Global bio-events: a critical approach : proceedings of the first international meeting of the IGCP Project 216, ''Global biological events in earth history''

Lecture Notes in Earth Sciences Edited by Somdev Bhattacharji, Gerald M. Friedman, Horst J. Neugebauer and Adolf Seilacher

8 Global Bio-Events A Critical Approach Proceedings of the First International Meeting of the IGCP Project 216: "Global Biological Events in Earth History"

Edited by Otto H. Walliser

Springer-Verlag Berlin Heidelberg NewYork London Paris Tokyo

Editor Prof. Dr. Otto H. Walllser University of GSthngen Institute and Museum for Geology and Palaeontology Goldschmidt-Str. 3, D-3400 Gottingen, FRG

ISBN 3-540-17180-0 Springer-Verlag Berlin Heidelberg New York ISBN 0-38?- 17180-0 Springer-Verlag New York Berlin Heidelberg

This work is subject to copyright. All rights are reserved, whether the whole or part of the material is concerned, specifically those of translatzon,reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar 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 payable to "Verwertungsgesellschaft Wort", Munich © Springer-Verlag Berhn Heidelberg 1986 Printed in Germany Printing and binding' Druckhaus Beltz, Hemsbach/Bergstr 2132/3140-543210

PREFACE This 5.

volume

contains

ALFRED

Republic

the c o n t r i b u t i o n s

WEGENER-Conference

of Germany,

international biological

21 - 24 May

meeting

events

of

(a) the s t a t e - o f - t h e - a r t

the i n t e r n a t i o n a l intended

During

according

Deutsche

of

of P r o j e c t

carried

out in

216.

a more c r i t i c a l

have b e e n

University,

100

registered.

and 34 f u r t h e r

to the i n t e n t i o n

about

contributions

have b e e n

that the d i s c u s s i o n

s h o u l d prevail.

a few D e v o n i a n events have been d e m o n s t r a t e d

through

(International

Paliontologische

programme

from G S t t i n g e n

at out-

Schiefergebirge.

The c o n f e r e n c e was s p o n s o r e d by

IPA

first

of g l o b a l b i o - e v e n t s .

, 7 key-notes

in the R h e i n i s c h e

UNESCO/IUGS

to the r e c o g n i t i o n

are n e e d e d for f u r t h e r research,

24 c o u n t r i e s

At the f o u r t h day, crops

the

21 6 : " g l o b a l

of their c a u s e s

to a c h i e v e w i t h these d i s c u s s i o n s

from

3 days

discussed,

in r e s p e c t

to the m e m b e r s

participants

Pro j ect

to d i s c u s s

cooperation

to the p r o b l e m s

In a d d i t i o n

I GCP

of new d a t a

(c) the s t r a t e g i e s w h i c h

approach

This c o n f e r e n c e was

the

and to the a n a l y s i s

(b) the p r e s e n t a t i o n

It was

1986.

at the

Federal

in e a r t h h i s t o r y " .

The aim of the c o n f e r e n c e was,

bio-events

w h i c h have b e e n p r e s e n t e d , held in GSttingen,

the f o l l o w i n g

institutions:

IGCP Palaeontological

Association)

Gesellschaft

Forschungsgemeinschaft

IGCP N a t i o n a l

C o m m i t t e e of the F e d e r a l

R e p u b l i c of G e r m a n y

State of N i e d e r s a c h s e n U n i v e r s i t y of G S t t i n g e n The c o n f e r e n c e w o u l d not have b e e n p o s s i b l e w i t h o u t these

institutions.

members during a short

But great

thanks

and s t u d e n t s of my institute, the c o n f e r e n c e . time w i t h o u t

the s u p p o r t

of

is also due to all those staff who s u p p o r t e d me b e f o r e

and

This volume w o u l d not have b e e n p r e p a r e d

the e x t r a o r d i n a r y

e f f o r t of Mrs.

in such

Martina Noltk~mper.

Otto H. W a l l i s e r

CONTENTS

Ill

PREFACE

INTRODUCTION WALLISER, O,H.: The IGCP in earth history" WALLISER,

O.H. : Towards

Project

216

"Global

biological

events

1 a more

critical

approach

to b i o - e v e n t s

LOTTMANN, J., SANDBERG, Ch.A., SCHINDLER, E., WALLISER, O.H. ZIEGLER, W.: Devonian events at the Ense area (Excursion to the R h e i n i s c h e s Schiefergebirge) GENERAL

& 17

ASPECTS

* BOUCOT, A.J.: magnitude,

E c o s t r a t i g r a p h i c c r i t e r i a for e v a l u a t i n g c h a r a c t e r and d u r a t i o n of b i o e v e n t s

* SEPKOSKI, J.J., periodicity * HOLSER, W.T., variations

Jr.:

Global

bioevents

and the q u e s t i o n

PRECAMBRIAN

25 of 47

TO

LOWER

PFLUG, H.D. & REITZ, Proterozoic

E.:

factors 75

changes

in the 95

M.A. : Global

THE

biological

events

in 105

M. : P r e c a m b r i a n - C a m b r i a n TO

boundary

BOUNDARY

biotas

and events

& CHEN

Xu:

A big

109

ORDOVICIAN/SILURIAN

* BARNES, C.R.: The faunal e x t i n c t i o n event n,ear the O r d o v i c i a n Silurian boundary: a c l i m a t i c a l l y induced crisis RONG J i a - y u China

63

CAMBRIAN

Evolutionary

* SOKOLOV, B.S. & FEDONKIN, the late P r e c a m b r i a n

ORDOVICIAN

the

MAGARITZ, M. & WRIGHT, J.: Chemical and isotopic in the world ocean d u r i n g P h a n e r o z o i c time

* WILDE, P. & BERRY, W.B.N.: The role of o c e a n o g r a p h i c in the g e n e r a t i o n of g l o b a l b i o - e v e n t s

BRASIER,

5

event

of latest

Ordovician

121

in

127

~TORCH, P. : O r d o v i c i a n - S i l u r i a n b o u n d a r y (Prague Basin - B a r r a n d i a n area)

event

in Bohemia 133

ERDTMANN, B.-D.: Early O r d o v i c i a n eustatic cycles and their b e a r i n g on p u n c t u a t i o n s in early n e m a t o p h o r i d (planktic) graptolite evolution

139

LINDSTROM,

153

SILURIAN

M.: TO

Global

bio-events

in the O r d o v i c i a n ?

PERMIAN

SCHONLAUB, H.P.: S i g n i f i c a n t g e o l o g i c a l events in the zoic r e c o r d of the Southern Alps (Austrian part)

Paleo-

163

CHLUP~, I. & KUKAL, Z.: R e f l e c t i o n of possible global D e v o n i a n events in the B a r r a n d i a n area, C.S.S.R.

169

BECKER, R. Th.: Ammonoid e v o l u t i o n the " K e l l w a s s e r - e v e n t " - r e v i e w results

181

* C o n t r i b u t i o n which Event C o n f e r e n c e

has been

before, during and after and p r e l i m i n a r y new

presented

as k e y - n o t e

during

the Bio-

Vl

FARSAN, N.M.: Frasnian mass event or c u m u l a t i v e ?

extinction

- a single

catastrophic 189

FEIST, R. & CLARKSON, E.N.K.: E v o l u t i o n of the last c o r y p h i n a e (Trilobita) d u r i n g the Frasnian

Tropfdo199

RACKI, G.: Middle to Upper Devonian b o u n d a r y beds of the Cross Mts: b r a c h i o p o d r e s p o n s e s to eustatic events HLADIL, J., KESSLEROVA, event in Moravia

Z. & FRI~KOVA,

O.:

Holy 203

The K e l l w a s s e r 213

MC GHEE,G.R., Jr., ORTH, Ch.J., QUINTANA, L.R., GILMORE, J.S. & OLSEN, E.J.: Geochemical analyses of the Late Devonian "Kellwasser Event" s t r a t i g r a p h i c horizon at S t e i n b r u c h Schmidt (F.R.G.)

219

KALVODA, J.: Upper Frasnian and Lower T o u r n a i s i a n events e v o l u t i o n of c a l c a r e o u s f o r a m i n i f e r a - close links to climatic changes

225

and

STREEL, M.: Miospore c o r r e l a t i o n b e t w e e n North American, German and Uralian (Udmurtia) deep facies through Appalachian, Irish and Belgian platform and c o n t i n e n t a l facies near the Devonian/Carboniferous boundary

237

INGAVAT-HELMCKE, R. & HELMCKE, D.: Permian f u s u l i n a c e a n of Thailand - event c o n t r o l l e d e v o l u t i o n

241

TRIASSIC

TO

JURASSIC

SCHAFER, P. & FOIS-ERICKSON, E.: Triassic Bryozoa e v o l u t i o n a r y crisis of Paleozoic S t e n o l a e m a t a WHATLEY, R.: ostracoda

faunas

Biological

events

in the e v o l u t i o n

and the 251

of Mesozoic 257

RIEGEL, W. , LOH, H., MAUL, B. & PRAUSS, M. : Effects in a black shale event -- the T o a r c i a n P o s i d o n i a NW Germany

and causes Shale of 267

CRETACEOUS

* KAUFFMAN, E.G.: High r e s o l u t i o n event and global C r e t a c e o u s Bio-events

stratigraphy:

BRUMSACK, H.-J. : Trace metal a c c u m u l a t i o n the C e n o m a n i a n / T u r o n i a n Boundary Event

regional 279

in black

shales

from 337

HILBRECHT, H. , A R T H U R , M . A . & S C H L A N G E R , S.O. : The C e n o m a n i a n Turonian b o u n d a r y event: sedimentary, faunal and g e o c h e m ical c r i t e r i a d e v e l o p e d from s t r a t i g r a p h i c studies in NWGermany

345

DAHMER, D.-D. in Europe

353

~ ERNST,

CRETACEOUS/TERTIARY

G.:

Upper

Cretaceous

Event-Stratigraphy

BOUNDARY

BESSE, J., BUFFETAUT, E., CAPPETTA, H., COURTILLOT, V., JAEGER, J.-J., MONTIGNY, R., RANA, R., SAHNI, A., VANDAMME, D. & VIANEY-LIAUD, M.: The Deccan Trapps (India) and C r e t a c e o u s T e r t i a r y b o u n d a r y events

365

KNOBLOCH, E.: P a l a e o f l o r i s t i c and p a l a e o c l i m a t i c changes in the C r e t a c e o u s and Tertiary periods (Facts, problems and tasks)

371

MART~N-CLOSAS, C. & SERRA-KIEL, J.: Two examples of e v o l u t i o n c o n t r o l l e d by large scale abiotic processes: Eocene nummulitids of the S o u t h - P y r e n e a n Basin and Cretaceous C h a r o p h y t a

VII 375

of Western Europe HANSEN, H.J., GWOZDZ, R., HANSEN, J.M., BROMLEY, R.G. & RASMUSSEN, K.L.: The diachronous C/T plankton extinction in the Danish Basin

381

SIREL, E., DA~ER, Z. & SOZERI, B.: Some biostratigraphic and paleogeographic observations on the Cretaceous/Tertiary boundary in the Haymana Polatlz Region (Central Turkey)

385

WIEDMANN, J.: Macro-invertebrates boundary

397

and the Cretaceous-Tertiary

FEIST, M. (Coordinator): Bio-events in the continental realm during the Cretaceous-Tertiary transition: a multidisciplinary approach

411

TERTIARY

PANTIC, N.: Global Tertiary climatic changes, graphy and phytostratigraphy

paleophytogeo-

SCHLE!CH, H.H.: Reflections upon the changes of local Tertiary herpetofaunas to global events

419 429

THE IGCP PROJECT EVENTS IN EARTH

216 "GLOBAL HISTORY"

~T A

contribution to Project

BIOLOGICAL

GLOBAL BIO EVENTS

u WALLISER,

Otto

H.

*)

A b s t r a c t : The IGCP P r o j e c t 216 is c o n c e r n e d w i t h w o r l d w i d e t r a c e a b l e e x c e p t i o n a l c h a n g e s ( " e v e n t s " ) w i t h i n the b i o s p h e r e . The p r i n c i p l e o b j e c t i v e s of t h i s p r o j e c t , w h i c h n e e d s i n t e r d i s c i p l i n a r y cooperation, are the f o l l o w i n g : (I) S t u d y of t h o s e a b i o t i c ( g e o l o g i c ) p r o c e s s e s and e v e n t s w h i c h c a u s e global biological events (geological level); (2) R e c o n s t r u c t i o n of the o v e r a l l e f f e c t of g l o b a l g e o l o g i c e v e n t s on the b i o s p h e r e or p a r t s of it ( e c o l o g i c a l l e v e l ) ; (3) E v a l u a t i o n of the i n f l u e n c e of g l o b a l e v e n t s on e v o l u t i o n and e v o lutionary mechanisms (evolutionary level); (4) R e f i n i n g of s t r a t i g r a p h i c a l s c a l e s and of c o r r e l a t i o n m e t h o d s by c o m b i n a t i o n of b i o s t r a t i g r a p h y and e v e n t - s t r a t i g r a p h y (chronological level).

The

establishment

global

events

events"

cations

But

possible

Different may

have

which

In that

216

such

available

for

IGCP

-- s u c h

boundary

Project

216

as a b o u t

is the e l a b -

as d e t a i l e d

as e v e r

methods.

In so far,

and less

on hypothetical

be u s e d

a renewed

In the m e a n t i m e

theoretical

to d i s p r o v e in

for

their

own working

the f o l l o w i n g

this

project assump-

discussion

the m e m b e r s

possibilities.

data.

-- has b e e n

modern

should

publi-

of e x t r a - t e r r e s -

and l a b - w o r k

all

are d i s c u s s e d

of the

be as p r e c i s e

biological

the g e o s c i e n c e

of n e w g e o c h e m i c a l

new data

goal

with

the r e l e v a n t

as i m p a c t s

a main

should

"Global

time,

on a c c o u n t a few

are c o n c e r n e d

grew within

Cretaceous/Tertiary

then

or

only

and

which

events,

assumed

and e f f e c t s .

be o p e n

They

about

of the

Project

should

not

hypothesis.

A f e w of

paragraphs.

level global

abiotic

a direct

finally

or e v e n *)

all

to p r o v e

Geological

years.

both

at the

on f i e l d -

processes

latter

been

which

events'*

interest

few

which

The n e w d a t a

hesitate the

Therefore,

based

should

"Rare

to the b i o s p h e r e

by using

is m a i n l y

216

have

of n e w d a t a

causes,

last

microfossils

available. oration

199

on s p e c t a c u l a r

These

in r e s p e c t

projects

the b r o a d

the

stressed

planctic

IGCP

Project

during

bodies.

tions.

two

-- r e f l e c t s

community

tric

--

of

more

effect

then events

lead

events

may

have

different

on the b i o s p h e r e to an e v e n t .

and/or

processes

I n s t i t u t u n d M u s e u m fur G e o l o g i e D-3400 G~ttingen, F.R.G.

or t h e y

We a l s o may und

causes. may

should

overlap

These

trigger

consider

or a m p l i f y

Paliontologie

der

causes

processes, that

each

two other.

Universitit,

Lecture Notes in Earth Sciences, Vol. 8 Global Bio-Events. Edited by O. Waltiser © Springer-Verlag Berlin Heidelberg 1986

The

processes

may

interactions. periodic

exist

very

Furtheron,

or b o t h

logically

be

long

kinds

the may

lasting.

events

of

extremely

of

this

of

events

with

but

and/or

they

not

different

possible

sea-level

manifold

processes

overlap;

Last

In s p i t e cases

complex

may

least

events be

we

reactions

may

very

be

short

should

be

and

episodic

or

or

even

geo-

aware

that

there

effectiveness.

multicausality,

changes

actions,

or/and

we

black

observe

shales

that

play

in m o s t

an

important

role. In o r d e r and

chemistry, with

have

biosphere, whole

i.e.

range

event

chain

other

sedimentology,

or n e t w o r k

of

geosciences,

tectonics,

causes

such

geophysics,

as g e o and

even

of

that

a global

only

one

biotopes

happened,

or or

may

event

affects

a few

special

facies.

Those

then

influence

only

certain

biotopes

or

biotopes

parts

facies

in w h i c h

neighbouring,

of

within

a bio-

primarily

un-

biotopes.

Certainly, changes

complex with

level

the

logical

whole

is n e c e s s a r y .

to c o n s i d e r

affected

the

cooperation

oceanography,

the

the

evaluate a close

astrophysics,

Ecological We

to

processes,

an

within

food-chain.

attention

to

important

ecosystems, Therefore,

the

and

often

i.e.

deciding

role

in

to b i o - e v e n t s ,

play

the

relations

we

shall

pay

in

the

investigation

of

marine

phytoplancton.

realm,

we

observe

respect

to m a j o r within

special

Evolutionary level With

all

quence: mass This the

hitherto in

the

differences one

hand

events,

bio-events,

of

changes sudden

the in

be

strong

those

additional

the

other

especially

hand.

after

a main

"normal"

Chronological Many

the

It w i l l

an e v e n t --

between

and on

of

followed

indicates

evolution.

events

time-span

extinctions, clearly

known

a comparable

there

occur

a certain

influence task

of

evolutionary ones

Already

extinctions,

now

have

it

is

and

been

events

mechanisms by

obvious

the

radiations. have

elaborate

caused

quite

accelerate

to

se-

or e v e n

-- b y

global

project

steps

which

extinctions

interval

which

the

biological

on

the

on

the

global

that

global

evolution.

level

hitherto lithology,

occurrence

discovered

biological

sedimentology

of b l a c k

shales.

and

events

facies,

Often,

these

are

and

connected

for

example

litho-events

with with

occur

a

only

in

a certain

zone

and

part

can

thermore,

of

a biozone,

be u s e d

these

for

events

i.e.

this

a refinement

can

often

be

of

event the

traced

is

shorter

as

chronological

globally

a bio-

scale.

Fur-

within

the

relevant

there

are

world-

facies. Another

aspect

wide

developed

from

those

be u s e d

in

for

If

in

the

the

other

in

the

times.

are

for of

climatic

times

which

on

the

time-specific

the

they

may

be

in

ecological

the

cycles

of

the

may

these

well

differ

can

also

chronological

such

used

Often

side

facies

features,

units.

other

refinement.

refinement

periodic

as

certain

chronological

short-termed,

as w e l l

in

facies,

for

biostratigraphical

long-term

that of

These

and

possibility

lithology

that, of

fact

types

decipherment

latter

smallest

the

same

correlation

A further lays

is

the

as c l i m a t i c

for

the

subdivision

microcycles pattern.

contribute

scale cycles.

are

In c o n t r a s t

to

the

of

documented to

occurrence

bio-events. If we

cal

combine

scales,

graphy, least

event-stratigraphy

as b i o s t r a t i g r a p h y ,

volcanostratigraphy,

. Such

reached

accuracy

correlation scale

a combined

of

role

causes

but

scale

respect

smallest

contains

ordinary

in

and

processes

and

with and

In a d d i t i o n , data,

to

stratigraphi-

lithostrati-

etc.,

us

that

deciffering

led

other

we r e c e i v e

at

h olostratigraphical

resolution

manifold

which

a

provide

time

units.

in r e c o g n i z i n g

and

finally

will

to

time

so m u c h

with

chemostratigraphy,

magnetostratigraphy,

a multistratigraphical,

scale

the

this

such

the they

the

un-

worldwide

holostratigraphical will

global

these

an h i t h e r t o

to

play

events

an e x t r a -

as w e l l

as

events.

Subprojects All

the

above

concentrating to c e r t a i n

mentioned to

questions

certain

problems.

time

From

are

to

effets

on

--

Late

Precambrian

events

logical

innovations

play

--

are

The

been

events

much

Event

which

within

the

the

can

Some

those

of

have

been

event

investigated of

chosen,

are,

by

fossils

to c a u s e s

key-studies

of b i o l o g i c a l

important

be

groups

in r e s p e c t

the

(as c a s e s

will

to c e r t a i n

other

Devonian

and

analysis

be c o m p a r e d

Cretaceous Middle

problems

and

which

as w e l l

for

events,

as

example:

in w h i c h

bio-

role); (as

a case

of b i o l o g i c a l

its

boundaries.

events

a glaziation);

an o v e r a l l

then

younger

an

events

each

boundary

by

within

for

of

biosphere.

triggered

chosen

System, the

the

Ordovician/Silurian

which --

different

the

assumedly

and

levels,

System.

Devonian

as

of with

all

events

corresponding

Of s p e c i a l a case

of

The

within

has

investigations

interest a black

Devonian

a Palaeozoic

are:

shale

in

the

otomari

event

which

caused

only

Famennian the

minor

biotic

boundary

biosphere,

as

such

as

the

Devonian/Carboniferous sea

changes[

a black

the

shale

worldwide

boundary

Kellwasser

event

with

Event

extinction

event

as

at

enormous

the

of b i o h e r m a l

a case

of

Frasnian/

consequences

to

reefs[

short-time

the

change

in

level:

-- C l i m a t i c

changes

taxa

late

in

-- T h e

the

and

the

cesses

for and

an e v e n t changes

-- R e l a t i o n

acme

and

extinction

of

plant

Palaeozoic;

Palaeozoic/Mesozoic

example

appearance,

(Permian/Triassic)

which

has

in c l i m a t e

between

abiotic

eventually and

sea

events

boundary

been

event

caused

by

(as

an

long-term

pro-

level);

and

renewal

and

evolution

of

Jurassic

ammonoids: -- E s t a b l i s h i n g , graphy

in

the

comparison --

The

with

and

Relation

tion

of

extratelluric

these

case

as

cooperation

we the

of

biosphere Even

to if

by

(as

event

met

of

the

within

an e v e n t - s t r a t i -

Mesozoic,

the

and

for

Devonian):

a case

in w h i c h

probably

together);

glaziation

about

a grave

events

and

into

given

investigation

are

the

speciation

and

extinc-

also

of

the

indication

as m a n y

based

of g r e a t

partly

processes of

past

out

with

comparable

Only

with

this

about

details

of

methods

international

the

global

the

reaction

on palaeontological importance

stratigraphical

Furthermore

ecosystems

world.

synof

the

as p o s s i b l e .

to c o n s i d e r

of

carried

the

clear

about

correlation,

disturbance

value

to b e of

is m a i n l y

possible.

long-term

of g r e a t

and

refining

world-wide now

receive

project

results

have

regions

events

these

The

until

the

within

investigations

events

studies

shall

the

expected

sciences.

facts

correlation

example

boundary

quaternary

possible

chronism

than

worldwide an

mammals.

All

itate

equivalent

between

in as m a n y

the

and (as

Cretaceous/Tertiary

telluric --

refining

Cretaceous

the the

with the

in t h e

scales

biosphere, These

long-term

effects

existing

is

also

the

human

will

aspects

much

are

to o u r

facil-

smaller us

with

be

also

interference

In so own

geo-

triggered

might

recent

population.

a contribution

will

provide

which

of

applied

methods

time-intervals project

ecosystems.

by

for and

methods,

far

this

future.

TOWARDS BIO-EVENTS

A

MORE

CRITICAL

APPROACH

A contribution

TO

to Project

GLOBAL UIVES~

WALLISER,

Otto

H.

B I0 EVENTS

W-

*)

A b s t r a c t : G l o b a l b i o - e v e n t s are m a n i f o l d in r e s p e c t to c a u s e s and e x t e n t . T h e r e can be r e c o g n i z e d the f o l l o w i n g p a t t e r n s of g l o b a l b i o - e v e n t s : (]) i n n o v a t i o n - e v e n t s ; (2) r a d i a t i o n - e v e n t s ; (3) s p r e a d i n g - e v e n t s ; (4) e x t i n c t i o n - e v e n t s with stepwise or/and contemporaneous, rapid extinctions. P r o b a b l e c a u s e s for g l o b a l b i o - e v e n t s are (I) c o s m i c c a u s e s , s u c h as (la) c h a n g e s c a u s e d b y the r e v o l u t i o n of the s o l a r ' s s y s t e m w i t h i n the G a l a x y and (Ib) i m p a c t of c o s m i c b o d i e s ; (2) e a r t h - b o r n c a u s e s , n a m e l y (2a) b i o l o g i c a l c a u s e s ( m o s t l y b i o l o g i c a l i n n o v a t i o n s ) and (2b) a b i o t i c = g e o l o g i c a l c a u s e s . The l a t t e r imply, a m o n g o t h e r s , s e a - l e v e l c h a n g e s , c h a n g e s of the p h y s i c a l and c h e m i c a l c o m p o s i t i o n of the o c e a n and the a t m o s p h e r e , c h a n g e s of c l i m a t e , c h a n g e s of o c e a n o g r a p h i c p a r a m e t e r s . I m p a c t s of c o s m i c b o d i e s m a y then h a v e a c a t a s t r o p h i c e f f e c t , if o n e or s e v e r a l of the a f f e c t e d s y s t e m s are a l r e a d y n e a r to i n s t a b l e c o n d i t i o n s , the l a t t e r c a u s e d i n d e p e n d e n t l y b y o t h e r g e o l o g i c p r o c e s s e s . Holostratigraphy, that is the c o m b i n a t i o n of all a v a i l a b l e s t r a t i g r a p h i e s , s u c h as b i o - s t r a t i g r a p h y , event-stratigraphy, chemo-strat i g r a p h y a n d o t h e r s , p r o v i d e us w i t h an e x t r e m e h i g h t i m e - r e s o l u t i o n . In n e x t f u t u r e , the m a i n t a s k in o r d e r to a n s w e r o p e n q u e s t i o n s in r e s p e c t to c a u s e s a n d p r o c e s s e s in c o n n e c t i o n w i t h g l o b a l b i o - e v e n t s , w i l l b e to e l a b o r a t e m o r e and m o r e d e t a i l e d and p r e c i s e d a t a . T h e r e f o r e we need interdisciplinary cooperation.

Introduction Why

are g l o b a l

years,

do

Science; as for

why

short

for

historical

biotic

that

catastrophes, course, tions

of

with

a "higher",

all

why,

such

important

since

might

several

as N a t u r e in s e v e r a l

of e v o l u t i o n a r y

questions

or at l e a s t of e a r t h

science,

i.e.

time,

find

important

history, since

or respect,

and of g e o -

an a n s w e r

Deluge

t h a t the c a t a s t r o p h e s

more

"progressive"

extinctions,

especially

the

by

a

(e.g.G.

were

in the

known

late

have been

and m o r e mass

changes

are w e l l

about

the e v e n t s

to the s c r i p t u r a l

a macro-evolutionary

dominated *)

drastic

pre-Darwin

according

As a r e a c t i o n

journals

enormously

of t h e s e

of o u r

in the

terms:

happenings;

in

understanding

documentation

it w a s b e l i e v e d

In m o d e r n

space

reminiscence. means

or a b i o t i c

There,

fascinating

events

Parts

very beginning

tury.

such

permanent

a better

processes?

Events,

the

have

are g l o b a l

example

logical

events

they

since

18th c e n -

interpreted de C u v i e r ) .

followed "perfect"

extinctions,

as Of

by new creastandard. are c o n n e c t e d

pattern.

to D a r w i n ' s

considerations,

theory, thus

I n s t i t u t u n d M u s e u m fur G e o l o g i e D-3400 GSttingen, F.R.G.

gradualism

denying und

sudden

(or m i c r o - e v o l u t i o n ) changes.

Paliontologie

der

The

latter

Universitit,

Lecture Notes in Earth Sciences, Vol, 8 Global Bio-Events. Edited by O. Walliser © Springer-Verlag Berlin Heidelberg 1986

have been

explained

(e.g.

Lyell).

Ch.

In the e a r l y mental e.g.,

also

cussed

and

Since

the

versus

a certain

such

as t h a t

enormous

by

happenings and m o r e

of n e w

5th

have

available

review

data,

paper of

ontogenetic

changes.

have been

But

at the

have been

same

dis-

again but

versus

such

a few years hypothesis

ideas

this

of m a j o r

of s u c h

in o r d e r

became

assumption

of

bio-events.

hypotheses,

hypotheses

as the m o d e l l i n g

investigations

macro-evo-

discussion

to s e v e r a l

The

only

as p u n c t u a t e d

and the

lead

Nemesis.

k i n d of

phylogenetic,

the o c c u r r e n c e

latter

to s o m e

at the b e g i n n i n g

have

been

spectacular

to r e c e i v e

new

data.

international

But

meeting

to h y p o t h e s e s

then,

especially

at G S t t i n g e n

new

of

the

about

these

hypotheses

ones,

presented

to c o m b i n e

the

authors

]986,

IGCP

which

Project

the c a u s e s became

has

216,

tested

by

the

at the c o n f e r e n c e . standpoint

the

of b i o - e v e n t s

with

The

a short

the c o n f e r e n c e .

the

Each happening term,

we s h o u l d an e v e n t

intermediate

terms

restrict has

times

developments, is i n d e p e n d e n t

initial

processes. event

important

or u l t i m a t e

whether

chemistry,

which

of r e l a t i v e l y

means,

event,

bio-event

in o r d e r

it to e x t r a o r d i n a r y

This

of the q u e s t i o n

several

global

Therefore,

a time-span

respectively.

another,

Global

event,

is an e v e n t .

cases

ocean

to

back

revived,

WEGENER-Conference

attempts

H o w to h a n d l e

not

Since

as w e l l

in r e s p e c t

been discussed.

present

two

new basic

the f i r s t

funda-

Schindewolf,

events,

Simpson)

definitions,

impact

the d a r k d w a r f

basic

state-of-the-art

G.G.

swung

was

phyletic

in r e s p e c t

ALFRED

O.H.

in an e a r l y

biological

record

the f o u r t i e s ,

of g e o l o g i c a l

(e.g.

or/and

of the

stimulating

precise

also been

views

terms

of t h e s e

as also

At the

for r a p i d

micro-evolution.

about

into

of g e o l o g i c a l

again.

transformations besides

gradualism,

periodicity

and

discussed

the p e n d u l u m

on a c c o u n t

The c o m b i n a t i o n

and/or

preferred.

years,

versus

intensified

century,

The o l d d i s c u s s i o n

labels

equilibrium lution

genetic

processes,

subsequently

information

this

gradualistic

a few

of

have been

explanations

more

catastrophism. under

major

Orthogenetic

as c a u s a l

time,

of

changes

emphasized

used

a lack

decades

biological

phase.

by

that

stable

but

this

it is d e t e c t a b l e

etc.)

under

in m o s t

than

weak

event

it is the

the

affected

result

by

of o n e or

Thereby

(such

and

definition

is c a u s e d

worldwide.

consideration

has b e e n

this

or s l o w c h a n g e s

intended

final

event or whether

Then,

shorter

conditions

necessary

to w i s h y - w a s h y

happenings.

is r e m a r k a b l y

whether

the o b j e c t

biosphere,

not

it is

as l i t h o l o g y ,

in a g r e a t

extent

or o n l y

in a s m a l l

The

sector.

term biological

ordinary

event,

shortened:

change

within

the w o r l d

change,

Faunen-

and/or

Floren-Schnitt).

Pattern

of global

It c a n be

taken

a change

of

events

or

as a r u l e

appearance

meters,

such

tology)

or c h e m i c a l

After

it c a u s e

different In-the

emigration another,

some

extinction

of o n l y

If

a higher

rank,

Another is that

aspect

where

only

one

of

such

a species

taxon

categories

or

analysis

or

only

out

bio-

para-

as s e d i m e n -

a region,

one

imply

it n e e d s

or g l o b a l ; or

a few

already

of g l o b a l

important

taxa

the

event-

affects

burst,

are

regional

by

families,

member

extinction

we s h o u l d etc.,

one

be aware consist

that

have been

an e n t i r e

to be p r o v e n

of that

A.J.

eliminated. (a)

aspects,

(this

caused

we c o m e

species.

t a x a of

bio-events, In o r d e r

to

a careful

of the r e l e v a n t

the c r e a t i o n

and e x t r a o r d i n a r y ,

mentioned

of the

of s p e c i e s .

of g l o b a l

Boucot

the

of s p e c i e s .

we need

analysis

that

considerations,

and b a c k g r o u n d - c r e a t i o n cases

total

of o t h e r

in the f o l l o w i n g

in t h o s e

the

possible

is an i m p o r t a n t

subsequent

species

bio-events

a regional

it is w e l l

event-extinctions

unusual

listed. extent

of e c o s y s t e m s

always

Thereby

in the k e y - n o t e

these

for

are

regional

population

replacement

which

important

(b)

bio-events

or r e s t r i c t e d

or r e g i o n a l

level,

a few

it has

all

of g l o b a l

is i n c l u d e d

from

and

is r e a l l y

Considering

abiotic

or b a s i n - w i d e

questions

bio-event

the

as g e n e r a , which

background-

words:

the d i s -

In so far,

as w e l l

to

contemporaneously).

species,

the s p e c i e s

as p o i n t e d

other

lead

a change

of the

it a f f e c t

local

species.

triggers

is e s p e c i a l l y

cause-effect system,

one

aspect,

distinguish

did

of taxa,

of b a c k g r o u n d - e x t i n c t i o n

This

With

here

local

are v e r y

a global

or m o r e

food-chain,

I mention

such

a change

These

of

already

In our d e f i n i t i o n ,

general

parameters

connected.

in a s e c t i o n

categories

if t h e y

immigration

of o n e

an e v e n t

mass-mortality

existed

population

with

petrography

is it o n l y

categories

even

and

an e x t r a -

floral

of b i o - e v e n t s .

(e.g.

which

that

by

(including

extinction?

following,

stratigraphy

of a b i o t i c

is a l w a y s

in all r e g i o n s ;

mass

bio-event

not d i s c u s s e d ,

for

and/or

composition.

recognized

pattern

Thereby,

means

indirectly

its d i m e n s i o n :

is it s y n c h r o n o u s

a change

This

lithology

having

to e x a m i n e

or d i d

that

of t a x a

can b e r e c o g n i z e d as

stands

(faunal

bio-events

the e c o s y s t e m .

appearance

bio-event,

of o r g a n i s m s

eco-

volume).

or e x t i n c t i o n by

to the

the e v e n t . following

(I)

Innovation-event. in the w o r l d

Biological

of b i o t a .

As an e x a m p l e

tain cepha!opodes , leading ammonoids.

It has

an i m p o r t a n t times & M.A.

vation

and

of DNA,

existing

Radiation-event. certain short

taxa

Pflug

M. B r a s i e r ~

this

volume).

tion-event.

example

for

also

occur

Nevertheless,

occurs

innovation

and

of c e r -

innovations

B.S.

The f i r s t

Sokolov

foundation

structures, totally

affected

played

Phanerozoic

& E. Reitz,

the

inno-

new worlds

also

the p r e -

system. in Fig.

I, r a d i a t i o n s

to e x t i n c t i o n - e v e n t s , implies

of the

an u n u s u a l

mostly high

of

after

percentage

taxa.

Radiation-events

radiation

out b e l o w

subsequently

coiling

the

opened

and

feedback

A radiation-event

of

etc.,

changes

domination

of m e t a z o a n

influenced

to m a j o r

and e a r l y

H.D.

As p o i n t e d

interval.

of c r e a t i o n s

in P r e c a m b r i a n

in a d y n a m i c

appear

serve

of

surely

ecosystems

may

lead

that biological

mineralization,

This

may

long-termed

the c r e a t i o n

of s k e l e t a l

of e c o s y s t e m s .

(2)

especially

contributions

Fedonkin

of p r o t e i n ,

to the

to b e s u g g e s t e d

role

(compare

innovations

this

subsequently

in some

cases

only

after

kind

of d e p e n d e n c i e s

of m a m m a l s

and

such

to a b i o l o g i c a l

an i n n o v a t i o n - c a u s e d

an e x t i n c t i o n - e v e n t .

their

main

exists

innova-

The most

in the

radiation

evident

late

Triassic

the

K/T mass

after

extinction-event. (3)

Spreading-event. out

of s p e c i e s

very

difficult

spreading

out

one

from

hand,

example wide

may

Under

to c l e a r l y of n e w

unusual

serve

lites

of

(compare

also

latest

Silurian, Devonian

this

life

but

The m o s t

especially

when

example

at the

Event,

thus

a certain

event,

shows

well

the

groups several

of o r g a n i s m s .

extinctions

steps,

even

In o t h e r if t h e s e

to m a s s

may

within

cases, happen

Event occur

As an world-

due

among

to t h e

grapto-

this

Event

volume)

in the

at the b e g i n n i n g

occurrence.

are the

extinction-

extinctions, or

sudden

at the b e g i n n i n g

burst

bio-events

Kellwasser

hand.

Erdtmann~

its f i r s t

it is

on the

occurs

example

of B.-D.

a sudden

also

is o b v i o u s l y

transgrediens

increase

producing a real catastrophe

out

Another

after

evident

they

which

transgression

habit.

the

but

spreading

that

bio-events

on the o t h e r

spreading

After

species

events,

O/S

between

flabelliforme,

the g l o b a l

of s u d d e n

the n o r m a l ,

in t i m e s

the c o n t r i b u t i o n

System,

(4) E x t i n c t i o n - e v e n t s .

During

distinguish

Its u n u s u a l

uniformis.

of

the

with

kinds

to be m e n t i o n e d ,

spreading-events

a floating

is M o n o q r a p t u s

several

it has

"Dictyonema"

Ordovician.

innovation

term But

species

at and t o g e t h e r

of the

this

are u n i t e d .

the

in a v e r y

the a f f e c t e d

the e x t i n c t i o n s in a r e l a t i v e l y

as for

K/T Event. short

time,

ecosystems may short

occur time

or in

a

(compare the contributions Fois-Erickson; wise the

ones same

may

this occur

event.

Cretaceous

regressions,

by

several

change

of a l b e d o , for

the

has

been

Another The

above

al e v e n t s events

At the

change

of J.

mentioned

radiation. ent groups,

the The

may be explained

might

within

the f o l l o w i n g

step-

one

and

and e n d have been

of b i o t o p e s ,

parameters,etc.). are g i v e n

et al.,

the

in

in this

extinction

i.e.

& E.

and

during

loss

Hansen mass

event,

Event

then

iridium-event.

(see b e l o w ) . reflect

extinction

be c o m p o s e d

ones

K/T E v e n t

H.J.

stepwise

for e x a m p l e ,

sequence:

may happen by

at the

and of

of b i o - e v e n t s Thus,

Schifer

extinctions (e.g.

and of o c e a n i c

extinctions

this

of P.

of o r g a n i s m s

stepwise

of c l i m a t e ,

Kellwasser

patterns

latter

which

which

and

catastrophic

the e n d - P a l a e o z o i c

b y an a d d i t i o n a l

is the

following

groups serve

Wiedmann

to the e v o l u t i o n .

show

Becker

types,

of the r e g r e s s i o n s

K/T boundary,

superimposed example

may

during

effects

stepwise

the c o n t r i b u t i o n s volume).

Th.

Both

in d i f f e r e n t

As e x a m p l e s

caused

Examples

of R.

volume).

of

hypothesis

nomismogenesis l

influence

-- s h o r t

several

a certain

the

all k n o w n

major

interval

radiations

time-span. (compare

~

regularity

1):

< evolut, rate > select, stress <

r~i~iO~S ~=~

--

in d i f f e r -

This

Fig.

of g l o b -

bio-

<

niches

> evolutionary rate

g._.

® ~:

< selectional stress

@Z~il~C~i©l~

j

~ >>

niches

-I-

s.L

nomismogenesis

> increase <

Figure I. General pattern of the extinction sequence (for explanation see text).

--

interval

--

decrease radiation

10

In an u n d i s t u r b e d high.

This

means

recombinations

ecosystem,

that

only

evolutionary

rate

extinctions

tional

stress

possess niche.

is low.

The

present,

fewer

the

selectional

change

less

will be means

other

words,

high

evolutionary

an o c c u p a t i o n spect

of

This

manner

sequence

certain

balance

rate,

affected clearly

not

ecological a certain

global

aspects

for

Only

the

concern

This

extinctions

biological

the m a i n

events

of

or,

The

leads

to

in re-

the old

may

lead

to a

these

are

are

Thus,

the p u n c t u a t e d

we c o u l d

always

but

also demonstrates call

and v e r y

in

the quite

the

paradox In so

evolution

important

of

rate,

mechanisms,

of e v o l u t i o n a r y

problems

punctuated

in a g r a d u a l i s t i c

parameters,

which

represent

for a

or to i n t e r r u p t i o n s

accelerate

the u n d e r s t a n d i n g

latter

events

changed.

sequence

pattern

mechanisms.

versus

continues

the e v o l u t i o n a r y

systems.

evolu-

rate.

global

has

the

necessity

The

and e v o l u t i o n a r y

ratio

the

mutations

to a n o r m a l i z a t i o n

of o r g a n i s m s

Thereby stress

evolutionary

evolution:

far,

in the w o r l d

of

are

and r e c o m b i n a t i o n s ,

the s o l u t i o n

evolution

Thus,

which

of the

occurring

any

gradualism

although

the

lines.

other.

does

may b e a r

words:

selectional

to e a c h

equilibrium

also

macro-evolution,

other

evolutionary

that

forms

the n i c h e

evolution.

radiation.

through

caused

the s e l e c -

A lowering

of the g e n e t i c by

niches,

occur

newly

but without

and e v o l u t i o n a r y

of e c o s y s t e m s

to c a t a s t r o p h e s

mutation

and

stress

versus

With

perturbations

of

the n i c h e s

regular

equilibrium.

is e x p r e s s e d

the

to t h o s e

stress. more

and

Therefore

the d i r e c t i o n

of m u t a t i o n s

any c h a n g e

mutations

of n e w b i o t o p e s ,

into

for f u r t h e r

or q u a l i t y

rate

as t h e r e

respect

selectional

high,

is r e l a t i v e l y

occurring

for c o n q u e r i n g

relatively

relatively

to s e l e c t i o n a l

micro-evolution

the

without

with

competitors

m a y be u s e d

the q u a n t i t y

with

as s o o n

of e v o l v i n g

that

stress

to the e v o l u t i o n .

the c r e a t i o n

-- at l e a s t

ability

stress

rate becomes of

However,

potential

and r e c o m b i n a t i o n s tionary

contribute

or b y

is r e d u c e d

the p o t e n t i a l

selectional

a f e w of the n e w l y

successfully

by preceding

the

interesting

processes.

Causes

During been

the

taken

During

the

last

few

5th

ALFRED

been

reached.

been

appreciated,

other lead

causes,

Thereby

the i m p a c t of e x t r a - t e l l u r i c

but

author

for

the

initial

WEGENER-Conference, the

importance

it b e c a m e

independently

to i m p o r t a n t As the

years,

as an e x p l a n a t i o n

of

of

a more the

supplemented impacts

cause

b o d i e s has m a i n l y the m a i n

critical

impact by

of

the

or s o m e t i m e s

events.

approach

hypothesis

has

has w e l l

assumption,

that

enhanced

impacts,

by

also

bio-events. already

pointed

out

formerly

(Walliser

1984a,

1984b)

11

different causes

global

may

directly

lead

On the

which

These

such

process

Furtheron

hand,

we s h o u l d

of q u i t e

in the

course

Figure

leads

be

aware

different

of e a r t h

changes,

then

extent,

changes

ones),

an i m p o r t a n t

meters

also

Holser most

et

other

are of d e c i s i v e

to the

final

cause

final

only

a network

may

cause

trigger

for

when

thus

pro-

possibility

it o v e r l a p s

amplifying

final

causes

with

each

may

parameters

showing

al.

