o n , 1 0 - 1 1 , 56; F i g s . 4 , 2 2 , 5 6 , 2 8 ; 122; F i g . 59 calcareous
pressure
177-118; Fig.
shadow s t r u c t u r e ,
Fig.
30;
c a l c a r e o u s t u r b i d i t e and t e m p e s t i t e , c e m e n t a t i o n , 100-105; F i g s . 50-53 d e p o s i t i o n , 1 8 2 - 1 8 9 ; F i g s . 86, 8 8 - 8 9 , 186; F i g .
alternations, Figs. 19,21,24,27,33, 3 5 , 3 8 , 4 1 ; T a b l e 12 relationship to compaction in unlithifled alternations, 37; Fig. 17 carbonate curves, in limestone layers, 87-90; Table II; 91-96; Fig. 44-46 in types of marl limestone alternations, 114-116; Fig. 57; Figs. 68-69 maximum carbonate content, 107-109; Fig. 54 relationship to deposltional events, 99-I05; Figs. 49-53 carbonate mass balance calculation, 17,23-28; Figs. 8,11-13; 149-150 de~%mpactlon, 23-25; Figs. 11-13 errors, 21-22 in marl-llmestone alternations, 40-42; Fig. 19; 48; Fig. 21; 52; Fig. 24; 5 4 - 5 6 ; F i g . 27; 58; F i g . 29; 65; F i g . 33; 69; F i g . 35; 77; F i g s . 3 8 - 3 9 ; 81;
58; T a b l e 15
91-93 calcllutite fan d e p o s i t ,
in calcareous pressure shadow structures, 119; Table 15 in existing alternations, 84; Table II primary, 37; Fig. 15; 42,48,54-56,58, 65,69,77,81,84-86; Table II, 129-130, 1 5 0 - 1 5 3 ; F i g . 72 r e l a t i o n s h i p to compaction in l i t h i f i e d
88-89
carbonate content, at n e u t r a l v a l u e , 28-30; F i g s . 12,14; 8 5 - 8 6 ; T a b l e 11; F i g s . 4 3 , 7 7 , 7 8 a t w e a t h e r i n g b o u n d a r y , 2 9 - 3 0 ; F i g . 14; 63; F i g . 32; 8 5 - 8 6 ; T a b l e 11; F i g s .
4s,5v c a l c u l a t i o n u s i n g c o m p a c t i o n law, 14 determination, 7 f r a c t i o n s (primary, cemented, relic, dissolved), 28; Figs. 11-13; 160; Fig. 79
Fig.
41
restrictions for application, sampling, 22
19-21
carbonate neutral value, 28-30; Figs. 12,14; 85-86; Table ii; Fig. 43; Figs. 77-78 relatlonsblp to weathering boundary, 86; Fig. 43 cement content, content o f minor elements, 164; Fig. 80
determination, 2 3 - 2 8 ; Figs. 1 1 - 1 3 ; 1 2 5 - 1 3 0 ; Figs. 6 3 - 6 4 , 150 in m a r l - l i m e s t o n e a l t e r n a t i o n s , 84; T a b l e 11 nomogram, 128; F i g . 64 cement number, 128-129 c e m e n t a t i o n i n f i n e - g r a i n e d c a r b o n a t e s , 19, 117-123,130-139; F i g s . 65-68 calculation, 23-28; F i g s . 11-13; 125-130; F i g s . 63-64
208
in calciturbidites, in m a r l - l i m e s t o n e
100-105; F i g s .
50-53
alternation,
135-139;
F i g s . 67-68 i n p r e s s u r e shadow s t r u c t u r e s ,
117-118;
F i g . 58; T a b l e 15 c e m e n t a t i o n zone, 28-30; F i g s .
copying of primary stratification, 142 in event sequences, 100-105; Figs. 50-53 in marl-llmestone alternations,
13-14; Fig.
69;
141 chemical compaction, see also pressure dissolution,
130-132; F i g .
65-66
compaction, at the onset of llthlficatlon, 30,84; Table Ii; 113,115; Fig. 56 at the n e u t r a l c a r b o n a t e v a l u e , 166-169;
F i g . 81-82 calculation using compaction law, 14; Flg. 7; 149 c h e m i c a l , 130-132; F i g s . 65-66 differential, 63; F i g s . 3 0 - 3 1 ; 1 0 9 - 1 1 1 ; Fig.