(often

and of

This

other.

produce

have

show

In a d d i t i o n ,

bodies trigger

in s p i t e

of g l o b a l

changed

represented

of

events

& W.B.N. that

sea-

(inclusively

Berry,

in the in this

the m e n t i o n e d

we should

geologic

the

by b l a c k

conditions

is a l s o d o c u m e n t e d

P. W i l d e

contributions

of a g l o b a l

that

cases

and c h e m i c a l

role.

importance.

cause

be

para-

aware

processes

that

which

then

event.

A sedimentation

(

-C=

-Ce

/i ........

L_

It II II II II II

° m

b

II

physical & chemical conditions

a

of a c t i o n s ,

A further

other

in m o s t

the p h y s i c a l

the i m p a c t of e x t r a - t e l l u r i c lead

because

in s e d i m e n t o l o g y

climatic

of W.T.

the

may

etc.

comparable

flow-chart,

of

But

with

systems

to an event,

that

and c h a n g e s

volume.

cause

processes,

shales),

key-notes

or i n i t i a l

also

cause.

complex,

multicausality,

play

being

and d i f f e r e n t

history.

2 is a s i m p l i f i e d possible

final

other

causes,

An u l t i m a t e thus

feed back

or s e v e r a l

different

an u l t i m a t e

the

m a y be v e r y

a process

events

have

events.

produce

interactions,

is that

mentioned

other

then

another

may

the b i o s p h e r e ,

processes

reactions,

level

to s i m i l a r

influence

bio-event. cesses,

bio-events

a : = : : : : :

biotopes

%

BIO-EVENT

I

radiation extinction

f-

crisis

F i g u r e 2. S i m p l i f i e d f l o w - c h a r t , i l l u s t r a t i n g the c o m p l e x i t y s e l e c t e d e x a m p l e of g e o l o g i c a l p r o c e s s e s ( A = c h a n g e ) .

of

a

12

In o r d e r categorize (I)

to o b t a i n

the

causes

Extra-telluric (la)

Changes the

(Ib)

Galaxy of

(see

we

In

is

(2)

Earth-born (2a)

Biological

important

Barnes

~torch

the

or two

we

system

may

within

asteroids. cases.

lead

event

only

reached

In this

In c a s e

an u n u s u a l

may

already

and

in

one

in

then

any

to

an

critical,

weak

is

But

causes

the

have of

of

sea-water

of

the

an

at

least

of

the

not

of

ridges,

changes.

Rong

of

are

other

multiple

and/or

words:

of

ocean

chemistry

are

well

tectonics,

of

such

for

sea-

expan-

several

also

sea-level

composition

long-termed and

development

times.

and

causes.

composition

both,

of

Ingavat-Helmcke

chemical

the

and

of

orogenesis

as o n e

the

in p r e - P h a n e r o z o i c

& Chen

R.

flucexample

an u n d u l a t i n g

Thereby,

in

only

key-note

responsible

of

atmosphere.

role

classical (see

between

excluded

With

or

climatic

in p l a t e

hypothesis be

by

An a l r e a d y

relation

and

following.

Ordovician

processes

yet

different

important

ocean

rozoic

the

inno-

manifold,

caused

contribution

other

physical or

chemical

played

The

the

biological

be

the

be

contributions

even can

in

may

outgoing

of m i d - o c e a n But

sea-level

can

Changes

in

are

might

processes.

the

also

earth

for

These

mentioned

volume).

shown

these

above.

. These

further

formation

of

are

at

this

cases

causes.

tectonic

changes.

changes

But

also

correlated

development

atmosphere,

of

the

biosphere,

shorter with

fluctuations

major

Phane-

events.

Changes

climate.

Here

guish

between

long-term

processes

As

example

for

an

solar's

comets

to c a u s e

mentioned

changes

Helmcke.

level sion

the

impact

have

In m o s t

glaciation

regression

as

aspects,

processes.

ones

or b y

the

& D.

as

as

the

systems

= geological

tuations

P.

of

to d i s t i n g u i s h

case

already

1

C.R.

mentioned

chapter).

such

thorough

other

Sea-leve

is

following

try

causes. as

Abiotic some

revolution

bodies,

other

by

the

way:

causes

vations, (2b)

the

if c e r t a i n

conditions

of

causes the

as

the

view

following

should

impact

event,

by

cosmic

category the

the

= cosmic caused

Impact

case.

a general in

mentioned.

of

In

this

the

latter,

connection,

activity

to s h o r t - t e r m e d

sidered.

Of g r e a t

we

the

and

in t h i s

have

also

short-term

to d i s t i n -

fluctuations.

Milankovitch-eurve

also

climatic

interest

surely

the

influence

perturbations respect

is

of

has the

may

be

volcanic to b e

con-

contribution

13

of

J.

Besse

Indian K/T

et

Deccan

Iridium

already

hand hand

and g e n e r a l Changes

key-note of

the

itself

of

their

at

the

Upper been

combined

natural

the

that

indicates already

the

position. black

the

two

shale

even by

This

oscillation

tain

only

to d e p e n d

between

short-termed

of

been

upward reached

the a n o x i c

thus

that

movement only by

layer

contributing

deep

at the

top of

This

latter

occur

KW H o r i z o n

marks

shales

of the m e n t i o n e d limestones,

part

positions

anoxic

caused

to a s t e p w i s e

evident

-- is

palaeogeographical each

an e x t r e m e l y

may have

reefs

cephalopode

of the

important

of b l a c k

of the u p p e r

relatively

it has

shales

"Lower"

on the

pelagic rise

Black

Event of the

it b e c a m e

coral

The n u m b e r

opinion

time

of the m o s t

Horizon

the

causes

on a c c o u n t

Kellwasser

long

of the

role.

boundary)

KW H o r i z o n ) .

event.

Zone.

changes

mentioned

a few years

of w h i c h

g i~as

occurring

one

("Upper"

shale

author's

Since

Kellwasser

Oscillations

events

the

of b i o h e r m a l

Zone

seems

serve

marks

since

traceable

Lower

all t h e s e

may

are

(see the

an i m p o r t a n t

to t h o s e

Famennian.

or b l a c k

the

or l e s s

have

bio-event,

of

layer,

extended one

the

have

been

whereas rise.

or the o t h e r

disappearance

of c e r -

taxa. The

final,

Horizon. became of

But

overturn,

to the d e f i n e d

boundary

KW H o r i z o n ,

the

a slight

positions

minor

and

Palaeogeographically

high

on

effect

These

volume).

play

lead

close

gigas

KW H o r i z o n s

horizons,

layer.

reached

of

supports

a more

productivity

bio-events

this

before,

or m a y

the e x t i n c t i o n

anoxic

Upper

part

This

represents anoxic

history.

a typical

Berry~

certainly

given

Fr/Fa

the g l o b a l l y

below

are

atmosphere

of g r e e n h o u s e

the g l o b a l

As an e x a m p l e

Palmatolepis

the u p p e r m o s t between

etc.,

Frasnian

-- w i t h

with

facts

the the

to be c o n -

of b i o l o g i c a l

destratification,

(but o n l y

this

of

& W.B.N.

events

effects.

stages

Uppermost

few

parameters.

for m a n y

layer,

global

in e a r t h

for

has

in the

of

cause

only

system

sequence

oceanographic

boundary

event

processes

and CO 2 c o n t e n t

to a c y c l i c

currents

Devonian

connected

leads

P. W i l d e

recognized

this

long-term

interdependency

to the s t a t e m e n t s

trigger

bio-events that

of

ocean

According may

the

the f o r m a t i o n

as a p o s s i b l e

a self-perpetuating

and of O~

decisive

anoxic

major

in w h i c h

cooling. of

obviously

volume),

is c o n s i d e r e d

About

Here

in w h i c h

the one

the o t h e r

(this

Event.

known.

sidered, on

al.

Trapps

There,

extinct.

the w h o l e

rapid e.g., This

bio-event

time

biocoenosis

as in the b a s i n s .

happens

the m a n t i c o c e r a t i d most

probably

of b i o e r h e r m a l

Nevertheless,

this

at the

very

end

of the

ammonites

and

the h o m o c t e n i d s

coincides reefs,

with

upon

catastrophe

was

Upper

KW

the e x t i n c t i o n

the s h e l f s selective.

as w e l l The

14

best

explanation

time

of a c r i t i c a l

Upper

KW b l a c k

triggered in the

seems

shale.

then

Upper

(see c o n t r i b u t i o n s Probably,

each

Theoretically cosmic

of

about c a n be

investigations volume)

occurrence account

could

and of

seems

and of could

have

of

Raup

J.

G.R.

Hladil

et al.

McGhee

change

through

this

the o c e a n the

(this

with

the

is i n d i c a t e d

et al.;

triggered

happened

which

As s e e n

to be c o n n e c t e d

a climatic

have

of

time

needed

to the s o l a r calculated

volume).

overturn.

impact

of an

data.

a Fourier

the

cyclicity solar

system's

cases,

of

system

1984).

around (1962).

assumption

of

provides

us w i t h

a periodic

miss

exceptional Further of

aware,

impacts

that

and,

the

many

sometimes,

about

of

impacts

in t i m e s

hand,

that

also with

the p l a n e

of t h e

star

and

a periapproxi-

of the

32 Myr is c l o s e Galaxy,

with

an o s c i l l a t i o n

even

& Arthur

coincides

cratering

8 times

a companion

maximum

latter

for the D e v o n i a n

This

the c e n t r e

on the o t h e r

and c a l c u l a t i o n s

astrophysics, and g e o l o g i c

shall

Myr for

with

& Stothers

This

a highly

of

the

of c o s m i c of m a x i m a ,

in the

as

solar bodies. cosmic

intervals

may h a p p e n .

investigations

telluric we

be

the e a r t h

(Rampino

on

This c o u l d i n d i c a t e

to o s c i l l a t e

& Weaver

as c o u n t i n g

should

31

the

the p e r i o d i c

of F i s c h e r

32 Myr.

In a d d i t i o n ,

as w e l l

But we

only

Sepkoski;

calculated.

Own calculations

-- of

orbit,

bodies

of J.J.

or e v e n

But

calculated

calculation

revolution

the

changes

century.

analysis

major events.

-- e v e n b e t t e r

& Stothers

They

30 Myr has b e e n

of 8 Myr b e t w e e n

for

last

e v e r y 26 Myr. T h e y g o t t h i s c y c l e

With of

processes, the

(see k e y - n o t e

a 33 Myr p e r i o d i c i t y .

by T r u m p l e r

In b o t h excentric

explains

into

better

events

curve.

the d o m i n a n t

(Rampino

Perhaps

far

Sepkoski

periodicity

24 Myr or

with

leagues

occurring

is n e a r to a p a l a e o n t o l o g i c a l

s h o w an i n t e r v a l

system,

and

back

us w i t h

of e x t i n c t i o n

assuming

odicity

Galaxy

traced

of a b e s t - f i t

(1977),

mately

periodically

provided

a dominant

evidence

other

Kalvoda

factor,

in d e b a t e .

at a occurring

of p e r i o d i c i t y

Speculations

the

fall

In a d d i t i o n ,

factors

also

catastrophes

1984)

et al.

happened

the g l o b a l l y

additional

is s t i l l

Lottman

which

by

body.

The q u e s t i o n

this

J.

of t h e s e this

of this

or s e a - l e v e l

KW H o r i z o n .

overturn,

indicated

overturn,

of J.

a regression

t o p of the

an o c e a n

The n a t u r e

the f i n a l

contributions

volume),

to be

destabilization,

find

should

also

phenomena,

in the f u t u r e

of our b i o l o g i c a l

such

some

in c o o p e r a t i o n

consider

cosmic

as g r a v i t y

kind

and g e o l o g i c a l

of

colto

and magnetism.

a cosmic

events.

with

influences

rule,

which

15 High-resolution

event-stratigraphy

As shown by the k e y - n o t e s the c o m b i n a t i o n with

a high

time-resolution.

magneto-stratigraphy, stratigraphy

has

for global

prises

of events

even

important

leads

If we add all other

In addition

of the high

another

(this volume), provides

stratigraphies,

etc.,

resolution,

us

such

as

volcano-

we may call

it

the e v e n t - s t r a -

of the r e c o g n i z e d

events

can serve

in the field.

time-resolution, aspect:

of events

Kauffman

tectono-stratigraphy,

to the high

that many

to a much better

interdependencies

and E.G.

and e v e n t - s t r a t i g r a p h y

tephro-stratigraphy),

the advantage,

correlation

In spite

Barnes

chemo-stratigraphy,

(especially

holostratigraphy. tigraphy

of C.R.

of b i o s t r a t i g r a p h y

the e v e n t - s t r a t i g r a p h y

recognition

and s u b s e q u e n t

understanding

and processes

com-

analysis

of the d e p e n d e n c i e s

in both,

the b i o s p h e r e

and

and

the geosphere.

Conclusions Global

biological

Several

categories

Some kind

events

show

of causes

of p e r i o d i c i t y

detailed

data

For

aim m u l t i d i s c i p l i n a r y

this

field

as well

is most

Many of the open problems from

a broad

variety

of causes

as of patterns

and effects.

can be recognized.

probable.

can only be solved,

and l a b o r a t o r y

if further

investigations

cooperation

precise

and

are elaborated.

is necessary.

REFERENCES BARNES, C.R. (1986): The faunal e x t i n c t i o n event near the O r d o v i c i a n Silurian boundary: a c l i m a t i c a l l y induced c r i s i s . - This volume. BECKER, R. Th. (1986): Ammonoid e v o l u t i o n before, during and after the " K e l l w a s s e r - e v e n t " - review and p r e l i m i n a r y new r e s u l t s . - This volume. BESSE, J.; BUFFETAUT, E.; CAPPETTA, H.; COURTILLOT, V.; JAEGER, J.-J.[ MONTIGNY, R.; RANA, R.; SAHNI, A.; VANDAMME, D. & VIANEY-LIAUD, M. (1986): The Deccan Trapps (India) and C r e t a c e o u s - T e r t i a r y b o u n d a r y e v e n t s . - This volume. BOUCOT, A.J. (1986): E c o s t r a t i g r a p h i c c r i t e r i a for e v a l u a t i n g the magnitude, c h a r a c t e r and d u r a t i o n of b i o e v e n t s . - This volume. BRASIER, M. (1986): P r e c a m b r i a n - C a m b r i a n b o u n d a r y biotas and e v e n t s . This volume. ERDTMANN, B.-D. (]986): Early O r d o v i c i a n eustatic cycles and their bearing on p u n c t u a t i o n s in early n e m a t o p h o r i d (planktic) g r a p t o l i t e evolution.- This volume. FISCHER, A.G. & ARTHUR, M.A. (1977): Secular v a r i a t i o n s in the pelagic r e a l m . - Soc. Econ. Paleont. Mineral., Spec. Publ. 25, 19-50. HANSEN, H.J.; GWODZ, R.; HANSEN, J.M. ; BROMLEY, R.G. & RASMUSSEN, K.L. (1986): The d i a e h r o n o u s C/T plankton e x t i n c t i o n in the Danish Basin.This volume.

16

HLADIL, J.; KESSLEROVh, Z. & FRIAKOVA, O. (]986): The Kellwasser event in M o r a v i a . - This volume. HOLSER, W.T.~ MAGARITZ, M. & WRIGHT, J. (1986): Chemical and isotopic variations in the world ocean during Phanerozoic time.- This volume. INGAVAT-HELMCKE, R. & HELMCKE, D. (]986): Permian f u s u l i n a c e a n faunas of Thailand - event c o n t r o l l e d e v o l u t i o n . - This volume. KALVODA, J. (]986): Upper Frasnian and Lower T o u r n a i s i a n events and e v o l u t i o n of calcareous f o r a m i n i f e r a - close links to climatic c h a n g e s . - This volume. KAUFFMAN, E.G. (1986): High resolution event stratigraphy: regional and global Cretaceous B i o - e v e n t s . - This volume. LOTTMANN, J.~ SANDBERG, Ch.A.~ SCHINDLER, E.; WALLISER, O.H. & ZIEGLER, W. (1986): Devonian events at the Ense area (Excursion to the Rheinisches S c h i e f e r g e b i r g e ) . - This volume. McGHEE, G.R., Jr.; ORTH, Ch.J.; QUINTANA, L.R. ; GILMORE, J.S. & OLSEN, E.J. (1986): Geochemical analyses of the Late D e v o n i a n "Kellwasser Event" s t r a t i g r a p h i c h o r i z o n at Steinbruch Schmidt (F.R.G.).- This volume. PFLUG, H.D. & REITZ, E. (]986): E v o l u t i o n a r y changes in the Proterozoic. - This volume. RAMPINO, M.R. & STOTHERS, R.B. (1984): T e r r e s t r i a l mass extinctions, cometary impacts and the Sun's motion p e r p e n d i c u l a r to the g a l a c t i c plane.- Nature 308, 709-712. RONG Jia-yu & CHEN Xu (1986): A big event of latest O r d o v i c i a n in China. - This volume. SCMAFER, P. & FOIS-ERICKSON, E. (1986): Triassic Bryozoa and the e v o l u t i o n a r y crisis of Paleozoic S t e n o l a e m a t a . - This volume. SEPKOSKI, J.J., Jr. (1986): Global b i o e v e n t s and the q u e s t i o n of p e r i o d i c i t y . - This volume. SOKOLOV, B.S. & FEDONKIN, M.A. (1986~: Global b i o l o g i c a l events in the late P r e c a m b r i a n . - This volume. TRUMPLER, R.J. & WEAVER, H.F. (1962): Statistical A s t r o n o m y . - (Dover, New York). WALLISER, O.H. (1984a): Geologic Processes and Global Events.- Terra c o g n i t a 4, 17-20. -- (1984b) : Global Events and E v o l u t i o n . - Proc. 27th Internat. Geol. Congr. Moscow, P a l a e o n t o l o g y 2, 183-192. WIEDMANN, J. (1986): M a c r o - i n v e r T e b r a t e s and the C r e t a c e o u s - T e r t i a r y b o u n d a r y . - This volume. WILDE, P. & BERRY, W.B.N. (1986): The role of o c e a n o g r a p h i c factors in the g e n e r a t i o n of g l o b a l b i o - e v e n t s . - This volume.

DEVONIAN (EXCURSION GEBIRGE)

EVENTS TO

AT

THE ENSE RHEINISCHES

THE

AREA SCHIEFER-

NT U

L O T T M A N N , J a n *), S A N D B E R G , C h a r l e s A. **), S C H I N D L E R , E b e r h a r d , *), W A L L I S E R , O t t o H. *) & Z I E G L E R , W i l l i ***)

During

the

meeting

5th

Wildungen

realm

of

Locality

I: B l a u e r of

time, rise

Wildungen,

The

quarry

the

Ense

mann

(1893,

quarry

has

graphical

basaltic

repeatedly

been

investigations. (1965),

in c o n n e c t i o n Middle

cephalopod

limestones

age.

represented

in two

thick,

the u p p e r

posed time

of

one

has

cephalopod

(spilites)

could

reach

of r e e f s .

about

and D e n c k m a n n

they

(1901)

They

in the

also

I n s t i t u t u n d M u s e u m fur G e o l o g i e D - 3 4 0 0 G @ t t i n g e n , F.R.G.

**)

US Geological

***)

Naturmuseum und a.M. I , F.R.G.

Denver,

layer

mainly

to e a r l y

Event

other

Zone.

brachiopods,

in 2 l a y e r s .

Already

these

with

layers

Pal~ontologie 80225,

Senckenberg,

the

are c o m since

them

long

from

the

Beushausen

those der

10 cm

within

They

described

,

by nearly

is a b o u t

limestones

varcus

(1855)

Colorado

Forschungsinstitut

stratiand

comprises

Emsian

pumilio

of e a c h

are d a r k

und

with

the

of a c o n o d o n t

Upper

the

lenticular

correlated

time,

(1957)

sequence

of

of

and D e n c k -

this

& Ziegler

pumilio

Middle

occur

localities

and f o l d i n g .

with

pumilio". Roemer

*~

Survey,

shales

are s e p a r a t e d

15 cm.

Since

the e s t a b l i s h m e n t

lower

Wenziger~der

(1895)

in c o n n e c t i o n

The e x p o s e d

by faults

The

at the

the f a m o u s

here.

mainly

with

I-3 mm s m a l l ,

where

of

Bischoff

concerned

Both

situated

"Terebratula

Mountains,

(1900)

mainly

layers.

approximately as

The b a s i n

socalled

Holzapfel

from

intercalated

limestones.

Limestone,

known

Hartz

was

e.g.

Devonian.

It is c o m p l i c a t e d

3 m of c e p h a l o p o d

discoides

and

is one

mentioned, Thus,

for

field-trip

with

i.e.

h 64240)

(1885),

ammonoids

chronology

The

visited.

of W i l d u n g e n ,

r 10060,

Bruch"

Wittekindt

Frasnian

Ense near

to the p e l a g i c ,

volcanics

station

Waldschmidt

described

the

rises

international

at the

miogeosyncline.

the s e t t l e m e n t

4820;

"Blauer

Already

1901)

shallow

for

been

area belonged

by stable

the r a i l w a y

(GK 25 Bad

area.

have

as the f i r s t outcrops

Bruch

Weg

former

Ense

modified

and g a v e

800 m s o u t h e a s t

the

held

two D e v o n i a n

Schiefergebirge)

In G i v e t i a n

level

216,

the r e l a t i v e l y

morphologically

sea

WEGENER-Conference,

Project

the D e v o n i a n ,

limestones. the

IGCP

(Rheinisches

During

been

ALFRED

of t h e

basinal

A co.lribullon to Proiec! GLOBAL BIO EVENTS

from

the

Universitgt,

U.S.A. D-6000

Frankfurt

Lecture Notes in Earth Sden~s, ~1, 8 Global Bio-Events. Edited by O. Walliser © Spnnger-Verlag Berlin Heidelberg 1986

18

Ense

area

and e m p h a s i z e d

the two p u m i l i o Rheinisches The (]901)

layers

doubted out,

the

cephalid.

Ongoing

taxonomic

position

datings same

of

aspects

that

the u n d e r -

the p u m i l i o

time-horizons, least

from

(TSF)

have

lower

part

teristic

consists

for

cephalopod and b l a c k

and

shales

with

one

these

layers,

of

diate

that

sediments,

some

the

to c l a r i f y

the

if p r e l i m i n a r y has

mean?

always

Do all

the

aspects

microfacies,

allow

events?

short

(1960)

stringo-

palaeogeographical

etc.)

the

In this

event,

features

assumption case,

could

two

be t r a c e d

kind

Maenioceras the

Devonian

of n o d u l a r

Stage.

at

layers

styliolinids

styliolinids

are

example

charac-

solid

Then

follow

of l i m e s t o n e ,

surrounded

is the

limestone,

Stage.

and/or

facies

boundary:

The o v e r l y i n g

Pharciceras thin

of

of t i m e - s p e c i f i c

A characteristic

Middle/Upper

distinct

consist

the

intend

structure,

seasonal

intercalated

or n e a r l y

Schmidt

Africa.

represents

yield

on,

of the

Denckmann

juvenile

two h o r i z o n s

for d i s c u s s i o n .

the u p p e r m o s t

H.

problem":

does

morphology

Event,

through

either

then

an e x t r e m e l y

of a v e r y

limestone

Lottmann

"pumilio

of the

what

to N o r t h

presented

near

each

represent

representing

been

the

and o v e r l y i n g

layers

Later

parts

uncertain.

terebratulids.

sedimentological

of the p u m i l i o

the s e q u e n c e

is s t i l l

by J.

of f u n c t i o n a l

Mid-Europe

Besides

that

position,

position,

position,

in o t h e r

be a f r e e - s w i m m i n g ,

and to s o l v e

can b e v e r i f i e d ,

character

to the

might

investigations

stratigraphical

(stratigraphical

of p u m i l i o

assignment pumilio

significance.

recognized

and in M o r o c c o .

position

that

stratigraphical

also b e e n

Schiefergebirge

systematic

pointed

their

have

dark

which

homoctenids. by

a seam

In

of ra-

calcite.

The

same

sequence

the

sediments

with

radiate

in S o u t h meter

is also calcite

China.

for

Locality

with

the s a m e

known

from

the

Steinbruch

quarry

Lower

The

two

is a l s o

Famennian

Upper

In a d d i t i o n ,

represented

TSF can b e u s e d

the

recognized

since

already

(GK 25 A r m s f e l d

known

black

long

time.

has been of the

"Braunauer

limestones

Kellwasser

Kellwasser

the d e s c r i p t i o n s

as

cephalopod

Frasnian

presenting

quarry

characteristics the

in c e r t a i n

of

"styliolinite" localities

as an a d d i t i o n a l

para-

Schmidt

N N E of B r a u n a u n e a r W i l d u n g e n This

Morocco.

is i d e n t i c a l l y

In so far,

peculiar

event-stratigraphy.

2:

and

very

Event

to v.

arthrodire

Ka]kofen".

Horizons (Walliser

Koenen fauna

r 3509275,

have been

In the e i g h t i e s

known

4920;

made

Formerly,

quarried

Frasnian

and b u r n e d .

(Kellwasserkalke), 1980,

of the and

h 5661275)

1984),

last

century,

Waldschmidt. the q u a r r y

re-

are w e l l the

Especially

well

known

all

19

over

the w o r l d .

of the

Upper

Jaekel early

This

fauna

KW H o r i z o n .

(in the b e g i n n i n g thirties)

and

occurs

of

Stensi~

this

First

mapping

of the q u a r r y

already

in

The

locality

(]928)

and

Pusch

1968 found

Lange

in b o t h

layer"

of

stones now

on

its

known

1928),

surrounding

and W e d e k i n d

to

part

Koenen,

Gross

(in the

a r e a was

done by

worked

Schindewolf

samples by

70 c o n o d o n t

However,

in his

on the g o n i a t i t e

(]921),

assemblages.

the b u l k

geochemical

the

Schmidt

et al.

chronology (1958,

H.

Schmidt

They

occurrence

about

quarry.

have been

is in the

"fish

Most

colleagues

distribution

New geochemical

of this

recent

quarry

data

cooperate

and

"Kellwasserkalke" on p e l a g i c

lime-

data

are

volume).

sequence

197]).

the

investigations

(see this

in the

1962, Those

the f a u n a l

work

micro-facial

from

McGhee

(see b e l o w ) .

is s t u d y i n g

and

about

in his

Ziegler

& Ziegler

until

of v.

KW H o r i z o n .

(1972)

The c o n o d o n t based

also

descsribed

Upper

presented

in the b a s a l

(]935).

as T u c k e r used

was

century

Denckmann

KW H o r i z o n s .

the

Buggisch as w e l l

1894.

nodules

are the p u b l i c a t i o n s

(1922-1963).

Denckmann fauna.

in l i m e s t o n e

To m e n t i o n

are

with

is m a i n l y from

Sandberg

Schindler,

the d e v e l o p m e n t

of

who

the m i c r o -

facies. The the

Lower

Upper

several Event thick both

black

shales

of b l a c k

64

(layer

abundant such

layer

between

These

have been

in W e s t e r n a marked top of

shales

65

is the

these

two

that

the

a large

with

the c h a n g e s in p l a t f o r m ,

fall

Uppermost

black

limestones, besides

and into

of

Buchiola. two

7 cm b l a c k

overlying

40 cm

parts,

shales

layer

100 c o n -

last

observed

is a l r e a d y

occurrence

in l a y e r

64.

indicating

of h o m o c Then,

in the

a major

layers.

coincide

studying

and

KW

is a b o u t

cephalopods

p e l e c y p o d e , thus

boundary

Europe

The

occur

the m a i n

ostracods,

follow

cm b e l o w

still

horizon

can be s u b d i v i d e d Then

260

limestone.

goniatites

65 o c c u r s

intercalated

orhhocone

ca. there

However~

This

and e n t o m o z o a n

KW H o r i z o n .

grey

fact,

KW H o r i z o n .

and

(7 cm).

the

nodular

and e n d s

KW H o r i z o n s ,

KW H o r i z o n .

limestone

layer

finish

eustatic

the

Upper

Upper

as g o n i a t i f e s ,

observations

nian-Famennian

45 cm t h i c k to the

homoctenids

and m a n t i c o c e r a t i d

following

they

and

a partly

Remarkable

change

the

intercalated

(5 cm)

66) w h i c h of

tenids

the

and c o n s i s t s

The uppermost

sists

above

with

fossils,

layer

is a b o u t

In a d d i t i o n

is c o n n e c t e d

yielding

other

KW H o r i z o n

KW H o r i z o n .

the

results

in c o n o d o n t reefal,

Western

North

America.

in sea

level

in all

gigas

Zone

of

faunas

slope, Their

regions

and e x t e n d i n g

Sandberg across

and the

and b a s i n a l interim

the

Fras-

facies

findings

beginning

through

Ziegler:

near

Lower

show

the

and

20

Middle

triangularis

increase lepis, dance

in a b u n d a n c e

within of

beds

of

and t h e n of

this

Ziegler), ately

the

first

the

increases

abundance

to s i m i l a r Utah

eustatic

Icriodus gigas

drops

Upper

interval.

the

in B e l g i u m ,

of

This

Uppermost

Icriodus

at the b a s e rise,

Zones.

coupled Zone

from

Kellwasser

is m a r k e d

with

about

8 percent

Limestone,

in the u p p e r

Icriodus

increases

increases

observed

in o t h e r

down

part

the

a marked of

Schmidt

lower

of l a y e r

markedly

Palmatothe

abun-

to 0 p e r c e n t

reflecting

within

of

by

a decrease

at S t e i n b r u c h

to a f e w p e r c e n t

However,

fall

an e u s t a t i c limestone 65

(= 16 of

and p r o p o r t i o n -

palaeoenvironmental

settings

and N e v a d a .

REFERENCES

B E U S H A U S E N , L. (1900): Das D e v o n des n S r d l i c h e n O b e r h a r z e s . - Abh. PreuB. Geol. L.-A., N.F. 30, 383 p. B I S C H O F F , G. & Z I E G L E R , W. (1957): Die C o n o d o n t e n c h r o n o l o g i e des Mitteld e v o n s u n d d e s t i e f s t e n O b e r d e v o n s . - Abh. h e s s . L . - A m t B o d e n f o r s c h .

2_!, 136 p. B U G G I S C H , W. (1972): Zur G e o l o g i e u n d G e o c h e m i e d e r K e l l w a s s e r k a l k e u n d i h r e r b e g l e i t e n d e n S e d i m e n t e ( u n t e r e s O b e r d e v o n ) . - Abh. h e s s . L . - A m t B e d e n f o r s c h . 62, 68 p. DENCKMANN, A. (1893): S c h w a r z e G o n i a t i t e n - K a l k e im M i t t e l d e v o n d e s Kellerwaldgebirges.Jb. kgl. p r e u B , g e o l . L.-A. f. 1892 13, 12-15. -- (1895): ,Zur S t r a t i g r a p h i e d e s O b e r d e v o n im K e l l e r w a l d e u n d in e i n i g e n benachbarten Devon-Gebieten.Jb. kgl. p r e u B , g e o l . L.-A. f. 1894 15, 8-64. -- (]901): Der g e o l o g i s c h e Bau d e s K e l l e r w a l d e s . - Abh. p r e u S , g e o l . L.h., N.F. 34, 88 p. - - (1902): E r l ~ u t e r u n g e n zur g e o l o g i s c h e n S p e c i a l k a r t e y o n P r e u s s e n u n d b e n a c h b a r t e r B u n d e s s t a a t e n . - B e r l i n , 84 p. GROSS, W. (1932a): Die A r t h r o d i r a W i l d u n g e n s . - Geol. P a l i o n t . Abh., N. F. 19, 61 p. -- (1932b): Ein W i l d u n g e r A r t h r o d i r e in N o r d A m e r i k a . - P a l i o n t . Z. 14, 46-48. -- (1933): D i e W i r b e l t i e r e d e s r h e i n i s c h e n D e v o n s . - Abh. p r e u B , g e o l . L.A., N.F. 154, 83 p. H O L Z A P F E L , E. (1895): Das o b e r e M i t t e l d e v o n Schichten mit Stringocep h a l u s b u r t i n i u n d M a e n e c e r a s t e r e b r a t u m ) im R h e i n i s c h e n G e b i r g e . Abh. p r e u B , g e o l . L.-A., N.F. 16, 459 p. J A E K E L , O. (1903): 0 b e t R h a m p h o d u s nov. gen. ein neuer devonischer Holoc e p h a l e aus W i l d u n g e n . - S i t z . - B e r . Ges. n a t u r f o r s e h . F r e u n d e ~. -- (1904): 0 b e r n e u e W i r b e l t i e r f u n d e im O b e r d e v o n von W i l d u n g e n . - Z. dt. g e o l . Ges. 56, 1 5 9 - 1 6 7 . -- (1906): N e u e W i r b e l t i e r f u n d e aus d e m D e v o n yon W i l d u n g e n . - S i t z . Ber. Ges. n a t u r f o r s c h . F r e u n d e B e r l i n , 73-86. -- (1928): U n t e r s u c h u n g e n ~ b e r d i e F i s c h f a u n a v o n W i l d u n g e n . - P a l i o n t . Z. ~, 3 2 9 - 3 3 9 . K O E N E N , A. v. (1880): V o r l a g e yon F i s c h r e s t e n aus d e m O b e r d e v o n yon B i c k e n u n d W i l d u n g e n . - Z. dt. g e o l . Ges. 1880, XXXII, 6 7 3 - 6 7 5 . -- (1883): B e i t r a g zur K e n n t n i s d e r P l a c o d e r m e n des n o r d d e u t s c h e n O b e r d e v o n s . - Abh. kgl. Ges. Wiss. G~tt. 30. LANGE, F.G. (1968): C o n o d o n t e n - G r u p p e n f u n d e aus K a l k e n d e s t i e f e n O b e r d e v o n s . - G e o l o g i e a et P a l a e o n t o l o g i c a ~, 3 7 - 5 7 . M c G H E E , G.R., Jr.; ORTH, Ch. J.; Q U I N T A N A , L.R.; G I L M O R E , J.S. & OLSEN, E.J. (1986): G e o c h e m i c a l a n a l y s e s of the Late D e v o n i a n " K e l l w a s s e r

21

Event" s t r a t i g r a p h i c horizon of S t e i n b r u c h Schmidt (F.R.G.).- (this volume). PUSCH, F. (1932, 1935): B e o b a c h t u n g e n im Devon und Kulm der Wildunger Gegend.- I. + 2. Ber. an die Geol. L.-A. zu Berlin, 9 + 16 p. ROEMER, F.A. (1855): Beitr~ge zur g e o l o g i s c h e n Kenntnis des n o r d w e s t lichen Harzgebirges. III.- P a l a e o n t o g r a p h i c a ~, 1-46. SCHINDEWOLF, O.H. (1921): Versuch einer P a l i o g e o g r a p h i e des e u r o p i i s c h e n O b e r d e v o n s . - Z. dt. geol. Ges. 73, ]37-223. SCHMIDT, H. (1928): E x k u r s i o n bei W i l d u n g e n (Devon, etwas Silur und Karbon).- Paliont. Z. 9, 5-8. -- (1960): Die s o g e n a n n t e "Terebratula pumilio" als J u g e n d f o r m e n von S t r i n g o c e p h a l i d e n . - Paliont. Z. 34, 161-168. STENSIO, E. (1922): Uber zwei C o e l a ~ n t h i d e n aus dem O b e r d e v o n von Wild u n g e n . - Paliont. Z. 4, 167-210. TUCKER, M.E. (1971): Aspects of pelagic s e d i m e n t a t i o n in the Devonian of Western Europe.- Thesis, Reading Univ., 405 p. (unpubl.). -- (1973): S e d i m e n t o l o g y and d i a g e n e s i s of Devonian pelagic limestones ( C e p h a l o p o d e n k a l k e ) and a s s o c i a t e d sediments of the R h e n o h e r c y n i a n Geosyncline, West Germany.- N. Jb. Geol. Paliont., Abh. 142, 320-350. -- (1974): S e d i m e n t o l o g y of Palaeozoic pelagic limestones: the Devonian Griotte (Southern France) and C e p h a l o p o d e n k a l k (Germany).- Spec. Publ. internat. Assoc. Sediment. 1 t 71-92. WALDSCHMIDT, E. (1885): 0bet die d e v ~ n i s c h e n Schichten der Gegend von W i l d u n g e n . - Z. dr. geol. Ges. 37, 906-927. WALLISER, O.H. (1980): The g e o s y n c l i n a l d e v e l o p m e n t of the Variscides with special regard to the R h e n o h e r c y n i a n Zone.- in: CLOSS, H. et al. (eds.): Mobile Earth. Research Report Deutsche F o r s c h u n g s g e m e i n s c h a f t , 185-195 p., Boppard (Harald Boldt Verl.). -- (1984): Geologic processes and global events.- Terra cognita i, 1720. WEDEKIND, R. (1917): Die Genera der P a l a e o a m m o n o i d e a (Goniatiten).P a l a e o n t o g r a p h i c a 62, 85-184. WITTEKINDT, H. (1965): Zur C o n o d o n t e n c h r o n o l o g i e des M i t t e l d e v o n s . - Fortschr. Geol. Rheinld. u, Westf. 2, 621-646. ZIEGLER, W. (1958): C o n o d o n t e n f e i n 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 an der Grenze M i t t e l d e v o n - O b e r d e v o n und in der A d o r f s t u f e . - Notizbl. hess. L.-Amt B o d e n f o r s c h . 87, 7-77. -- (1962): T a x o n o m i e und P h y l o g e n i e o b e r d e v o n i s c h e r C o n o d o n t e n und ihre s t r a t i g r a p h i s c h e B e d e u t u n g . - Abh. hess. L.-Amt Bodenforsch. 38, 166 p. -- (1971) : S y m p o s i u m on Conodont Taxonomy - a Field Trip Guidebook, Post S y m p o s i u m E x c u r s i o n to Rhenish Slate Mountains and Hartz M o u n t a i n s . 47 p., Marburg.

GENERALASPECTS

ECOSTRATIGRAPHIC THE MAGNITUDE, BIOEVENTS

BOUCOT,

CRITERIA CHARACTER

FOR AND

EVALUATING DURATION

OF

*)

•T

con~6bufion

G L O BA L BIO EVENTS

lJ

Arthur J.

A

Abstract: In order to have the c a p a b i l i t y for r e c o g n i z i n g as many of the e x t i n c t i o n and a d a p t i v e r a d i a t i o n s in the fossil r e c o r d as p o s s i b l e we s h o u l d take a d v a n t a g e of the e c o s t r a t i g r a p h i c a p p r o a c h in our work. This means that we will c a r e f u l l y collect, s t r a t u m by stratum, d a t a about the s t r a t i g r a p h i c ranges of the i n d i v i d u a l taxa w i t h i n i n d i v i d u a l c o m m u n i t y groups, b i o f a c i e s n a r r o w l y c o n s t r u e d , as o p p o s e d to the all too c u s t o m a r y habit of l u m p i n g taxa from v a r i e d c o m m u n i t y g r o u p s t o g e t h e r i n d i s c r i m i n a t e l y . F o l l o w i n g this p r o c e d u r e e n a b l e s one to far more e a s i l y r e c o g n i z e as well, those brief i n t e r v a l s when p o r t i o n s of the e c o s y s t e m w e r e r e s t r u c t u r e d , w h i c h is i m p o r t a n t owing to the fact that such res t r u c t u r i n g c o m m o n l y c o i n c i d e s with e x t i n c t i o n and a d a p t i v e r a d i a t i o n events. It must be r e c o g n i z e d that major c h a n g e s in s u p r a - s p e c i f i c a b u n d a n c e are fully as u s e f u l in pin p o i n t i n g e x t i n c t i o n and a d a p t i v e r a d i a t i o n e v e n t s as are mere t a x o n o m i c c o m p i l a t i o n s . The e c o s t r a t i g r a phic a p p r o a c h also e m p h a s i z e s the fact that s o - c a l l e d "known" s t r a t i g r a p h i c r a n g e s are c o m m o n l y far less than "true" r a n g e s e x c e p t for the small n u m b e r of a b u n d a n t g e n e r a and their species. A w a r e n e s s of this last r e l a t i o n s h i p makes it clear that there is no such thing as a "Backg r o u n d E x t i n c t i o n Rate" w i t h i n any one c o m m u n i t y group, i.e., b i o f a c i e s , b e c a u s e the s p e c i e s to s p e c i e s name c h a n g e s w i t h i n the g e n e r a of each c o m m u n i t y g r o u p are m e r e l y e v i d e n c e of p h y l e t i c e v o l u t i o n , not the term i n a t i o n of a lineage. E m p h a s i s is p l a c e d on the i m p o r t a n c e of s e p a r a ting out the major e c o s y s t e m c o m p o n e n t s , such as the level b o t t o m from the reef c o m p l e x w h e n trying to r e c o g n i z e event horizons, i.e., c o m p i l a t i o n s that l u m p taxa from such e c o s y s t e m c o m p o n e n t s t o g e t h e r tend to blur the actual n a t u r e of the units b e i n g m i x e d together, g i v i n g rise to an a r t i f a c t u a l b a c k g r o u n d e x t i n c t i o n (and a d a p t i v e r a d i a t i o n ) rate. We now need to far more c a r e f u l l y s a m p l e beds above and b e l o w s u s p e c t e d event h o r i z o n s , c o m m u n i t y g r o u p by c o m m u n i t y group, in order to d i s c o v e r w h e t h e r or n o t the taxa i n v o l v e d in r a d i a t i o n s and e x t i n c t i o n s u n d e r g o a s i g m o i d a l c h a n g e in a b u n d a n c e or not. All of this r e q u i r e s that we c a r e f u l l y e v a l u a t e our d a t a a g a i n s t a s o u n d k n o w l e d g e of c l a s s i c a l b i o s t r a t i g r a p h y , b a s e d on the e v o l u t i o n a r i l y u s e f u l d a t a d e v e l o p e d d u r i n g the past c e n t u r y and more.