55; T a b l e 14; 1 2 1 - 1 2 2 ; F i g .
164-171; Figs.
59;
81-82
in c a l c a r e o u s p r e s s u r e shadow s t r u c t u r e s , 119; T a b l e 15 measurement, direct, 9-10; Fig. 4 m e a s u r e m e n t , i n d i r e c t , 1 0 - 1 1 ; F i g . 4; T a b l e 1; 5 6 - 5 7 ; F i g . 28 mechanical, 109,115,121-122; Figs. 59-60; 130-132; Figs. 65-66 r e l a t i o n s h i p t o CaCO3 i n l i t h l f i e d alternations, Figs. 19,21,24,27,29, 33,35,38,41 r e l a t i o n s h i p t o CaCO3 i n u n l l t h t f t e d alternations, 37; F i g . 17 r e l a t i o n s h i p to cement c o n t e n t , 128-128; F i g . 64 t o t a l , in m a r l - l i m e s t o n e a l t e r n a t i o n s ,
139; F i g . 69 t r a n s f o r m a t i o n i n t o p o r o s i t y , 31 c o m p a c t i o n l a w , 1 2 - 1 7 ; F i g . 5 - 7 ; 127; F i g . 1 3 0 - 1 3 2 ; F i g s . 6 5 - 6 6 ; 1 5 1 - 1 5 3 ; F i g . 72
d e c o m p a c t t o n , 25; F i g s . 1 5 , 3 7 p o r o s i t y , 2 0 - 2 1 ; F i g . 10; 2 3 - 2 5 ; F i g s . 1 1 - 1 3 ; 83; F i g . 4 I ; 84; T a b l e 11; in f l n e - g r a t n e d
31 diagenetic bedding, c a u s e s , 117-121;
carbonates,
135-139; F i g s .
concept, 2; Flg. 1
67-68
limestone layers, 91-105; Figs. 44-53 quantification, 5-32; Figs. 3 - 8 , 1 1 - 1 4 ; 147-153; F i g . 7 1 - 7 2 s i m u l a t i o n m o d e l s , 1 1 2 - 1 1 4 ; F i g . 56; 130-139; F i g s . 65-68; 151-153; Fig. 72 t r a n s i t i o n b e t w e e n d i s s o l u t i o n and c e m e n t a t i o n z o n e , F i g . 14; 141; F i g . 69 t y p e s , 8 7 - 9 0 ; T a b l e 12; 1 1 4 - 1 1 8 ; F i g . 57; 1 3 9 - 1 4 2 ; F i g . 69 diagenetlc system, c a r b o n a t e , 19-21 minor elements in dissolution zone, 187-170; Table 18 differential c o m p a c t i o n , 63; Figs. 3 0 - 3 1 ; 1 0 9 - 1 1 0 ; F i g . 55; 1 2 1 - 1 2 2 ; F i g . 59 d o l o m l t i z a t i o n , 169-170 e n h a n c e m e n t o f b e d d i n g r h y t h m , 110 e n r i c h m e n t of minor e l e m e n t s , 164-171; F i g s . 81-82 enrichment of particles, 110-111,164-166 f a c t o r o f e n r i c h m e n t , 111; T a b l e 14 petrographic changes, Ill differential s t r e s s , 117-121 d i f f u s i o n , 20; F i g . 9; 123 d i s s o l u t i o n c l e a v a g e , 142 d i s s o l u t i o n s e a m s , 20; F i g . 30; 6 1 , 1 4 1 ; F i g . 69 d i s s o l u t i o n z o n e , 2 8 - 3 0 ; F i g s . 1 3 - 1 4 ; F i g . 69; 141 dolomittzation, 169-170 distribution coefficient, 171 dolomtttzatton, 169-170
63;
application, 9 1 - 9 4 ; 1 0 7 - 1 0 6 ; F i g . 54; 1 3 0 - 1 3 8 ; F i g s . 6 5 - 6 7 ; 147 d e r i v a t i o n , 1 2 - 1 7 ; F i g s . 5-7 nomogram, 16; F i g . 7 prerequisites for application, 4,12 Cretaceous-Tertiary boundary, 71-75; Figs. 3 6 - 3 7 ; 7 7 - 7 9 , 8 3 ; Fig. 42
149-150 density gradient
33-90;
Figs. 15-43
e n r i c h m e n t i n d i s s o l u t i o n zone minor elements, 164-171; Figs. 81-82 particles, fossils, 110-111 factor calculating the dlagenetlc enhancement of primary carbonate fluctuations, 27; Fig. 13; 30; Fig. 14; 42,52,48,56,58,65,69,77, 81,85; Table 11 graded lutite beds, 186-189; Figs. 88,93 limestone layers, c a r b o n a t e c u r v e s , 8 7 - 9 0 ; T a b l e 12; 9 1 - 9 8 ; F i g s . 44-46 c e n t e r o f c e m e n t a t i o n , F i g . 1; 9 1 , 9 9 - 1 0 4 ; F i g . 49; 1 0 6 - 1 0 7 , 1 3 8 ; F i g . 68 relationship to deposltlonal events, 99-105; Figs. 49-53
209
thickness, content, lithtftcatton
relationship
to carbonate
distribution
97-98; F i g s .