Introduction The c o n c e p t another. phism

of b i o e v e n t s

has b e e n with us for a long time

One n e e d only m e n t i o n

affecting

the name of Cuvier

the o r g a n i c w o r l d d u r i n g

matic work which D'Orbigny

summarized

l ogie

this c e n t u r y

(]850-52).

c u s s i o n of major

extinction

from the Triassic, these r e l a t i v e l y

*)

During

events

the past,

in his

such

as well

Prodrome

there has b e e n

D e p a r t m e n t s of G e o l o g y O r e g o n 97331, U.S.A.

major

e x t i n c t i o n events,

& Zoology,

de

Oregon

State

as the systeP al~ont

o-

i n t e r m i t t e n t dis-

as that s e p a r a t i n g

or the C r e t a c e o u s f r o m the T e r t i a r y .

obvious,

in one form or

to c o n j u r e up c a t a s t r o -

the P e r m i a n

Additional

to

most of w h i c h were

University,

Corvallis,

Lecture Notes in Earth Sciences, Vol. 8 Global Bio-Events, Edited by O, Walliser © Springer-Verlag Berlin Heidelberg 1986

26

first

recognized

about

a number

of c o n c e r n

of

emplying

logic

or

we now have

important,

although

smaller

Stratigraphy

of t h i s

of

taxa,

the f o s s i l blem

century~

at all

record

of w h e t h e r

For w e l l

large

One

or n o t

over

significance

vals

new

in y o u n g e r

of s u c h

have

Zone.

These

units

time

increasingly

collecting

to m a n y

have

practice to the carried

by t h i c k n e s s

been

plots

which

many,

varied

position

commonplace

taxa

in the

to the e v e n t

(Fig. data the

have

to d i s p l a y

indicate

horizon's

sometimes

of the g r a d u a l

from pro-

either

be

the e v e n t

horizon.

elimination

Cretaceous

sort,

time

need

while

interval.

]A)

may

from

that

the

the r e c o r d

a l s o be p r o v i d e d

has

considering

of

event's

to n o t e

adaptive

(1984)

inter-

significant

(Fig.

IB) e l i m i n a t e d

Kauffman

by

to d e t e r m i n e

"brief"

to the s u s p e c t e d

plots

a few

in t i m e - d i v e r s i t y

alternatively,

Similar

from

time

disappearance

as s u b s e q u e n t

or

more detailed

zonally

I)

com-

Stage

centimeter

This

a greater

(Fig.

adjacent or,

and

inter-

it h a s b e c o m e

a relatively

rock

the

Period,

sometimes

boundary.

time

time

ranging

of the o b v i o u s

(Fig.

the

intervals

a geologic

fossils,

data

of

a

leaving

plotting

geologic

time duration

abrupt

position.

interpreted

The

when

without

a paleontologic

involved

this

of e x t i n c t i o n

In t h i s d e c a d e

event

are o n l y g r a d u a l l y

I) f o l l o w i n g

terminal

not

column,

taxa

the

an event,

as a "time"

record,

than

occupied

stratigraphic

prior

can

event

horizon

varied

for w h a t

of years.

at a s i n g l e

many,

following

the g e o l o g i c

of s e d i m e n t a r y

it m i g h t

commonly

eliminated

the e v a l u a t i o n

years

out b e c a u s e

judged

It has

or n o t

correlative

by graphically

no l a r g e r

to c o l l e c t

val,

loosely

in q u e s t i o n .

suspected

the e x t i n c t i o n

or w h e t h e r

were The

discussion

of

done

an a b s o l u t e

millions

common

Most

in r e c e n t

or not

as

of the b i o -

is w h e t h e r

on up,

the f o s s i l

taxa during

been

whether

fossils,

here

"abruptly",

event

has b e e n

and

adjacent has b e e n

from

the e v e n t

commonly

Series,

years

events

the n e c e s s i t y ,

evaluation

'~gradually".

has b e e n

strata.

of v a r i e d

a geologic

centimeter,

there

events

and s u c c e e d i n g

involved

concern

appeared

additional

b).

the utility,

in the

the s p e c i e s

an e x t i n c t i o n

monly

million

taxa

scale,

concern

also be addressed.

a century

or a b s e n c e

preceding

from

of t a x a d i s a p p e a r

any descendants

presence

levels

Of g r e a t

increasing

1984a~ out

*) m e t h o d s

" i n s t a n t a n e o u s l y 'i or

can define

number

(Walliser

is to p o i n t

such events.

" g r a d u a l l y '~, m u s t

events.

paper

ecostratigraphic

effects

affected

last

to E v e n t

The p u r p o s e for

in the

radiations

provided

the n a t u r e

ample of

event.

*)Ecostratigraphy is b a s e d on the o b s e r v a t i o n that f o s s i l s c o l l e c t e d in v a r i o u s t i m e i n t e r v a l s do n o t o c c u r in a r a n d o m m a n n e r . The f o s s i l f l o r a and f a u n a are n e i t h e r a h o m o g e n i z e d , u n i f o r m m i x t u r e o c c u r r i n g e v e r y w h e r e in the w o r l d , nor a set of n o n - r e p e t i t i v e o c c u r r e n c e s in which every fossil locality provides a unique mixture.

27 T~ugh-

IA.

18.

Tex~

A B C D EF

TQKQ

i

]I I' ............. ............I]ll]t .............. 125456 1 2 3 4 5 6

F i g u r e I. Time-Diversity Diagram indicating (IA) an i n s t a n t a n e o u s interpretation of a b i o e v e n t h o r i z o n . T a x a ( b e l o w t h e b i o e v e n t h o r i z o n ) t h a t b e c a m e e x t i n c t are n u m b e r e d f r o m o n e to "n" whereas ( a b o v e the bioevent horizon) taxa that subsequently a d a p t i v e l y r a d i a t e d are l e t t e r e d ~'A" t h r o u g h "n". Time-Diversity Diagram indicating (IB) a g r a d u a l i n t e r p r e t a t i o n of a b i o e v e n t h o r i z o n . T a x a a r e l e t t e r e d a n d n u m b e r e d as in Fig. IA ( a b o v e ) . N o t e t h a t the taxa, b o t h a b o v e and b e l o w the b i o e v e n t h o r i z o n , are m i s cellaneous taxa belonging to a v a r i e t y of c o m m u n i t y g r o u p s , i.e., m o s t of t h e m do n o t c o - o c c u r in a n y i n d i v i d u a l c o m m u n i t y .

How of

should

tion

of

followed

by

gradual

is

evaluate

taking of

are

It

to

place

a year

thousand

within

to to

a few a few

be

dJ.stinguished

a

few

hundred

capability years nae

shown

hope

of

from

of

that

with

some

taxa,

by

Or,

these

are

others

are

the

In the

must

cha-

terms

light

answer.

questions

extinc-

instantaneous

are

artifacts? to

versions

gradual

bioevents

whereas

taxa?

questions

the

trying

But, be

of b i o e v e n t s

instantaneous events

further

took

Once

we

time

(except

annual

rapidity

to u n d e r s t a n d

younger

measuring

instances

feature

of

if

our

the

evaluated!

a bioevent

which

years).

that

varied

sampling

thousands

those

precisely

varves

for

"instantaneous"

characterized

varied

meaning

of

decades tens

in m o s t

to b e

of

in of

a geologically

thousand

for

is p o o r

any

critical

any

are

difficult

rapidity

is

have

in

merely are

to h a v e

the

Introduction: if w e

these

versus bioevents

it p o s s i b l e

coming

instantaneous

some

others Is

coming

abrupt

samples

bioevent

to

taxa?

"gradual" that

whereas

a gradual an

these

possible

varied

by

and

available

view

it

taxa,

of

racterized

term

Is

varied

extinction

How

one

bioevents?

place are

time

in

the

back

in

over in

interval

a few

record,

should

a few

million

or

p r e - C 14 d o m a i n

in y e a r s

or

uncommon

Even

(fractions

Quaternary;

for

value).

evaluated

Bioevents

the

the

such

be

causation.

even

within

a few

the

cases

even our

thousand as

Cenozoic

lamiwhere

28

our

capabilities

sal

stratigraphy,

sive

for o n e

zoic,

there

short, will

able

whose

time

few hundred

event

thousand

the p a s t

attempt time

I need

text.

remind

By

"ecostratigraphic do not

as d i s c r e t e

taxonomically

entities.

unrelated

tions,

assemblages,

should

take

organisms,

or w h a t e v e r

advantage

of

this

with

those

over

of

the K - T b i o -

nature

involved.

I will

for b e t t e r

in an e c o s t r a t i g r a p h i c

their

for

matters

What

the p o s s i b i l i t i e s

evolve

advantage

you

together

con-

the f a c t

taxonomic

with

other,

biofacies,

happen

purposes

of

own higher

in c o m m u n i t i e s ,

fact

a few

the

taking

term

occupied

a

these

I mean

they

to b e

over

of

within

other

of y e a r s

place

which

we

discussion

of d a t a

and o u t l i n e

Rather,

thousands

took

of b i o e v e n t s

solely

time

that

useful

Paleo-

of y e a r s

bioevents

the m a s s

context"

evolve

some

it is u s e f u l

to c o n c e r n

is to r e v i e w

for

here

much

y o u of

the o l d e r

thousands

of

reverimpres-

at the v e r y

that

a few

are

But~even

as c o n t r a s t e d

due

towards

in the h u n d r e d s

between

and recognition

organisms

units

years

not

than

magnetic

dating

reliably

it is p r o b a b l e

of y e a r s .

has b e e n

six

directed to w o r k

no b e t t e r

working

years

There

to do now,

resolution

that

Therefore,

discriminate

of y e a r s .

--

trying

to e s t i m a t e s commonly

age d e t e r m i n a t i o n ,

and p a l e o n t o l o g i c

have been

a few millions

to r e l i a b l y

millions

absolute

difficulty

scale.

and m o r e

to e v e n

during

attentions

restricted

at best, range

isotopic

chemostratigraphy,

is g r e a t

human

be

for

associa-

to p r e f e r .

of b i o e v e n t

We

recognition

and d e f i n i t i o n . Biostratigraphers the

fossil

52).

record

I first

in the Early

since

became

Somerset Devonian

County,

I learned

later,

the U.S.

lections facies not

of

continuity

tions

monly

northern

employed

Survey

had

Our

dating

had

for

very

this

my c o l l e a g u e s rations

biofacies

long

same

I also

noted,

the

Again,

Survey,

of b i o s t r a t i g r a p h e r s .

but

which

this

reflected

It a l s o

them

of the m o r e

Maine.

parts

made

was

not

for

My

of the

of g e n e r a that

genera

more

com-

useful

abundant them

much

unique

the e x p e r i e n c e

accounted

collections,

that

common

col-

this bio-

my c o l l e a g u e s ,

which

conclusion

fossil

County,

in o t h e r

made

and

fossils.

Stratigraphy

of f o s s i l

less

1850-

working

Silurian

their

that

reaffirmed

as d i d

ranges

Late

and

Somerset

of the

species

student

I identified

experience

ranges,

whereas

I mapped

geologists,

of

of

(D'Orbigny

and s t u d y i n g

character

merely

stratigraphic

purpose.

at the

where

for f i e l d

the s p e c i e s

stratigraphie

and c o r r e l a t i o n ,

commonly useful

shorter

the

century

for w h o m

a routine

continuity

as a g r a d u a t e

the P a l e o n t o l o g y

Survey,

experience

of b i o s t r a t i g r a p h e r s .

had

by

biofacies

last

collecting

to the m i d - P a l e o z o i c

column.

individual

the

pattern

age

in t i m e w a s

of

of this

Maine,

also

Geological

unique

at the

stratigraphic

within

this

Silurian-Devonian

a feature

colleagues

of

while

while

aware

the m i d d l e

aware

strata

Branch

of

have been

for

genera less

to m e or

had by gene-

the m a n y

comments

29

we made

to hopeful

and make

a bigger

obtaining

some

us to give

period,

however,

for me,

matters,

of these

1975,

Community

clear

of e c o l o g i c monly

1982,

unable

to evaluate

communities. an evolving Other record

in what

ginning

ranges

them

How to r e c o g n i z e

and d e f i n e 1982,

to r e c o g n i z e ging here.

type

item

of many

Community

or B i o f a c i e s

tic,

shelly,

as possible. number

pelagic, When

of i n d i v i d u a l s

conclusions

etc.)

represented

summary

of these

made:

relations);

being

3) The n u m e r i c a l l y

topic,

with

being

within

the fossil

biofacies

have

varying

definite,

In a series aspects

summarize

such

an interval

prepared,

to each genus

long ranthe problem

in terms

defined

of g e o l o g i c

time

made of the

the following

abundant

genera

are

2 for a d i a g r a m m a t i c

less

abundant

of species, to the

genera

in of the

as g r a p t o l i -

and counts

and species

(see Fig.

proportional

of how

as the String o c e p h a l u s

biofacies

as long

(be-

units).

or the n a r r o w l y

things

for

or to consider

is that

of large

I) The n u m e r i c a l l y

estimated

present

the case

such

abundant

com-

We are p r e s e n t l y

samples

2) The n u m e r i c a l l y

more

other,

with

a series

defined

species

kind

the commonly,

group,

the It has

in some

as is so commonly

by a time s e q u e n c e

inversely

genus;

eurytopy

i.e.,

2).

term c o m m u n i t y

which

I will b r i e f l y

have been

by a single

are r e p r e s e n t e d

of such species

through

belonging

are c o m m o n l y

usually

commonly

including

thing

I discussed

problem,

(not b ~ o a d l y

the samples

association a community.

groups),

is to obtain

authors,

do not evolve

of c o n t e m p o r a r y

(= my term c o m m u n i t y

biofacies

these

discussed

ecostratigraphically:

b)

in 1970

as it

(Fig.

it an association,

groups,

record.

a sampling

The c r i t i c a l

community

community

of the fossil

It is largely

science. same

and define

biofacies

1984a,

1983)

ecologic-evolutionary

bioevents

1983,

enough

to ponder

particularly

of c o e v o l u t i o n

sets

1983,

this

was

Beginning

the b i o l o g i s t s

community

(Boucot

u%ility

evolution

The c r i t i c a l

by distinct

of papers

(1978,

or levels,

to term

During

I started

1982,

organisms

in intimate

the point.

I termed

time

(1978,

community

may be termed

or prefers

is b e s i d e

in 1975

that

of

of b i o e v e n t s .

or not one prefers

is c h a r a c t e r i z e d

coincident

during

chance

that would

the e v o l u t i o n a r y

forebears. b, c)

significance,

previously

the level,

facies,

terms,

their

They evolve

Whether

1984a,

and r e c o g n i t i o n

I have

taxa,

pondering

to the field

a better

fossils

age d e t e r m i n a t i o n " .

any time

1983,

the b e g i n n i n g

vacuum.

unrelated

to have

ranging

for my p r o f e s s i o n a l

by o r g a n i s m s

since

go back

-- their b i o s t r a t i g r a p h i c

now discuss

evolution:

followed

in order

short

precise

spend

data

1978,

and will

more

a more

on the d e f i n i t i o n

pattern been

you

"that you had b e t t e r

collection

I did not

as it has been

(see also,

bears

fossil

of the rarer,

enable

significance

geologists

also

with

abundance tend

of such

genera the number of each

to be more

things

eury-

as occur-

30

fence

across

a greater

munity

groups

genera

also

abundant

in w h i c h

tend

genera

Level several

or l e s s e r a genus

to be far far m o r e

bottom

marine

thousand

shelf

width,

occurs;

more

and w i t h

the

4) The n u m e r i c a l l y

cosmopolitan

number more

geographically,

of c o m -

abundant

and

the

less

provincial. environment

specimens

commonly

samples

of m e g a b e n t h o s

include

the

species

which

of m a n y

include rare

genera. H o w to r e c o g n i z e zons

bioevents:

is to f o l l o w

the

The

time

carefully

noting

are m a j o r

ecologic-evolutionary

by marked

community

to n o t e w h e r e same

part

noid

thicket,

varied

have

extensive,

been

part

to the m a j o r

discussed

at s o m e

Its r e a l l y routine,

How n o t

to r e c o g n i z e

views

approach

a

background

vals

1852)

can

time

units,

~tages

this

so-called

background

provided

a statistical

fails

events. some

This

kind

tistical tistical natural

that

to d e f i n e approach

treatments) treatments history

such

fails

must

attempt

can be not

only

of p a l e o n t o l o g i c

misleading,

a basic

but

and can

in that

to b e c o m e

during

called part

are

summarized events.

assumption

operative

His

for w h i c h

that

there

lengthy

(1983)

ecologic-

to D t O r b i g n y ' s

then weighed

r at e

. In

(1850-

against

his

1986

level

taxonomic

events.

Raup's

approach

as w e l l

paper

units

as

approach

is a v e r y d u l l

events

is

inter-

tool

as o t h e r

does

sample

(as in all s t a -

quality

and t a k e n unless

is b e i n g

then weight actually

account

not

bio-

that evolution

data,

of w h a t

has

Namely,

extinction

and that

ago,

willing

(1986)

extinction

be e v a l u a t e d

to e v a l u a t e

is o n l y

for f a m i l y

to r e c o g n i z e

these

data.

of e x t i n c t i o n

ion

from

to p r a c t i s i n g

support.

a statistical

understanding

reasonable

major

vacuum,

long

I have

extinct

cri-

relatively

beginning

in l a r g e

treatment

and r e c o g n i z e

of e c o l o g i c a l

what

units

immediately,

Raup

type bioevents

to r e c o g n i z e

to r e c o g n i z e

with which

r ate

correspond

). E x t i n c t i o n

of h o w

little

the

bottom,

In fact,

if o n e

He m a k e s

(essentially

Raup

an e x a m p l e

one.

level

horizons.

available

bioevents:

provide

which

easy

manifest

w i t h i n

the

so f a m i l i a r

and definition

ext inc t ion

of g e o l o g i c

evolutionary

very

and d e f i n e

is a " s t a t i s t i c a l "

length,

literature

readily

on the r e c o g n i t i o n

the b i o s t r a t i g r a p h e r

bioevent

there

terminology,

-- not m i x i n g

a procedure

I mean

where

made

changes

within

hori-

By this

horizons

changes

biofacies

remaining

Such

bioevent

path.

it in t r a d i t i o n a l

of the e n v i r o n m e n t

familiar

his

and s u b u n i t

global

biostratigraphic

this

to r e c o g n i z e

distributed

To put

i.e.,

biostratigraphers. with

unit

ecosystem.

the w a y

dull

globally

are m a j o r ,

or o t h e r

way

biostratigraphic

changes.

ecosystem,

of the

points

horizons

unique,

group

there

of the

parts

easily,

those

easiest

honored

of.

Purely

accompanied

dealt varied

obscure

with, parts

occur

by

sta-

a sound,

as w e l l of t h e

significant

in

as a sample

matter.

81

Specifically,

I am c o n c e r n e d

of the marine

ecosystem

largely zoan

decoupled

thicket

complex ranges

gives

rise

taxa enter

families, genera

probably

ranges

less common are being Although taxa

taxa.).

sampling

far

ment dealt genera

level

or at least 13,

evolution

facies~ dant ber

evolution

of c o m m u n i t y group)

the c o m m u n i t y

even

having

it is clear

community

group

phyletic

introduces family

level

concept

for which

(Figs.

ecostratigraphic

of

extinction

manner.

true

the We are,

of taxa,

and their

record

and s t e l l a r o i d

true ranges.

size

and

species

that

type

1982,

short

longer

"stochastic, within

I have d i s c u s s e d

ranges;

ranges[

stable

not occur

abun-

of com-

to any extent

within

each evol-

ecologic-evolutionary

Jablonski background

one

(1986,

Fig.

unit~

13)

extinction"

analyses

bio-

fixed num-

number

ecologic-evolutionary if

1986,

(long-ranging

and species

each

is the norm.

is largely,

the c o m m u n i t y

stratigraphic

does

with

and

(see J a b l o n s k i

stratigraphic

of the g e n e r a

is obvitreat-

that deal

unit

which

unit~

the well

known

the generic

Following

1983)

rare

with

(1986)

treatments

of assuming

the

increases.

families

Raup's

of b i o s t r a t i g r a p h y

is no evidence

by rare

ranges!

when d e a l i n g

the

those

than would

that

majority

the fossil

having far

into

for such e x c r u c i a t i n g l y

2, 2A) during

evolution

there

ranges

ignored

that c l a d o g e n e s i s

evolution

the concept

implies

known

(Would

leading

is that

represented

assumption).

1978,

an

family

entry

viewpoint

as our sample

groups/ecologic-evolutionary

munity

anagenesis,

and species

and species

of family

an e c o l o g i c - e v o l u t i o n a r y

the data

when

taxa,

"statistical"

error

this

1975,

fitting

rare g e n e r a

rate

of the c l a d o g e n e t i c

making

(Boucot

model

during ving

within

significantly,

concept

genera

Similar

the additional

for a d i a g r a m

as the basic

be their

cases

part of the data

of rare g e n e r a

pelmatozoan

must

families.

into

it was

For example,

of many

of what

with

fall

specific

ranges

short

the times

their

groups

as reef

stratigraphic

ecolo-

quality

is obvious

animals,

megafossils.

stratigraphic ously

ranges

as well

on which

for the great

for most

problem

as the soft b o d i e d

skeletonized

Fig.

known

extended

and bryo-

and in some

the sampling

equalled

ideal

algal,

from unlike

far shorter

indeed

evolutionarily

communities

about

equal

parts

bottom

in most higher

of more

those

of taxa

by p r o v i d i n g

from

have

this

The

level

mixing

out

shorter

initiation

is a b a c k g r o u n d

samples

far from

regularly this

there

were

communities,

view

record

unfortunate

of fossils

unfortunately,

This

to a f a l l a c i o u s

commonly

our

which

significantly

a later

the majority

and species,

be the case were known

from

to separate

as pelmatozoan,

ammonoid

have

is based).

that

Additionally

(such

pelagic

the g e o l o g i c

to the c o n c l u s i o n

example)

the c o - o c c u r r i n g

of the record

gic units

record.

than

the failure

other

and which

resulting

extinction

the bulk

level

communities,

(commonly

earlier

(in this

from each

communities),

with

which

units,

the data

in an

a

32

HIGH

ABUNDANCE

~

LOW

s~ A BICDEH211 gG

°J,il 23

21

~

t

" ~

!

)nn'u

s 5 4

' Zl

z

N1

!IN U i i "" STENOTOPIC

TENDENCY

, EURYTOPIC T E N D E N C Y

PROVINCIAL T E N D E N C Y COSMOPOLITAN

TENDENCY

F i g u r e 2. Diagrammatic representation of the f o s s i l r e c o r d of a c o m m u n i t y g r o u p t h r o u g h an i n t e r v a l of t i m e m e a s u r e d in a f e w f i v e s or t e n s of m i l l i o n s of y e a r s . T h e g e n e r a ( l e t t e r e d ) and t h e i r d e s c r i b e d s p e c i e s ( n u m e r a l s ) are a s s i g n e d l i n e w i d t h s b a s e d on t h e i r r e l a t i v e a b u n d a n c e as i n d i v i d u a l specimens. N o t e t h a t t h e s p e c i e s of the r a r e r g e n e r a t e n d to be b o t h m o r e r a p i d l y e v o l v i n g , and a l s o h a v e a m u c h p o o r e r f o s s i l record correlating with their numerical abundance (rarer) as i n d i v i d u a l specimens (from B o u c o t , 1984, Fig. I). N o t e t h a t t h i s f i g u r e p r e d i c t s t h a t it w i l l be t h e l e s s a b u n d a n t genera, which are also more stenotopic, and m o r e p r o v i n c i a l , which will be s u b j e c t to the e a r l i e s t e x t i n c t i o n , w h e r e a s the m o s t a b u n d a n t g e n e r a , and t h e i r s p e c i e s , w h i c h are a l s o m o r e e u r y t o p i c , and m o s t c o s m o p o l i t a n , w i l l be the l a s t to go.

33

I'III'N F i g u r e 2A. (Left) C l a d o g e n e t i c p a t t e r n c o n c l u d e d to be c h a r a c t e r i s t i c of the o r g a n i s m s b e l o n g i n g to i n d i v i d u a l e c o l o g i c - e v o l u t i o n a r y units and subunits. Note that c l a d o g e n e s i s is r e s t r i c t e d to that brief m o m e n t in time when new c o m m u n i t y units first appear. C l a d o g e n e s i s here refers to M e f a c l a d o g e n e s i s , i.e., q u a n t u m e v o l u t i o n m e d i a t e d p h e n o m e n a . B i o g e o g r a p h i c a l l y m e d i a t e d D i a c l a d o g e n e s i s can, of course, occur a n y w h e r e w i t h i n an e c o l o g i c - e v o l u t i o n a r y unit. (see Boucot, 1978, for d e f i n i t i o n s of M e t a c l a d o g e n e s i s and D i a c l a d o g e n e s i s ) (Right) C l a d o g e n e t i c p a t t e r n of the standard, r a n d o m t h r o u g h time type, w h i c h ignores the c o n s t r a i n t s i m p o s e d by what we k n o w about community e v o l u t i o n . Note that this view p e r m i t s c l a d o g e n e s i s to occur at any time w i t h i n an e c o l o g i c - e v o l u t i o n a r y unit, or subunit, and is also cons i s t e n t w i t h i m p o r t a n t c h a n g e s in s p e c i e s level d i v e r s i t y w i t h i n any e c o l o g i c - e v o l u t i o n a r y unit or s u b u n i t as c o n t r a s t e d with the view outlined in "Left". Such random, w i t h i n e c o l o g i c - e v o l u t i o n a r y unit changes in d i v e r s i t y do not occur. If is only by " s u p e r i m p o s i n g " family trees d e r i v e d from e c o l o g i c a l l y u n r e l a t e d , major parts of the g l o b a l e c o s y s t e m (such as level bottom, reef c o m p l e x of c o m m u n i t i e s , p e l m a t o z o a n thickets, sponge forests, b r y o z o a n thickets, p e l a g i c c e p h a l o p o d units, f r e s h w a t e r , etc.) that one can s i m u l a t e the u n n a t u r a l r a n d o m c l a d o g e n e t i c pattern.

So much for how

not

to r e c o g n i z e

and d e f i n e b i o e v e n t s .

The way to

recognize

them is to take full a d v a n t a g e of the known c h a r a c t e r i s t i c s

community

evolution

as d e t a i l e d

S u i t a b i l i t y of d i f f e r e n t t a x o n o m i c tion of e x t i n c t i o n events I cannot

recall

having

differing

taxonomic

adaptive

radiations.

different

taxonomic

ability

about

the f a m i l i a l ly level

Clearly,

ment.

and lower levels.

4 diagrams

it clear

that

if

pp.

62]-624)

of s u m m a r i e s

from the s t r a t i g r a p h i c one r e m a i n s

of s p e c i a l

statistical

as c o n t r a s t e d w i t h h i g h e r

prepared

taxonomic

tools

or at

levels of p r e c i s i o n

(1978,

some of the r a t i o n a l e

syntheses

will be r e l a t i v e l y dull

events,

within

and

I said

p r e p a r e d for

It has b e e n clear for some time

and r e m o v a l s

in time

Earlier

significance

and d e f i n i -

the s u i t a b i l i t y of

the use of s y n t h e s e s

afford differing

the t a x o n o m i c rate

introductions

Figure

2 makes

though,

levels does

randomly distributed

about

for the r e c o g n i t i o n of e x t i n c t i o n

to d i s c r i m i n a t e b i o e v e n t s .

something

levels for the r e c o g n i t i o n

read a s e r i o u s d i s c u s s i o n

levels

of

above.

that fami-

record

are not

the same e n v i r o n -

for this c o n c l u s i o n .

level c h a n g e s / t i m e

Figure

interval

for the r e c o g n i t i o n of b i o e v e n t s

levels.

This c o n c l u s i o n

about

species

34

level

bioevents

cies

(Fig.

2)

fairly

high

sample

to s e e

reflect employ

which

rate

the

ges

by m e a n s

above

natural

conditions

to

is

recognize

the

the to

fact

that

terminal

different rise

whereas

the

phology

to

although

is

of

millions

is

be

of

as

genera

it w i l l

change

that

crossing

and

their

the

generic

Such

to

because

of

lineachange

rate

if o n e

would

not,

operating

of

under

situation

is

obviously

natural).

If

one

clearly

not

one

tend

might

species

scale

bioevents

from

large

that

background

true

species

This

generic

of

spe-

proper

here

years.

modern

viewed

particularly

also

measure

a human

present,

of

change

in d i f f e r e n t

large

on

a very

extinction

to d i s c u s s

time

hardly

specific genera

genera the

some

somewhat

that

they

new

may

more

setting

one

The

more

any

be

seen

will

be

just

to

the

to be

employs

(Fig. very

within other

far

2)

hard

ecolo-

due

more

of

This when

finds

that

to

resistant

abundant

things

genera

ecologic-evolutionary

commonly

up

than

level

level.

within

instances.

better

of

from

the

(1966)

or

genera).

for

undergo

enough

phyletically being

the

dealing

loss

half

the

half

tend

not not

in m o r -

subgenera

it w i l l

species,

are

unit,

change

evolved

case

with

In

on

all

contain

Pal eon than

be

to

groups,

such

as

ate

and

difficult,

recognize

some

number

and

for

basic

of

that

here,

higher

the

relations. (data and of

the

mammal

culled

Romer's

the

bival-

families

echinoid

the

recogni-

l ogy half

the

half

eutherian

radiation

and

genera

nautiloid

half

levels

extinction.

P aleonto

5 genera,

listed

adaptive

possess

the

generic

families

during

indicate half

the

those

new

from

5 genera,

families half

of

a small

t ology

and

evolution

does

derives

9 genera,

and

specific

zones

level

t ebr

families

trilobite

3 genera,

the

quantum

adaptive

generic

In vet

less

at

generation

extinctions

ammonoid

the

families

the

the

such

the

t e br ate contain

from

families

T r e at is e Ver

of

of

failure

that

utility

most

the

result

zones

the

all,

4 genera, chiopod

not

definition

families

genera,

do

little

and

First

reason

adaptive

does,

tion

the

on

rate.

of

is e n t i r e l y

level

their

high

absence

It

and

bioevents.

What

ve

in

basic

taxa

a few

rate

but

the

other

justify

The

into

The

it r e a s o n a b l e

This

use

from to rare

genera

define

evolution.

in

a fairly

taxonomic

going

genera

to t h e

to g i v e

even

at

genera

extinction.

Turning far

of

speciation

abundant

units,

such

of

common

in t h e

species

can

a low

or d e f i n e .

gic-evolutionary

rates

measuring

that more

such

speciate

rate

time one

less

radiation.

(of w h i c h

event of

there

of

were

the

adaptive

makes

units true

an e x t i n c t i o n

of

phyletic

be

species

or

levels of

to

it d i f f i c u l t

background

course,

that

make

background

is d i a c h r o n o u s

is m e a s u r i n g

course

phyletically

will

term

continuing

the

of

an e x t i n c t i o n

the

that

refers

articulate families

mean

8

families

number

bra4 of

35 Through-

~o~.g

3A.

A ' BCDEFG Genera and their spe¢ios belo.gi.Q to G single Community Group

3B.

C~mun~! Gfoup~

B C

,...---,--

D

E

F

n

H I

_[itiI........... i

B~OEVENTHORIZON

J'

_~_ --" ~

.....

o,,zl,T[/FlITl o, ,

i i ii 4

3

5

,I

6

23

4

56

7

8

910,

Genera ond their |p~©ill belongI.Q lo a eit~Qle Community GroUp

Figure 3A. T i m e - D i v e r s i t y Diagram i n d i c a t i n g an i n s t a n t a n e o u s interpretation of a b i o e v e n t horizon employing data from a single c o m m u n i t y group. Taxa are lettered and numbered as in Fig. I. Note here that the taxa within each c o m m u n i t y group have the same upper and lower stratigraphic ranges. Figure 3B. T i m e - D i v e r s i t y Diagram i n d i c a t i n g a g r a d u a l i n t e r p r e t a t i o n of a b i o e v e n t horizon e m p l o y i n g data from a single c o m m u n i t y group. Taxa are l e t t e r e d and numbered as in Fig. I. Note here that the taxa within each c o m m u n i t y group have the same upper and lower s t r a t i g r a p h i c ranges. Taxa, b e l o n g i n g to these c o m m u n i t y groups, which fail to reach the bioevent horizon may r e a s o n a b l y be e x p e c t e d to have truly b e c o m e extinct prior to that boundary, rather than possibly being the result of environment not present i m m e d i a t e l y adjacent to the boundary, as is possible when e m p l o y i n g the m i s c e l l a n e o u s type data d i a g r a m m e d in Fig. IB. The same is true for d i a c h r o n o u s appearances of new taxa above the bioevent horizon.

genera and

occurs

in families

22 r e s p e c t i v e l y ) .

mopolitan,

eurytopic

forms,

present

in more

to families follows

from

this

be stenotopic, cators

Therefore,

achieve

for

merely

lacking

Because

result

instead

any utility

(9, 8,

of the genera,

of the genera,

and short they

are lumped

containing But,

merely

ranging,

will

number

family

phyletic,

of r e c o g n i z i n g

it for what

percentage

of g e n e r a work,

indi-

will be

since

one can

directly,

as evidence

rate within

which

of

which

"background

it actually

evolving

or defining

of g e n e r a

tend to

intra-ecologic-evolutionary

level

for r e c o g n i z i n g

It

as family units.

ranges

at the g e n e r i c

extinction

7, cos-

tend to b e l o n g unit.

those which

is needless

by p l o t t i n g

9,

ranging,

will be r e a s o n a b l e

together

a small

this

7, 10,

long

than one e c o l o g i c - e v o l u t i o n a r y

of m i s t a k i n g

phyletic

of the large

a minority

purpose.

evolution

rate"

routine

if

more g e n e r a

the s t r a t i g r a p h i c a l l y

the majority

families this

the problem

phyletic

extinction

and

those

the same

bypasses unit,

that

provincial,

of e x t i n c t i o n s

more useful

that contain

Secondly,

true

belong

is --

community

groups,

extinctions,

to families

that

36

include

a large

of i n c l u d i n g ranges

of

number

a few

families

Going long been

recognized,

adaptive

zones,

following

taxa,

of

here

to a l s o

include

it has

events

point

extinction

of

subclass

character

a very

are

points

out

they

judged

from

phylum

level

followed

of

relative

adaptive some

abundance

overall

and

on the

nity groups,

i.e.,

compilations

at v a r i e d

tedious, logic

I would

vacuum.

extinction and some most

orders, mian. orders

are

and

classes

Permian lower

classes,which

also

sees

seem

that

to f e a t u r e

anything

such such

plus

things

to

to be

The

of

taxa,

does

occur

a fair

at the

subclass

level

seems number

true

for

large

species,

The

terms,

in an e c o -

of s u p e r f a m i l i e s

as is a l s o

the o t h e r s .

their

statistical

familial

of an u n u s u a l l y

in t h e s e

bryo-

and of c o m m u -

Frasnian-Famennian

including

major

appearing

not

number

although

introplus

adaptive

pure

of

features

a large

the

to d i s c u s s

At the r i s k

event

Ordovician

as b i v a l v e s ,

In t e r m s

evolution

to and

important

seems

as the c o r a l s ,

of h i g h e r

level~

it f r o m

as

is no s i m i l a r

event

as i m p o r t a n t

involved,

at p r e s e n t

1985)

the s u b c l a s s

There

as it is to d i s c u s s

the e x t i n c t i o n

distinguishes

is n o t too well d e f i n e d

The

comm.,

in A n t a r c t i c a

below

the s u r v i v o r s

although

down

Cambrian

in

and s u p e r f a m i l i e s ,

eliminated.

categories

are

families

levels.

also

(oral

a

(and e x t i n c t )

of m a n y

Ordovician

are

that

unique

from

the

to p h y l u m .

Rowell

brachiopods.

at the s u p e r f a m i l i a l

and s o m e

The

terminal

-- i t e m s

Cambrian

abundances

again

flavor

sees

Lower

include

units,

own

and e v e n extinc-

terminal

from

taxonomic

prominently,

orders

prominent

ecologic

term

The

it is f u l l y

relative

emphasize

The

very

terminal

in a b u n d a n c e , which

its

of t h e i r

notable.

the

the m a j o r

Cambrian

taxa

Upper

event.

articulate

and e x t i n c t i o n s

effects

the

the l o s s

changes

has

Lower

and s p e -

as s u b f a m i l y of

of

changes

generic

(I u s e

as to s u b c l a s s

very

The

radiations

each

It has

distinct

evolutionary

units

record

because

involves

trivial

Extinctions

are not

new classes

ostracodes,

radiations

the

the o r i g i n a t i o n

terms

that

although

trilobites.

features

major

the

of h i g h e r

into

and s u p e r f a m i l y

event

by

duction

chance

to p l o t

au c o n t r a i r e !

that

family

of the

example,

event.

truly

fossil

to c a t e g o r i z e

time

levels

suprageneric

which

survived

extinction

(Arenigian)

zoans,

at this

a family

a better sense

extinction,

with

recognized

number

level,

a fine

associated

Phanerozeic chiefly

such

The e n d

large

are v e r y h a r d

archaeocyathids

the

within

the m a r i n e

of view.

to p h y l u m

that

place

long b e e n

affecting

statistical

have

better

lead,

as t h e i r

as c o n t r a s t e d

taking

But,

Simpson's

evolution,

life,

changes

tribe).

it m a k e s

taxonomic

as w e l l

level

family

the

and h i g h e r

quantum

in the h i s t o r y

and c o n s e q u e n t l y

forms,

directly.

and h i g h e r

tion

ranging

to the f a m i l y

families

cific

of g e n e r a ,

long

the

number plus

terminal

but

to be of

some

Triassic

certainly

to p h y l u m

Perof

does

levels

not in

37

the m a r i n e most

environment.

of the o t h e r s

cussions). nized

(see K a u f f m a n

My point

and d e f i n e d

again e m p h a s i z e

The end C r e t a c e o u s

here

at the f a m i l y

that the m a j o r

significantly

terrestrial

environment.

taxa

and h i g h e r terminal

(1983)

of e x t i n c t i o n s d e m a n d s

mic units be c o n s i d e r e d .

their h i g h e r

remaining,

and s p e c i e s

terms

during

them,

levels.

as f a m i l i a l

One should,

evolving

taxa.

recognizing, taxonomic with

occurring within Changing

defining,

statistics.

these m a t t e r s

to i n t e r p r e t

Practising

ignore

stratigraphic

Smith.

requi-

and b i o g e o -

not only as mere as i m p o r t a n t w h e n

paleontologists

as are have d e a l t

We s h o u l d do our best

information

of b o t h e x t i n c t i o n s

it if we w i s h

These b r i e f c o m m e n t s level

ways.

the m a j o r

When one

in w a y s c o n d u c i v e

and a d a p t i v e r a d i a t i o n s .

to truly c o m p r e h e n d

the m y s t e r i e s

of

summary)

also s h o u l d make it c l e a r

extinction

events d i f f e r

that

in terms o f

taxo-

from each other

in m a n y

adds to this the a d d i t i o n a l d a t a of c o - o c c u r r i n g

in the r e l a t i v e

adaptive

is one

and a d a p t i v e r a d i a t i o n s .

nomic

brief

are fully

since the time of W i l l i a m

to a b e t t e r u n d e r s t a n d i n g

a b u n d a n c e of

and d e s c r i b i n g e x t i n c t i o n e v e n t s

the mass of b i o s t r a t i g r a p h i c

We s h o u l d not extinctions

relations

to cha-

Ecostratigraphiy

of e v o l v i n g e c o l o g i c

in

but

in n u m b e r s

structure

a set of e n v i r o n m e n t s ,

abundance ranking

similar

trying

to r e l a t i v e

aspect of the problem.

that f o s s i l s be s t u d i e d as m e m b e r s

levels,

when

The study of c h a n g i n g c o m m u n i t y

g r a p h i c units

the case

truly very dif-

to c h a n g e s

taxonomic

res

and also

and

the p e r s i s -

to the four groups,

individuals

to a p p r o a c h this

and

of t a x o n o -

as is also

is not

pay a t t e n t i o n

levels

the

time -- a s i n g l e g e n u s

of taxa at d i f f e r e n t

g o o d way

especially

But,

restricted,

as well

extinctions

like to

the later C r e t a c e o u s ,

and the r h i p i d i s t i a n s ,

at s u p r a f a m i l i a l

as well.

I would

characterizing

is a fact.

of s p e c i m e n s b e l o n g i n g

and r e c o g n i z e

And,

that all of the h i p p u r i -

to the p r e s e n t

and s p e c i f i c

abundance

very d i f f e r e n t racterize

the fact

disappear

automatically with

at the g e n e r i c

levels.

recog-

e x t i n c t i o n e v e n t s do not appear

and that one b i o g e o g r a p h i c a l l y

of pure

for d i s -

that more than m e r e s t a t i s t i c s

For example,

the r h y n c h o c e p h a l i a n s

ferent

1986,

from

are most e a s i l y

that the d e f i n i n g ,

tence of the n a u t i l o i d c e p h a l o p o d s

with

and J a b l o n s k i

to d i f f e r

with those in the n o n m a r i n e ,

I p o i n t e d out e a r l i e r

tid b i v a l v e g e n e r a

seems

is that major b i o e v e n t s

to c o i n c i d e

ranking

1984,

event

abundances

and c o m m u n i t y g r o u p s p r e s e n t

then it b e c o m e s

radiation

The e v o l u t i o n a r y

events

clear

even b e g i n

and e n v i r o n m e n t a l

(Boucot

changes 1983,

that no two major e x t i n c t i o n or to p o s s e s s

significance

the same c h a r a c t e r i s t i c s . of this u n l i k e n e s s

is un-

certain. Also

to be r e c k o n e d w i t h

the m a j o r e x t i n c t i o n

is the p r o b l e m c o n c e r n i n g why,

e v e n t s we h a v e a g e o l o g i c a l l y

after

instantaneous

some of adaptive

38

radiation gically gory

affecting

lengthy

I am t h i n k i n g

after

the

Frasnian benthos

of

terminal

the l e v e l

events,

or

bottom

for

any

just h o w e v o l u t i o n

complexes,

whether

such

operates.

as the r e e f

the m a j o r ,

ecologic-evolutionary

are m e r e l y

stochastic

the

struck

by

Becker,

course the

the

and

occur

probability,

initial

in v i e w

radiation growth

and

then

Alfred some

non-level

level

at t i m e s

bottom

other

environ-

causes.

of t h e i r

This

is t h e

ising

those

specimens

whose

ever,

no e v i d e n c e

ing w h e t h e r

or n o t

affects

mere

susceptible

that

additional

sigmoid

this

all of

pattern

type

the

taxa within research affects

or w h e t h e r

communities,

higher

taxa.

The

answer

radiation

may

us s o m e t h i n g

each

certain with

to t h i s

consequent as w e l l

out

and

communities

that

shown

adulthood.

containing

of n e w

possibilities

the

therefore, or n o t

higher

are e l i m i n a t e d

radi-

or o n l y

whether

How-

concern-

adaptive

community

extinction

by many

character-

Conference

of e a c h

the

to a m a x i -

It is e s s e n t i a l ,

to the f o r m a t i o n about

reach

subsequent

communities

community

up

curve

te d e t e r m i n e

and s p e c i e s

these

they

the

subsequent

as t h a t

Wegener

a particular

community.

the g e n e r a

other

when

Alfred

among

and d i s a p p e a r a n c e

builds

as w e l l

of e x t i n c t i o n

be carried

before

adaptive

ceases

at the

taxa within

dependently,

tell

growth

presented

from

horizon

is the d i s t i n c t

is to s a y

of g r o w t h

species,

supporting

as t h e i r

This

at first,

type

taxa

There

as w e l l

I was

Messrs.

to a b i o - e v e n t

the d e c a y

pathway.

slowly

to a s i n g l e

strongly

prior

that

taxon

a sigmoid

procedes

evidence taxa

interval.

evidence,

to any h i g h e r

off.

on B i o - E v e n t s particularly

of d e s c e n d a n t

time

belonging

was

of

radiation

a distinct

or d e c a y

Conference

presented

populations

ation

is the

the m a n y

unknown

the p a r t i c i p a n t s ,

extinction

follows

tapers

Wegener

of

Ziegler, the

adaptive

over

taxa belonging

adaptive

the

that

that both

subsequent

survivors

mum,

of

fact

Kauffman,

the c o n c e p t

of the

they

bio-

of c o m m e n t

of

of the

involve

ex-

Yet

to e x p l a i n

of c o m m u n i t i e s ,

units

or

equivalent Scythian)

of b i o e v e n t s

During

and

events

cate-

rebounds

are u n k n o w n .

attempts

initiation

complex

than

depth

Also worthy

the

ment

Dynamics

that

latter

Llandoverian),

(all of the

phenomenon

is a g e o l o -

delayed

of the

shelf

Permian

this

there In the

environment's

two-thirds

theory

or n o t

others

radiation.

as c o n t i n e n t a l

The r e a s o n ( s )

concerning

bottom

terminal

into

after

adaptive

(about

as far an

to be c o m p r e h e n d e d

question

whereas

and

Ordovician

(the F a m e n n i a n

events.

groups,

before

are c o n c e r n e d ) ,

tinction need

many

delay

taxon

in

this in-

t oto

a mixture

and subsequent community

types

for c o e v o l u t i o n .

of

39

Conclusions In view terms,

of the basic

nature

it is obvious

following: suspected

tained

in order

as possible.

to get

naturally,

sample

immediately will

event

be obtained

it be possible

localities

2) these

horizon from

of the c o m m u n i t y

varied

groups

below

samples

community

known

immediately

the q u e s t i o n

after,

horizon,

of

samples

zonal data

to exist d u r i n g

the event

the

as many,

should be ob-

3) these

and only

the

and above

groups

where

4) after,

in c o m m u n i t y requires

representing

as possible.

localities

and s u c c e e d i n g

to evaluate

viewed

of b i o e v e n t s

from i m m e d i a t e l y from

possibilities.

preceding

record,

as many d i s t i n c t i v e

to the s u s p e c t e d

tes no d i s c o n f e r m a b l e ficant

samples

must be o b t a i n e d

environments

should,

of the fossil

an u n d e r s t a n d i n g

I) f o s s i l i f e r o u s horizon

varied

adjacent

that

indicaa signi-

the time

has been

"gradual"

or

obtained

"instan-

taneous" Only

after

such

tely u n d e r l y i n g possible abrupt

disappearance

within

as well

gradual

changes

necessary viously

older

groups

are i n v o l v e d

thought

answers.

But,

as pointed

is i n a d e q u a t e

need

must be expended.

answering.

quate

community

group

sample

in any one b i o g e o g r a p h i c marine

community

types

a real p r o b l e m nitively major able

which

covering

a large

the s a m p l i n g

answer

in terms a major

effort will to sterile

It is unlikely,

have

tend

discussed

of time and money

back

example,

This

for our

purposes.

be o b t a i n e d

through

careful

Figure

sampling

that

based

of varied

that

what,

with-

level

sampling even begin

this may pose

if one

is to defi-

in some effort

on i n a d e q u a t e

from one region

3 outlines

with

will

Again,

type of major

and forth,

that data

be adequate

sections

but

more

of an ade-

distributed

sea floor,

needed,

pre-

localities

as widely

it is r e a s o n a b l e

to be made.

many

here.

done

answer,

when d e a l i n g

spaced

the

to the q u e s t i o n s

reliable

involve

to occur

closely

requirement

question

the sampling

area of former

measured,

arguments for

probably

from the

whether

is far more

that the o b t a i n i n g

It is unlikely,

organisms,

a few c a r e f u l l y

to satisfy

will

unit.

then

for o b t a i n i n g

answers

of a more

groups

will

type of sampling

definitive

it be or an

taxa from

respectively,

previously

It is also clear

of new

in d e t e r m i n i n g

out earlier,

In the interests

will

a gradual

Such sampling

horizons,

This

immedia-

of the c o m m u n i t y

appearance

suitable

for p r o v i d i n g

labor

of only

or not.

that

horizon

indeed,

to be c o n s i d e r e d

than

the strata

bioevent

horizon.

and younger

need

from

is,

each

or gradual

post-bioevent

which

bottom,

there

of taxa from w i t h i n

whether

community

comprehensive

or not

as an abrupt

sampled

obtained

the s u s p e c t e d

whether

the overlying,

it clear

have been

and o v e r l y i n g

to d e t e r m i n e

present,

make

samples

cases

is prefersamples.

of the world will in principle,

community

groups.

can

40

It is also clear diately below,

adjacent

that

if

to the s u s p e c t e d b i o e v e n t horizon,

one c a n n o t be c e r t a i n w h e t h e r

with o £ h e r c o m m u n i t y g r o u p s s u s p e c t e d horizon, b e c a m e than those known event horizon. do not occur localities that

some c o m m u n i t y g r o u p s

extinct

immediately

above or

any not s h a r e d

adjacent

to the

or a d a p t i v e l y r a d i a t e d

immediately

from

adjacent,

adjacent

later

to the s u s p e c t e d b i o -

extinct

the i m m e d i a t e l y

artifact

from as w i d e l y s c a t t e r e d

might p r o v i d e

taxa b e c a m e

that we make

mere s a m p l i n g

earlier

either

taxa,

Only a very large sample of those c o m m u n i t y g r o u p s w h i c h

immediately

as possible,

those known

that do occur

from s t r a t a

their u n i q u e

is c r u c i a l

their u n i q u e

are not found imme-

one w i t h

a basis

earlier,

or a p p e a r e d

adjacent

every s a m p l i n g

position.

for s u s p e c t i n g

d a t a that could m a t e r i a l l y m i s l e a d our t h i n k i n g

later,

than

In other words,

effort p o s s i b l e

i n f l u e n c e on our t h i n k i n g

a set of

it

to d i s s o c i a t e

and c o n c l u s i o n s

from

into error of one kind

or another. For example, Danish

Raup

area that

(]986,

These d a t a s h o w e d

Jablonski's

ably r e p r e s e n t s mental

shift

term).

of the a p p r o p r i a t e

community

ably a gap

that will be filled

sampling lies

is e n t i r e l y

and higher)

represented higher with

although typical

bally)

Permian,

where

(but not c e r t a i n l y )

example being

remedied

Permian

crinoids,

tetracorals

echinoids,

taxa

(fami-

these same taxa are

they last occur~

as c o n t r a s t e d

descendant

and

in the Lower

suitable

has been well e n o u g h s a m p l e d

affecting

a sampling localities

are f o u n d and sampled,

taxa are p r e s e n t

(a

r e p l a c e d by M i d d l e T r i a s s i c

stromatoporoids,

probably represents

if e c o l o g i c a l l y

K-T b o u n d a r y

of

the g l o b a l

families

w i t h no corals of any kind k n o w n

Danish example

globally

totally distinct

(think also of the high level c h a n g e s

brachiopods,

in

of the Middle T r i a s s i c where d i s t i n c t l y d i f f e r e n t ,

potentially

hexacorals,

elsewhere

level

More i m p o r t a n t l y ,

on

prob-

level gap r e p r e -

(Lower T r i a s s i c ) ,

but not all cases by

local e n v i r o n -

omission,

sampling

and even class

a d e q u a t e to show that many high

taxa in the y o u n g e r

the b e g i n n i n g

taxa",

Raup then goes

local

For the Lower T r i a s s i c e x a m p l e

are truly absent.

in many,

level,

in with e x p a n d e d

in the S c y t h i a n

taxa such as corals.

"Lazarus

for the e x i s t a n c e

(community group).

and s p e c i f i c

the major o r d i n a l

s e n t e d by the a b s e n c e varied

as

effect c a u s e d by a slight,

type

this minor g e n e r i c

with

to these

region.

and species

in the b r a c h i o p o d r e c o r d prob-

the e n v i r o n m e n t n e c e s s a r y

to c o m p a r e

the K-T region,

(he refers This gap

a mere s a m p l i n g

that r e m o v e d

a very l i m i t e d

articulate brachiopod genera

interval

1986,

4) cites d a t a from

the C r e t a c e o u s - T e r t i a r y b o u n d a r y

that c e r t a i n

are absent for a brief using

Fig.

incorporates

whereas

T r i a s s i c glo-

the a r t i c u l a t e

and b r y o z o a n s ) .

artifact

immediately

adjacent

the Lower T r i a s s i c

to c o n v i n c e most w o r k e r s

The

that could be to the

anomaly

of its reality.

41

It is also clear of the P h a n e r o z o i c statistics

that each of the major

has its own d i s t i n c t i v e

p r o v i d e d by v a r i e d

taxonomic

p h y l u m on down,

in the c h a n g i n g

in the c h a n g i n g

community groups

data,

that no two major

in terms of the

from the s u b c l a s s

abundances

present.

e x t i n c t i o n events

character

levels

relative

extinctions

terminal

of major

It may well be,

and

taxa,

and

in view of this

of the r e c o r d r e s u l t e d from the same

m i x t u r e of causes. In the p r e v i o u s d i s c u s s i o n ation of the c o n t i n e n t a l obviously crucial

I have r e s t r i c t e d myself

shelf d e p t h e q u i v a l e n t m a r i n e fauna.

to a b e t t e r u n d e r s t a n d i n g

w h e t h e r or not they s i m u l t a n e o u s l y and aquatic)

and m a r i n e

s a t i o n be c o n s i d e r e d . strongly

higher

land plants do not c o r r e l a t e

ations

in the m a r i n e

realm c o r r e s p o n d

plants.

Mesozoic

and C e n o z o i c

ing plants sequent

adaptive

e x t i n c t i o n event clan-earlier no e v i d e n c e

higher

similar

r e c o r d s be

treated

(Gray

1985)

in the d e f i n i t i o n

graphic

Jablonski

higher

for n o n m a r i n e

in the m a r i n e world,

land plant events. animals,

A truly

which

comparisons difficult. synthesis

it is c r u c i a l

and d e f i n e b i o e v e n t s .

as well

reef c o m m u n i t y

currentthat

taxa in w i t h that for the far b e t t e r

We still have

thicket,

algal

complex,

and other

as for their upper

M i x i n g d a t a on the known

and

at a c o n f i d e n c e

is not yet available,

animal b i o e v e n t

of most p e l m a t o z o a n

thicket,

communities,

ranges.

shows

(1986) has made simi-

s e p a r a t e l y from those of the level b o t t o m

trying to r e c o g n i z e

bryozoan

Ordovician

land plant spore flora

level of b i o s t r a t i g r a p h i c

mals when

s p o n g e forest,

of the f l o w e r -

f o l l o w e d by sub-

The t e r m i n a l

bottom marine organisms

way to go

level b o t t o m

extinctions

is

the O r d o v i -

animal w i t h m a r i n e

B e c a u s e of the far lower

their

Swamp

where

to that for the m a r i n e b i o t a

for n o n - l e v e l

Paleozoic,

on land,

of any type.

global biostratigraphy

ly a v a i l a b l e

the a p p e a r a n c e

about the later e x t i n c t i o n events

makes n o n m a r i n e

Palaeophytic,

time terms

from the Coal

in the m a r i n e world.

n o n - c o r r e s p o n d a n c e w i t h major,

zonal, level

representing

in the sea has no p a r a l l e l

Silurian,

land

The P a l a e o p h y t i c - M e s o p h y -

the change

times of major

radiations

for e x t i n c t i o n

lar c o m m e n t s their

are not

in the

the h i g h e r

time terms

fossil

among the

and the M e s o p h y t i c - C e n o p h y t i c b o u n d a r y

Cretaceous,

-- these

affecting

cau-

adaptive radi-

e x t i n c t i o n events

to this fact.

Permian,

to the M e s o z o i c Flora,

land plant

innovations

the p a l e o z o o l o g i c a l

testifies

it is

(terrestrial

very well w i t h s i m i l a r

of the p a l e o b o t a n i c a l

is in the later

in the m i d - L o w e r

that major

nor that major

But,

that we learn

that e x t r a - t e r r e s t r i a l

of the h i g h e r

in time w i t h events

and C e n o p h y t i c w i t h

tic b o u n d a r y Flora

the c o n c l u s i o n

realm,

The d i a c h r o n i s m

Mesophytic

in order

Present knowledge

supports

of b i o e v e n t s

affect both n o n m a r i n e

environments

record

marine

to a c o n s i d e r -

and lower

stratigraphic

ranges

ania long

thicket, non-

stratiof their

k n o w n level b o t t o m taxa for put-

42

A Decoupled,non-Level Boflom, Oil feren'i Trophtc Level e~ernsnt~

B Lewl 8 o ' ~ t o m CommunityGroup TOXG

o~E=O~y~t*i

~

C Oeco~pl~d,S~m~lar Trophic Level ~ternenfsof non-Level Bottom

....

commu~

i Ecologic Evolullonory Unit Boundory

___

T• I

J

If

~ ~SrUnit E ~ o l o

O i c

Evolutionory Boundary

Unit Evol~fionar7

Ecologic Boundory Terminol ExtlncliQn

~

Adoptive R~di(~tlon

F i g u r e 4. D i a g r a m o u t l i n i n g the t i m i n g of c l a d o g e n e t i c - a d a p t i v e radia t i o n e v e n t s a f f e c t i n g d e c o u p l e d p o r t i o n s of the e c o s y s t e m . C o l u m n "A" r e c o g n i z e d the p r e s e n c e of e c o l o g i c a l l y , e v o l u t i o n a r i l y d e c o u p l e d p o r t i o n s of the e c o s y s t e m w h i c h are t a x o n o m i c a l l y u n a f f e c t e d by s i g n i f i c a n t e x t i n c t i o n and a d a p t i v e r a d i a t i o n e v e n t s w h i c h m a t e r i a l l y a f f e c t o t h e r p o r t i o n s , s u c h as c o l u m n s "B", and "C". N o t e too, t h a t w i t h i n S I M I L A R t r o p h i c u n i t s a d a p t i v e r a d i a t i o n s s i g n i f i c a n t l y a f f e c t i n g one p o r t i o n of the s i m i l a r t r o p h i c l e v e l n e e d n o t c o r r e s p o n d in time to t h a t a f f e c t i n g a p a r a l l e l part. This a p p l i e s to s u c h t h i n g s as a d a p t i v e r a d i a t i o n s g i v i n g r i s e to the reef c o m p l e x of c o m m u n i t i e s , or p e l m a t o z o a n t h i c k e t c o m m u n i t y c o m p l e x e s on the one h a n d as c o n t r a s t e d w i t h the s t a n d a r d l e v e l bottom community groups. A real life e x a m p l e s i m i l a r to this d i a g r a m m i g h t b e the a d a p t i v e r a d i a t i o n of h i g h t r o p h i c l e v e l S i l u r i a n - D e v o n i a n v e r t e b r a t e s t h a t in no w a y c o r r e s p o n d s to that of the l e v e l b o t t o m or r e e f c o m p l e x of c o m m u n i ties. R e c a l l t h a t a s i g n i f i c a n t n u m b e r of the v e r t e b r a t e s s a i l r i g h t t h r o u g h the F r a s n i a n - F a m e n n i a n , m i d - U p p e r D e v o n i a n e x t i n c t i o n (McGhee, 1982, p. 492) e v e n t w i t h no t a x i c c u r t a i l m e n t of any c o n s e q u e n c e , and that the r e a l a d a p t i v e r a d i a t i o n g i v i n g r i s e to the S i l u r i a n - D e v o n i a n reef c o m p l e x of c o m m u n i t i e s is w e l l a f t e r (Late W e n l o c k i a n , m i d - U p p e r S i l u r i a n ) the a p p e a r a n c e of the l e v e l b o t t o m c o m m u n i t y g r o u p s f r o m w h i c h the r e e f t a x a p r e s u m a b l y w e r e d e r i v e d b y a d a p t i v e r a d i a t i o n .

poses

of b i o e v e n t

diachronous ecologic

extinctions

units

affecting merely

may

the m o r e

stochastic

examine

the

to f i n d

stable events

and i n s t a n t a n e o u s

that

we not timing

controls

fall can

into occur

can

only

adaptive

level

lead

to c o n f u s i o n

radiations

another

class

bottom

-- w e n e e d

of

these

of b i o e v e n t s

units,

(Fig.

the d a t a

The

non-level incapable

or p o s s i b l y

to c o m p i l e

4).

these

bottom of

are

and c r i t i c a l l y

evidence.

different more

dual

event

and

represent

available

In c o n s i d e r i n g prepared

recognition

than

bioevent

one

events the

trap

type

are p r e s e n t of t h i n k i n g

in the f o s s i l

over bioevents.

Some

horizons

of e v e n t .

in the that

record.

of t h e s e

through

time

It m a y b e record. only

There

controls

one

are

we m u s t

that

It is c r u c i a l type

of b i o -

probably

may have

be

both gra-

acted

many in a g e o -

43

logically

instantaneous

cometary-asteroid past.

Others,

climatic tely

the

such

gradient

thinks

European

of

as g e o l o g i c a l l y

here.

about

much

position

as w e l l

quandary

as my o w n b r i e f

a true understanding ation,

bioevents,

much geologic

and

understanding

that

lations these the

from

from

of p r o b a b l e well

studied

possible.

This

is an a r e a

largest

serves

as s t i l l

need

for

ting

and s e c t i o n

one

Promised

by s a m p l e

more

here

for

of m e r e

where

warning

about

Mere

sample

sample

adequacy.

with

al.'s

in b o t h

is m u c h

into

as is in

(1986)

account

of M o n t a n a as w e l l fossil

as the collec-

how penetrating,

veiled

corre-

large,

reliability

adequacy,

There

is s t i l l

all the

only

of the w o r l d

et

no m a t t e r

radi-

of as

coincidence,

Paleocene

precision

logic,

of u n d e r s t a n d i n g

Sloan

that

translate

be p r o v i d e d

early

admit

with

We f i n d

conclusion

adequacy.

in the v e r y

than

adaptive

tempered

an a r e a

in a

review,

analysis

chance

If we

be

rather

to d i r e c t l y

we m u s t

as l a r g e

biostratigraphic

measuring.

Land

from

of s c i e n c e

dinosaurs

far g r e a t e r

no s u b s t i t u t e the

samples

part determined anomaly

and e f f e c t ,

and

about

rates.

we m u s t

careful

for us.

In o r d e r

the

extensive

extinction

provide

on

ultimately

1986,

as p o s s i b l e ,

can

the p o s s i b i l i t y

reliable,

of p o s t - l r

data

materials.

cause

radiation

In all h o n e s t y

behind

immedia-

be wary

of b i o e v e n t s ,

through a most

biology

our g e o l o g i c

correlations

area

1983).

only

paleontologic modern

adaptive

the c a u s e s

the c a u s e s come

and

in g l o b a l one

impacts

continually

(see J a b l o n s k i ' s

summary,

of

will

changes

interglacial

to the

in the r e c e n t

manner[

r a t e d a t a we may,

to c o n s i d e r

in the p r e s e n t

major

we must

extinction this

but

in the g r a d u a l and

ascribed

much discussed

slow,

glacial

collecting

as the e f f e c t s been

In all of this

of d i f f e r e n t

better

have

may have behaved

are c a r e f u l

being

such

that

Pleistocene

flora

effects

manner,

impacts

work

is

to be done;

in m o r n i n g

fog.

Acknowledgements I am m o s t Alfred

grateful

Wegener-Conference,

to the u l t i m a t e in the

to P r o f e s s o r

and w i s h

I learned to t h a n k

assistance.

I am also

indebted

Geophysical

Sciences,

University

cism

of an e a r l i e r

necessarily Johnson, helpful

my l o n g with

version

be held

of

deal

all of

at O r e g o n

it t h r o u g h

for

their

Department

of the

constructive

criti-

although

he s h o u l d

the c o n c l u s i o n s . State

the

participating

participants

for his

arranged

husbanded while

Jablonski,

the m a n u s c r i p t ,

colleague items.

David

of C h i c a g o ,

for

for h a v i n g

patiently

a great

my f e l l o w

to Dr.

responsible

term

several

H. W a l l i s e r

and for h a v i n g

publication.

Conference,

Otto

University,

not

Dr.

J.G.

was

most

44

REFERENCES

BOUCOT, A.J. (1970): P r a c t i c a l taxonomy, z o o g e o g r a p h y , p a l e o e c o l o g y , p a l e o g e o g r a p h y and s t r a t i g r a p h y for S i l u r i a n and D e v o n i a n b r a c h i o pods.- N. Amer. Paleont. C o n v e n t i o n , Chicago, 1969, Proc. F., 566-611, -- (1975): E v o l u t i o n and E x t i n c t i o n Rate C o n t r o l s . - Elsevier, 427 p. -- (1978): C o m m u n i t y E v o l u t i o n and Rates of C l a d o g e n e s i s . - Ev. Biol. 11, 545-655. -- (1982): E c o s t r a t i g r a p h i c f r a m e w o r k for the Lower D e v o n i a n of the North A m e r i c a n A p p o h i m c h i S u b p r o v i n c e . - N . Jb. Geol. Pal~ont., Abh. 163

81-121. --

(1983): Does e v o l u t i o n take place in an E c o l o g i c a l Vacuum? II.- J. Paleont. 57, 1-30. -- (1984a): The P a t t e r n of P h a n e r o z o i c C o m m u n i t y E v o l u t i o n . - Proc. 27th Internat. Geol. Congr. ~, 13-21, P a l a e o n t o l o g y , VNU Press. -- (1984b): C o n s t r a i n t s p r o v i d e d by e c o s t r a t i g r a p h i c m e t h o d s on c o r r e l a tion of s t r a t a and b a s i n analysis, by means of f o s s i l s . - Proc. 27th Internat. Geol. Congr. ~, 213-218, S t r a t i g r a p h y , VNU Press. -- (1984c) : E c o s t r a t i g r a p h y . - in: SEIBOLD, E. & M E U L E N K A M P , J.D. (eds.): S t r a t i g r a p h y Quo Vadis?. AAPG Studies in G e o l o g y 16, IUGS Spec. Publ. 1_£, 5 5 - 6 0 .

D'ORBIGNY, A . ( 1 8 5 0 - 5 2 ) : P r o d r o m e de P a l & o n t o l o g i e . 197, 190, 99 p.

Masson, 394, 427,

GRAY, J. (1985): M i c r o f o s s i l r e c o r d of the h i g h e r land plants: A d v a n c e s in u n d e r s t a n d i n g of early t e r r e s t r i a l i z a t i o n , 1 9 7 0 - 1 9 8 4 . - Phil. Trans. Roy. Soc. London B 309, 167-195. JABLONSKI, D. (1986): Causes and c o n s e q u e n c e s of mass e x t i n c t i o n s : A c o m p a r a t i v e approach, in: ELLIOTT, D.K. (ed.): D y n a m i c s of E x t i n c t i o n , Wiley, 183-229. KAUFFMAN, E:G. (1984): The fabric of C r e t a c e o u s m a r i n e e x t i n c t i o n s , in: BERGGREN, W.A. & VAN C O U V E R I N G , J.A. (eds.): C a t a s t r o p h e s and Earth H i s t o r y . - P r i n c e t o n Univ. Press, 151-246. McGHEE, G.R., Jr. (1982): The F r a s n i a n - F a m e n n i a n e x t i n c t i o n event: A p r e l i m i n a r y a n a l y s i s of A p p a l a c h i a n m a r i n e e c o s y s t e m s . Geol. Soc. Amer., Spec. Pap. 190 491-500. RAUP, D.M. (1986): B i o l o g i c a l e x t i n c t i o n in e a r t h h i s t o r y . - S c i e n c e 231, 1528-1533. ROMER, A.S. (1966): V e r t e b r a t e P a l e o n t o l o g y . - Univ. C h i c a g o Press, 468 p. SLOAN, R.E.~ RIGBY, J.K., Jr.~ VAN VALEN, L.M. & GABRIEL, D. (1986): G r a d u a l d i n o s a u r e x t i n c t i o n and s i m u l t a n e o u s u n g u l a t e r a d i a t i o n in the Hell Creek F o r m a t i o n . - S c i e n c e 232, 629-633. WALLISER, O.H. (1984a): G e o l o g i c P r o c e s s e s and Global E v e n t s . - Terra Cogn i t a 4, 17-20. -- (1984b): Global Events, Event S t r a t i g r a p h y and " C h r o n o s t r a t i g r a p h y " w i t h i n the P h a n e r o z o i c . - 27th Internat. Geol. Congr., A b s t r a c t s ~, 208.

APPENDIX

In the b o d y of this paper I have s t r o n g l y w a r n e d a g a i n s t the u n t h i n k i n g use of t a x o n o m i c c o m p i l a t i o n s in the r e c o g n i t i o n and d e f i n i t i o n of ext i n c t i o n events. By u n t h i n k i n g I have i n c l u d e d the a c c e p t a n c e of "known" ranges of taxa as e q u i v a l e n t to "true" ranges. I have i n s i s t e d on the use of e c o s t r a t i g r a p h i c p r i n c i p l e s in order to avoid this s a m p l i n g error, w h i c h is a very s e r i o u s one. I w o u l d now like to b r i e f l y d i s c u s s a t y p i c a l example. In 1971 I d e s c r i b e d a new, u n i q u e genus of Ludlow age, Upper S i l u r i a n b r a c h i o p o d from the K l a m a t h M o u n t a i n s of n o r t h e r n C a l i f o r n i a and the R o b e r t s Mountains of E u r e k a County, Nevada. The genus was named Aenigmastrophia. The shells are e x c e s s i v e l y rare; two s p e c i m e n s k n o w n from a s i n g l e locality in the Klamaths, and three s p e c i m e n s from two l o c a l i t i e s in the

45

R o b e r t s M o u n t a i n s . The c o l l e c t i o n s of S i l u r i a n b r a c h i o p o d s f r o m w e s t e r n N o r t h A m e r i c a m a d e b y m y s e l f and o t h e r s s i n c e W W I I n u m b e r in the m a n y tens of t h o u s a n d s of i n d i v i d u a l s p e c i m e n s . The c o m m u n i t i e s w i t h i n w h i c h A e n i g m a s t r o p h i a o c c u r s are r e l a t i v e l y w i d e s p r e a d and e x t e n d b e y o n d the L u d l o w in m a n y p l a c e s . A e n i q m a s t r o p h i a r e p r e s e n t s a u n i q u e f a m i l y l e v e l t a x o n w i t h o u t d o u b t , and p r o b a b l y r e p r e s e n t s a u n i q u e s u p e r f a m i l y as well. If , h o w e v e r , o n e w e r e to u s e the a v a i l a b l e d a t a for this e x c e p t i o n a l l y r a r e g e n u s one w o u l d p r o b a b l y r e s t r i c t it to a s m a l l p a r t of L u d l o w t i m e for b o t h t i m e of o r i g i n a t i o n and e x t i n c t i o n . In v i e w of its r a r i t y t h i s w o u l d , o b v i o u s l y , b e m o s t m i s l e a d i n g . The k e y to m o r e s p e c i m e n s of o r i g i n a l l y v e r y r a r e t a x a is l a r g e r c o l l e c t i o n s f r o m e c o l o g i c a l l y favorable locales. J.G. J o h n s o n (oral c o m m . , 1986) c o m m e n t s t h a t one of the N e v a d a c o l l e c t i o n s (loc. 4435) b e l o n g s to the L u d l o v i a n age s i l u r i c u s Zone w h e r e a s the s e c o n d c o l l e c t i o n (loc. 917) b e l o n g s to the top of the u n d e r l y i n g p l 0 e c k e n s i s Zone, i.e., the t w o o c c u r r e n c e s c o u l d b e v e r y c l o s e in time. J o h n s o n also c o m m e n t e d t h a t his g e n u s A n t i s t r i x ( J o h n s o n ]972) is a t e r e b r a f u l i d " f r o m a f o u r - f o o t i n t e r v a l of beds, m i d - M i d d l e D e v o n i a n of L o n e M o u n t a i n , N e v a d a - is k n o w n n o w h e r e e l s e " . He a l s o r e m i n d e d me t h a t the L o c h k o v i a n n o t a n o p l i i d g e n u s C a l l i c a l y p t e l l a f r o m C a r l i n N e v a d a is k n o w n f r o m a b o u t 12 s p e c i m e n s c o l l e c t e d o n a s i n g l e b e d d i n g p l a n e ( B o u c o t & J o h n s o n 1972). It is also w o r t h p o i n t i n g out t h a t the E a r l y Devonian terebratulid genera Prorensselaeri&, Mendathyris, Cloudothyris, L i e v i n e l l a , a n d C l o u d e l l a are all s i n g l e l o c a l i t y , v e r y r a r e taxa, and that t h e r e are many, m a n y s u c h s i n g l e l o c a l i t y taxa; f u l l y e n o u g h to m a k e f o r m a n y p r o b l e m s if one i n s i s t s on e m p l o y i n g the t e r m b a c k g r o u n d e x t i h c t i o n rate. S e p k o s k i (oral comm., 1986) at the A l f r e d W e g e n e r - C o n f e r e n c e m e n t i o n e d to me that he n o w is e l i m i n a t i n g f r o m his d i v e r s i t y t h r o u g h t i m e c o m p i l a t i o n s t h o s e t a x a r e s t r i c t e d in the r e p o r t e d r e c o r d to a s i n g l e s t a g e ~ t h i s is a w o r t h w h i l e and n e c e s s a r y step, b u t I w o u l d e n c o u r a g e p e o p l e m a k i n g s i m i l a r c o m p i l a t i o n s to f u r t h e r c o n s i d e r t h a t t h e r e is n o t h i n g s a c r e d a b o u t the s i n g l e s t a g e in this r e g a r d , p a r t i c u l a r l y if t h e r e is a n y f o u n d a t i o n f o r m y c o n t e n t i o n s a b o u t the n a t u r e of c o m m u n i t y e v o l u t i o n w i t h t h e i r i n d i c a t i o n s that a l 1 of the s u p r a s p e c i f i c t a x a w i t h i n an e v o l v i n g c o m m u n i t y g r o u p s h o u l d h a v e a b o u t t h e s a m e s t r a t i g r a p h i c r a n g e -- b o t h r a r e and a b u n d a n t t a x a -- w i t h the possible exceptions mentioned earlier about sigmoid curve disappearance of s o m e of t h e s e t a x a w i t h i n a c o m m u n i t y p r i o r to an e x t i n c t i o n e v e n t , as w e l l as the s u b s e q u e n t g r a d u a l , s i g m o i d i n t r o d u c t i o n of t h e s e t a x a d u r i n g an a d a p t i v e r a d i a t i o n . B O U C O T , A.J. (]971): A e n i g m a s t r o p h i a , New Genus, a difficult Silurian b r a c h i o p o d . - S m i t h s o n i a n C o n t r i b u t i o n s to P a l e o b i o l o g y ~, 1 5 5 - 1 5 8 . -- & J O H N S O N , J.G. ( 1 9 7 2 ) : C a l l i c a l p t e l l a , a n e w g e n u s of n o t a n o p l i i d b r a c h i o p o d f r o m the D e v o n i a n of N e v a d a . - J. P a l e o n t . 46, 2 9 9 - 3 0 2 . J O H N S O N , J.G. (]972): The A n t i s t r i x b r a c h i o p o d f a u n u l e f r o m the M i d d l e D e v o n i a n of c e n t r a l N e v a d a . - J. P a l e o n t . 46, 1 2 0 - 1 2 4 .

GLOBAL

BIOEVENTS

AND

THE

QUESTION

A contribution

N?

OF

to Proiec~

PERIODICITY

GLOBAL

U

SEPKOSKI,

J. John Jr.

*)

gtO EVENTS

Abstract: The h y p o t h e s i s of p e r i o d i c i t y in e x t i n c t i o n is an e m p i r i c a l claim that e x t i n c t i o n events, while variable in magnitude, are regular in timing and t h e r e f o r e are serially d e p e n d e n t upon some single, ultimate cause with c l o c k l i k e behavior. This h y p o t h e s i s is controversal, in part b e c a u s e of q u e s t i o n s regarding the identity and timing of certain e x t i n c t i o n events and b e c a u s e of s p e c u l a t i o n s c o n c e r n i n g p o s s i b l e catastrophic e x t r a t e r r e s t r i a l forcing mechanisms. New data on e x t i n c t i o n s of marine animal g e n e r a are p r e s e n t e d that d i s p l a y a high d e g r e e of periodicity in the Mesozoic and Cenozoic as well as a s u g g e s t i o n of nonstationary p e r i o d i c i t y in the late Paleozoic. However, no p e r i o d i c i t y is evident among the as yet poorly d o c u m e n t e d e x t i n c t i o n events of the early and m i d d l e Paleozoic.

Introduction Extinction than

events

several

disappear. was

The

introduced

koski

(1984)

families.

are brief

million idea

years that

that

1986,

controversial 1985),

including

agents

questions

in the analyses

In this

paper,

discuss

what

causal

agents

and present hypothesis

are implied.

of p e r i o d i c i t y Paleozoic

Meaning

of p e r i o d i c i t y periodic

& Sepanimal nonrandom

(see also Raup has

proven very

Kerr

1985,

Maddox

of some

small

extinc-

of c a t a s t r o p h i c

some

of these

of e x t i n c t i o n

I then review

forcing

several

at the genus

in the Mesozoic

questions.

and what

criticisms

level.

and C e n o z o i c

These but

I first

kinds

of

of the idea support leave

the

the

unclear.

series

of p e r i o d i c i t y

claim based

conclusion 1984,

in time

of marine

significantly

the validity

to clarify

and analyses

in the

rical

This

spaced by Raup

periodicity

(Hallam

and the n e c e s s i t y

I attempt

new data

The h y p o t h e s i s

were

a 26-Ma

1986).

is meant by p e r i o d i c i t y

versus

of e x t i n c t i o n s

less

of taxa

the periodicity.

pattern

Random

and s u p p o r t e d

events

of reasons regarding

normally

numbers

might be r e g u l a r l y

analysis

& Raup

time,

which unusual

(1977)

as d i s p l a y i n g

a variety

to explain

events

extinction

Sepkoski

for

of g e o l o g i c

during

& Arthur

in a s t a t i s t i c a l

and could be d e s c r i b e d

tion used

these

by Fischer

They found

& Sepkoski

intervals long,

in e x t i n c t i o n

on s t a t i s t i c a l

*) D e p a r t m e n t of the G e o p h y s i c a l cago, Illinois 60637, U.S.A.

assessment Sciences,

events

is b a s i c a l l y

of p a t t e r n University

an empi-

in the fossil of Chicago,

Chi-

Lecture Notes in Earth Sciences, Vol. 8 Global Bio-Events. Edited by O, Walliser © Springer-Verlag Berlin Heidelberg 1986

48

Random; II 11 !1 !!i

F i g u r e 1. E x a m p l e s of r a n d o m ( " i n d e p e n d e n t " ) and p e r i o d i c series of events.

I

I

I1

Periodic: !111111111111 record. lar

It is a c l a i m

to b e

strictly

illustrates events. coins for

the c o n t r a s t

The upper,

this

event

separated

by

long

terized

by

of

nature

this

is one

another,

some

timing

as

of

The

the

previous

the r a n d o m

ance because Mixed The

two

time

Various

series

after

to b r e a k events

series

relative

by f l i p p i n g The

trails, can

This

but

the

occur

when

intervals

events

are

of

events

others

may be

series

long g a p s .

independent

I

frequency

between

while

in an i r r e g u l a r

variably

Fig. of

a pair

expected

together

results

and s o m e

and

series

(i.e.

series,

each

is s e p a r a t e d in Fig.

one

from

1 has

in four)

event

charac-

Time

series

of one

is d e p e n d e n t

it b y

the s a m e

but

has

imposed

serial

in Fig.

I are end m e m b e r s

each

appear

a constant

frequency

a very

on the inter-

of e v e n t s

different

appear-

dependency.

more

period

less

sis of R a u p identified

result

some from

make

(1986),

events

errors

have

could

events

occur

a standard

the

when

time

deviation

in the c h r o n e m e t r i c

or

occur,

intervals be long,

periodic the

time

scale

length

In the

of 2.4

or

events

intervals

although

tends

between irregu-

period

component.

length,

regular

a nonstationary,

between

a stochastic

in the p e r i o d

still

factors.

of a r e c o v e r y

cannot

can make

would

for e x a m p l e ,

more

operation

extreme,

intervals

situation

or c o n t a i n s

"wobble"

there

At the o t h e r

would

This

of t i m e

This

of p a t t e r n s

dependent

appear

the

subsequent

series.

although

pairs.

length

periodic

which

of a s p e c t r u m versus

series

For e x a m p l e ,

during

regular,

some

& Sepkoski

reflect

the r a n d o m

in a r a n d o m

regular.

is a f u n c t i o n

make

of i n d e p e n d e n t

regular.

event,

between

variable,

as w e l l

can

less

up clusters

lar g a p s

appear

dominance

constraints

periodic

might

the

series

series

reflecting

time

of

length.

time

as h e a d s .

time

one

time

series

and p e r i o d i c

are f l i p p e d .

periodic

periodic

are too r e g u -

generated

clusters

coins

events constant

was

c a n be e x p e c t e d

as w h e n

between

approach

landed

events

intervals.

In a s t r i c t l y

val.

in four

they

random

series both

some

loose

intervals

that

between

when

irregular;

time and

random

and r e c o r d i n g

are v e r y

that

random

Ma~

analy-

between this

it c o u l d (or b o t h ) .

just

49

Obviously,

if the

difficult

to d i s t i n g u i s h

Other events

standard

situations

and

events.

Missing

in t h e i r

Early

periodic

Early

a beat"

gap

but

or w h e n

in the d a t a . series

Cretaceous

Cretaceous

(see b e l o w ) ,

"skips

of M e s o z o i c

appears

for

may

when

found

extinction

better

Jurassic

missing

result

(1986)

in the M i d d l e

a Middle

include

when

is so s u b d u e d

& Raup

familial

to b e f i l l e d

no c a n d i d a t e

events

can be

analysis.

series

an e v e n t

Sepkoski

and the o t h e r

series

in s t a t i s t i c a l

aperiodic

identified

in the

one

a periodic

it c a n n o t

one

a random

a periodic

degrade

process

gaps

is large,

might

the p e r i o d i c be

from

that

intermixed

deviation

events,

Jurassic.

data

event

that two

are

The

analyzed

can y e t be

identified. Time signals

series with

as c l u s t e r s

that

long,

can

the

identify

multiple,

history

ation

of

produced

is the This

event

does

does

of not

techniques events

can

Implications Observation series

produces

from

that

the event

with

makes

preclude

be

is

analysis)

noted,

not been

time

however,

observed

produce

series

of

large

series

perhaps

in

in the

similar

& Klein appear

animals

of p e r i o d i c i t y . signals

The o c c u r -

regular

Many

so l o n g

and t h u s

(as s u g g e s t e d

1984). less

record

mammals.

cause

Martin

oper-

to

the f o s s i l

for m a r i n e

a separate

series

regular

reflect

terrestrial

see

discovery

may

outcomes

An e x a m p l e

a time

distinguish

but

some

each of

a random or

limit

single,

event

or

the s y s t e m

(There

of e v e n t s

in no w a y

it d o e s

indicates the r a n g e

external

that

some

causes

but

statistical

as the r o g u e

systems.)

what

caused

of p o s s i b l e

causal

agent

internal

each

is no t h e o r e t i c a l

in e v o l u t i o n a r y of

that

hypothesis;

events

that

processes)

causes

fit

of p e r i o d i c i t y

of e v e n t s ,

cycle

It s h o u l d have

series

Fourier

cause

either

nal

(e.g.

as w e l l

too f r e q u e n t .

for

interval.

time

forcing.

periodic

suggests

fated

agents

not

behavior

time

observed

regular

extinction

still

as the

techniques

periodicities

periodic

predation

are n o t

periodic

events"

so l o n g

Pleistocene

necessarily

two or m o r e

"missing

periodicities.

causal

the

aperiodic

of

contain

events.

an i n d e p e n d e n t

the h u m a n

rence

may

in a b a s i c a l l y

independant

terminal

appears by

separate

by

interference

statistical

interfering

events

those

However,

most

of e x t i n c t i o n

Aperiodic

from

wavelengths

of e v e n t s .

sufficiently

that

result

different

event

to o c c u r

implications

series

which

suggests

a single

cause

varing

with

dynamic

justification

Both

either

the

for

It

clocklike

(autocorreafter

some

a 26-Ma

set

inter-

are v e r y d i f f e r e n t

multiple,

irregularly

regular

causes.

through

independent time.

50

Another is t h a t

implication

a causal

to all o t h e r s .

taceous

et al. of

might

hypotheses (Davis

is n o w

However,

1980,

1984~

are

impact

events

temporal

duration, and

mentally

sensitive

to d e t e r m i n e

event

agent

search

extinction

if t h e i r

and e n v i r o n m e n t a l of

not

was

time

variables,

such

necessitate

periodicities

that

coincidental

with

amplifying

empirical of

(and b e t w e e n of the

series

1985).

that

signatures

and g e o g r a p h i c

suggested

possible

its

efforts

large

or

events);

periodic

of t a x o n o m i c

long

if t h e s e d i s p l a y

does

event

the o t h e r

& Matese

It r e m a i n s

character

Crebody

speculative

been

important

patterns

that

several

Whitmire

for

terminal

Cretaceous

have

that

catas-

the

of e x t i n c t i o n ,

events

of the d e t a i l e d

geologic

1984;

possibility,

(3) i n v e s t i g a t i o n

and

impacts.

a rogue

(1) f u r t h e r

to d e t e r m i n e

similar;

by

applicable

the hypothesis

inferred

agents

one,

extraterrestrial

the t e r m i n a l

the C r e t a c e o u s

caused

m a y be ties

a large

impacts,

forcing

periodic

at o t h e r

investigation

that

it has b e e n

with

this

event

a necessary

associating

of

Since

& Stothers

was

to t e s t

including

impacts

further

]984). series,

at the e n d of were

one

not

of e x t r a t e r r e s t r i a l

impact

ultimate

another,

In o r d e r

needed,

multiple

tion

of

for

implication

evidence

the

associated

events

the e n d - C r e t a c e o u s the o p e r a t i o n effects.