46-48
incongruent dissolution,
of fine-grained
19,120-121,135-139; Figs. onset,
carbonates,
reaction
30,42,48,52,56,61,65,69,77,81,
t i m e , 154; F i g .
relationship 81-82
1 2 1 - 1 2 2 ; F i g . 60; 139; T a b l e 16; Fig. 72 t i m i n g , 31-32
73
to compaction, 164-171; F i g s .
relationship to total carbonate content, 158-160; F i g s . 77-78 strontium
marl-llmestone a l t e r n a t i o n ,
Angles 1 section, Vocontlan Basin, 44-48; F i g s . 20-22 Angles 2 section, Voconttan Basin, 48-52; F i g s . 22-24 Angles 3 section, Vooonttan Basin, 52-56; Figs. 22,25-27 F o s s o m b r o n e s e c t i o n , The M a r c h e s , 1 0 0 - 1 0 4 ; F i g s . 50-52 Gelslngen section, South German Basin, 105; Flg. 52, Flg. 86 Gubblo 1 section, Umbrlan Apennines, 7 1 - 7 9 ; Figs. 36-39 Gubbio 2 section, Umbrlan Apennines,
79-81; Figs. 36,40-41 Gubbto 3 s e c t i o n , Umbrlan A p e n n i n e s , 8 1 - 8 4 location, 2-4; Fig. 2 Logls du Pin section, SE France, 56-61; Figs. 28-29 Neuffen i section, South German Basin,
6 3 - 6 6 ; Figs. 32-33,36,48-86 Neuffen 2 section, South German Basin,
67-69; F i g s . 34-35,48,86 P o r t o Empedocle section, 35-38; Figs. 15-17,22 p r i m a r y d e p o s i t i o n , 174-190; F i g s . 84-93; 38-42;
s i m u l a t i o n m o d e l s , 1 1 2 - 1 1 4 ; F i g . 56; 130-139; F i g s . 65-68; 151-153; Fig. t y p e s , 8 7 - 9 0 ; T a b l e 12; 1 1 4 - 1 1 6 ; F i g . 139-142; Fig.
171 154-156; F i g s .
7 4 - 7 5 ; T a b l e 17
67-68
194; F i g . 94 R h e l n e s e c t i o n , N o r t h German B a s i n , F i g s . 18-19 s a m p l e s and a n a l y s e s , 34; T a b l e 2
coefficient,
content,
noncarbonate fraction
158 in l i m e s t o n e s ,
12
pore solution, c o m p o s i t i o n , 171-173; T a b l e 19; F l g . 83 expelled via compaction, 123 porosity, at the onset of llthlflcatlon, 31,84; Table ii; 121-122 burial reduction in calcilutltes
(calcite), 3 1 , 1 2 4 ; F i g . 61 c a l c u l a t i o n u s i n g t h e c o m p a c t i o n l a w , 14 d e c o m p a c t t o n , 2 0 - 2 1 ; F i g . 10; 84; T a b l e 11 determination, 7 inversion during burial, 123-125; Figs. 60-61 primary in c a l c i l u t i t e s , 21 r a p i d d e t e r m i n a t i o n in l t t h i f l e d c a r b o n a t e s , 149; F i g . 62 r e l a t i o n s h i p t o CaCO S i n llthlfied carbonates, Figs. 19,21,24,27,29,33, 3 5 , 3 8 , 4 1 , 6 2 ; 125 r e l a t i o n s h i p t o CaCO3 i n u n l t t h i f t e d c a r b o n a t e s , 37; F i g . 16 t r a n s f o r m a t i o n i n t o c o m p a c t i o n , 31 p r e s s u r e d i s s o l u t i o n o f CaCO3, 1 1 7 - 1 2 1 ; F i g . 69 r a p i d methods, 147-53; F i g s .