1982,

Rampino

an i m p a c t

all e x t i n c t i o n

although

to h y p o t h e s e s

the p e r i o d i c

also b e

this

with

of c l o c k l i k e

et al.

developed

persuasive

extinction

is a m e m b e r events

periodicity

There

mass

(Alvarez

hypothesis

It is l a r g e l y

of e x t i n c t i o n trophism.

of p e r i o d i c i t y ,

(2)

extinc-

selectivity,

distribution of o t h e r

are

environ-

as s t a b l e

isotope

congruent

with

ratios,

that

of e x -

tinction.

Previous Summary

work

on e x t i n c t i o n

of w o r k

on f a m i l i a l

Raup

& Sepkoski's

city

in e x t i n c t i o n s

(1984)

Late

Permian

a data

base

on f o s s i l

this

part

(stages)

recognized

are

register

the

from

the d a t a

in o r d e r

ger

portions

out of

of

than

of

This 2160.

of m a r i n e

These

is m o r e

26-Ma

and b e c a u s e accurate

the

culling

left

The metric

the

scale

time

the

39 s a m p It w a s

of e x t i n c t i o n before

families

especially a residue chosen

because

and

m u s t be e l i m i n a t e d

the s i g n a l ~

families

selected

Paleozoic.

signal

all e x t a n t

periodi-

animals

data were

in the e a r l i e r dampen

Therefore,

to e n h a n c e

sample

a statistical

available

species

extinction.

the r e c o r d .

an i n i t i a l

was

record

families

all c o n s t i t u e n t

will

of

interval.

shorter

that

claim

on an a n a l y s i s

families

of the g e o l o g i c

implicitly

since

initial

to M i o c e n e

ling units

events

data

was b a s e d

in the

for

periodicity

over of

a family

were the

culled youn-

567 f a m i l i e s

to m e a s u r e

extinc-

51

tion i n t e n s i t y was tions d i v i d e d by data.

This m e t r i c scales

and avoids

potentially

In order

though

Several

tive

p o s s i b l e bias, time series

involved

analyses

a bootstrap

(or,

to r a n d o m i z e d of events

unpredictably)

maxima.

This

Raup & S e p k o s k i

(see S e p k o s k i

events; The

see S e p k o s k i

test s h o w e d

cantly better significant 1986)

that

text was d e s i g n e d

corroborated

assumed

events.

times

Subsequent

in u n c u l l e d f a m i l i a l d a t a

in p r e l i m i n a r y g e n e r i c d a t a

the

Also,

be-

a de facto recoafter

into the r a n d o m i z a t i o n

than the r a n d o m i z e d v e r s i o n s . maxima

test rela-

to vary

small procedure.

the o b s e r v e d data fit a 26-Ma p e r i o d i c i t y

extinction

and m a x i m a

1986).

The p r i n c i p a l

to assess o n l y

to p e r m i t m i s s i n g

was built

& Raup

events,

"randomization")

(which were

(reasonable for r e b o u n d

1984)

treated

to the o b s e r v e d m a x i m a

cause m a x i m a had to be s e p a r a t e d by at least one stage, 12 Ma

(1984)

on the data.

more properly,

and not their m a g n i t u d e s

very time of about

at risk

as if they were e x t i n c t i o n

functions

and was c o n s t r u c t e d

of e x t i n c -

in the c u l l e d

of stage d u r a t i o n s .

were p e r f o r m e d

the fit of p e r i o d i c

as the n u m b e r

in each stage

to the n u m b e r of f a m i l i e s

estimates

some most c e r t a i n l y were not

that m e a s u r e d

timings

computed

of f a m i l i e s

extinctions

in their

statistical

analysis

extinction,

inaccurate

to m i n i m i z e

all local m a x i m a even

percent

the total n u m b e r

signifi-

tests using

only

(Sepkoski

& Raup

(Raup & S e p k o s k i

1986)

have

this result.

Criticisms These

analyses

have b e e n s u b j e c t e d

have b e e n r a i s e d

concerning

(answered by d e m o n s t r a t i n g taxonomic

level

in g e n e r i c

employed

data);

to a number of c r i t i c i s m s .

(I) the c u l l i n g comparable

results

(3) the a c c u r a c y

the most

accurately dated

and

(1985a).

He a r g u e d

of e x t i n c t i o n . familial sity. jor"

critique

various

He a s s e s s e d w h i c h and p r e s e n t e d

consistency

treatments

To d e m o n s t r a t e

data using

statistical

published

that p a l e o n t o l o g i c

and that d i f f e r e n t

significant

100 Ma are analyzed[

(4) the use of n o n s t a n d a r d

The m o s t e x t e n s i v e

noisy

last

comparable

of the c h r o n o m e t r i c

( a n s w e r e d in part by d e m o n s t r a t i n g

1986)[

in u n c u l l e d data);

(answered by d e m o n s t r a t i n g

employed

this,

to d a t e

he c o m p u t e d

a tabular

summary

(see below).

has b e e n by H o f f m a n data

are very

very d i f f e r e n t 20 time series

and m e t r i c s

patterns from the

of e x t i n c t i o n

that he c o n t e n d e d events

scales

r e s u l t s w h e n only

techniques

local m a x i m a in the series w e r e

in the t i m i n g of e x t i n c t i o n

time

(2) the

patterns

see Raup & S e p k o s k i

and c h r o n o m e t r i c

can g e n e r a t e

time scales

Questions

of the f a m i l i a l d a t a

"minor" displayed

inten-

or

"ma-

little

and t h e r e f o r e no p e r i o d i -

city. I agree w i t h but w o u l d c o n t e n d

Hoffman's

conclusion

that noise

that

the f a m i l i a l d a t a

in itself does not n e c e s s a r i l y

are n o i s y preclude

52

discovery noisy

of

that

a question together, in b o t h

when the

weakly

will

I have without maxima cise.

tend

maxima,

Upper

time

series.

such

as the

Middle

to b e

series

series.

intervals

available

is t h a t

so

to s u c h

"stack",

noise

tend

varying

are

approach

is to

random

and t h u s

signal,

data

by

assigning

with

minor

Fig.

2 illustrates

containing

and M a e s t r i c h t i a n , intervals

Pliensbachian, also

are

the d a t a

A common

will

or add deviate

to c a n c e l

or a d d

in a c o n s i s t e n t

direc-

amplified.

I to s t a g e s

Permian

is w h e t h e r

directions

nonrandom

Hoffman's

But o t h e r

Miocene,

40

time

and negative

time

question

is d i s c e r n i b l e .

The p r e s u m p t i o n

whereas

stacked

in e a c h

proper

at all

multipe

As e v i d e n t ,

as the

The

series.

positive

together tion,

pattern.

no p a t t e r n

form

I 1

I

of

0 to s t a g e s

2 to s t a g e s

the r e s u l t mass

form s t r o n g

that

of

in the

extinction Upper

the

with

this

such

stacked events,

Eocene,

time

major

exer-

extinctions,

peaks

smaller

Cenomanian,

indicating

I

and

well-known

containing

Thithonian, peaks,

maxima,

values

series

and are not

I

26-Ma Periodicity :50

0 2O o

O0

i0

0

','

'J ....

......

200

I~i"' 100

Geologic

I. . . . . f ' " i

0

Time

F i g u r e 2. T i m e s e r i e s of e x t i n c t i o n in the M e s o z o i c and C e n o z o i c c o m p i l e d f r o m d a t a in T a b l e I of H o f f m a n (1985a). The s c o r e s w e r e c o m p u t e d b y a s s i g n i n g v a l u e s of 0 to no m a x i m a , I to m i n o r m a x i m a , and 2 to m a j o r m a x i m a in e a c h of H o f f m a n ' s 20 e x t i n c t i o n t i m e s e r i e s and t h e n s u m m i n g t h e v a l u e s for e a c h s t a g e . T h e 2 6 - M a p e r i o d i c i t y of e x t i n c t i o n f o u n d b y R a u p & S e p k o s k i (1984) is i n d i c a t e d b y the v e r t i c a l l i n e s ; this p e r i o d i c i t y f i t s t h e i l l u s t r a t e d p e a k s r a t h e r w e l l . The t i m e s c a l e is f r o m Harl a n d et al. (1982) w i t h d u r a t i o n s of J u r a s s i c s t a g e s b a s e d on W e s t e r m a n n (1984). T i c s a l o n g the a b s c i s s a i n d i c a t e s t a g e b o u n d a r i e s .

53

entirely series cal

random.

fits

lines

In fact,

a 26-Ma

periodicity

in the f i g u r e .

periodicity,

Hoffman's

New data

analyses

Generic

and

to c i r c u m v e n t

a new data

and e x t i n c t i o n reports

rather

series

well, than

would

in the s t a c k e d

as i n d i c a t e d

falsifying

appear

by

time the v e r t i -

the h y p o t h e s i s

to l e n d

of

support.

problems

on f o s s i l

(1986).

data

to a f i n e r

have been

Below

in the f a m i l i a l

marine

I present

genera

data,

with

stratigraphic

presented new

in

of

been

com-

of o r i g i n a t i o n

framework.

Sepkoski

analyses

I have

times

Preliminary

(1986)

a somewhat

and R a u p more

&

refined

of the d a t a .

Fig. metrics

set

resolved

on t h e s e

Sepkoski version

700

rather

Thus,

time

of p e a k s

data

In a t t e m p t piling

the p a t t e r n

3 displays

time

of g e n e r i c

series

extinction

Number of Extinctions

~a

~'

for

the m i d - P e r m i a n

(compare

to Fig.

to R e c e n t

I in S e p k o s k i

5o I e~i

#.

for

four

& Raup

Percent Extinction

I 4OO

i

3OO W

°: IliA"

A

X

200

A

o°

tOO

'0"Ii"~

80 [ - - eo~

"I ..... ~ .... I ..........

Total Extinction Rate

I..... t' "'I

2o

ol 'V'I"%"I

.....

roJ ~ o'~°~' ~

J ....

I .....

K .....

I"i

"i-i: "'I

Per-Genus Extinction Rate

6o •~

Ld

4o

,#,°~

.,,~,

o,mo

.~

)2

20

oj ,6, '.I' "~'T

200

I00

Geologic Time

'.' "J .... I .....

zoo

K .....

1oo

I'i' '"I" ' " '

o

Geologic Time

F i g u r e 3. T i m e s e r i e s for f o u r m e t r i c s of g e n e r i c e x t i n c t i o n i n t e n s i t y f o r the P e r m i a n ( S a k m a r i a n ) to R e c e n t , s h o w i n g the o c c u r r e n c e a n d m a g n i t u d e of e x t i n c t i o n e v e n t s . The t i m e s c a l e is the s a m e as in Fig. 4. T i c s a l o n g the a b s c i s s a i n d i c a t e s t a n d a r d s t a g e s and n o t s a m p l i n g i n t e r v a l s . D o t s r e p r e s e n t c o m p u t e d v a l u e s and are p l a c e d o v e r the c e n t e r s of the s a m p l i n g i n t e r v a l s . A b b r e v i a t i o n s a l o n g the o r d i n a t e s are " E x t . " = n u m b e r of e x t i n c t i o n s , "Gn." = n u m b e r of g e n e r a ( s t a n d a r d d i v e r s i t y ) , and "Ma" = million years.

54

1986). tion

The metrics

are simple

(number d i v i d e d

ber d i v i d e d genus

stages

rate

of the sampling

intervals

Miocene three;

are split

into

amalgamated

Coniacian,

Pliocene

in 51 sampling

standard

deviation

A total

ling

of

times

intervals

data

The g e n e r a 15,780 g e n e r a Excluded When

between

over

ric d i v e r s i t y reflects richly their

Mark

fossiliferous originations When

It is largely between

differences change

effects:

in Fig.

in their

the positions data

.675)

might gene-

probably

of c e r t a i n

appear

to have

from

the data

decreases

to

set,

.286.

differences

in a p p e a r a n c e

3 and those

published

Note,

however,

of e x t i n c t i o n

that

by

these

maxima

do not

sets.

extinction

3 present

amplitudes.

in Fig.

(1986).

(r =

stratigraphic

are culled

that produces curves

of e x t i n c t i o n

(Guadalupian

genera

intervals.

it more

that

to single

and o r i g i n a t i o n s

of the

governing

1985b),

rare g e n e r a

and culled

series

Permian

to

105 sampling

processes

Hoffman

confined

& Sepkoski

The time

spacing

All

interval.

correlation

produce

extinction

the complete

in the this

studies

extinctions

and Raup

a subset

taxonomic

such s i n g l e - i n t e r v a l between

of M e s o z o i c - C e n o z o i c

tion

1977,

only

extensive

formation

Patterns

nonrandom

are

samp-

subdivided.

correlation

Although

from e q u i l i b r i u m

& Flessa

are q u a n t i t a t i v e ;

between

5594

in p r o p o r t i o n

stratigraphic

is a high

and o r i g i n a t i o n s

this m a n i p u l a t i o n

(1986)

has

to specific

the i l l u s t r a t e d

to single

there

and e x t i n c t i o n s

the g e n e r i c

Sepkoski

3, of w h i c h

the intervals

for

Phanerozoic.

as r e s u l t i n g

monographic

intervals.

is used,

of e x t i n c t i o n s

(cf.

the c o r r e l a t i o n

in Fig.

represent

compiled

are those c o n f i n e d

the entire

be i n t e r p r e t e d

and

of 5.5 Ma and

that have been

over

3 actually

have been

sample

numbers

intervals

This m a n i p u l a t i o n

a mean d u r a t i o n

8 % to stages

in Fig.

that

genera

into

the Turonian

data.

used

the total

Leonardian, and Lower

and the Albian

of 67 Z are r e s o l v e d

are d i s t r i b u t e d

the h i g h - r e s o l u t i o n

the d u r a t i o n s

Campanian,

and Olenekian,

are r e p r e s e n t e d

of e x t i n c t i o n

and another

low-resolution

is

1.2 Ma.

of 9773 g e n e r a

The

with

(num-

which

The Sakmarian,

("substages"),

and Pleistocene.

intervals

rate

and per-

stratigraphic

so as to make

Tithonian,

Induan

extinc-

extinction interval),

probability",

as possible.

Bajocian,

are the

percent

For all metrics,

two intervals

resulted

extinct.

as even

stages

and the

"extinction

or amalgamated

Rhaetian),

total

of the sampling

by diversity).

subdivided

(including

of extinctions,

diversity),

duration

(also called

rate divided

have been

Norian

by standing

by e s t i m a t e d

extinction

the total

numbers

a visual

maxima,

The two highest

and Tatarian)

impression

coupled maxima

with

of fairly

uniform,

considerable

are g e n e r a l l y

and the Maestrichtian.

These

varia-

the Upper intervals

55

contain

670 and 695 g e n e r i c

to 76 % e x t i n c t i o n at the familial for families). would

result

Permian

across

level) Using

from

includes

lower

peaks

tude.

Five

families

that

(Sepkoski

a maximum

analysis The

Upper

event

shape

Eocene,

peaks

spikes

in shape

stage was

this

Despite

tions

and,

perhaps,

events larly cene ley

identified

(1984,

1986)

labelled

extinction

a uniformity total

above,

there

as c o n t a i n i n g

metrics

of the d u r a t i o n

in the

scaled

adjacent

intervals,

.017 and

fairly

series.

a small

in the

other

Norian,

no consis-

of most spaced

maxima

=

.026).

perturbations. extinction

that

are irregu-

by Stan-

The lower

a sharp

peak

to sample

Bajoin the

from under-

(estimated

also contains

If

to p e r t u r b a -

however,

the p r e c e d i n g

per

the P l i o - P l e i s t o -

event.

interval

in

and

in some

recognized

3, forms

failure

it is

is a r e m a r k a b l e

maxima

include

to

variation

Tithonian

has been

some-

rather

so that

of r e s p o n s e

this may result,

with

vary

in e x t i n c t i o n

there

extinction

in Fig.

coupled

maxima

However,

evenly

These

which

especially

to the left of the upper

as

an

.020 e x t i n c t i o n s

(upper

of the sampling

of the Bajocian)

on

appears

intervals

extinction

are several

to time;

also

events;

long-term

of shape,

rate

end of the series,

extinction

nian,

stage.

in the m a g n i t u d e

in two of the graphs

based

for the maxima

sampling

a uniformity

of nine

the time

in ampli-

Tithonian,

to the next,

of the six smaller

estimation

the d u r a t i o n

a single

lesser

tendency

several

from one maximum

it suggests

through

at the right

cian,

over

this n o n u n i f o r m i t y

to the

scattered

Aptian

variation

is real,

of the time.

but not observed,

of the six

is some

of the six range b e t w e e n

In addition

The

real,

in the p e r - g e n u s

com-

is scaled

series

extinction

stochastic

genus-Ma

pattern

Miocene.

represents

five

maximum,

upper

pattern

metrics;

this

in time

or simply

in a m p l i t u d e

(which

data.

There

over

values

Norian

600 genera)

Pliensbachian,

amplitudes

extending

The upper

and more u n i f o r m

predicted,

in familial

centered

intensity

in the data. similarity

spaced

the

these

in the Upper

extinction

recognized

and Middle

is apparent

not clear w h e t h e r extinction

evenly

to 17 %

maxima are six or more

to the b e t t e r - d o c u m e n t e d

in this

(1979)~ level

of e x t i n c t i o n s

(about

extinction

have been

on the metric.

as broad

as a major

to 57

(compared

of Raup

the number

diversity

1986):

and r e l a t i v e

as sharp

tency

& Raup

of p e r i o d i c i t y

depending

when

rally

maxima

comparable

extinction

curves

corresponding

(compared

at the species

appears

the larger

appear

of these

Cenomanian,

than

also

low standing

among

Permian

in the Maestriehtian.

to the Maestrichtian,

Distributed

Upper

the r a r e f a c t i o n

the Rhaetian)

respectively,

33 % in the M a e s t r i e h t i a n

a 92 % e x t i n c t i o n

to the r e l a t i v e l y

appear

the entire

and

and 60 Z e x t i n c t i o n

parable

what

extinctions,

as half

extinctions

Aalenian. a maximum

The Carin all

58

extinction

metrics.

tion

as y e t u n r e c o g n i z e d

event

simply

an a r t i f a c t

genera

in the

studied

taxa

It is not c l e a r

resulting

from

succeedingNorian; in the

whether

in d e t a i l e d

Triassic,

failure

reflects

to s a m p l y

ammonoids, do not

this

which

show

a true

biostratigraphic many

are

Upper

the m o s t

a distinct

peak

extinc-

analyses

or

Triassic thoroughly

of e x t i n c t i o n

in the C a r n i a n . Autocorrelation Because

of p e r s i s t i n g

an e x t i n c t i o n set

rather

nique

analysis questions

event,

than

it is

just

available

for

desirable

selected assessing

series

data

is a u t o c o r r e l a t i o n

lating

data

in e a c h

of

intervals

among

analyses

lation

sampling

backward

to p r o d u c e

and

thus

data

(although

vals

in the g e n e r i c

servative

see

since

The

was

some

Autocorrelation will

produce

perfectly tions

move

half

wavelength,

will

decrease

sampling

signal,

back

intervals, in the

or t r e n d s 4 displays

sistent

with

This

cycle

drift

temporal

increase

tion between

x I0.5/2), viously

The

computed

at l a g s

some

This

is c o n s i s t e n t from

the

of

of e v e n t s

Ma

and

familial

of

evidence 9.5/2)

data

26.2

for

the

that

positive

such

at a lag

with

of

a periodic 28.9

& Raup

a

as i r r e g u l a r

"background"

and

four

is c o n -

at a lag of 5.

+_ I Ma p e r i o d

(Sepkoski

in the m e a n ) .

(although

trends,

is thus

the

events,

low-frequency

to p o s i t i v e

or l e v e l

that

unequal

spectra")

10

one-

Factors

a pattern

from

A

autocorrela-

include

(5.5 M a x

with

properties

or d e c r e a s e

6 through

low-frequency

pattern 26.1

vary

3, a n d b a c k

inter-

the c y c l e .

of a p e r i o d i c

All s h o w

correlations

a lag of

in a m p l i t u d e

3.

of

at lag e q u a l s

events,

increase

familial

m a y be c o n -

one w a v e l e n g t h .

presence

sampling

sampling

produce

("autocorrelation

in Fig.

of

periodic

autocorrelations

of the p e r i o d i c

repeated

between

will to -I

at lag e q u a l s of the

correlograms

events).

which

nature

as l o n g - t e r m

indicating

a wavelength

on t h e

extinction

around

is t h e n

downward

with

(such

periodicity.

I, to n e g a t i v e

depending

zero,

varied

durations.

with

curve,

set n u m b e r

previous

equal

series

in the d a t a ,

amplitude

of g e n e r i c

of

to +I

in i n t e r v a l

corre-

of a u t o c o r r e -

results

a time

as in a s i n e

noise

variation

remains of

in time

some

duration

although

data

tech-

involves

lag c a n b e

of the

The m o r e

its use,

generic

statistical

lagged The

equal

1984).

One

a spectrum

the n a t u r e

+I at lag e q u a l s

the m a g n i t u d e

variation

Fig.

& Pena

permit

results

with data

assumes

constitute

the e n t i r e

technique

is e s s e n t i a l l y

by

not

of p e r i o d i c i t i e s

This

in the s e r i e s .

analysis

variance

from

metrics

interval

analysis

varying

cyclic

that

analysis.

precluded

data

or d o e s

maxima.

the s t r e n g t h

what

Kitchell

does

to a n a l y z e

extinction

or f o r w a r d

coefficients.

intervals

as to w h a t

Ma

signal

(5.5 Ma

length

1986).

extinc-

pre-

Note

that

,57

'4F

'

' Number

of Extinctions

.4

.Z

Extinction

.z

,

~__ 0 ,4

Percent

.

.

.

.Total . .

,

.,..w....

' Extinction Rate

.4 L .

I J

.

I

.

.

.

.

.

.

.

.

,.{

Per-GenusExtinction Rote

0

J

ii

-.2c

-.4

Lag F i g u r e 4. C o r r e l o g r a m s for the four time series in Fig. 3. A u t o c o r r e l a t i o n s were c o m p u t e d for 49 i n t e r v a l s ( L e o n a r d i a n to P l i o - P l e i s t o c e n e ) with lags of I to 11. Prior to c o m p u t a t i o n , d a t a w e r e t r a n s f o r m e d to l o g a r i t h m s to m i n i m i z e v a r i a t i o n in a m p l i t u d e among events and r e c a l c u lated as r e s i d u a l s from r e g r e s s i o n s on time to e l i m i n a t e simple t e m p o r a l trends.

this r e s u l t Hoffman

is not c o n s i s t e n t w i t h

& Ghiold

(1985)

and H o f f m a n

lags of 4 and 8 s a m p l i n g Paleozoic Although

extinction

(1985a)

p r o p o s e d by

predicts

low peaks

at

patterns

the a u t o c o r r e l a t i o n

in the P a l e o z o i c .

analysis

provides

extinction,

Fig.

the w h o l e of the Paleozoic.

variously

subdivided

Again,

to p r o d u c e s a m p l i n g

(standard deviation

= 1.4 Ma).

further

support

for peri-

it r e v e a l s no e v i d e n c e of peri-

5 illustrates

rate over

duration

which

intervals.

o d i c i t y in M e s o z o i c - C e n o z o i c odicity

the r a n d o m walk model

the p e r - g e n u s stages

intervals

extinction

and series have b e e n averaging

Of the 6257 g e n e r a

5.5 Ma in

occurring

in

58

.t0

.0~ O

t .06

d

/qL¢

C9

• .04. X

Ld

,02

0

''

.....

I ' 56o

'

'e'

'I

's ' I " ' b " l ' 46o

'

'c

' I'# s6o

'

"

Geologic Time F i g u r e 5. P e r - g e n u s e x t i n c t i o n r a t e for the P a l e o z o i c . P l o t t i n g c o n v e n t i o n s are the s a m e as in Fig. 3. The t i m e s c a l e is f r o m H a r l a n d et al. (1982), w i t h s t a g e s in the C a m b r i a n r e s c a l e d f r o m S e p k o s k i (1979); O r d o v i c i a n f r o m the a v e r a g e of M c K e r r o w et al. (1980), Gale & B e c k i n s a l e (1983), and R o s s & N a e s e r (1984); S i l u r i a n f r o m the a v e r a g e of B o u c o t (1975), J o n e s et al. (1981), G a l e & B e c k i n s a l e (1983), and H a r l a n d et al. (1982); and D e v o n i a n f r o m B o u c o f (1975).

more

than

one

have

been

resolved

to a s t a g e

stratigraphic

Correlograms tion

metrics

for

display

autocorrelations of

8 to

of

the

I] w h e n

Carboniferous

these

and C e n o z o i c , is

actually

Permian and

thus

and

of

(Gzelian)

at the e n d

between

time

contains

in a m p l i t u d e

events

this

some

at the e n d

the o t h e r

in m a g n i t u d e . I to

However,

in e x t i n c t i o n

system.

and

Permian. longer

between

However,

the

late

Serpuk-

are n e a r l y

the w a i t i n g

times

Mesozoic

= 3.1

in e x c e s s

Paleozoic

The

the e x t i n c t i o n

time between

is s o m e w h a t

lags

in the u p p e r

in the

deviation

the w a i t i n g

which

maxima

between

than most

(standard

with

These

spaced

lower

the

portions

events.

the o t h e r

evenly

for

some

in the

of the

extinc-

Generally,

7 and n e g a t i v e

is a n a l y z e d .

20

subdivisions.

and

events,

intermediate

as for

times

another

one

37 Ma

though,

and

or t h r e e

maxima,

is c o n s i d e r a b l y

Triassic

two

Carboniferous

Devonian

about

of

extinction

intervals

into

regularity

are r a t h e r

of the

compatible,

may be

lags

Paleozoic

two e x t i n c t i o n

averaging

Upper

for

their

as w e l l

variation

the U p p e r

and

events

split

series

no c y c l i c positive

66 % of

60 s a m p l i n g

has been

do e x h i b i t

at the b a s e

Stephanian equal

are

of the

that

the e n t i r e

Paleozoic

hovian

to one

or s e r i e s

interval,

Ma).

This

the

Upper

of

30 Ma

and p o s t -

59

Triassic

Mesozoic.

extinction decaying needed

over

Prior

change

Devonian,

However,

5 displays

with

maxima

The

events

last

may reflect

Most

high

although

without

terminal the upper

the Upper

Ashgillian.

Permian

extinction

of fewer

the O r d o v i c i a n evidently

genera

there

Lower

Extinction

There

Cambrian,

are high

trilobites,

The s e e m i n g l y middle

Paleozoic

(1985)

the rest events

of

coupled

of endemic

high

average some

inten-

treatments

in the Ludlovian. of extinction.

appears

The well-

as a p r o n o u n c e d

is c o m p a r a b l e

1000).

the lower

noted by Boucot

peak

in a m p l i t u d e

duration,

(435 out of a p p r o x i m a t e l y

with

and T r e m p e a l e a u a n .

among

smaller

of the shorter

in the Cambrian

in the Devonian.

events

and upper

by House

over

of extinction;

over

of periof the

Earlier

Llanvirnian

(1983)

to

reflects

around

in

which the

Ordovician.

Middle

bachian,

are

the six extinc-

extinction

maxima

maximum

to the event

patterns

and Upper

apparent

because

to

relatively

peaks

is a low m a x i m u m

corresponds

top of the

and frequent

extinction

This

event but,

Frasnian,

recognized

of other,

a low maximum

two

analyses

over most

intensities

also displays

mass

upper

correspond

average

any d e f i n i t e

contains

the

length

indication

intensities

Givetian,

a combination

Ordovician

statistical

and Hangenberg)

suggest

that

the period

is no positive

maxima

The high

Silurian

however,

The O r d o v i c i a n

over

lower

provinciality

of the

of the data,

there

extinction

in the

the D e v o n i a n

known

high

suggests

with

speculation.

two of these

ammonoids.

sities

this

(the Kellwasser

with g e n e r a l l y

times

more d e t a i l e d

or reject

for D e v o n i a n

genera.

in w a i t i n g

may be n o n s t a t i o n a r y

to the Carboniferous, Fig.

Famennian. tion

time.

to c o n f i r m

odicity.

Such

periodicity

The last

documented

chaotic

pattern

certainly

it may be too early

does

to c o n c l u d e

Fig.

5 represents

more

highly

at best

with

detailed

biostratigraphic

House

1985),

are needed b e f o r e

thesis

are

resolved

average maxima

broadly

intensities, in the

lower

two reflect by Palmer

that

estimate

analyses

biomere

definitive

]984)

of e x t i n c t i o n

data

for

the

and others.

in the early

absent.

patterns, data,

intervals testing

and

However,

is d e f i n i t e l y

and t a x o n o m i c

over

Dres-

extinction

any periodicity.

of critical

to those

especially

maxima

periodicity

stratigraphic

similar

Botomian,

(]979,

of e x t i n c t i o n

not suggest

a rough

global

appear

and

coupled e.g.

the hypo-

available.

Conclusions Multiple 26-Ma

lines

of s t a t i s t i c a l

periodicity

nerozoic.

However,

evidence

in e x t i n c t i o n this

events

periodicity

now exist over

cannot

for

the last be e a s i l y

an a p p r o x l m a t e l y 250 Ma of the Phatraced

back

into

60

the Paleozoic. the

There

late P a l e o z o i c

combinations

is a s u g g e s t i o n

but no positive

of periodic

portions

of that era.

addition

to more

tinction

patterns,

taxonomic geologic needed

include

selectivity,

information

similar mine

their

their

work

models

on p r e c i s e l y are.

From

and the source

and q u a n t i t a t i v e

information

of their

events

and middle

observations, analyses

in

of ex-

of the duration,

will

and

provide

occur

and how

we might better

clocklike

in

or even

distribution,

Such studies

when e x t i n c t i o n this

studies

and g e o g r a p h i c

events.

events,

in the early

to test these

comparative

environmental

periodicity

for p e r i o d i c

events,

needed

detailed

of e x t i n c t i o n

effects

cause

and aperiodic

Future

sophisticated

correlates

of a n o n s t a t i o n a r y

evidence

deter-

behavior.

Acknowledgements I thank Chappell support

James

Quinn

for help from

for s u g g e s t i n g

in i n t e r p r e t i n g

NASA grant

autocorrelation results.

analysis

This work

and Richard

received

partial

2-282.

REFERENCES ALVAREZ, L.W.[ ALVAREZ, W.; ASARO, F. & MICHEL, H.V. (1980): E x t r a t e r r e s trial cause for the C r e t a c e o u s - T e r t i a r y e x t i n c t i o n . - Science 208, 1095-1108. ALVAREZ, W.; ALVAREZ, L.W.; ASARO, F. & MICHEL, H.V. (1982): Current status of the impact theory for the terminal C r e t a c e o u s e x t i n c t i o n . in: SILVER, L.T. & SCHULTZ, P.H. (eds.) : G e o l o g i c a l I m p l i c a t i o n s of Impacts of Large Asteroids and Comets on the Earth. Geol. Soc. Amer., Spec. Pap. 190, 305-316. -- • KAUFFMAN, E.G.; SURLYK, F.; ALVAREZ, L.W.; ASARO, F. & MICHEL, H.V. i1984): Impact theory of mass e x t i n c t i o n s and the i n v e r t e b r a t e fossil r e c o r d . - Science 223, 1135-1141. BOUCOT, A.J. (1975): E v o l u t i o n and E x t i n c t i o n Rate C o n t r o l s . - Elsevier, Amsterdam, 427 p. -- (1983): Does e v o l u t i o n take place in an e c o l o g i c a l vacuum? II.- J. Paleont. 57, 1-30. DAVIS, M.; HUT, P. & MULLER, R.A. (1984): E x t i n c t i o n of species by periodic comet s h o w e r s . - Nature 208, 715-717. FISCHER, A.G. & ARTHUR, M.A. (1977): Secular v a r i a t i o n s in the pelagic realm.- in: COOK, H.E. & ENOS, P. (eds.): D e e p - W a t e r C a r b o n a t e Environments. Society of Economic P a l e o n t o l o g i s t s and M i n e r a l o g i s t s , Spec. Publ. 25, 19-50. GALE, N.H. & BEC--KINSALE, R.D. (1983): Comments on the paper "Fission track dating of British O r d o v i c i a n and Silurian s t r a t o t y p e s " by R.J. Ross and others.- G e o l o g i c a l Magazine 120, 295-302. HALLAM, A. (1984): The causes of e x t i n c t i o n . - Nature 308, 686-687. HARLAND, W.B.; COX, A.V.; LLWELLYN, P.G.; PICKTON, C.A.G. ; SMITH, A.G. & WALTERS, R. (1982): A Geologic Time Scale.- C a m b r i d g e Univ. Press, Cambridge, 131 p. HOFFMAN, A. (1985a) : Patterns of family e x t i n c t i o n d e p e n d on d e f i n i t i o n and g e o l o g i c a l t i m e s c a l e . - Nature 315, 659-662. -- (1985b): Biotic d i v e r s i f i c a t i o n in the Phanerozoic: d i v e r s i t y indep e n d e n c e . - P a l a e o n t o l o g y 28, 387-391.

61

HOFFMAN, A. & GHIOLD, J. (1985): R a n d o m n e s s in the pattern of "mass e x t i n c t i o n s " and "waves of o r i g i n a t i o n " . - Geol. Mag. 122, I-4. HOUSE, M.R. (1985): C o r r e l a t i o n of m i d - P a l a e o z o i c ammonoid e v o l u t i o n a r y events with g l o b a l s e d i m e n t a r y p e r t u r b a t i o n s . - Nature 313, 17-22. JONES, B.G.; CARR, P.F. & WRIGHT, A.J. (1981): Silurian and Early Devonian g e o c h r o n o l o g y -- a r e a p p r a i s a l with new evidence from the B u n g o n i a L i m e s t o n e . - A l c h e r i n g a ~, 197-208. KERR, R.A. (1985): Periodic e x t i n c t i o n s and impacts c h a l l e n g e d . - Science 227, ]45]-1453. KITCHELL, J.A. & PENA, D. (1985): P e r i o d i c i t y of e x t i n c t i o n s in the g e o l o g i c past: d e t e r m i n i s t i c versus s t o c h a s t i c e x p l a n a t i o n s . - Science 226, 689-692. MADDOX, J. (1985): Periodic e x t i n c t i o n s u n d e r m i n e d . - Nature 315, 627. McKERROW, W.S.; LAMBERT, R.St.J. & CHAMBERLAIN, V.E. (]980): The Ordovician, Silurian, and D e v o n i a n t i m e s c a l e s . - Earth and P l a n e t a r y Science Letters 51, I-8. MARK, G.A. & FLESSA, K.W. (1977): A test for e v o l u t i o n a r y equilibria: P h a n e r o z o i c b r a c h i o p o d s and Cenozoic m a m m a l s . - Paleobiol. 3, 17-22. MARTIN, P.S. & KLEIN, R.G. (]984): Q u a t e r n a r y Extinctions: A ~ r e h i s t o r i c R e v o l u t i o n . - Univ. of Arizona Press, Tuscon, Arizona, 892 p. PALMER, A.R. (1979): Biomere b o u n d a r i e s r e - e x a m i n e d . - A l c h e r i n g a ~, 33-41. -- (1984): The b i o m e r e problem: e v o l u t i o n of an idea.- J. Paleont. 58, 599-611. RAMPINO, M.R. & STOTHERS, R.D. (1984): T e r r e s t r i a l mass extinctions, c o m e t a r y impacts and the Sun's motion p e r p e n d i c u l a r to the g a l a c t i c p l a n e . - Nature 308, 709-712. RAUP, D.M. (1979): Size of the P e r m o - T r i a s s i c b o t t l e n e c k and its evolut i o n a r y i m p l i c a t i o n s . - Science 206, 217-218. -- & SEPKOSKI, J.J., Jr. (1984): P e r i o d i c i t y of e x t i n c t i o n s in the geologic past.- Proc. National Academy of Sci., U.S.A. 81, 801-805. -- & SEPKOSKI, J.J., Jr. (1986): Periodic e x t i n c t i o n of families and g e n e r a . - Science 231, 833-836. ROSS, R.J., Jr. & NAESER, C.W. (1984): The O r d o v i c i a n time scale -- new r e f i n e m e n t s . - in: BRUTON, D.L. (ed.) : Aspects of the O r d o v i c i a n System. U n i v e r s i t e t s f o r l a g e t , Oslo. SEPKOSKI, J.J., Jr.(1979) : A kinetic model of P h a n e r o z o i c t a x o n o m i c diversity. II. Early P h a n e r o z o i c families and multiple e q u i l i b r i a . Paleobiol. 5, 222-251. -- (1984): A k ~ n e m a t i c model of P h a n e r o z o i c t a x o n o m i c diversity. III. P o s t - P a l e o z o i c families and mass e x t i n c t i o n s . - Paleobiol. 10, 246-267. -- (]986): An o v e r v i e w of P h a n e r o z o i c mass e x t i n c t i o n s . - in: JABLONSKI, D. & RAUP, D.M. (eds.): Pattern and Process in the History of Life. Springer, Berlin. -- & RAUP, D.M. (1986): P e r i o d i c i t y in marine e x t i n c t i o n e v e n t s . - in: ELLIOTT, D.K. (ed.): Dynamics of Extinction. Wiley, New York, 3-36. STANLEY, S.M. (1984): Marine mass extinctions: a d o m i n a n t role for temp e r a t u r e . - in: NITECKI, N.H. (ed.) : Extinctions. Univ. of Chicago Press, Chicago, 69-117. -- (1986): Anatomy of a regional mass extinction: P l i o - P l e i s t o c e n e decim a t i o n of the Western Atlantic b i v a l v e fauna.- Palaios I, 17-36. WESTERMANN, G. (1984): Gauging the d u r a t i o n of stages: a n~w appraisal for the J u r a s s i c . - Episodes 7, 26-28. WHITMIRE, D.P. & MATESE, J. (1985): Periodic comet showers and Planet X.Nature 313, 36-38.

CHEMICAL WORLD

AND

ISOTOPIC DURING

OCEAN

VARIATIONS PHANEROZOIC

IN TIME

•?

THE

U

HOLSER, WRIGHT,

W i l l i a m T. *), J u d i t h ***)

MAGARITZ,

Mordeckai

**)

&

A contribution toProject

GLOBAL BIO EVENTS

Introduction We

ask

the q u e s t i o n

extinction

events

such

a connection

with

a dramatic

the f r a c t i o n

as to w h e t h e r

and c h a n g e s might

drop

in the c y c l e s

tively,

a connection

in the

cycles

external

of n u t r i e n t

but

such

as y e t

be

elements

and o t h e r

there

carbon,

indirect:

as a m a j o r

waters which

elements

mass

might

that

will also

as s u l f u r .

be common

answers,

that

associated

would

level.

major

imagine

extinction

in s e a

partial

between

can

may be

as w e l l

both

regression

are o n l y

One

extinction

in s u r f a c e

to b i c a r b o n a t e

might

is any r e l a t i o n chemistry.

mass

in p r o d u c t i v i t y

of c a r b o n

factor,

question,

be direct:

of o r g a n i c

changes

there

in o c e a n

decrease lead

to

Alternaand c h a n g e s

results We ask

and m a n y

of an

the

remaining

puzzles. Evidence events

-- of

Holser

(1984)

for

in the

and

been

Holland

work

long-term

(]986). review

ocean After

some

in our r e s e a r c h

and e a r l y done

al.

I will

(mainly

-- b o t h

of the w o r l d

et

material,

done

Paleozoic

voluminous

changes

the c o m p o s i t i o n

this background recently

secular

Mesozoic,

elsewhere

with

on the

trends

has

been

and s h o r t reviewed

recapitulating

specific

group) only

studies

on t r e n d s

passing

Cretaceous

by

some

of

that have

and e v e n t s

mention

and T e r t i a r y

of the and

its

boundary.

Some

general

Certain

controls

aspects

chemistry.

on o c e a n

of the w o r l d

It is a l a r g e

currents

on a t i m e

downflow

of c o l d d e n s e

The m a i n rivers, are

at

ments

input

least -- s u c h

special

for

although

most

equally

of

waters

elements

some

(e.g.,

important. Sr into

circumstances

*)

Department

**)

Isotopes D e p a r t m e n t ,

***)

Department U.S.A.

of

are of p a r t i c u l a r that

of h u n d r e d s

polar

as Ca and

geological

ocean

reservoir

scale

for

chemistry

Geology,

of y e a r s ,

is e r o d e d

and v e r t i c a l l y

and carried

main

limey

muds,

-- the

University

outputs or

same

are

into

Eugene,

State

the

by the w o r l d

common

systems sedi-

requiring

of e l e m e n t s

Rehovot,

Arizona

by

by

of y e a r s .

hydrothermal

in s e d i m e n t s

pair

of O r e g o n ,

Institute,

Sciences,

ridge

to its

horizontally

of t h o u s a n d s

mid-ocean

Their

importance

is m i x e d

on a s c a l e

Ca)

Weizmann

Geological

today

into eva-

U.S.A.

Israel. University,

Tempe,

Lecture Notes in Earth Sciences. Vol. 8 Global Bio-Events. Edited by O, Walliser @ Springer-Verlag Berlin Heidelberg 1986

64

porites.

Those e l e m e n t s

relative

to m i x i n g

difficult

(REE),

times

S, St)

trace metals).

of many of these e l e m e n t s

c o n t r o l l e d by their

The r e l a t i v e from this

the biomass,

column.

(Corg)

to the u n d e r l y i n g water

times

masses

in t o d a y ' s

ocean,

at low l a t i t u d e s .

and s e d i m e n t s

of Corg

that might may form b l a c k

the s u p p l y of o x y g e n

on s h a l l o w s h e l v e s are a l s o

and a high e f f i c i e n c y

s h a l l o w waters.

may

in the

to

that drive

are r e p l a c e d by w a r m salty b o t t o m

S h a l l o w shelves

of Corg

oxygen

or s o m e t i m e s

in s u r f a c e w a t e r s

Alternatively,

w a t e r s g e n e r a t e d by e x c e s s e v a p o r a t i o n

rapidly sedimenting

are

with

and d i s s o l v e d

Thus e x t r a o r d i n a r y s u p p l i e s

and sulfide.

circulation

high productivity

C, rare-

and d e p t h

b o t t o m w a t e r s may be g r e a t l y r e d u c e d if the cold polar waters,

basins

and more

(e.g.,

particularly

zone in the s e d i m e n t s

have b e e n g e n e r a t e d by high p r o d u c t i v i t y

vertical

are long

in the s u r f a c e w a t e r s .

s u r f a c e water

rich in Corg

times

that have short r e s i d e n c e

inputs of o r g a n i c c a r b o n

in an anoxic or s u b o x i c

overlying water

muds

in the ocean that

are b o t h mere h o m o g e n o u s

The v e r t i c a l c i r c u l a t i o n

i n v o l v e m e n t with

primary productivity

result

(e.g.,

to m o d i f y than those w i t h short r e s i d e n c e

earth e l e m e n t s profile

with r e s i d e n c e

times

This

or b o r d e r i n g

conducive

to both

of its s t o r a g e

important

parameter,

a

in the the e x t e n t

of s h a l l o w s h e l v e s

in any g e o l o g i c a l

period,

is a f u n c t i o n of e u s t a t i c

(as well

as local)

rise of sea level,

which

in turn may be c a u s e d by an

increase

in m i d - o c e a n

ridge

activity,

m e l t i n g of c o n t i n e n t a l glaciers,

or other g e o p h y s i c a l

processes

genic chemical

is a c o m p l e x fabric of i n t e r c o n n e c t e d c h e m i c a l ,

cycle

logical

and p h y s i c a l

enhance

or d a m p e n

Changes

that are less well u n d e r s t o o d .

processes,

an e x t e r n a l

including

vs.

such as the i n c i d e n c e

c a l c i t e 8oids

atmospheric

in this c o m p l e x c h e m i c a l

evaporites at least

(Wilkinson et al.

chemistry

have

imposed

the late

Holser,

limits

have s u g g e s t e d through

time.

in h a l i t e

of the v a r i a t i o n

(Holland et al.

such as halite,

of the sea water

Maynard

tors of c h a n g e sediments, (REE),

1985)

anhydrite,

Mineralogical

or of a r a g o n i t e changes

& Cruikshank

from which 1986).

in the e x o g e n i c cycle

or i s o t o p e s

of m a r i n e

elements

Inventories

b l a c k shales,

they were d e p o s i t e d

are found by s t u d y i n g species:

of a p a r t i c u l a r e l e m e n t

and phosthe c h e m i -

(Ronov

St,

Nd).

1980,

indica-

the ratios,

the r a r e - e a r t h

(S, C,

since

through

But some of the most u s e f u l

of c l o s e l y r e l a t e d c h e m i c a l

in

C o m p a r i s o n of

crystals

of these

1986).

s y s t e m may be

tell us more than we have yet a p p r e c i a t e d c o n c e r n i n g

cal h i s t o r y

bio-

that may either

record.

vs. calcite,

of fluid i n c l u s i o n s

Paleozoic

time of rock types, phorites

in the g e o l o g i c a l

of d o l o m i t e

CO 2 p r e s s u r e or c a t i o n ratios

major e l e m e n t

loops

forcing.

from a s t e a d y state

i n f e r r e d from a v a r i e t y of clues markers,

feedback

The exo-

elements

in

65

A chemical These

elements

They or

example:

are

follow

taken

der

of

where

1986).

sediments with

Ce(anom)

= log

that

the

analyzed

both

the

sea w a t e r

bit

a strongly

panel

Black

seas,

have

Apparently

is a m e a s u r e

in the s u r r o u n d i n g

result

these

is c l o s e

in t h e s e

oceans.

to zero,

shelf

limestones,

only

means

that

mixture

of

Permian

shelf

ventilated graphic

1986). current across

are n o t

negative

top

are e n d e m i c , the R E E

metal

incluin

hydrox

grains,

-

or in

in a n o x i c

anomaly.

system

prevailing

analysis

in over

These

but

zero

Alternating for

one

these

a reducing

into

conditions

actually but

taken this

surface

waters

from

to see

a

-0,5

Pennsylvanian like

today's

the b i o s t r a t i g r a p h i c

and

welloceano-

(1978). to e s t a b l i s h samples

in the F i u l e n

Flinzen

layers

and o x i d i z i n g

unusual

the C a m b r i a n / O r d o v i c i a n

anoxic

were

The

t i m e we b e g i n

in the

confirm

conodonts. Paleozoic

environment,

and

of d e t a i l e d

reducing

of

of c o n o d o n t s

near

good data

set

in the

a prevelance

in D e v o n i a n

relations

Ce(anom)

in the e a r l y

Ce(anom)

much

have

of P a l e o z o i c

I):

Ce(anom),

we h a v e

yet

models

exhi-

in the

cerium

activation

re-circulated

Beginning

& Wilde

near

oceans

are r e - d i s s o l v e d

mainly

the s a m p l e s

of B e r r y

the n e g a t i v e

Ce(anom)

Thus

is m i s s i n g

authigenic

the n e g a t i v e

(Fig.

indicating

Ce has b e e n

samples

zoic/Cenozoic, shows

the

ocean.

We d o n ' t

carriers

apatite,

which

deeps.

slightly

model

all

and s e d i m e n t a r y

to r e m o v e

trend

Of c o u r s e

from

anoxic

is,

as

indicate

levels.

conditions

The Ce t h a t

in f i n e

REE by neutron

a long-term

Ce(anom)

offshore

these

shale

as s h o w n

-- t h a t

(Ce) w h e n

expressed

the n ' s

of the o x i d a t i o n / r e d u c t i o n

of b i o g e n i c

is

zero

shells

cerium

of t o d a y ' s

anoxic

Schra-

modern

seas.

measured

200 m i e r o s a m p l e s first

, where

sediments.

adsorbed

coating

is r e - c i r c u l a t e d

Ce(anom)

We h a v e

is f o u n d

Wright,

in m o s t

and n e o d y m i u m ,

to -1.0,

where

near

in a v e r a g e

hydroxides

nodules.

and Ce

Ce(anom)

those

a "rare-earth

pattern

in m o s t

= -0.1

as c o n o d o n t s

1984;

to s t a n d a r d

apatite

regions

cecord

e t al.

+ Nd(n)] >

Ce(anom)

geochemistry.

such

in the e l e m e n t

lanthanum

are n o r m a l i z e d

However

apatite

ferric

manganese

I.

they

of this

deficiency

and b i o g e n i c

in t h e i r

apatite,

(Wright

feature

[2La(n)

values

closely

diagenesis

sea water

neighbors

negative

like

the d e e p - s e a ides--

in e a r l y

<3Ce(n)/

very

in b i o g e n i c

A striking

REE

Sea,

Ce a r e

Thus

its

of F i g u r e

as the ding

another

is a g l a r i n g

compared

Elements

readily

the o v e r l y i n g

& Holser

marine

one

up most

ichthyoliths,

pattern"

Rare Earth

strata.

boundary,

a trend

from

layers, (Wright,

Holser

In a n o t h e r

are

Basin

with

& Schrader in a c c o r d

detailed

shows

the M e s o -

Solnhofen

alternating

conditions

Ce(anom)

the

for

with

study

variations,

even

66

-I 0

F i g u r e I. C e ( a n o m ) of REE in p r e s e n t sea w a t e r and b i o g e n i c a p a t i t e (upper p a n e l ) , and in f o s s i l a p a t i t e (lower h i s t o g r a m s ) . D a s h e d line approximately separates o x i d i z i n g c o n d i t i o n s on the left f r o m r e d u c i n g c o n d i t i o n s on the r i g h t . After Wright, Schrader & H o l s e r (1986).

-05

0

0.5

0

05

I

-lO

~0.5 Ce

within

the

small

range

stratigraphically rent

in C h i n a

of +0.1

within

(Wright,

Miller

possibilities

for d e t e r m i n i n g

the o x i d a t i o n

system

of

sections

is g r e a t ,

in the

to -0.1

a wide

area

& Holser both

of sea w a t e r .

Mississippian,

the c o s t s

of F i g u r e

of w e s t e r n 1986).

trends

onom

I , that North

Thus

this

and w h i l e

and e x p e n s e

of b o t h

stable

are

the

but diffe-

approach

and s h o r t - t e r m

We are n o w b e g i n n i n g

in time

are c o n s i s t e n t

America,

has

variations a detailed

potential

in study

of this

method

are one

of the

large.

Isotopes Ratios most

of i s o t o p e s

informative

markers

and r a d i o g e n i c

of c h a n g e s

species

in the e x o g e n i c

cycle.

The devia-

67

[ k

]i S-bacteria reduction ~/ _ ~ 3 4 S - --40%0

Shale S$'d

Ocean Ssft

Shale Corg

Crystallization ! ~A~4S = +1.4%0L

Ocean Ccarb

ir~" Young(IvIOR)~ Hydrothermat cxcha~. _~! I basalticSr j - ~ 0,704 I i L

Evaporite s~ft _~L

A13C ~ 0%0

Ocean Sr

<:'t; 1 Old (cretonic)

Erosion

~ 0.720

ASr[= 0 Fossil

Sr

[ F i g u r e 2. Schematic i s o t o p e s in the o c e a n .

tions

from

average

appreciate

these

the

cases

per

thousand

changes

of

crustal

from

input

ratios

sources

or d e p o s i t i o n

biotic

effects

(O).

The

forms

ation as Nd)

or

%,

tend and

fluxes

well

residence

time

standard. and

Nd),

"del"

There

S),

are m a n y

in F i g u r e

2: for b o t h

sulfur

reduction.

respectively.

The

this

change

carbonate

story.

ratios

-- Sr f r o m

such

mixed

in the o c e a n it s h o u l d

long

basalts

reflect

old

like

times,

more

sediments.

are s i m p l e

residence

at m o s t

much

elements

-- Sr f r o m

young

Sr h a v e

these

in sea w a t e r

isotope

S and

of

local

S the

those

but

re-

reduced

and s u l -

inputs

Sr

(as w e l l

do not

frac-

a balance

on

have

fraction-

continental

times

ratio

isotopically

if the

without

and s u l f a t e

Isotopes

The

carbonate

heavier,

is r e c o r d e d

specific

isotope

mediated

lighter

remaining

for

evaporation

C and

or b a c t e r i a l

are

in

in p a r t s

causes

(O),

of d i f f e r i n g

in s h a l e s ,

easily

during

biologically

mainly

Sr

sediments:

temperature

in a m i l i e u

and

notation

associated

fractionations

(O, C,

out

to m o r e

is the d e v i a t i o n

its

to be p r o p o r t i o n a l l y

isotope

that

in the

value

S, C,

during

of h e a v i e r

isotopes

stated

in o r d e r

of

occurs

corresponding

ridges.

probably

sen

35-40

so t h e i r

lighter

laid

the r e l a t i o n s

a del

Sr,

isotopes

sulfur,

is a d i f f e r e n t

input

ocean

are

of

same,

in t h e

tionate, the

the

S,

or d i a g e n e s i s

and

in s e a w a t e r

remained

are

in s e a w a t e r

(C,

by photosynthesis

Z and

they

S, w h e r e

in s e d i m e n t s

effects

of c a r b o n

20-25

fate

(C),

fractionation

duction

by

main

and

of

are s m a l l ;

an i n t e r n a t i o n a l

(H, O)

major

ratios

deviations

H, O, C,

in i s o t o p e

differing

representation

of

granites,

the m i d -

that

they

are

Nd has

such

a short

inputs

(Keto

& Jacob-

1985). Carbon,

although

it has

a substantial

residence

time

in the

ocean

68

~13c, %o

0

//,•'-•l

I

0

!

2

0 ,

'~'

C H z O ~ H ~ O ÷ C02 a }

2 ~Z~

'

I

-;iC

~ CHzO~HzO

+ COz

F

A

i B~'C{CH,O) =- ZO°/~ I PHOTIC

CARBON P U M P

B}3C P R O F I L E

PRODUCTIVITY

MODEL

F i g u r e 3. F r a c t i e n a t i o n of c a r b o n i s o t o p e s b e t w e e n s u r f a c e and d e e p w a t e r s , b y d o w n w a r d t r a n s f e r of Corg. (a) -- m e c h a n i s m ; (B) -- a v e r a g e p r o f i l e of the p r e s e n t w o r l d o c e a n ; (C) -- e f f e c t of d e c r e a s i n g p r o d u c t i v i t y c > b > a on the c a r b o n i s o t o p e g r a d i e n t . A f t e r B e r g e r & V i n c e n t (1986).

as a w h o l e ,

is p r e s e n t l y

differentiated

fractionation

that

surface

into deeper

of

layer

I-2 Z, b e t w e e n

tivity

(Fig.

estimate

which

variations

For

attempts

found

among

The

for

long-term

trends,

Paleozoic

long

term,

those the

are

less

34S

that

those

of the m e a n

intense

of d e l

of t h i s

of F i g u r e

isotope

represents of v a r i o u s

vital

shows

13C,

produc-

of

4 (Holser

ratios

origins:

series,

incorrect

and d i a g e n e s i s .

a curve

1984)

in the m i x e d

a statistical

effects,

some

recognized high

del

to i n t e r m e d i a t e and t e n d

in d e l

in s u l f a t e s

in t h e s e

like

age A pri-

is the m a t c h

of the b e s t

already

34S,

to s e d i m e n t s ;

dramatic

the o x y g e n

in a g r a d i e n t

is a m e a s u r e

in any s e g m e n t

where

ocean

by

a productive

worldwide.

exhibits

from

results

13C f r o m

1986).

"noise"

age c u r v e

which

variations

of d e l

theory

a balance

basins

and r e t u r n s

in c a r b o n

out

two r e s e r v o i r s

del

which

the c u r v e

fractionations,

isotope

of s u l f i d e

time

trends

separafe

sulfur

Permian,

through

into

light

This

ratios,

confidence

The e a r l y flux

& Vincent

to s m o o t h

local

criteria

with

and deeps,

isotope

long-term

assignments, mary

for

Corg

waters.

surface

3, B e r g e r

"Age c u r v e s "

ocean.

"pumps"

it d r o p s

(Veizer

than

20 y e a r s

of a h i g h

to a m i n i m u m

levels

in the M e s o z o i c .

to g e t

lost

13C in c a r b o n a t e s

of the

more

indicative

established

et al.

1980);

atmosphere

two o x i d a t i o n / r e d u c t i o n

would

systems.

to b e

in the

Variations

in the n o i s e .

tend

In the

inverse

this w a s

ago.

net

to

predicted

on

only be maintained

by

The m e c h a n i s m

that

69

IO0-

,

[~,

KI £

__~

200-

4

Pt

~!! ......... ~:

1

MI

400-

'---' SI

.....

OI 500-

I ......

6oo

'l ....

I ....

I'!'"1

+t0

_~

....

50-2

suLfate,%o CDT

6Z4S

i'''l''~l'

L ....

20

-0*

'

2

4

I

'

~ '

T

Q707 0,708 0.709 0.710 -0+

6~3Ccnrbonate, %0 PDB 87Sr/86Sr apatite,~rbonc~e

200 400

Sea level

F i g u r e 4. Age c u r v e s of S, C, and Sr in m a r i n e s e d i m e n t s , and V a i l s e a - l e v e l c u r v e . S h a d i n g g i v e s r a n g e of u n c e r t a i n t y ; d a s h e d lines, l a c k of d a t a . A f t e r H o l s e r (1984).

drives

this

balancing

of r e d u c t i o n poor

that

to t h o s e

& Raiswell

term

trends

The

were

detected

of

microfossil

Berger

of

regimes

euxinic

o n the that

marine

proportions

are

sulfur-

basins

is o s t e n s i b l y

generated

the c u r v e s

C and

are

the S c u r v e .

This

ridge

convincingly

of the

some

of

10 y e a r s

that

time

isotope

the

ago

in the

limited

sharp

(Holser

C and

for

relation

activity

(Berner

by quite

S, i t ' s

suggests

has b e e n

long-

some

suggested,

modelled.

changes

slices

of

glaciation,

Miocene & Vincent

1977),

under

only

been

stratigraphy

Late

has

anoxic

Of p a r t i c u l a r

in the

5 years

allowed

events

have

control.

and C r % t a c e o u s

recession

interest

last

sudden

curve

by very detailed

stratigraphic

13C a s s o c i a t e d

Miocene

by

S isotope

revealed

Cenozoic

I-2 h in d e l the

are p u n c t u a t e d in the

maximum

in the

and mid-Cretaceous 1986).

age c u r v e s excursions

Sr c u r v e s

is a v a i l a b l e

and paleomagnetic

of s h a r p

Pleistocene

earlier

than

-- m i d - o c e a n

not been

trends

events

control

nition

those

cause

has

age c u r v e

processes

resemble

Although

profiles

may depend

events

important

close

but

in c o n t i n e n t a l

in s u l f u r - r i c h

Sr i s o t o p e

common

long-term

shifts.

of

the

the s y s t e m

Isotopic

occur

proximate

underlying but

that

is o b s c u r e ,

place

1983).

Although different

act

take

the

clear

with

(Arthur

et

The both

recog-

the w a n i n g

of s e a

is the v e r y

from

level,

and

al.

1985,

sharp

but

70

short-lived anomaly

negative

at the

Although some

of

the

beginning with

have

isotopic

biotic

by

mapped

form,

boundary

Some

high

et

shown

by

boundary,

but

section,

exhibit

anomaly.

In the

three

for

only

& Arthur

iridium 1986).

the

that

events

20 m

investigations

high

Paleozoic,

they

are

are

associated

peak

are

which

into

the

a sharp

drop

of d e l

sections

1986).

Siberian

We

plat-

in b i o l o g i c a l lower

pro-

Tommotian,

with

13C in the m i d d l e

designated

are p r o b a b l y

Chinese

the

of d e l

also

13C > 5 ~,

et al.

the V e n d i a n / T o m m o t i a n

The d e c l i n e

continued

that

on

30 m a c r o s s

1986).

of d e l

(Knoll

in a s e c t i o n

for

a moderate

in C h i n a

iridium

mapped

al.

by t h i s d r o p

sections

a prolonged

in d e t a i l

Siberian

weak

these

the

during

and e x t e n s i v e of

to l o w v a l u e s

decrease

5, M a g a r i t z

recovery Two

reversions

a sharp

cambrian/Cambrian our

large

time w i t n e s s e d

final

signalled

a temporary Tommotian.

are so

(Zachos precise

with

events.

shows

(Fig.

ductivity

is less

characterized.

episodic

the

which

13C a s s o c i a t e d

boundary

control

events

Proterozoic

punctuated

of d e l

Cretaceous-Tertiary

stratigraphic

to be w e l l

major Late

excursion

not

as the

13C a s s o c i a t e d

the d e l

Pre-

correlative

with

13C a n o m a l y

(~2000

yr)

above

the b o u n d a r y .

The

differ

by orders

of m a g n i t u d e :

5000

scales m,

with a

is

of t h e s e

200 m,

I m,

respectively.

-9

-8

~la O, % -6

-7

-5

-4

-3 250

-0~-.-.:0

--~ - ~ - - -

200150 ~

3

c'=~ o

ICX3

..... o"" F3 -4

-2

0

2

4

0

81~C, %o

F i g u r e 5. P r o f i l e s of c a r b o n (solid line) and o x y g e n ( d a s h e d line) i s o t o p e s a c r o s s the V e n d i a n - T o m m o t i a n b o u n d a r y o n the S i b e r i a n P l a t f o r m . A f t e r M a g a r i t z et al. (1986) .

71

The del

Carboniferous

34S,

section

as w e l l in N e w

Sakmarian), other

of del

which

major

minimum

during

In c a r b o n Basin,

Clark

to

in the

late

early

profiles

Carboniferous,

Permian,

evaluated

and

from

at the

changes

rise

Lower

Middle USA,

to C h i n a

(Holser,

not b e e n

interval.

of

and

We h a v e

in the

also

re-

210 220 230 240

k LII

\

seen

in d e t a i l

to a m i n i m u m

L]

Tr ~ ' ~ p----~------REDUCED

"~"~Srm / ~Sr

&

the h i g h

r--J

rr2Ibc <- -

of

The r e g r e s s i o n ,

ic,0

P2 r°t REGRESSO I N "~,)

Trias-

Zechstein

1 i l.w_spot : r...J [

~

only

Triassic.

Magaritz

mapped

slide

I NO~N~

l~I rsnl TRA ......

to

-- a h i g h

the C a p i t a n i a n

P/Tr boundary.

this

remain

34S is at its

in the

in the

manifestation

isotopes

at the

during

boun-

worldwide;

-- w e s t e r n

Alps

end of

it has

stage

are s h o w n

Del

abruptly

P/Tr b o u n d a r y

Strontium

abruptly

results

values

the

is the f i n a l

1986a).

low v a l u e s

anomalies

1986b).

everywhere

although

Permian.

sea-level

it r i s e s

the

to

regression/trans-

transition

Typical

to m o d e r a t e

begins

with

These

our

basins.

& Magaritz

we f i n d

this

1985).

with

& Magaritz

excursions

correlate

one

(~Namurian-

extinction

Atokan/Desmoinesian

here.

of T e t h y s

13C and

measured

(Holser

sharp

in d i s t a n t

until

just b e l o w

Apparently

the e a r l y

& Ross

del

We h a v e

Carboniferous

events

here

and

(Holser

again

7Z that

late

Permian/Triassic

time,

falling

disappears

1986).

through

6

in the w a t e r s

13C of +3

abruptly

the

average

4).

of b a c k g r o u n d

two of t h e s e

c a n be g i v e n

Permian

isotope

and

the

even

A: R o s s

in F i g u r e

(Fig.

extinction

13C p r o f i l e s

summary

(Skythian),

spans

Morrowan-/Atokan

investigated

of h i g h

ratio

that

at l e a s t

by del

schematically

a time

an i n t e r v a l

(in W e s t p h a l i a n

We h a v e

also

to f i n d

at the

a very brief

del

across

13C o c c u r ;

be c o n f i r m e d

sic

Mexico,

surprised

gressions, daries

was

Sr i s o t o p e

to c o m p a r e

profiles

We w e r e

as

OXIDIZED

, B~4S

P~ SQ~

mean.

,*

,

0

I

I

]0 20 % MARfNE

I

150

I

~

~

0,707 0.708 eTsr/SSSr

I

10

I

15

I

270

I

+20 25 8~SS,~/~

0

12a°

+5 B13 C, o/,~

F i g u r e 6. S c h e m a t i c r e p r e s e n t a t i o n of e v e n t s a c r o s s the P e r m i a n / T r i a s i c b o u n d a r y : sea level, s t r o n t i u m i s o t o p e s , s u l f u r i s o t o p e s , and c a r b o n i s o t o p e s (all in m a r i n e s e d i m e n t s ) . For c a r b o n a s t r a t i g r a p h i c p r o f i l e is s h o w n s o l i d , m e a n s of l i t e r a t u r e v a l u e s d a s h e d , and s p o t v a l u e s as s t a r s . A f t e r H o l s e r & M a g a r i t z (1986b).

72

already very

well

fast,

sequent

known

nearly

to o c c u r

in the

250 m in the

transgression

was

late

last

even

Permian,

stage

faster

seems

of the

in the

to h a v e

Permian,

first

and

substage

happened the

sub-

of the e a r l y

Triassic. Iridium China

whether dium sus

has b e e n

(Sun et al. these

was

et

affairs,

rather

of e x t i n c t i o n , been both had

al.

than

furnishing

and

level

cause

has

same

emerged

the s h a r p

a pulse

the

incident

a ready and

drop

from

regression of h e a v y

Spathian

high

the

some deeps

in t h e

tion

raised

34S in the r e m a i n i n g

Regression

sions,

data

which

F i g u r e 7. and c h e m i c a l

dissolved early

as a c a u s e from

may

(Asaro

et al.

P/Tr b o u n d a r y

in

1983).

as to Iri-

in the T r a n s c a u c a -

of a d r o p

this

earlier

salts

ocean,

in del

new

The

to v e r y

is that

13C m a y h a v e

reduced

from

can o n l y

where

previously

of d e l

eroded

we

had

analysis

level.

34S,

interrelations

that

highs

of sea

marine

of g l a c i a l

to the

Sr i s o t o p e s

Permian

Triassic

of P e r m i a n - T r i a s s i c

temperature

of d e l

the C a r b o n i f e r o u s ,

have been

solution

so far f r o m

tify

liminary

P/Tr b o u n d a r y

is s o m e q u e s t i o n

to our p i c t u r e

salinity,

that

del

at the

there

anomaly

at the

complexity

in a m a j o r

also generated Concerning

but

1983).

tectonics,

extinction

nents.

found

adds

What

a common

not

data

suggested.

1985),

a significant

for b u t

isotope

in a few s a m p l e s

Xu et al.

represent

looked

(Alekseev The

detected

1984,

the c o n t i -

speculate

effectively

excess

base

sulfur

stra-

reduc-

sulfate. 13C is s u p p o r t e d

although origin,

by the p r e -

the C a r b o n i f e r o u s were

apparently

not

regresso

S u m m a r y of e x t i n c t i o n events e v e n t s t h r o u g h the P h a n e r o z o i c .

T

+

~

c

+

__

,~

~

c

i

K

+

cCs

I00

~G

J

+ 200 AGE, Mo

P

500 M

--~

~

~

! c/s

-

I

t

0

I

F~

iO0

C/S

600

73

effective

in e x t i n g u i s h i n g

there

also

was

to have

regression vity,

would

these work

Near

regression

the final

drop

have d e c r e a s e d

and burial

(Brasier

previously

abetted

accumulated

among

extinctions, lasting

cult

with

to connect

in the g e o c h e m i c a l

niches,

available

to reduce

shelves

regressions, some hundreds

an impact

although

previous

origin.

investigation

in del

of thousands Clearly

of mass

producti-

habitats.

highs

All of

of del

13C,

of the excess

Corg

or paralic

drops

model

diversity,

shelf

boundary

this seems

In the classical

by the r e - o x i d a t i o n

on shallow

cal parameters,

1982),

13C.

ecological

of biota by reducing

probably

the P r e c a m b r i a n - C a m b r i a n

in del

in the same d i r e c t i o n

and they were

tions

a major

preceeded

biota.

basins.

13C,

The rela-

and other

of years,

much

remains

extinction

events.

chemi-

are diffito be done

Acknowledgements

The

stratigraphic

for

this kind

stratigraphers

control

geochemists

urge

continued

Foundation

depends

and p a l e o n t o l o g i s t s

and other your

and sampling

of g e o c h e m i s t r y

Grants

in attacking

collaboration.

EAR 8115985,

that

is an e s s e n t i a l

largely

on a long

that have g e n e r o u s l y the problem Supported

8319429

framework

list of biohelped

of e x t i n c t i o n

by U.S.

and 8400222

National

both us

events.

We

Science

to the U n i v e r s i t y

of

Oregon.

SELECTED

REFERENCES

ALEKSEEV, A.S.; BARSUKOVA, L.D. ; KOLESOV, G.M. ~ NAZAROV, M.A. & GRIGORYAN, A.G. (1983): The P e r m i a n - T r i a s s i c b o u n d a r y event: Geochemical i n v e s t i g a t i o n of the T r a n s c a u c a s i a section.- Lunar Planet. Sci.14, 7-8. ARTHUR, M.A.~ DEAN, W.E. & SCHLANGER, S.O. (1985): Variations in the global carbon cycle d u r i n g the C r e t a c e o u s related to climate, volcanism, and changes in a t m o s p h e r i c CO2.- Amer. Geophys. Un. Geophys. Monogr. 32, 504-530. ASARO, F.; ALVAREZ, L.W. ; ALVAREZ, W. & MICHEL, H.V. (1983): Geochemical a n o m a l i e s near the E o c e n e / O l i g o c e n e and P e r m i a n / T r i a s s i c b o u n d a ries.- Geol. Soc. Amer. Spec. Pap. 190, 517-528. BERGER, W.H. & VINCENT, E. (1986): D e e p - s e a carbonate: Reading the carg o n - i s o t o p e signal.- Geol. Rdsch. 75, 249-269. BERNER, R.A. & RAISWELL, R. (1983): Burial of organic carbon and pyrite sulfur in sediments of P h a n e r o z o i c time: A new theroy.- Geochim. Cosmochim. Acta 47, 855-862. BERRY, W.B.N. & WILDE, P. (1978): P r o g r e s s i v e v e n t i l a t i o n of the oceans -- an e x p l a n a t i o n for the d i s t r i b u t i o n of Lower P a l e o z o i c black shales.- Amer. J. Sci. 278, 257-275. BRASIER, M.D. (1982): Sea-level changes, facies changes and the Late P r e c a m b r i a n - E a r l y Cambrian e v o l u t i o n a r y e x p l o s i o n . - Precamb. Res. 17, 105-123. HOLLAND, H.D.~ LAZAR, B. & McCAFFREY, M. (1986): E v o l u t i o n of the atmosphere and oceans.- Nature 320,27-33.

74

HOLSER, W.T. (]977): C a t a s t r o p h i c chemical events in the history of the ocean.- Nature 267, 403-406. -- (]984): Gradual and abrupt shifts in ocean c h e m i s t r y during Phanerozoic time.- in: HOLLAND, H.D. & TRENDALL, A.F. (eds.): Patterns of Change in Earth Evolution. S p r i n g e r - V e r l . / D a h l e m Konf., Berlin, 123143. -- & MAGARITZ, M. (1986a): A carbon isotope profile in marine Pennsylvanian c a r b o n a t e rocks from New Mexico.- (in revision). -- & MAGARITZ, M. (1986b): Events near the P e r m i a n - T r i a s s i c b o u n d a r y . (in prep.) -- ~ MAGARITZ, M. & CLARK, D.L. (1986): C a r b o n - i s o t o p e s t r a t i g r a p h i c c o r r e l a t i o n s in the Late Permian.- Amer. J. Sci. 286, 390-402. -- ~ MAYNARD, J.B. & CRUIKSHANK, K.M. (]986): Modelling the natural cycle of sulphur through g e o l o g i c a l time.- in: BRIMBLECOMBE, P. & LEIN, A. V. (eds.): Evolution of the Global B i o g e o c h e m i c a l Sulphur Cycle. Wiley, New York (in press). KETO, L.S. & JACOBSEN, S.B. (1985): The causes of 87Sr/86Sr variations in seawater of the past 750 million years.- Geol. Soc. Amer. Abstr. Progr. 17, 628. KNOLL, A.H.~ HAYES, J.M.~ KAUFFMAN, A.J.] SWETT, K. & LAMBERT, I.B. (1986): Secular v a r i a t i o n in carbon isotope ratios from Upper Proterozoic successions of Svalbard and East Greenland.- Nature (in revision). MAGARITZ, M.[ HOLSER, W.T. & KIRSCHVINK, J.L. (1986): C a r b o n - i s o t o p e events across the P r e c a m b r i a n / C a m b r i a n b o u n d a r y on the Siberian Platform.- Nature 320, 258-259. RONOV, A.B. (1980): O s a d o c h n a y a O b o l o c h k a Zemli.- Nauka, Moscow, 80 p. (Transl. Inter. Geol. Rev. 24, 1313-1388 (1982)). ROSS, C.A. & ROSS, J.R.P. (1985): Late P a l e o z o i c d e p o s i t i o n a l sequences are synchronous and w o r l d w i d e . - Geology 13, 194-197. SUN Yiyin~ XU Daoyi~ ZHANG Qinwen] YANG Zhengshong~ SHENG Jinzhang~ CHEN Chuzhen~ RUI Lin~ LIANG Xiluo[ ZHAO Jiaming & HE Jiwen (]984): The d i s c o v e r y of iridium anomaly in the P e r m i a n - T r i a s s i c b o u n d a r y clay in Changxing, Zhejiang, China and its s i g n i f i c a n c e . - Internat. Geol. Congr., 27th, Moscow, Abstr. 8, 309-310. I VEIZER,_~.~OLSER W.T. & WILGUS, C.K. (1980): C o r r e l a t i o n of 3C/12C and J S/J S secular v a r i a t i o n s . - Geochim. Cosmochim. Acta 44, 579-587. WILKINSON, B.H.[ OWEN, R.M. & CARROLL, A.R. (1985): Submarine h y d r o t h e r mal weathering, g l o b a l eustacy, and c a r b o n a t e p o l y m o r p h i s m in Phanerozoic marine oolites.- J. Sed. Petrol. 55, ]71-183. WRIGHT, J.~ SEYMOUR, R.S. & SHAW, H.F. (1984): REE and Nd isotopes in conodont apatite: Variations with g e o l o g i c a l age and d e p o s i t i o n a l e n v i r o n m e n t . - Geol. Soc. Amer. Spec. Pap. 196, 325-340. -- ~ MILLER, J.F. & HOLSER, W.T. (]986): Conodont c h e m o s t r a t i g r a p h y across the C a m b r i a n - O r d o v i c i a n boundary: Western United States and southeast China.- in: AUSTIN, R.L. (ed.) : Conodonts: Investigative Techniques and Applications. Horwood, London (in press). -- ~ SCHRADER, H. & HOLSER, W.T. (]986): Variations in rare earth element d i s t r i b u t i o n s of Recent and fossil apatite and p a l e o r e d o x of ancient oceans.- Geochim. Cosmochim. Acta (in revision). ZACHOS, J.C. & ARTHUR, M.A. (]986): P a l e o c e a n o g r a p h y of the C r e t a c e o u s / Tertiary b o u n d a r y event: Inferences from stable isotopic and other data.- P a l e o c e a n o g r a p h y ~, 5-26.

A contributlon

THE ROLE GENERATION

OF

OCEANOGRAPHIC FACTORS OF GLOBAL BIO-EVENTS

IN

THE

to Project

GLOBAL u~N

WILDE,

Pat & BERRY,

William

B.N.

Bto -

EVENTS

*)

Introduction The oceanic nity

and volume

physically patterns, have

environment

changes

the past

and chemically. water

occurred

gical

over

have

world

mass

provided has

some

habitats, cular,

could

a background

lerating

identify voke

various

It will

seasonal their

be

high

provide

noise

without

producing

to a basic rapid

storms,

taxa that

that have

marine In partiin acce-

review

events

to in-

biological such

like events,

to which

to

is to

the p o t e n t i a l

to effect

as tides,

because

time or e v o l u t i o n a r y

pattern

and

that

can not adapt

of this

term or local

environmental

various

development.

intent

or E1 Nino

nitrate, likely

may be a factor

to the ocean

of g e o l o g i c

evolutionary

oceanographic

perties

of the ocean

various

depths

include

and flow, except

The

as

of

change

organisms

adapt

change.

processes

The physical

These

in terms

events

phenomenon

that short

tropical

that m o d i f y

and e l i m i n a t i n g

modifications

assumed

frequency

it seems

evolutionary

The b i o l o -

in the ocean

phosphate,

oceanic

chemistry

evolution.

realm

nutrients:

environment.

oceanographic global

upwelling,

Physical

changes

element

both

current

physical-chemical

Accordingly, those

influence

periodic

in the o c e a n i c

sufficient

change.

particularly

and would

evolutionary

the change

organisms.

to sali-

system

in temperature,

These

chemical

respect

is a d y n a m i c

time

for b i o l o g i c a l

with

of the chemical

or long

years

over

with

and n o n - c o n s e r v a t i v e

interaction

changes,

episodic

600 million

stable

and g e o g r a p h i c a l l y .

by p h y t o p l a n k t o n i c

oceanographic

relatively

Variations

formation,

with depth

seen by the b u f f e r i n g silica

although

and i n t e r a c t i o n s

rates

latitudes

density-stratified homogenized

are those

to the density between

into

by the wind

or deep water

from

about

4000 m) forms

at high

among water

where water two major

(Salinity), masses.

masses

layers.

to a depth

of about

These

the mass

are forming,

mass

100 meters.

two layers

formation ocean,

the ocean

or mixed

(average

The depth

layer lower

is is layer

about

are s e p a r a t e d

*) Marine Sciences Group, D e p a r t m e n t of Paleontology, fornia, Berkeley, C a l i f o r n i a 94720, U.S.A.

pro-

at

and the oceans.

water

In the present

The upper

1000 m to the b o t t o m

latitudes.

that produce

and the flow of water

the atmosphere

evaporation-precipitation

and mixing

at high

processes

relating

University

by a of Cali-

Lecture Notes in Earth Sciences, VoL 8 Global Bio-Events. Edited by O. Walliser © Springer-Verlag Berlin tteidelberg 1986

76

Density

Figure 1 . Temperature, Salinity, Density Diagram. Modern T-S curves after Monin et al. (1977).

30

j/

~

25

\

. . . .

/

%

~Jl

/

•

~

~o/ i.,./

P

as Sigma-T

/

9-~

-

\ ,P//~}temperate-ttoaical /6"

/;

V:

~/

".. .........

,~/

c~ E

A

t-

~/

...IV

lo/ / I t/I,i/ I /

~

t/

~o/~I

5

f

o/ j

--2

:32

I

r '#' ~'.e

t i

~,-,,~,

,/ ~i , r . ..f

/

.'/

, I

/

~"/

%,. ,7 o ,?,,,ly

/

/

.../.., ..

9' ,//

<\'#i

/

33

34

O

/

35

36

37

38

Salinity%o 8604-003

Figure 2. Global Oceanic Volumes. Data from M o n t g o m e r y (1958).

5 0 '"

i

i

i

f

i

Volumes ~ 1

l

i

1

l

Temperature 2

40

~

3o

~

2o

o 0

10

-2

0

2

4

Temperature

6

8

10

(Celsius)

i

1

I

i

I

33

34

35

36

37

Salinity %o

77

boundary

layer

respectively

in w h i c h

as the t h e r m o c l i n e

by the p h y s i c a l tween v a r i o u s contours

oceanographer

water

of d e n s i t y

the v a r i a t i o n s deep

temperature

masses

and d e n s i t y

and the p y c n o c l i n e .

to study o c e a n i c

in the p y c n o c l i n e

of d i f f e r e n t

tool u s e d

and m i x i n g be-

is found

to the initial

of v o l u m e s

l a t i t u d e water

along

the s u r f a c e

is c o n s t r u c t e d are mixed,

a straight volumes

of water

and

so that

the resul-

line c o n n e c t i n g

of each.

indicating

and the u n i f o r m i t y

plot w i t h

I). Thus on a T-S plot

and s a l i n i t y

the two points

proportional

(Fig.

The d i a g r a m

tant d e n s i t y of the m i x t u r e

of cold h i g h

A basic

structure

are e x a g g e r a t e d w h i l e

temperature

the p r e s e n t d i s t r i b u t i o n

r a p i d l y known

is the T-S or T e m p e r a t u r e - S a l i n i t y

as S i g m a - T o v e r p r i n t e d

layers plot as close c l u s t e r s .

when w a t e r s

change

Fig.

2 shows

the p r e d o m i n a n c e

of o c e a n i c

salinity.

Chemical processes The c h e m i c a l sition

oceanographic

of the d i s s o l v e d

among sea water, can be c l a s s e d salinity); vity);

the a t m o s p h e r e

(Fig.

3) as

(2) n u t r i e n t

ly s t u d i e d

affect

Such p r o c e s s e s

the o c e a n s by rivers,

replacement,

environment

such

processes

composition through

diagenesis;

and s e d i m e n t a t i o n ;

Nutrient

zone,

of sea water o b v i o u s l y

of m a t e r i a l

modification The major

mechanism,

the d i s s o l v e d

is t h r o u g h

the phy-

may be m o d e l l e d by

representing marine (1963)

into

by pre-

of the c h e m i c a l

transfer

between

world

related elements

(modified from R e d f i e l d et al.

primary

and R i c h a r d s

(1963)):

Zn,Se C d , B e , C u Ni,Rn R a > ' ' ' ' n to pmoles

these e l e m e n t s

are b o u n d

in the living o r g a n i s m

in

proportion.

In oxic waters, into

w a t e r column:

or not s u f f i c i e n t -

of d i s s o l v e d m a t e r i a l

of m a r i n e biomass,

and n u t r i e n t

[(CH20)I06(NH3)I6H3PO4] ~Ni

ments b a c k

acti-

to a t m o s p h e r i c c o n t e n t

removal

and the m a r i n e b i o l o g i c a l

use of an ideal m o l e of a p h y t o p l a n k t o n ,

In the p h o t i c

to

interactions within marine

introduction

as pH or redox p o t e n t i a l .

of sea w a t e r

their p r o p e r

The d i s s o l v e d c o n s t i t u e n t s

(4) n o n - c o n s e r v a t i v e

include

b a s e d on the b u l k c o m p o s i t i o n

productivity

interaction

(composition related

(composition related and

volcanoes,

cipitation,

toplankton.

and sea floor.

the n u t r i e n t

influence biological

content

to the c o m p o -

assigned.

Processes that

food webs.

that r e l a t e

and the c h e m i c a l

( c o m p o s i t i o n b u f f e r e d c h i e f l y by b i o l o g i c a l

in sea water);

to be

are those

of the ocean

(I) c o n s e r v a t i v e

(3) n o n - n u t r i e n t gases

and s o l u b i l i t y

would

processes

content

upon death,

sea w a t e r

oxidative decay matter

as the o r g a n i c

particle

sinks

releases through

the elethe

78

2

~

{

~ °s

~

z

~

z

d

0 O,.20

~dSd

-

~

V

~s~

Z

V

7

Z

o~oN

~ ~

F i g u r e 3. Periodic table from Quinby-Hunt & Turekian

of the d i s s o l v e d (1983).

elements

in

o

o

sea-water.

Data

79

M o l e P h y t o p l a n k t o n + ]38 02 --> 106 C O 2 + 132 H 2 0 + H N O 3 + H 3 P O 4 + T r a c e M e t a l s Thus,

dissolved

in the

photic

remain

constant

zone~

In a n o x i c nitrite

nutrients

rapidly

increase

in d e e p w a t e r

waters,

as the

and n u t r i e n t - r e l a t e d

(Fig.

initially,

oxidant

with

metals

to the b a s e

are

of the

at a m i n i m u m

pycnocline,

then

4).

oxygen

ammonia

is r e p l a c e d

being

the

by nitrate

reduced

nitrogen

and end

pro-

duct: M o l e P h y t o p l a n k t o n + 53 N O _ - --~ 106 C O 2 + 16 NH 3 + 53 NH 4 + H 3 P O 4 + T r a c e M e t a l s Trace

metals

would

a m m o n i u m ion w a s + NH 4 + Trace

build

Metals

As the c o n c e n t r a t i o n tions

of

up

available

in s u c h

--~

Metal

of a m m o n i a

the d i s s o l v e d

waters

to p r o d u c e

trace

until

soluble

sufficient

metal

ammonia

as

amine:

Amines

in this

metals,

zone

most

far

of

exceeds

the m e t a l s

the c o n c e n t r a would

be c o m -

plexed. As a n o x i c i t y fate becomes

increases

upon

consumption

However,

dissociated

H2S would

complexes

react

amine column

of d i s s o l v e d

Trace

metals

( N i , Z n , C u , C d , H g , etc.)