71-72
sedimentary lags,
87-89
182; F i g s .
s e d i m e n t a r y o v e r b u r d e n , 84; T a b l e 11 72 57;
69
mechanical compaction, 109,115,121-122; Figs.
59-60; 130-132; F i g s . 65-66 i n f l u e n c e on b e d d i n g r h y t h m , F i g s . 4 4 , 4 6 ; 95-96,107-111,115-116 M i l a n k o v i t o h c y c l e s , 1 - 2 , 1 1 4 , 1 9 4 ; F i g . 94 m i n o r e l e m e n t mass b a l a n c e c a l c u l a t i o n , 160-164; F i g s . 79-80 minor e l e m e n t s in the c a r b o n a t e f r a c t i o n , c o n c e n t r a t i o n , 50; F i g s . 2 3 , 3 4 ; 79; F i g . 40; 1 5 6 - 1 6 0 ; F i g . 76 c o n c e n t r a t i o n in the v a r i o u s c a r b o n a t e fractions, 164; F i g . 80 d e t e r m i n a t i o n , 1 5 4 - 1 5 6 ; F i g . 74; T a b l e 17
a t t h e o n s e t o f c e m e n t a t i o n , 84; T a b l e 11; 1 2 1 - 1 2 2 ; F i g . 60 s e d i m e n t a t i o n r a t e s in m l c r t t l c c a r b o n a t e s ,
42,48,52,56,61,65,69,77,81 Selbold model, 143-145; Flg. 70 simulation models, bedding rhythm, 112-114; Flg. 56 carbonate curves in cementation zone,
95-96; F i g . 46 d l a g e n e t l c s e p a r a t i o n , 130-139; F i g . 6 5 - 6 8 s l u m p i n g , 186; F i g . 90 South German Upper J u r a s s i c , 1 7 4 - 1 9 0 ; F i g s . 84-93 s t a n d a r d i z e d noncarbonate f r a c t i o n , 12-14; F i g s . 5 - 7 ; 22-23,130-132; F i g s . 6 5 - 6 7 , 7 2 ; 143
210
i n f l u e n c e on t h e t y p e o f b e d d i n g , F i g . 1 0 7 - 1 1 2 , 115-116 rapid determination,
147-149; F i g .
46;
71
r e l a t i o n s h i p t o CaCO3 i n l i t h i f i e d c a r b o n a t e s , 40; T a b l e 3; F i g . 41; 46; T a b l e 4; F i g . 21; 50; T a b l e 5; F i g . 24; 53; F i g . 26; 5 6 - 5 7 ; T a b l e 6; 65; T a b l e 7; 67; T a b l e 8; 75; T a b l e 9; F i g . 38; 81; T a b l e 1O; 84; T a b l e 1 1 r e l a t i o n s h i p to cement c o n t e n t , 127-128; Fig. 64 s t r o n t i u m c o n t e n t , 158 stylolites, 20; F i g s . 9 , 3 0 ; 6 1 , 7 3 ; F i g s . 37,40; 79,141
submarine channel, Figs. 87,89-91 sulfate reduction,
30,31;
182-187; F i g s .
170-171
t e m p e s t i t e , 105; F i g s . 5 3 , 8 8 ; 186 trace elements, see minor elements "underbed", "upperbed", 99-104; Figs. 49-52
w e a t h e r i n g b o u n d a r y , 2 9 - 3 0 ; F i g . 14; 63; F i g . 32; 85; T a b l e 11; 86; F i g s . 4 3 , 5 7 relationship to carbonate neutral value, 86; F i g . 43