The d e c a y

of p h y t o p l a n k t o n

reduction

of n i t r o g e n

to s u l f i d e

with

to the

constant

Black

Sea

by

state,

transfer

50 to

100

ductivity given

of

the r e l e a s e d

sulfides]

thus

metals

depleting

+ S 2- --~ anoxic

to a m m o n i a , of t r a c e

waters

waters

Sulfides

would

then reduction metals

metals

rich

Metal

proceed

of s u l f a t e

as s u l f i d e s .

would

decrease

in s u l f i d e s

by

Thus

con-

or r e m a i n

as s e e n

in the

5).

and c h e m i c a l

from depth

changes

occur.

locations,

stratification

significant

of w a t e r

meters, could

into

dissolved

in a n o x i c

any

the g e n e r a l

various

sul-

interactions

the d e n s i t y

a steady

compounds

(Fig.

many

particulate

sinking

situation,

depth

Physical-chemical With

nitrite,

metals:

the p r e c i p i t a t i o n

oxic

with

to f o r m

with

and m e t a l

modern

and

thermodynamically

the water

trary

of n i t r a t e

favored oxidant: 2_ M o l e P h y t o p l a n k t o n + 53 SO 4 --~ HCO 3 + 53 H2S + 16 NH 3 + H 3 P O 4 + T r a c e M e t a l s

106

the

name

effect into

in s p e c i e s

The

process

of u p w e l l i n g

and f r o m

various

of

the o c e a n

on m a r i n e

the p h o t i c

zone.

composition

of v e r t i c a l and

occurs

depths.

biota

generally

must Here,

in

the u p p e r

and p h y t o p l a n k t o n

advection at v a r i o u s

in

be c a u s e d

of w a t e r rates,

prois at

80

F i g u r e 4a. Oxic C o n d i t i o n s in m o d e r n open ocean: N u t r i e n t s after B a i n b r i d g e (1979) and Q u i n b y - H u n t et al. (1981).

I

I

I

I

Pacific Ocean Near Hawaiian Islands 200

400

600

800

100(

120( 0

10

20

30

50

40

~;:~:i:::::~:i.1 Nitrate Concentration (pmol/kg)

0 ~

1.0 2.0 3.0 4.0 Phosphate Concentration (pmol/kg)

5.0

8604-002

F i g u r e 4b. Oxic C o n d i t i o n s in m o d e r n open ocean: Trace m e t a l s d a t a after B r u l a n d (1980).

0,~-~----]----.i & ~ , 200

I

t

I • ......

o--,--.-,

\~ '\\

400

A

%. \.

Cadmium Copper Nickel

Zinc

\ \!

600

•

\

!l !l ~J

O

I

800

"\ \

"\

x

71 :!

?1

40 &

1000

h'

: to.,, .A A

2000

3000 I

0

~

I

l

100

200

....

I

300

,,

400

t \

i

i

500

600

700

Concentration (ngtkg) 8604-005

81

10 -s Moles Phosphorus 0

2

4

6

Figure 5. Anoxic C o n d i t i o n s in the Black Sea. Phosphorous after Fonselius (1974). Trace Metals after Brewer and Spenser (1974

8

+200 - ~ " ~ " 0 -f~

t

-soo -I

'\

\ a

\

I -1000 ]

t

\

I

L

-I~oo J~

{

~ ;z

1

-2000

'

0

I

L

I

i

2

4

6

8

10

t 0 -8 Moles

Types

of u p w e l l i n g

Three

main

time

scales:

t y p e s of u p w e l l i n g

may be i d e n t i f i e d

functioning

with

various

I. P l a n e t a r y A. d i v e r g e n c e depth

of water

relatively

shallow

10 to 80 m e t e r s / m o n t h B. d i s p l a c e m e n t

Peng

1982,

p.

known but II.

& Reed

renewal

resident

or one mixing

of deep water

presumably

much

of the wind

stress.

Effective Vertical

rise:

1963). of water

time

masses

is about

at source.

1000 years

Slow:

(Broecker

&

cycle.

to the surface less

caused by winds.

(Wilde

than one modern

& Berry mixing

1984).

Rate un-

cycle.

Regional

A. seasonal lar

Present

20)

transport

as a f u n c t i o n

(Wooster

by c o n t i n u a l

millimeters/day.

C. o v e r t u r n

by Ekman

Ekman

to p l a n e t a r y

B. o f f - s h o r e

(high pressure Ekman

advection

near

the equator).

III.

Local

A. o b s t r u c t i o n & Hogg

1980)

B. c l o s e d

moving

by a s e a m o u n t

through

eddy c i r c u l a t i o n

West

(Wooster

by current

of current

and uplift

off

upwelling

Coast). & Reid off

Characteristics

shore

producing

simi-

1963). (Peru-Chile

Taylor

Current

columns

(Owens

continuity.

producing

low p r e s s u r e

(Robinson

1983).

82

C. B e r n o u l i

uplift

D. b r e a k i n g

internal

Duration The

through

constricted

waves

straits

(Stommel

in s h a l l o w

water

(Hall

different

water

into

et

& Pao

al.

1983).

1971).

of u p w e l l i n g

injection

of c h e m i c a l l y

have

affects

tion

of the u p w e l l i n g

for modern

related

coastal

be s i g n i f i c a n t l y

to v o l u m e event.

upwelling.

greater

of w a t e r ,

Fig.

depth

6 indicates

The v o l u m e s

than

those

the

of

the

the

layer

source,

volumes

generated

produced

surface

by

by

and d u r a latitude

overturn

in c o a s t a l

would

would

upwelling.

Changes in density stratification Destabilization

of

into

zone

ges

the p h o t i c

the

in the c h e m i s t r y

tion

of c h e m i s t r y

the o x i d i z e d the s u r f a c e through

of

surface layer

(2) o p e n i n g

of o v e r t u r n

I shows

thinnest water tion

the s t a b i l i t y

glacial

the b a s e

from warm

displacement bility

climates

pycnocline.

from

sources

Fig. of

some

by normal

for

geophysical

the c h e m i s t r y

life

of f o r m e r l y

or w h e n

processes

or b y

for

and

a change

are

the

of

a transi-

initiated

oceans

(3)

demonstra-

for displacement

can b e the

taxa,

niches,

conditions

zone

in

change

taxa.

climates

stabile

of

of w a t e r s

restricted

affected

to the p h o t i c

Overturn

event

chan-

a func-

of e x i s t i n g

for v a r i o u s

the m o s t

be

evolutionary

range

the e n e r g e t i c s

climates.

physical

the

would

deep-water rapid

to the c h e m i s t r y

instituting

the o c e a n

7 gives

of

bring

inducing

Such changes

to n e u t r a l l y

the p y c n o c l i n e

to c o o l e r

by

of

produces

would

for

in r e l a t i o n

Modification

or e x p a n d i n g

food

which

potential

ocean.

or r e s t r i c t i n g

of n e w n i c h e s

Generation

column

water

the p o t e n t i a l

restricting

that

the u p p e r

layers.

has

or

ting

water

the g r e a t e s t

of the u p w e l l e d

(I) d e s t r o y i n g

opening

Table

oceanic

has

by massive

at l o w

sta-

in the m a j o r

source

of w a t e r . As s h o w n by climatic

in Fig. change

graphically. latitudes the c o l d

edge

relatively der b u t

of

less

the

saline

the

(HLWb)

becomes

the

high

high

latitude denser

of

maximum

water

forms

latitude water

where

(SMW)

the

deep

can be caused

water

water

water

At the o n s e t fall

below

salinity

shifts

temperature

Thus,

overlain of

a cold

5 ° C,

maximum,

geo-

at h i g h

is f o r m e d

in m i d - l a t i t u d e s .

the b o t t o m

water.

from

the

the d e n s e s t

temperatures

than water

of o v e r t u r n

the d e n s e s t

climates

5 ° C (HLWa),

salinity salty

occurrence

source

non-glacial

n o t go b e l o w

warm but

where

an o b v i o u s

where

During

does

8,

at this

by colperiod

this

water

displacing

83 F i g u r e 6. Coastal Upwelling Volumes-Eastern Atlantic Ocean - a f t e r W o o s t e r & R e i d (1963). •

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11

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0.929

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9

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5

_ t

~ 200

400

600

800

1000

1200

I

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Rise in Meters Contours in E R G S t g r a m assuming I cm 3 weighs 1 gram

84

UNIT

Z

(thickmess

I08E

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I04N/2~ 2

m)

(Hz)

/N X 60

I04U

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Non-Glacial

CLIMATE P r e - or Postglacial

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2900

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T a b l e I. S t a b i l i t y in m a i n p y c n o c l i n e for v a r i o u s C l i m a t e s - a f t e r W i l d e & B e r r y (184, p. 148). Z = m o d e l t h i c k n e s s of p y c n o c l i n e - after W i l d e & B e r r y (1982); E = s t a t i c s t a b i l i t y ( H e s s e l b e r g & S v e r d r u p 1915); N = buoyancy frequency (Gill 1982, p. 5 1 - 5 2 ) ; b = v e r t i c a l s h e a r (Munk 1966, p. 710). S t a b i l i t y i n c r e a s e s w i t h h i g h e r v a l u e s .

F i g u r e 8. Global Oceanog r a p h i c M o d e l as a f u n c t i o n of c l i m a t e - m o d i f i e d a f t e r W i l d e & B e r r y (1984). D a s h e d lines encompass major water mass sources. EQW STW SMW SSW MW

Equatorial Water Sub Tropical Water Salinity Maximum Water Shelf Sea Water Metiderranean Water (model f o r h i g h s a l i n i t y s h e l f sea) HLW = High Latitude Water

Density as Sigma-T 3O

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= = = = =

Climates: Warm Climate (light pattern) - high latitude (HLWa) s e a t e m peratures greater than 5 ° C and SMW densest and d e e p w a t e r . Pre or P o s t Glacial Climate (light p a t t e r n and i n t e r m e d i a t e pattern) - high latitude (HLWb) s e a t e m p e r a t u r e l e s s t h a n 5°C b u t no s i g n i f i c a n t s e a ice f o r m a t i o n .

2O

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33

HLWc 34 35

36

37

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Salinity %o 8604-004

85

that ice

water will

(HLWc) the

in

an o v e r t u r n .

form

as

in

seen

mates

the

tudes

warms

high

ditions

potential

For

above

the

of

near

of

the

the

tropical

the

deep

tudes.

For

low

pics as

due

the

to

of

less

of

a particular

of

the

dense

at

the

occurs

The

deep

likely

water due

to w a r m e r

oceans

at h i g h

becomes

denser

major

is

of

latithan

prior

forming, by

water

as

can

the the

latitude

be

overturn During

only

slightly

climates,

would

be

of

case

the

the

high

in

tro-

areas

wind

overturn

lati-

the

case,

significant

effects

the

at m i d - l a t i -

to b o t h

In e i t h e r

have

high

the

the

and

volume

masses. the

such

produced

first

due

simple

rate

of

climate. At

global

model

water

Thus,

deep

divergence

be

found

Such

where

areas

or d i v e r g e n c e

ceased

or

other the

could

decimated

water

has

areas

biota be

the

will

where

or

of

locations,

water.

has

dis-

formation

principally

formation

extent

locations

However,

such

overturn

At c o n v e r g e n c e s

overturn.

displacement

The

geographic

the

and

of

rising

downsinking

areas

For

volume

elsewhere.

maximum,

would

usual

density.

a function

mass

of

of g r e a t e r

occur

surface

refuges the

water.

the

the

cold

effect

which the

on

thus

water

repopulate

of

con-

change.

formed

mid-latitude

a special

the

salinity with

would

the

sup-

from

an

already

become where

would

"homes"

during

as be

the

water

be

for

relataxa

overturn.

overturn

effect of

to

cli-

climatic

equator.

was

at

overturn,

of

the

cessation

deep

water

climates,

surface

thermal

and

varies

into

of d e e p

Accordingly,

toward

from

by w a t e r

insignificant.

unaffected

function

the be

depends

density,

mix

tively

of

the

an o c e a n i c

climates

experience

upward

sources,

where

later

is

sea

advection.

overturn

sources

are

Types

would

overturn

masses

that

The

vertical an

volumetrically

by

would

or d o w n s i n k i n g

will

or

caused

warm

oceans,

or d i l u t e d

overturn

denser

return

direction

cold

subtropical

cold

mid-latitude

pressed

of

latitudes

during

for

the

source.

of

the

latitude

convergence

onset

of

water

various

on

upwelling

enhanced

here,

even

again

source

required

boundaries

In g e n e r a l ,

high

and

water

upwellings,

the

the

overturn

the

to

cussed

as

water

eventually,

overturn Upon

occur

geographic

high

latitudes.

eastern

coastal

no

column.

would

depend

by

an o v e r t u r n the

the

from

as

and

continues,

to p r o d u c e

However

mid-latitude

mid-latitude

colder

tudes

trend

water

stability

overturn,

of

the

would

caused

generated

direction

ocean.

overturn

in

zero

overturn

displaces be

of

5 ° C and

change

an o v e r t u r n

would

cold

quantities

modern

for

the

water.

to

sequence

source

the

stability

latitude Due

sufficient

in

increasing

If

on b i o t a the

in

the

chemistry

photic of

the

zone deep

of

such

water

overturns

displaced

to

would the

be

a

surface.

88

Oxic

overturn:

metals ents

causes

upwelling problem toxic

area,

effects.

followed

to the

water

for

1982)

showed

the

fact

by

Experimental

increased

on o t h e r

potent

and

in o t h e r

occur

turn, warm due

higher

effects during

potentially

lack

of

a toxic

available

chelation red-tide

may be some

taxa.

thermal

effect

on o x y g e n - b r e a t h i n g

Anoxic

overturn:

organisms

with

the

effect

potential

(1984)

and W i l d e

waters

based

Benthic

on t h e

organisms

of v a r i o u s

their

shifts

upward

the c h e m i c a l

habitat.

species

ocean.

rate

could

& Caperon

to i n c r e a s e d to u p w e l l e d 1963).

found

phowater

Secondary

with

"red

algae

mortality

pro-

in f i s h

mortalities

level

of n u t r i e n t

of

an o x i c

over-

climate

to a

initially

of o v e r t u r n

available have

is c o l d

by s u r f a c e

of the s o u r c e However,

was

slow

nutrients

catastrophic and well

not b e

could effects

oxygenated,

any s i g n i f i c a n t

would

would

change

during

differ

as the

a chance

of

oxidants

invasion

However,

water

of

in

anoxic of h o w

et al.

anoxic (Fig. anoxic

of the w a t e r

relatively

to c o n v e r t

the r i s e .

Wilde

or d i s p l a c e m e n t ,

During

dwelling

as a f u n c t i o n

zonation

the c o m p o s i t i o n

upwelling

became

equilibria.

dissolved

most

of u p w e l l i n g .

may have

of the u p w e l l e d

a chemical

of d o m i n a n t

be effected

to n e a r - s u r f a c e

if the w a t e r

the c h e m i c a l

proposed

In s i m p l e

composition

(Terry

for

of d e e p

a glacial

there would

organisms

change

have

at the r a t e

This

responses

sequence

would

compositions

lying

equilibrium

(1986)

If the

conditioned

productivity

additional

thought,

viability

effect

from

primary

but

is n o t

they

Such mass

a threshold

have

in the

and o t h e r

mass

1963).

may

a

organisms.

on s u c h

would

cause

As this w a t e r

the d e p t h

well-oxygenated

depth

the r e d o x

with

the

effects,

Inhibitory

increase

the m o d e r n

metals.

been

if the less

that

programs

The major

reduce

type bloom.

on n o n - p h o t o s y n t h e s i z i n g there

occur.

then

on the

have

trace nutri-

waters

lag,

chelators

a transition

would

The

as G o n y a u l a x

suggesting

toxic

noted

in P r o v a s o l i

upwelling

(Provasoli

the b l o o m

occur

to p e r m i t

produce

organisms

of

metals

inhibitory

of m e t a l

such

is

not properly

Conversion

if i n g e s t e d

would

climate~ to the

which

before

which

enough

during

This

trace

studies

initially

Dinoflagellates

neurotoxins

at the p e a k

enrichment

was

photosynthesis

(1971)

was

and

additional

in s u r f a c e

(see d i s c u s s i o n

organisms

conditions.

duce

of

al.

water

addition

productivity

et

Also,

Energy

nutrients of

is a v a i l a b l e .

productivity.

the d e e p

organisms. Thermal

increased

of n u t r i e n t s

increased

deep water

water, upwelling

upwelling

Barber

rise

that

Ocean that

tosynthesis.

tide"

for light

However,

initial

use b y p h o t o s y n t h e t i c

effects

In g e n e r a l ,

conditions

tropics.

inhibitory

immediately

has

well-oxygenated

depth.

favorable

in the

or

due

with

occurs when sufficient

Peru-Chile

was

In p r e s e n t

increase

each

9). waters over-

zone

slow upwelling,

to the

local

during

overturn

redox the

87

Brochert (1965)

Wilde (1986)

Oceanic Concentration

i

OXIC

Rhodes and Morse (1971)

Demaison et aL (1983)

AEROBIC

OXICAEROBIC

02 Zone DYSAEROBIC

<"/-.%

NITRIC

I:~

P

=

/4... e.~ .:

r~

SO2 A"" .c% • =

-~S

H2S Zone

SULFATIC

=

ANOX1CANAEROBIC

ANAEROBIC

CO2 Zone

NITROUS CARBOXYLIC

0'

CARBONIC

CO2--*" CH4

-~, Figure

whole

9.

pycnocline

before the

Oceanic

a new

various

layer.

This

equilibrium ions

assumes

kinetics. waters,

into

or

various

on

Wilde

Wilde

are m i x e d

oxidation

the m i x i n g present

as a f u n c t i o n

model of

So t h e r e

as a f u n c t i o n are p r e s e n t

is f a s t e r

and k i n e t i c s

anoxic

zone

will

being

the f o l l o w i n g

zonation

surface

the r a t e

of

of r e a c t i o n s

or w i t h o u t

predicts

is time

of k i n e t i c s ,

in the

than

in the s o u r c e

zone u n c h a n g e d

(1986)

(1986).

rapidly.

when,

states

of m i x i n g

ions

the p h o t i c

The

layers

layers

the r a t e

Depending

into

states.

surface

that

the

- after

is e s t a b l i s h e d

in v a r i o u s

chemical

the s u r f a c e

Zones

and s u r f a c e

oxidized

to h i g h e r

Redox

in the

with

reach

oxidized influx

overturned

pycnocline. I.

Nitric

to O x i c

II.

Nitrous

III.

Carboxylic

IV.

Sulfatic

nitrate,

high

trace

nitrite,

ammonia,

In g e n e r a l ,

ammonia

the

ammonia,

productivity

green

algae

and

the b l u e

greens

zones

above

the

Sulfatic

due

hurt

metal

(Eppley

et

such groups.

complexes

tration

would

trace

metal

complexes

trace

metal

complexes

to O x i c sulfide,

not

ammonia

to O x i c ammonia,

compounds

metals

to O x i c

be

would

al. The

no

would

to t h e i r

1969). effect

trace

metals

of p h o t o s y n t h e t i c

Simple

be e n h a n c e d preference

organisms

in a n o x i c

by precipitation

such

by u p w e l l i n g for

non-sulfidic

or i n h i b i t i o n

be d i m i n i s h e d

lowered

free

reduced anoxic

caused overturn

as s u l f i d e s .

as the

from

all

nitrogen

waters

would

by the metals as t h e i r

and

concen-

Such enhanced

88

productivity extremely

may c r e a t e vast

toxic for higher

organisms,

areas of

organisms

"red tide" consuming

any anoxic water w o u l d be toxic

catastrophic

Bio-events

effects

and

conditions

such algae.

that

are

For r e s p i r i n g

and anoxic o v e r t u r n w o u l d have

on such groups.

overturns

The c h e m i s t r y of the w a t e r c o l u m n w o u l d be c h a n g e d e i t h e r by u p w e l l i n g or o v e r t u r n from the v a r i o u s redox onto the shelf organisms space.

The i n t r u s i o n of these zones

at high stands of sea level w o u l d e f f e c t not only the

in the water

c o l u m n but also

the b e n t h o s

and their

Both e p i f a u n a and i n f a u n a w o u l d be r e s t r i c t e d

o v e r l y i n g o x y g e n a t e d waters. redox c o n d i t i o n s o v e r t u r n noted.

since With

Permo-Carboniferous

fossilized,

levels

T a x a in h i g h e r

common

It w o u l d

in u p w e l l i n g

have

overturn. respect

longer

that

are

are s e v e r a l

little or no fossil affected

may have b e e n c a u s e d i n d i r e c t l y

The t o x i c i t i e s

"red tide"

w o u l d be

i n f l u e n c e d by c h a n g e s

associated with

conditions

a rapid

w o u l d affect

all higher

if the toxin is r e l e a s e d a short food web,

a f f e c t e d most.

into

that are

Such g r o u p s

also

to lower p r o d u c t i v i t y g e n e r a t e d by rapid oxic over-

if the event

The f o l l o w i n g ability

taxa survive,

may r a d i a t e

to g e n e r a l l y into

characteriStics

so there must

is the r e s u l t of an o v e r t u r n .

living in c o n v e r g e n c e

food webs due

These g r o u p s

to their

likely.

forms such as n e k t o n c o u l d avoid modi-

any e x t i n c t i o n b i o - e v e n t m o s t

o c e a n or n e a r - s h o r e g r o u p s

vity there.

leave

seem that o r g a n i s m s w i t h areas,

less

These o r g a n i s m s

w h i c h may be d i r e c t l y

as

be a r e f u g e for s u r v i v o r s

generally

which

to the b l o o m o r g a n i s m s

w o u l d not be a d a p t e d During

of

and type of p o s s i b l e

levels were not n e c e s s a r i l y

Motile

of sea water.

attracted

status

is d e r i v e d from o r g a n i s m s

The d e m i s e of m o b i l e s p e c i e s

in p r o d u c t i v i t y

the water.

events

trophic

in food supply,

in the c h e m i s t r y

organisms

intervals

anoxic o v e r t u r n s b e c a m e

above p h y t o p l a n k t o n ,

d i r e c t l y by the o v e r t u r n . fied water.

to b o t t o m s w i t h

the p o s t u l a t e d

g e n e r a l l y ones w i t h h a r d parts.

trophic

increase

10 shows

the C a m b r i a n w i t h

glaciation,

record.

by c h a n g e s

Fig.

living

the v e n t i l a t i o n of the oceans by the end of the

The e v i d e n c e for e x t i n c t i o n

turn.

zones.

(downsinking)

lower p r i m a r y p r o d u c t i -

the u p w e l l i n g

areas

Least a f f e c t e d

A. B. C. D. E. F.

A. B. C. D. E.

Eutrophic B e n t h i c life stages Benthic feeders Short food web Oxygen respirers/infauna M i g r a t o r y in water c o l u m n

after

typifies generic groups

to s u r v i v e an overturn.

Most a f f e c t e d

Open

areas

Oligotrogphic Euplanktonic Near shore < 50 m d e p t h Long or c o m p l e x food web Anaerobes

with

an

89

A A AA A = Anoxic overturn Oxic overturn

A

O

AO

AO

C

i i

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600 E U.

I

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I I I t

i I Iii I

I~1 III,

,iiii, i 2 ~,

.....

~il

I I II I I I IIIIIIl Il Il I I I I I I I I Iltll]lI]lllt II I II II[Il 1l ltlll l ~ l l l l t l i l I II

l~l,l,ll Id,

0

II 300

Off shelf

"700~ ee ":~'~ "L÷÷

N

+

o,o

E{

~"

~?÷

,

" ÷~ "~ ~-÷, .÷'F÷

"' : ~,:

.÷÷ i .

III

0 rc

g 300

Sea Level Changes I

......

I

I

Present value Glacial

Land I

I

~ - ~

I

I

I

I

I

.........

Absolute edge of shelf Black Shale interval Potential anoxic w a t e r without sulfide Potential anoxic w a t e r with sulfide

interval

Cooling interval

F i g u r e 10. Possible Relationship among Overturns, Mass Extinctions, Climate, and Shelf Conditions - m o d i f i e d f r o m W i l d e & B e r r y (1984). R o w I: D i s t r i b u t i o n of F a m i l i e s a f t e r R a u p & S e p k o s k i (1982). O v e r t u r n s p a i r e d at o n s e t and r e t r e a t of c o l d i n t e r v a l s . A b s o l u t e t i m e of c r o s s i n g of 5 ° C i s o t e r m at h i g h l a t i t u d e s is n o t k n o w n . R o w II: G l a c i a t i o n (dark p a t t e r n ) and c o l d i n t e r v a l s (light pattern) a f t e r F r a k e s (1979). C l i m a t i c c u r v e a f t e r M e y e r h o f f (1970). R o w III: R e d o x c o n d i t i o n s on the S h e l f . S e a l e v e l c u r v e a f t e r V a i l et al. (1977).

The

causes

replacements, likely

to b e

overturns

and

of and

such

complex

other

complex

events

bio-events

and

modification

varied. of

the

in Major

as m a s s the

extinctions,

geologic

oceanographic

chemistry

of

sea

record

faunal also

events water

are

are

such just

as some

90

of the probable tion,

which

particular

contributory

causes

should be factored biological

for changes

into a complete

in the pace

of evolu-

investigation

of any

event.

Acknowledgements The authors and offering

wish

job in preparing tions.

Partial

physics, Marine

M.S.

Quinby-Hunt

suggestions.

and d e s i g n i n g

support

University

Sciences

SELECTED

to thank

many useful

for r e v i e w i n g

University

by the This

the m a n u s c r i p t

Krup did her usual

the m a n u s c r i p t

was provided

of California.

Group,

M.A.

and e x e c u t i n g

Institute

the

of Geology

is c o n t r i b u t i o n

of California,

excellent illustraand Geo-

MSG-86-008

of the

Berkeley.

REFERENCES

BAINBRIDGE, A.E. (1979): GEOSECS Pacific final h y d r o g r a p h i c data report, 22 August 1973 to I June 1974, R/V Melville: Geosecs O p e r a t i o n s Group Publ. 32, np. BARBER, R.T.; DUGDALE, R.C., MacISAAC, J.J. & SMITH, R.L. (1971): Variations in p h y t o p l a n k t o n g r o w t h a s s o c i a t e d with the source and conditioning of u p w e l l i n g water: I n v e s t i g a c i o n Pesquera 35~ 171-193. BORCHERT, H. (1965): F o r m a t i o n of marine s e d i m e n t a r y iron ores.- in: RILEY, J.P. & SKIRROW, G. (eds.): Chemical Oceanography. Acad. Press: London 2, 159-204. BREWER, P.~. & SPENCER, D.W. (1974): D i s t r i b u t i o n of some trace metals in the Black Sea.- in: DEGENS, E.T. & ROSS, D. (eds.): The Black Sea - Geology, Chemistry, and Biology. Amer. Assoc. P e t r o l e u m Geologists Mem. 20, 137-143. BROECKER, W.S. & PENG, T.-H. (1982): Tracers in the S e a . - E l d g i o Press, 689 p. BRULAND, K.W. (1980): O c e a n o g r a p h i c d i s t r i b u t i o n s of cadmium, zinc, nickel and copper in the north Pacific.- Earth and P l a n e t a r y Sci. Letters 47, 176-198. BRYDEN, H.L. & STOMMEL, H.M. (1984): Limiting p r o c e s s e s that d e t e r m i n e basic features of the c i r c u l a t i o n in the M e d i t e r r a n e a n Sea.- Oceanologica Acta ~, 289-296. DEMAISON, G.J. & MOORE, G.T. (1980): Anoxic e n v i r o n m e n t s and oil source bed g e n e s i s . - Amer. Assoc. Petroleum G e o l o g i s t s Bull. 64, 1179-1209. EPPLEY, R.W.; ROGERS, J.N. & McCARTHY, J.J. (1969): Half s a t u r a t i o n c o n s t a n t s for uptake of nitrate and ammonium by p h y t o p l a n k t o n . - J. P h y c o l o g y 5, 333-340. FONSELIUS, S.[. (1974): Phosphorous in Black Sea.- in: DEGENS, E.T. & ROSS, D. (eds.): The Black Sea - Geology, Chemistry, and Biology. Amer. Assoc. P e t r o l e u m Geologists Mem. 20, 144-150. FRAKES, L.A. (1979): Climates T h r o u g h o u t Geologic Time.- Elsevier, Amsterdam, 310 p. GILL, A.E. (1982): A t m o s p h e r e - O c e a n D y n a m i c s . - Acad. Press, London, 662p. HALL, M.J. & PAO, Y.-H. (1971): Internal Wave b r e a k i n g in a T w o - F l u i d system.- Boeing Sci. Res. Lab. Doc. DI-82-I076, 141 p. HESSELBERG, T. & SVERDRUP, H.V. (1915): Die S t a b i l i t ~ t s - V e r h ~ I t n i s s e des Seewassers bei v e r t i k a l e n V e r s c h i e b u n g e n . - Berg. Mus. Arb. 15, 16 p. MEYERHOFF, A.A. (1970): C o n t i n e n t a l Drift, II. H i g h - l a t i t u d e evaporite deposits and g e o l o g i c history of Arctic and North Atlantic Oceans.J. Geol. 78, 406-444.

91

MONIN, A.S.; KAMENKOVICH, V.M. & KORT, V.G. (1977): V a r i a b i l i t y of the Oceans (translated from R u s s i a n ) . - Wiley, New York, 241 p. MONTGOMERY, R.B. (1958): Water c h a r a c t e r i s t i c s of the Atlantic and World Ocean.- D e e p - S e a Res. 5, ]34-]48. MUNK, W. (]966): Abyssal R e c i p e s . - D e e p - S e a Res. 13, 701-730. OWENS, W.B. & HOGG, N.G. (1980) : Oceanic o b s e r v a t i o n s of s t r a t i f i e d Taylor columns near a bump.- D e e p - S e a Res. 27, 1029-1045. PROVASOLI, I. (1963): O r g a n i c r e g u l a t i o n of p h y t o p l a n k t o n f e r t i l i t y . in: HILL, N.H. (ed.): The Seas. ~, W i l e y - I n t e r s c i . , New York, 165-219. QUINBY-HUNT, M.S.; FANNING, K.~ ZIEMAN~ D. ~ WALSH, T.W. & KNAUER, G.A. (]98]): Nutrient and D i s s o l v e d Oxygen Studies at OTEC sites.- in: Proc. 8th Ocean Energy Conf.: Marine Technol. Soc., Washington, D.C., 537-545. -- & TUREKIAN, K.K. (1983): D i s t r i b u t i o n of the Elements in Sea-Water.EOS 64, 1 3 0 - 1 3 1 . RAUP, D.M. & SEPKOSKI. J.J. (1982): Mass e x t i n c t i o n s in the marine fossil record.- Science 2!5, 1501-1503. REDFIELD, A.C.; KETCHUM, B.H. & RICHARDS, F.A. (1963): The influence of o r g a n i s m s on the c o m p o s i t i o n of s e a - w a t e r . - in: HILL, N.H. (ed.): The Seas. ~, W i l e y - I n t e r s c i . , New York, 26-77. RHODES, D.C. & MORSE, J.W. (1971): E v o l u t i o n a r y and ecologic s i g n i f i c a n c e of o x y g e n - d e f i c i e n t marine b a s i n s . - Lethaia 4, 4]3-428. RICHARDS, F.A. (1965): Anoxic basins and fjords.- in: RILEY, J.P. & SKIRROW, G. (eds.): Chemical O c e a n o g r a p h y . Acad. Press., London ~, 611-645. ROBINSON, A.R. (ed.) (1983) : Eddies in Marine Science.- S p r i n g e r - V e r l . , Berlin, 609 p. STOMMEL, H. ; BRYDEN, H. & MANGLESDORF, P. (1973): Does the M e d i t e r r a n e a n o u t f l o w come from great depth?- Pure and Applied Geophys. 105,874-889. TERRY, K.L. & CAPERON, J. (1982): P h y t o p l a n k t o n a s s i m i l a t i o n of carbon, nitrogen, and p h o s p h o r o u s in response to e n r i c h m e n t s with d e e p - o c e a n w a t e r . - D e e p - S e a Res. 29, 1251-1258. VAIL, P.R.; MITCHUM, R.M., Jr. & THOMPSON, S, III (1977): Seismic stratig r a p h y and global changes of sea level, part 4: Global cycles of r e l a t i v e changes of sea level.- in: STANLEY, D.J. & KELLING; G. (eds.) Seismic S t r a t i g r a p h y - A p p l i c a t i o n s to H y d r o c a r b o n Exploration. Amer. Assoc. P e t r o l e u m Geologists Mem, 26, 83-97. WILDE, P. (1986): Model of Redox Zonation in the Late P r e c a m b r i a n - E a r l y Paleozoic Ocean: s u b m i t t e d to Amer. J. Sci. -- & BERRY, W.B.N. (1982): P r o g r e s s i v e V e n t i l a t i o n of the O c e a n s - P o t e n tial for Return to Anoxic C o n d i t i o n s in the P o s t - P a l e o z o i c . - in: SCHLANGER, S.O. & CITA, M.B. (eds.): Nature and Origin of C r e t a c e o u s C a r b o n - R i c h Facies. New York, Acad. Press, 209-224. -- & BERRY, W.B.N. (1984): D e s t a b i l i z a t i o n of the oceanic Density structure and its s i g n i f i c a n c e to Marine "Extinction" events.- Palaeogeogr., Palaeoclim., Palaeoecol. 48, 143-162. WOOSTER, W.A. & REID, J.L. (1963): Eastern B o u n d a r y C u r r e n t s . - in: HILL, M.N. (ed.): The Seas. ~, W i l e y - I n t e r s c i . , 253-280.

PRECAMBRIAN TO LOWER CAMBRIAN

EVOLUTIONARY

PFLUG,

CHANGES

Hans

A review

D.

& REITZ,

is p r e s e n t e d

Proterozoic, microbial

with

light the

microscope

studies,

the

in c h e r t s , times.

electron

and

U

interaction

carbonates

appearance in t h i n

microscope

(TEM).

iron

They

with

have

preserved

EVENTS

of

in the

organic

under

the

the r o c k

formation back

the b e s t

under

analyzed

On the b a s i s

the

BIO-

Fossil

are c h e m i c a l l y

can be t r a c e d

cyanobacteria

~oProject

GLO BA L

between

the r o c k

sections

microscopes.

sediments

and s t r u c t u r a l l y

of

A contributlon

of l i f e

of m e t a z o a n s .

sections

of m i c r o o r g a n i s m s

and

evidence

interrelationships

in d e m i n e r a l i z e d

and coccoid

lithified

available

to the

spectrophotometer

Filamentous

becoming

first

be d e t e c t e d

and e x a m i n e d

transmission

in m i c r o p r o b e s

*)

reference

the

•?

PROTEROZOIC

of the c u r r e n t l y

and

can

THE

Erhard

special

activity

micrestructures

IN

of s u c h of m i n e r a l s

to

Archean

chance

of

in the s e d i m e n t s .

Microbiota All

known

zation.

organisms

These

utilize

metals

metal

organic

m a y be c a p t u r e d

metallo-thionines

or in e x t r a e e l l u l a r

the c e l l

sheath.

ties metal are

wall

and

of m e t a l s

at t h e i r

complexes.

attracted

Such

Certain

cell

position

and b u r i a l

produced

by s u l f a t e - r e d u c i n g

metal tion

enrichment of

of the d e a d

sedimentary

geological of m i c r o b e s The

record is

these

can

are e v i d e n t l y

with

be d e m o n s t r a t e d time

on well

and b i o s p h e r e

(Fig.

] ). The s t r a t i f o r m

(2400

Bacteria

- ]700

After

may

react

metallic

with

to the

correlation

Such

forma-

between

the e v o l u t i o n a r y

ions de-

HzS

sulfides.

it l e a d s

iron

- 2800

are

the

history

MY)

indicate

apparently

involved

occur

Structures

*) G e o l o g i s c h - P a l i o n t o l o g i s c h e s D-6300 Gie~en, F.R.G.

most

of s t r o m a t o l i t e s

preserved and b o u n d

in the e v o l u t i o n

formations

MY ago.

formation

dependent

steps

2300

charged

because

the

major

tion.

quanti-

insoluble

the p o s i t i v e l y

A worldwide

with

The b a n d e d

of

as

and b i o p o l y m e r s .

and f o r m

and

organias

such

large

aggregates

the m e t a l s

interest

of m i c r o b e s

of the

Proterozoic

when

ligands

ore d e p o s i t s

ore deposits,

coincide

immobilize

such

indicated.

interaction

facies

can

by f o r m i n g

cell,

ore d e p o s i t s .

of

networks

bacteria

is of s p e c i a l

cell

macromolecular

occurs

charged

in t h e i r traps

microbes

surface

adsorption

to n e g a t i v e l y

complexes

in i n t r a c e l l u l a r

of the

occurrences. to p e r i o d s

terrestrial

gold

and u r a n i u m

anoxic

conditions

in the often

resembling

formation

ores

Institut, U n i v e r s i t i t

of the

lower

deposi-

the f a c i e s .

in the s u b s e q u e n t

spherical

Several that

atmosphere

during of

and

time

span

or f i l a m e n t o u s

GieBen,

Lecture Notes in Earth Sciences, Vol. 8 Global Bio-Events. Edited by O. Waltiser © Springer-Verlag Berlin Heidelberg 1986

96

PERIODS

V

ICu-SULFIDESIPbS,ZnSi Ag2S I

B,F

e

I I

l I

I

-3100

-3900 Figure I. Chronological distribution of stratiform ore deposites and crustal activity. Ordinate: time in million years (MY); stages I-V: suggested increase of atmospherical oxygen (partly after Meyer 1985).

Plate

I.

Microfossils

of the Proterozoic

and Cambrian

Figs. 1-12. Microfossils from the Gunflint Banded Iron Formation, Schreiber locality, Ontario. (I-5) Gunflintia minuta Barghoorn (Cyanobacteria); (6-9) Huronispora microreticulata Barghoorn (Cyanobacteria) ; (I0) cf. Bavlinella sp. Shepeleva (Cyanobacteria); (11) Eomicrhystridium sp. Deflandre (Algae); (12) Eomicrhystridium barghoorni Deflandre (Algae). (Bar 10 bm, see Fig. 12) Figs. 13-15. Sphaeromorph acritarchs (Prasinophyta) from the middle Belt Super group (Montana/Idaho). (13) cluster of Leiosphaerida specimens; (14) Nucellosphaeridium sp. Timofeev; (15) Montanella beltensis Pflug. (Bar 10 um, see Fig. 14) Figs. 16-18. Middle Cambrian acanthomorph acritarchs from North-Eastern Bavaria, Germany. (Bar 10 bm, see Fig. 18) Figs. 19-23. C y a n o b a c t e r i a (cf. Nostoc) from cherts of the Spilitic Group, Bohemian Upper Proterozoic. (Bar 10 ~m, see Figs. 22, 23)

97

Q

~:~

~o

@!ii I 0

¸

2

98

cyanobacteria There

are

bacteria,

are m o s t

also

many

such

as the

The main of

time

the e a r l y

650

MY ago

are f o u n d

was

3).

elaborated

dominated

1200

by

morphology

can be

- 650

thus

MY ago

as far

time,

occurs.

It is s u g g e s t e d

accompanied in the c e l l Oldest old

cies")

of

appearance

the p r e c e e d i n g They

from

indicate

that

of

point

significance

that

with

the Copper

Proterozoic

is c o n c e r n e d .

algae

a decrease

was in i r o n

recently (PI.

reported

I, Figs.

from

the ca.

11-]2).

About

2000-MY-

a dozen

types

("form

The s p e c i m e n s

occur

in c l e a r

two c o m m o n that

in

chert

eukaryotic

Gunflint than

organisms,

Plate

2.

Fossils

I, 5.

Pteridinium

from

Figs.

2,

Fig.

4.

Ernionorma

Figs.

6,

7. E r n i o b a r i s

Fig.

8.

Bar = 10 mm

Consequently

subsequent the

These

Kuibis-quartzite,

concretor sp.

to the

Prasinophyta,

spectra.

simplex

91abra

Huronispora

of c y a n o b a c t e r i a n was

sp.

spe-

and

affinity.

in a d i v e r s i f i e d

their

origin

must go

MY ago.

G~rich

schneiderh~hni

Kuibisia

with

phytoplankton

times.

2000

Proterozoic,

Figs.

together

representatives

phytoplankton

3. R a n g e a

which

phyteplankton

of e u k a r y o t i c

coupled

III,

onwards.

the y o u n g e r

of e u k a r y o t i c

the e v o l u t i o n

in s t r o m a t o l i t e s period

morphological

earlier

in the

prokaryotes

hitherto.

of e u k a r y o t i c

elements

oxidized

different

In the y o u n g e r group

requiring

to f o u r

stage

to t i m e s

as a z u r i n

prokaryotes

identified

suggest

evolutionary

such

to

enzymes

time,

biological

of O n t a r i o

a stromatolitic sp.,

copper

fully

as a m a r k e r

in c o p p e r ,

most

that

1100

and o t h e r

formation.

have been

Formation

findings

back

that

with

At the s a m e

their

from

oxygenated

as t h e i r

coincides

]983).

belonging

Gunflintia The

(Ochiai

IV.

1984).

phytoplankton,

aerobic

1-10).

precipitating

(Cloud

proteins,

redbeds

diversification

an i n c r e a s e

have been

portions

first

acritarches

Gunflint

specimens

the

by

iron

interpreted

At this

copper

make

are k n o w n

increasingly

formation

in c e r t a i n

1, Figs.

of iron

At p r e s e n t ,

in p e r i o d

the b a n d e d

became

a few

In fact,

widespread

A few red beds

atmosphere deposits

Only

(P1.

and o t h e r s

eukaryotic

3).

also found

atmosphere.

type

cooper

1

BIF

occurrence

of the

IV in Figs.

are

became

a more

on the

stratiform

in e u k a r y o t e s .

sediments

in P r e c a m b r i a n

Metallogenium

for

(period

an o x y g e n - r i c h

(Fig.

reports

diversification

and p l a s t o c y a n i n s

with

common

GOrich Pflug

1930

1972

1972 Hahn

& Pflug

unicellular

Nama

1930

1986

Gunflint, become

system,

another

the d o m i n a n t organisms

Namibia

are

99

100

-}500

\\ I x I \

1000

500

! !

400

/

/ 300 e._

200

\i

# t

'

.'

1000

2000 1500

,% #=

loo

Z

50

,

,

700

"

|

,

I

500

i

300

~

200

|

100

0

MILLIONS OF YEARS F i g u r e 2. D i v e r s i t y of e u k a r y o t i c p h y t e p l a n k t o n s p e c i e s in the last 2000 MY p l o t t e d on l o g a r i t h m i c s c a l e s . A b s c i s s a : t i m e in MY, o r d i n a t e : n u m b e r of k n o w n s p e c i e s , a c r i t a r c h s and p r a s i n o p h y t e s , --- m o d e r n phytoplankton.

commonly

placed

been

reported

Ming

1985).

of

1980,

part

Pflug

evolution

of

periods

about

It s e e m s

eukaryotic

Paleozoic

oldest

1400

took

from they

to

the

representatives

Formation

known where

from

plankton

of l o w d i v e r s i t y of the

also

13-14),

sequence

1985).

The

Daihongyu

are

I, Figs.

the

& Reitz

algae.

1680-MY-old

microbiota

(Pl.

of the

at the e n d

the g r e e n

the

Similar

Idaho/Montana

and m i d d l e

Two

among

from

of C h i n a

the

Beltian

series

in the

lower-

occur

}}00-MY

in age

available

a periodical

(Horodyski

evidence course

that

(Fig.

are i n d i c a t e d

in the r e c o r d ,

one

the o t h e r

at the c l o s u r e

of the

one

have (Lei-

the 2).

located Protero-

zoic.

Metazoa

The

fossils

belong the

from

to the

preserved

apparently

Kuibis

oldest

age b r a c k e t

often

the

610

quartzite

metazoans

known.

- 650 m i l l i o n

in a d e t a i l e d

the r e s u l t

(Nama s y s t e m ) The age of the

years

(Early

three-dimensional

of s y n s e d i m e n t a r y

in S o u t h stratum

Vendium). condition

processes

The

West falls

Africa into

fossils

which

are

is

of s i l i f i c a t i o n .

Most

101

STROMATOLITES I O2

I

MARINE PLANTS

MARINE METAZOA TRACES

PLANKTON IBENTHOS

I

BODIES

'-0

kl

V

-/uu

MY

N -1500

III -2300

-3100

-3900 F i g u r e 3. C h r o n o l o g i c a l d i s t r i b u t i o n of life. For e x p l a n a t i o n Fig. I ("Stromatolites" after Walter & Heys 1985).

of the finds groups

belong

to the p r o b l e m a t i c

Pteridiniida,

petalonamian

body

Rangeida

is a t h i n - w a l l e d

The general

symmetry

of e x t e r i o r

ribs

any known plankton in this

and interior

of the s h a l l o w

postulated

tube

this

zone

time,

that was

plankton

several

calcareous

cones which

of a telescope.

tral

annelides

this

phylum

but

(Hahn

known

Cambrian

mode.

from

through

produced

of Argentina.

uncomparable as sessile

It is worthy

much

more

blooms

Germs

are possibly

and B r a s i l i a

than

comprises

1972,

organism

structure

primitive

has

with

the in

also been Vendian. a calof

is composed

of

comparable

related

to

to note

increase

Riphean/early

by a w o r m - l i k e

The family

well

A massive

are set one into the other

1985a).

Namibia

are

is C l o u d i n a

The p r e s e r v e d

cavity.

the pattern

reasonably

in the late

The

lived

phytoplankton

The Cloudinidae

evidently & Pflug

sea.

the sub-

I-7).

a voluminous

they

coincides

of the Kuibis

probably

feeding

that

phosphogenesis.

particularly

representative

sessile,

appearance

Proterozoic

of the photic for

Another

Lower

their

with

2, Figs.

The P e t a l o n a m a e

on the bottom

the b i o m a s s

Cloudina,

septa.

feeders

that

(P1.

this can be seen from

We b e l i e v e

of late

Petalonamae

sack c o m p r i s i n g

of metazoans.

context

segments

is bilateral,

phylum

commencement

careous

group

and E r n i e t t i d a

see

to

to ances-

any known member the Vendian

and A c u t i c l o u d i n a

from

of

genera

the

102

Additional Kuibis

finds

recently

(Hahn

representatives similarity rather

ximately

conical

shape

but

ship

2, Fig.

members cysts from

probably

also

8).

a medusa

the K u i b i s

is p r o b a b l y

of

served lobes Some

The g e n e r a

is

in d e t a i l e d

condition

ved

megafossils

data

is of

in a t h r e e

specimen bella

werneri

resemble

the

living

A gap

separates

The d i s c o n t i n u i t y Schindewolf

lineages

(1954)

remnants

Grosso

a relation-

in w h i c h Medusae

as

nematoare u n k n o w n

stratum

which

age

Sokolov

of o r a l

Hahn

face

tentacles

position

with

& Pflug

1980).

Esfor-

is p r e radial the

Brazil), according

to r a d i o -

fossils

are p r e s e r -

by

600

MY).

their

same

Stephanocyphus

Precambrian to a m a j o r & Fedonkin

The

in t h e i r

and C a m b r i a n break

Pre-

All

named

Corum-

structures

morphology.

record

shows

certainty

faunal

periderm.

of o r g a n i s m ,

1985b).

fossil with

The

chitinous

kind

& Pflug

traced

which

Young

lobes.

(Southwestern

(ca.

to the

c a n be the

subumbrella

horizon

of the p r e s e n t

corresponds and

appro-

interpreted

the Y o u n g - P r e c a m b r i a n

Its

Scyphomedusae(Hahn

]982,

Scyphozoan

from

in a l t e r n a t i n g

condition

belong al.

affinity

of

in c e r t a i n

mean

are

this

convergence

in an o v e r l y i n g

600 MY).

in a s h a l y

Vendian

comparison

Precambrian

Cambrian.

found

(Hahn et

A critical these

late

resembles but

"polyp"

Ceriantharia

yet d e v e l o p e d .

appear

showing

in M a t o occur

a solitary

not n e c e s s a r i l y

fossil

arranged

dimensional

hitherto

they

(ca.

resemble

At C o r u m b ~ - L a d ~ r i o

a morphological

and K u i b i s i a

not

closely

(Pennatularia),

to r e c e n t

Ausia

f r o m the

age.

Iran

tentacles

of

"Coelenteroid"

a medusoid

of C e n t r a l

fenestrata

glabra,

must

were

but

Vendian

of the f e a t u r e s

metric

of

quartzite, late

and b o d y

cambrian

similarity

generation

Persimedusites di f o r m a t i o n

Kuibisia

branch

Ausia

Veretillum

is c o m p a r a b l e

this

of an e a r l y

and

1985b). genus

have been described

the r e s u l t

a relationship.

features, (PI.

& Pflug

of the r e c e n t

is m o s t

than

of e a r l y m e t a z o a n s

into world

that the of

f e w of lower

Metazoa.

i n the s e n s e

of

(1984).

REFERENCES

CLOUD, P. (1984): The C r y p t o z o i c b i o s p h e r e : Its d i v e r s i t y and g e o l o g i c a l s i g n i f i c a n c e . - Proc. 2 7 t h I n t e r n a t . Geol. C o n g r . M o s c o w ~, 1 7 3 - 1 9 8 . HAHN, G.; HAHN, R.; L E O N A R D O S , O.H.; PFLUG, H.D. & W A L D E , D . H . G . (1982): K ~ r p e r l i c h e r h a l t e n e S c y p h o z o e n - R e s t e aus d e m J u n g p r ~ k a m b r i u m B r a s i l i e n s . - G e o l o g i c a et P a l a e o n t o l o g i c a 16, 1-18. -- & PFLUG, H.D. (1980): Ein n e u e r M e d u s e n - F u n d aus d e m J u n g - P r i k a m b r i u m v o n Z e n t r a l - I r a n . - S e n c k e n b e r g i a n a l e t h a e a 60, 4 4 9 - 4 6 1 . " -- & -- (1985a): Die C l o u d i n i d a e n. ram., K a l k - R ~ h r e n aus d e m V e n d i u m und Unter-Kambrium.S e n c k e n b e r g i a n a l e t h a e a 65, 4 1 3 - 4 3 1 . -- & -- (1985b): P o l y p e n a r t i g e n O r g a n i s m e n aus d e m J u n g - P r i k a m b r i u m ( N a m a - G r u p p e ) von N a m i b i a . - G e o l o g i c a et P a l a e o n t o l o g i c a 19, 1-13. M O R O D Y S K I , R.J. (1980): M i d d l e P r o t e r o z o i c s h a l e - f a c i e s m i c r o b i o t a f r o m the l o w e r B e l t M o u n t a i n s , M o n t a n a . - J. P a l e o n t . 54, 6 4 9 - 6 6 3 .

103

LEI-MING, Y. (1985): Microfossils from Precambrian rocks of the Daihongyu F o r m a t i o n of Jixian, North China.- Acta Palaeont. Sinica 24, 112116. MEYER, Ch. (1985): Ore metals through g e o l o g i c history.- Science 227, 1421-1428. OCHIAI, E. (1983): Inorganic c h e m i s t r y of earliest s e d i m e n t s . - in: PONNAMPERUMA, C. (ed.): C o s m o c h e m i s t r y and the origin of life. 235276, Dordrecht, D. Reidel, P.C. PFLUG, H.D. & REITZ, E. (1985): Earliest P h y t o p l a n k t o n of E u k a r y o t i c A f f i n i t y . - Naturwiss. 72, 656-657. SCHINDEWOLF, O.H. (1954): U~er die m S g l i c h e n Ursachen der groBen erdges c h i c h t l i c h e n F a u n e n s c h n i t t e . - N. Jb. Geol. Paliont., Mh. 457-465. SOKOLOV, B.S. & FEDONKIN, M.A. (1984): Organic world of the Vendian p e r i o d . - Proc. 27th Internat. Geol. Cong. ~, 159-170, VNU Sci. Press. WALTER, M.R. & HEYS, G.R. (1985): Links between the rise of the Metazoa and the decline of s t r o m a t o l i t e s . - P r e c a m b r i a n Research 29, 149-174.

GLOBAL BIOLOGICAL PRECAMBRIAN

EVENTS

IN

THE

A contribution 1o PmiecI

LATE

GLOBAL BlO EVENTS

uN~

SOKOLOV,

The

Boris

S.

*) & FEDONKIN,

Precambrian history

whole

history

of life.

Michael

~ J

A. **)

of life on Earth c o n s t i t u t e s However,

classical

just 6/7 of the

paleontology

developed

200 years only on the basis of s t u d i e s of the Phanerozoic, latest stage of the e v o l u t i o n of b i o s p h e r e .

But it was

w h i c h saw indeed g l o b a l

cardinal

events

the f o r m a t i o n

systems,

the e v o l u t i o n

of living

getic m e c h a n i s m s . building

composition erable

the

took place

The most appearance

stage of g e o l o g i c a l

that once having

primarily

We know about

i.e.

tillite

history,

Of great

To a c o n s i d -

when the most

new P h a n e r o z o i c

organization

could appear many

times

important eon. the

(Metazoa).

but

could

is

it seems

p r o d u c e by

(in g e o l o g i c a l

sense)

Unlike m e t a z o a n

such

organiza-

in various k i n g d o m s

conditions.

the a p p e a r a n c e of M e t a z o a

horizon,

appearance,

in the Vendian.

on e n v i r o n m e n t a l

This

re-

in the

interest

of tissue o r g a n i z a t i o n

in the h i s t o r y of b i o s p h e r e

event e v i d e n t l y

took place b e f o r e

the

as in the e a r l y half of the Vendian,

above g l a c i a l deposits,

known

as the L a p l a n d i a n

we can see the r e m a i n s

or Varan-

of a higly d i f f e r e n t i a t e d

of animals.

Some w o r k e r s

relate

with an abrupt d e c r e a s e in the

changes

is c h a r a c t e r i z e d by a b r u p t l y

period of time

of the V e n d i a n period,

directly

world

drastic

and l i t h o s p h e r e .

of their

the m e t a z o a n

which we o b s e r v e

o n l y from i n d i r e c t data.

garian

animals

for a short

multicellularity

beginning

in the p r e - P h a n e r o z o i c

a qualitatively

an exact m o m e n t

appeared,

several radiations

depending

and its ener-

vivid event of the Late P r e c a m b r i a n was e v i d e n t l y

of m u l t i c e l l u l a r

a diversity,

the Precambrian, c o n n e c t e d with

of the cell

in the P r e c a m b r i a n .

and p r e p a r e d

We c a n n o t d e t e r m i n e

tion,

of life

over

the

phenomena.

of the c u r r e n t c e n t u r y

knowledge

Late P r e c a m b r i a n

events

hydrosphere

all that are b i o g e n i c

second half

increasing

resulted

s y s t e m s of our planet,

of its a t m o s p h e r e ,

extent,

The

These p r o c e s s e s

of e c o l o g i c a l

and p r o c e s s e s

i.e.

Late Riphean,

important global matolites

in the q u a n t i t y

Vendian

event

as b e n t h i c

the a p p e a r a n c e

and wide e x p a n s i o n of M e t a z o a and d i v e r s i t y

and e s p e c i a l l y

is t'~king place d u r i n g

communities,

being

of s t r o m a t o l i t e s

in the Early this time

the most

typical

*)

D e p a r t m e n t of Geology, Geophysics, G e o c h e m i s t r y of the USSR A c a d e m y of Sciences, 117901 Moscow,

**)

Paleontological Institute Moscow, U.S.S.R.

Paleozoic. interval.

An

Stro-

of the s h a l l o w

and Mining U.S.S.R.

of the USSR A c a d e m y of Sciences,

Sciences 117321

Lecture Notes in Earth Sciences, Vol. 8 Global Bin-Events. Edited by O. Walliser © Springer-Verlag Berlin Heidelberg 1986

106

water

basins

reduced

for

The sion

of E a r t h

simplest

turbations

the

and

which

in the

Vendian

of o t h e r

in o r d e r

to u n d e r s t a n d

Many workers, important

Riphean. and

who

event,

during

being

is not d e v o i d

formed,

and

Vendian,

the d i v e r s i t y Then,

microfossils lites. T h e i r building

with

groups

It c a n n o t ecosystems largest

one

which

resulted

seas.

This

turbidity

the

from

zone,

productivity

is not

by o t h e r

The

of v a s t

of

stromatoreef

level

led

temperature, of s t o r m s , have

led

with

climatic

in the c h a r a c to r e g r e s s i o n ,

seas

and s h e l f

a high

water

and r e d u c i n g to an a b r u p ~

are w i d e s p r e a d ,

the d i s a p p e a r a n c e

of

to be the

of g l a c i e r s

alterations

could

stromatolites

in-

including

considerable

sea

frequency

the c o n t i n e n t s

slightly

is k n o w n

epiplatform

as f a l l i n g

of the

in the e v o l u t i o n

interaction

of

Precambrian

half

of the d i v e r s i t y

which

sharp

is

and o t h e r s ) .

moment

lowering

and e v e n

of the

the c a s e w i t h

entailed

stimulated

other

fossils

organisms,

glaciation,

Upper

to e a c h

these

second

algae

of a l g a l

the

of m i c r o f o s s i l s

and m i c r o f o s s i l s

lithosphere

where

in the

an o u t b r e a k

a turning

increasing

of

one m o r e

with

parallel

correlation

But

calcareous

as w e l l

of the

of m a t e r i a l

the q u a n t i t y

this

of Earth.

which

as c o m p a r e d

decreased

sees

but

that

and

circumstances

of

to an

Precambrian

diversity

in the d i s a p p e a r a n c e

transport

Riphean

refer

Late

initial

as

Late

of t a x o n o m i c

occupied

Glacial-eustatic

narrowing decreasing

wall,

history

changes,

because

We s h o u l d in the

the s y s t e m a t i c s

Varangarian

hydrosphere

and g e o g r a p h i c

in the

fall

Vendian,

Cambrian

be e x c l u d e d ,

ter of h a b i t a t .

reduction

noticed

of s t r o m a t o l i t e s

(Archaeocyatha,

in the

atmosphere,

the

Proterozoic,

the s t r a t i g r a p h i c

became

the

for

by b i o -

stromatolites

Upper

diversity

because

organic

became

and e x p a n -

destroyed

is n e c e s s a r y out

events

to see w h e t h e r

Early

habitats

suddenly

appearance

mats,

complicated.

of c o n t r a d i c t i o n s .

creases.

the

the

in the

their

Precambrian,

still

which forced

abiotic

is an a b r u p t

and

units

and

became

it.

It is d i f f i c u l t

Late

then

to be m o r e

acritarchs

stromatolites

is the

of the s t r o m a t o l i t e

studied

that

and

event

cyano-bacterial

and

biological

years,

of time.

of s u b s t r a t e ,

seems

analysis

microfossils

of this

formation,

The c a u s e

3 billion

period

cropped

stability

of b i o h e r m

communities.

almost

short

explanation

of M e t a z o a ,

phases

during

a relatively

of some

furtheron groups

to

of

phytoplankton. The groups

Varangarian of

survived Vendian

invertebrates "a g r e a t

period,

expansion

giaciation

cold"

marked

of t h e s e

probably

of w h i c h gave

we k n o w

rise

by b e c o m i n g

animals,

known

s a w mass nothing.

to r a d i a t i o n warm now

extinction But

the g r o u p s

in the l o w e r

and g i g a n t i c

as the

of s o m e

half

which of

transgression.

Ediacarian

fauna,

the Rapid

became

an

107

obstacle The

on

time.

was

Metazoa,

occur

Russian The

Metazoa

soft

about This

the

of

a factor

the

of

of

of

the

in

of

the

period

and

(the

of

diversity

middle

many

meduzoids

Vendian

short

taxonomic

evolution

extinction

forms

in

of

water

the

as

this and the

groups

small

Kotlin

of

trace

Horizon

half

can

the

of

the

of

compare

half

of

the

event,

if

it

seem

of

be

we

small

can

Vendian

This

be

with

abrupt algae

can

took

be

indicative

all in

the

the

of

of

in

Metazoa

the

deposits

buried

of

the

vivid

eutrophication

results

favour

could

consequences.

is e s p e c i a l l y

of

negative

soft

considered

place,

sizes

the

phenomenon

of

or m i n i a -

increase

in

fossils

forms

dimensions

indeed

groups

speculate

shelly

gigantic

of d e c r e a s i n g an

to h a v e

invertebrates.

evolutionary-morphological

can

fossil

of m e g a s c o p i c

Vendian

and

of

Vendian

groups

decreasing

vendotaenid

factor

in

Cambrian

Vendian.

and

disappearance

extinction

hypothesis

Vendian of

the

The

second

basins

the

if we

Lower

But

Upper

as

surviving

the

the

selective

of

type.

of

Platform

with

probable,

flora

marine

such

second

the

ecological

half

Russian

worked

the g r o w t h

phytoplankton

the

Ediacarian

macrophyte

on

This

that

stromatolites.

a relatively

slow the

of

along

more

survival.

of

of

in

confirmation

Stage

the

of

half

dimensions

Metazoa

Kotlin

shallow

took

Vendian

phenomena,

Stage of

of

second of

the

But

seems

important

in

biomass

time.

problematic

Metazoa

animals

to

since

Metazoa

second

decreasing

indirect

to b e g i n

extinction

bodied

An

seems

an e p o c h

relationship.

turization

lead

by

the

Tommotian

bodied

of

a relatively

mentioned

hypothesis

the

domination

Platform).

and

the

previous

of

of

rare

in

above

a causal

as

followed

the

of

half

A period

as o n l y

fossils the

Metazoa

first

down.

Vendian

of

towards

diversification

In t h e

slowed

of

way

domination Rapid

of

the

for

forms

the

of

fauna.

having

small

dimensions. The

discovery

which

has

about

a gigantic

which

ate

not

considered

as

zoa

been

only one

remains

from of

crease

in

benthos, sils,

the in

which

increasingly At

the

actinomycetes made

outbreak

The

end

of

recently

the

the

the Late

dimensions

become

of

the

by

also

(the

an

animals,

more

of

the

at

Kotlin

tissues.

abrupt

vendotaenid

allows

fall

the This of

event

soft

algae,

assumption age, can

bodied

also Meta-

taphocoenoses.

Rovno

infauna.

thallom

consumers

animal

for

Vendian

of of

large,

colonized end

but

causes

Vendian

particular

the

Fnilovskaya),

of b a c t e r i a l

algal, of

on

(M.B.

Stage),

again

primarily

This

among

is c l e a r l y

complicated

and

sees

an

abrupt

in-

representatives

seen

deeper.

from The

trace

sea

of fos-

floor

is

infauna.

Vendian

some

groups

of

Metazoa

begin

to b u i l d

a

be

108

mineral

skeleton,

beginning basis

of the

sponges

and

forms

age was

was

since

quences

the for

important of

groups

Late the

future

Upper

Vendian

half fauna

sizes

history;

6) the

in the s i z e s

ginning

of the of

graphical

Riphean]

situation.

half

which

of the

the

skeleton

All t h e s e

and

sea

events

took

Metazoa

that

during of

of m a n y

groups

floor

interval and

of m i n e r a l 7) r a p i d

expansion

place

the

of

deof increase

skeleton radiation

at the b e -

against

geochemical

the

Metazoa

and p o s s i b l e this

Vendian; their

of the g e o l o g i c a l ,

appearance

phytoplankton

and e x p a n s i o n

appearance

at the end of the

conse-

The m o s t I) the

of c e r t a i n

Vendian

of t h e

remains.

of s t r o m a t o l i t e s ,

during

of the

tapho-

Metazoa

considerable

the e x t i n c t i o n

survived

of

the b e g i n n i n g

Prevendian

radiation

5)

bodied

its b i o s p h e r e .

of the

colonization

mineral

had

3) the e x t i n c t i o n

furtheron

changes

in g e n e r a l

the f o l l o w i n g :

of the d i v e r s i t y

Vendian;

Metazoa

and the

expansion

on s k e l e t a l

which

and

were

4) the r a p i d

Cambrian.

abrupt

saw e v e n t s

in the s e c o n d

with

mainly

tendencies

of s k e l e t a l

Vendian

Late

as to a c h a n g e

age.

towards

vertical

the V e n d i a n .

of some g r o u p s

of the

The

fossils

tendency

With

of

interval

increasing

of

as w e l l

the

half

of o r g a n i s m s ,

invertebrates

substrate.

by

led to a s h a r p

of the p l a n e t

of i n f a u n a ,

in s o m e g r o u p s

is m a r k e d

concentrate

this

glaciation;

creasing

ground

of

ichnofossils

of s o f t

Precambrian

and p r o b a b l y

in the f i r s t

of

second

of

as

Tommotian

the d e v e l o p m e n t

of the f o s s i l i z a t i o n

2) the r e d u c t i o n

in the

Laplandian

the

the

events

Metazoa;

started

by b e n t h o s

paleontologists

Thus

the

which

a period

then

the

forms

of t r a c e

at the

at the

became

primitive

of the b o d y

development

evident

Skeleton

such

in the g e o m e t r y

that

ones)

above

saw events

inhabited

over

by

of s e d e n t a r y

situation:

Cambrian

The c h a n g e

becomes

Stage).

including

and d e e p e n i n g ,

and g r o w t h

Cambrian

zone

groups

in the h i s t o r i c a l

(primarily

innovation

(the T o m m o t i a n

some

followed

complication

complication

the

for

Archaeocyatha.

If we o b s e r v e towards

nomic

Cambrian

of r a d i a t i o n

at the R o v n o

Early

and this b i o l o g i c a l

the back-

and g e o -

PRECAMBRIAN-CAMBRIAN AND EVENTS

BRASIER,

Martin

Geological boundary

BOUNDARY

of these

has

Conoidal

recently

elements

Small

Until

microfossils

while

recently,

(1983)

regions,

Avalon-Baltic

Research

successive

though,

and Comley

sclerites

tured

Rhombocorniculum,

spp.

in the

1986).

molluscs

tes t r i s u l c a t u s

cata

the most

evolutionary

resist-

series

also provide

premier

of

important

research

summarised

(1984).

Richly

are becoming

into suc-

by Soko!ov

&

fossiliferous better

known

in

below.

Bornholm-Scania

In this

plus

and T o r e l l e l l a

has

region,

CPMs 1983,

the earliest lentiformis

of Geology,

Hull

and Lapworthella, (Brasier

species

a similar

]986).

Of

sculp-

in England

sequence

whose

and

of Rhombo-

succession. yet to be c o n f i r m e d

however,

Anabarella

Landing

elucidated

hyolithelminth

to M a s s a c h u s e t t s

Fomitchella

has

Limestone

is the e l a b o r a t e l y

successive

Newfoundland

England,

and England

valuable

also confirms

Aldanella,

than

in Siberia

three

Hyolithes

Rhombocorniculum

Eccentrotheca

the most

with

fossiliferous

of Shropshire,

stratigraphy

& Fletcher

*) D e p a r t m e n t

Limestone

work

in s o u t h e a s t e r n

lent or older

but highly

is similar

Rhombocorniculum

(Bengtson

upon

recently

as will be outlined

undoubtedly

Unpublished

comm.

fossils',

remains.

information.

successions

Sunnaginia,

of a p p e a r a n c e

pers.

shelly

skeletal

they are r e l a t i v e l y

indicates

fallen

of c o n o d o n t - l i k e

fossils,

contains

trilobites.

successions

these

strata

'small

problematica

and

by the lack of an

seem to be among

since

& Sokolov

boundary

order

corniculum

has

and Rozanov

species

Torellella,

work

Platform,

on the c o n d e n s e d

of Nuneaton

Siberia.

recent

Calibration

in strata without

invertebrate

(CPM's)

and tubular

emphasis

is hampered

the earliest

and p a l a e o e c o l o g i c a l

Precambrian-Cambrian other

upon

of d i m i n u t i v e

on the Siberian

Zhuravleva

however, especially

focussed

molluscs

biostratigraphic

cessions

scale,

BI 0 -

EVENTS

the P r e c a m b r i a n - C a m b r i a n

in Earth history.

for b i o s t r a t i g r a p h y

ant and widespread, species.

across

point

events,

a diversity

phosphatic

promising

events

turning

agreed b i o s t r a t i g r a p h i c Attention

A contr/bufion toProject

GLOBAL

UNESI~O

and e v o l u t i o n a r y

representing

T

*)

mark a major

interpretation

BIOTAS

from

(Dr.

the e a r l i e s t

assemblage

and Heraultipegma,

sp.

1984).

assemblage in England.

University,

tube

and L a p w o r t h e l l a This

assemblage

bearing

Hull

HU6

rich

7RX,

Anabari-

ludvigseni may be equiva-

Sunnaginia

The third

comparable

E. Landing,

neoimbri-

assemblage

U.K.

Lecture Notes in Earth Sciences, X,bl. 8 Global Bio-Events. Edited by O, Walliser © Springer-Verlag Berlin Heidelberg 1986

110

contains

monoplacophorans

and b i v a l v e (e.g. gp.

Fordilla

Brasier

1984)

This a s s e m b l a g e

Newfoundland latum

Randomia

sp.,

CPMs

1986).

A fifth a s s e m b l a g e exsolutum

n. sp.,

has CPMs

trilobites

of the

and b r a c h i o p o d

about this

level

form.

(e.g.

The first

l a p w o r t h e l l a cornu gp., e f f u s u m gp.

Botsfordia caelata

Rushton

compares

appearance

of g a s t r o p o d

insolutum,

R. c a n c e l l a t u m

trilobites

(e.g.

(Brasier,

with R. c a n c e l l a t u m

assemblage.

Aldanella

Siberian

attleborensis these

lentiformis,

occurs

Fallotaspis;

unpublished)

in the

R.

Zone

The g a s t r o p o d

two main areas.

Rhombocorniculum

in s t r a t a b e a r i n g

Rozanov

whereas

Plat-

provides

and L a p w o r t h e l l a cornu p r o v i d e h i g h e r

R. i n s o l u t u m n o t a b l y

in S i b e r i a

Callavia

also b e c o m e c o m m o n from

correlation between

assemblages with Torellella

Bornholm-Scania

R. c a n c e l -

1966).

Successive

of c o r r e l a t i o n .

to

R. c a n c e l l a t u m ,

with late

well with that found on the

the lowest d a t u m for p o s s i b l e

radiolata

in E n g l a n d and N e w f o u n d l a n d .

Serrodiscus bellimarginatus

succession

Mobergella

through England

assemblage contains

Zone t r i l o b i t e s

and M i c r o d i c t y o n

Pelagiella

This

from Bornholm,

The f o u r t h

emarginatus

and T o r e l l e l l a b i c o n v e x a

of the b u t t o n - l i k e

occurs w i d e l y

(Brasier

and P r o s i n u i t e s

R. i n s o l u t u m

plus r e m a i n s

and/or early C a l l a v i a

aurorae

& Sokolov

trilobites

points

the first

1984) first

and appear

A n g l o - A v a l o n region.

Tethyan successions Biostratigraphic sections (e.g.

correlation

is s t r e n g t h e n e d

Xing et al.

Bhatt et al. of n o r t h e r n quences

1984)

1985) Iran

of s o u t h e r n

and also from the

(Dr. B. Hamdi,

in prep.).

the

in w e s t e r n

Elburz

sequence

Mongolia

and e v e n t - s t r a t i g r a p h y

Mambetov

1981)

linking

(e.g.

from

The H i m a l a y a n

s t r a t a of K a z a k h s t a n

the s t r a t i g r a p h y

(e.g.

and Elburz

se-

very c o m p a r a b l e w i t h of S i c h u a n p r o v i n c e

also c o m p a r e s with the et al.

of India

the Elburz m o u n t a i n s

and M a i d i p i n g

Voronin

boundary

out of China

Himalayas

1982).

allow further c o r r e l a t i o n with

and R h o m b o c o r n i c u l u m - b e a r i n g

with

('Tethyan')

and l i t h o l o g i e s

those of M e i s h u c u n of Yunnan p r o v i n c e

sequence

Lesser

plus new data on sections

show a s u c c e s s i o n of faunas

of China while

Asiatic

by the w e a l t h of new data c o m i n g

Salany-Gol Bio-,

litho-,

the T o r e l l e l l a

(e.g.

Missarzhevsky

&

of S i b e r i a and A v a l o n - B a l t i c

the Tethyan belt. Clastic

groups

plus

C h i n a and

strata bearing sapropelic

Iran,

ated with

material

algae of the Chuaria occur

the latter o c c u r r e n c e

tubes of H y o l i t h e l l u s the T e t h y a n

large

(data of Dr.

zone in Spain,

the first

traces

in the s u c c e s s i o n s

of

a s s o c i a t e d with e a r l y p h o s p h a t i c

B. Hamdi).

a similar

arthropod

low down

and V e n d o t a e n i a

algal

At the w e s t e r n

limit of

a s s e m b l a g e was found

of M o n o m o r p h i c h n u s

associ-

and d i m i n u t i v e ,

111

complex This

deposit-feeding

suggests

and Cambrian, Across dolomites algae.

here

much

dolomites

I skeletal

and u s u a l l y

a major

trimerate

tubes gp.,

(e.g.

Assemblages

of this

(Nowlan

Zone

Zone

gp.) CPMs

on the Yangtze chella

late

this

The base the

Yangtze

carbon

Linan

trilobite while

(e.g.

Bigotina

(Sdzuy

of diverse korobkovi

age,

gastropod

gp.,

The simple

in China.

The change

or above

calcareous

by the appearance the basal

so it seems

Condensation

cycle

that

of this

Latousun-

assemblage

Kazakhstan,

lithological

facies

of the

Tommotian

attleborensis

Karatau,

from

phosphorite-chert

to shallow

with

and

Aldanella

sclerites.

Torellella

suggest

Zone

of

a

II may span

zone may have

1985)

disconformity clays

then by black

and

to France

Allonia

pentactina

but

cancellatum

suggested

low-mid

appears of this

1979)

with

first

(e.g.

Dore

occurs

the This

through & Reid

below

the

archaeocyathids,

trilobites

of Callavia

level

beyond

(Rozanov

at the

bearing

pentactina.

Atdabanian

by the a p p e a r a n c e

in Siberia

discontinuity

& Hewitt

Spain

across

anomalous

and may be traced

tripodophora

and in Spain with

Correlation

and

with

shales

Pakistan

province

ferromanganese-enriched

ferruginous

by i r i d i u m - e n r i c h e d

in India

is p r o b l e m a t i c a l

(Brasier

conulariids Lopochites).

into n o r t h w e s t e r n

and A r c h i a s t e r e l l a

Here,

1969).

Protoherztina

(e.g.

tripodophora

Rhombocorniculum

England

In Maly

part of this

Hsu et al.

faunal

Archiasterella

aspect

correlation

followed

Allonia

1978).

deposited

I include

places.

also occurs

the r e d l i c h i i d

marked

Zone III is a w i d e s p r e a d

isotopes

assemblage

within

and the A l d a n e l l a

Atdabanian.

Platform,

chancelloriids

1965,

suggests

in many of

Zone

Conotheca),

and range

zone reverts

or low A t d a b a n i a n

the T o m m o t i a n - l o w e s t obscured

Asia

wiwaxiid-type

The datum

in the upper

Tommotian

strata

of

sclerites

Latouchella

either

to M a s s a c h u s s e t t s .

biconvexa

(e.g.

are also common

of the

Zone of Siberia

Newfoundland cf.

numerous

part

gp.

the top of such

protoconodont

in the addition

Zhijinites

Platform.

korobkovi

naginicus

elements

up into

and c a l c a r e o u s

towards

phosphatic-clastic

hyoliths

(e.g.

may occur

and the upper

appear

Typical

across

differ

plus of

passes

stromatolites

trisulcatus,

occur

]979).

Vendian

1985).

shells

I to II faunas

units

through

et al.

between

0.

often

event.

(Brasier

epoch'

assemblage

and w i w a x i i d - t y p e

type

II assemblages

attleborensis

Zone

Vendian

circothecid

et al.

monoplacophoran-type

cambroclavid

late

of Anabarites

Hexangulaconularia)

Canada

called

assemblages range

simple

'Cambrian-type' 'transitional

this m a c r o a l g a l

phosphogenic

anabarica

of

of a

informally

of Asia,

with d i s t i n c t i v e

Zone

during

traces

the e x i s t e n c e

the Tethyan

of Bigotina & Sokolov

with

1984).

top of R. insolutum

and c o m p a r a b l e

strata

Zone

area early A beds

in s o u t h e a s t e r n

in

112

-

-

T

-

[

~

~

---T

'

=

~

,~..~

Protohertzina anabarica group

---'---'"~"~"

--

-

- - - - - r -

j

"

-

-

xJ

o

~

o

j

I

""" I Hertzina elongata group

! 1

-

-n

~

]

I o.ozo,oo,o ,o.o, ,o

/ I I I I j Toretlella curva I ~" I Tore,ell~lentlformis

Sunnaginia

Rhombocorniculum cancellatum ~ OOooOC~D~O~ Rhombocorniculum exsolutum n.sp. ~ r~no~DoOOODmono,

imbricata

unnaginia

neoimbricata

t $unnaginia parva

unnaginia angulata

ccentrotheca ~randis

|

/I

~'~a tir'"°"ori, °o '"'"I"' I |

Lapworthella bella

/

_[ |

I

I

|

/

oooooo

I

I Lapworthella cornu g r g u p Q o

F i g u r e I. E x a m p l e s of s e r i e s of c o n o i d a l Precambrian-Cambrian b o u n d a r y beds.

Newfoundland Kazakhstan in C h i n a anomaly

may (e.g.

(e.g.

compare

Luo

reported

et al.

by

of c o n o i d a l (e.g.

I and

that

2 show

phosphatic

Rhombocorniculum)

alo

boundary.

below

Thus (1985) This

suggested

microfossils

the R. c a n c e l l a t u m

& Mambetov

1984).

Hsu et

insolutum-cancellatum Figures

with

Missarzhevsky

phosphatic

the

1981)

and on

iridium

from

China

and

correlation

composite

vertical

useful

and r a n g e s

of other

for

Zone

top of

from

in

Zone

II

carbon-isotope

may be c l o s e

broad

microfossils

r~[]C:

to the

is still ranges

'backbone'

potentially

tenuous.

of s e r i e s

biostratigraphy

useful

marker

113 TOMMOTIAN

[

ADTABANIAN --F-----

I~l

I E o

~o

=,

= ~ ~

5" '" ~

==Io

o B

BOTOMIAN ] TOYONIAN

-

"---q---------

~=

-

o .~

I

£o

_

I

J _= _ _ _ k ~

Fomitchella acinaciformis

-

~,

~ o = oB =

__

I

I[

I

F~la infundibuUformis 1 I Camenella garbowskae i I J I Mobergellal~ i

Hadirnopanella knappologica

"-~'~pa nellaapicata ~T~lina

Platy[olenites antiquissimus

I

trisulcatus group

muttiforata

8alterella maccullochi l

J

l

~

I 1

I Chancelloria AIIonia Archtasterena

F i g u r e 2. microfossils

Suggested and s m a l l

ranges shelly

of s o m e o t h e r fossils.

potentially

important

microfossils

and s m a l l

shelly

fossils

Aldanella).

The

provisional

and

correlation

of

The

term

stricto

the

Tommotian begins

interval

Avalon-Baltic

and

is h e r e i n

above

the

names

used

are

e.g.

informal

Siberian

in a l o o s e

Protohertzina

ones

sequences, sense;

anabarica

marker

ranges

relating

to the

for d i s c u s s i o n Tommotian

are

only.

sensu

interval.

Bioevents The

explosive

shows

distinct

evolution phases

of

which

invertebrates,

including

may be provisionally

those

with

determined

skeletons

as f o l l o w s .

114

1. The d i s a p p e a r a n c e have been Avalon

of the large,

contemporaneous

region

(Brasier

with

volcanic

appearance

spherical

and r i b b o n - l i k e

Chuaria

to have

ic tubes complex

coexisted

3. Extensive assemblage gonitic

feeders

dolomitic

tubes

(Anabarites,

also p e r m i n e r a l i s e d some

change

4. A major

transgressive

carbon

5. Coiled,

sculptured

cursors,

time Mg:

waters

conditions

of organic

suggesting

this

invasion

and p a l a e o c l i m a t i c

the early creased rather

also

Tommotian

carbonate

suggesting

a period

synchroneity

insolutum

chronously

plus

including

I ? ara-

tubes

hyolithellus) cyanobacteria

initiated

time.

1984)

suggesting

in Zone

I of the

pulse

1984).

and oceanic

Other

The positive

1985)

areas

show

~ 13C spike

may relate

in

to d e p o s i t i o n

an u n k n o w n

origin

in clastics

without during

and may indicate

(Magaritz

and Aldanella known

of varying

a

hyoliths

pre-

a transgres-

and c a r b o n a t e s

allathecid

including

organic

korobkovi

and widely,

The negative

locally

'bloom'

et al.

1985)

of

and paterinid

~ 13C trend r e c o r d e d

that

may relate

of i n v e r t e b r a t e

through to in-

skeletons,

productivity. culminate

of s t i l l s t a n d

cycle

metaliferous

cancellatum

skeletons

phosphat-

in Fe-Mn or l i m o n i t i c

and emergence,

first

is needed.

took place

though

evidence

Calcite

crusts, for

biomineraliza-

in the R h o m b o c o r n i c u l u m

interval.

where

niculum

here.

trilobites

plan,

of the L a t o u c h e l l a

of Siberia

7. A new d e p o s i t i o n a l belt,

this

at the top of this cycle

tion of o l e n e l l i d

are

Calcareous

& Shergold

settings,

deposition,

carbonates

large

(Monomorphichnus

& Voronova

was

Archaeocyathans,

than to d e c l i n i n g

6. Returning

these

were invaded by a Zone

phosphatic

suddenly

They occur

appeared

with

0.

skeletal

et al.

from

ecological

brachiopods

Anglo-

episode.

molluscs

(Zone

forms.

in the

of Sabellidites,

to a t r a n s g r e s s i v e

at about

sive pulse

opportunistic

This may

Ca ratio.

(Cook

appeared

II).

Zone

(Riding

(Magaritz

during

groups

events

In places,

tubes

Protohertzina).

in response

of Siberia

attleborensis

varied

of p h o s p h o g e n e s i s

perhaps

fauna.

clasties,

of arthropods

hyoliths),

at this

of s t r a t i f i e d

the Yudomian

worm

habitats

but

(e.g.

in pCO z and/or episode

Tethyan belt, overturn

and traces

carbonate

spines

Vendotaenia.

organic

in t r a n s i t i o n a l

of low d i v e r s i t y

and phosphatic

and igneous

of s a p r o p e l - b e a r i n g

with

of H y o l i t h e l l u s deposit

Charnia

1985).

2. The w i d e s p r e a d

known

soft-bodies

continued

times

are

black

initiated shales

in the

to appear

and in such

mineralisation

was

a way

during

were deposited,

Avalon-Baltic

widely

during

that ecological

implicated.

Zone

region.

this

III in the Tethyan and in RhombocorCalcitic

interval,

controls

trilobite

though dia-

of chitin

bio-

115

8. Pelagic China

eodiscoid

and in late

trilobites

Atdabanian

Avalon-Baltic

region.

reached

widest

early

their

to early

Archaeocyathan extent

during

significant Botomian

reefs

this

V times

in Siberia

in

and the

remains

maximum

also

of the

biomineralisation?

sequence

of events,

with

its strong

of the m e g a s c o p i c

Charnia

of d i m i n u t i v e

skeletal

suggests

in the Plate

late

trophic

anoxia

for

Phases

have

press).For (Piper

Holser have

provided

Worm

tubes

resemble

(e.g.

could

a major

which 1982).

inhibit occur

1985)

at this

allows

stage,

calcite

model

inhibit

the f o r m a t i o n

et al.

1983),

especially

place

trilo-

palaeocenaographic

removal

hydrothermal

settings.

organic

in u p w e l l i n g

notably should

of seawater (c.f.

Precambrian

Kastner times

and Mg ++ c o n c e n t r a t i o n s

remains

(Riding Local

1985,

have

occurrences

and early molluscs). removal

led to a

Kazmierczak

be a t h e o r e t i c a l

(Lucas

gen-

skeletons

of S a b e l l i d i t e s

could u l t i m a t e l y

its local

phosphorites

remains

or a g g u l u t i n a t e d

I fauna. would

1985)

of d o l o m i t e

in the early

event'

of

also

invertebrates.

Banks

in latest

sulphate

could

Such a removal

formation

deposit

vents

first

sul-

34S event

feeding

(e.g.

in

anoxic,

of light

(Yudomski

for s u s p e n s i o n

tubes

of apatite,

of s e d i m e n t a r y

massive

Mg/Ca ratios

Anabarites

fossils--

the

assembly

and their

Zone

enhanced

of brine-rich,

skeletons

skeletons

to be

of a s u p e r c o n t i n e n t a l

vents

A 'magnesian in the

shelly

sequential

took

as found

by the time of the

(e.g.

-- small

to Recent

high

in

all need

Brasier,

the local

Although

of this

seem to have

where

is a w i d e s p r e a d

reduction

tic and high-Mg

cipitation

food source

tubular

of f l u c t u a t i o n s

nutrient

event.

around

biomineralization,

and P l a t y s o l e n i t e s . significant

bacteria

place

level.

(e.g.

bacteria

in h y d r o t h e r m a l

by b a c t e r i a

Tucker

basins,

took

low sea

fronts'

the

appearance

in sea level,

on b i o m i n e r a l i s a t i o n

rifting

Carboniferous

the earliest

1983)

erally

oceanic

Sulphide

from

increases

led to the f o r m a t i o n

by anaerobic

be sought

sulphate ef al.

Vendian

changes

'biomineral

fossils

spanning

Jevent'

of r e l a t i v e l y

transgressions

imprint

have

and small

1977).

perhaps

their

could

of

and if may be that

example,

isotopes

major

in this unique

of trace

1979)

left

1982)

marginal

role

evolution

(Brasier

events

and toxicity,

signals

and the phased

that some

a period

and the m i g r a t i o n

their

chemical fauna

and oufgassing,

of the Cambrian

sequential bites

during

volcanicity

supply

examined

fossils,

Precambrian,

changes,

upwelling,

al.

times

and e c h i n o d e r m

transgressive

disappearance

phur

in Zone

Cambrian.

Sequential This

became

et

of a r a g o n i -

expectation Since

can lead

Mg "++ ions

to the Pre-

& Prevot

1984,

Kastner

or t r a n s g r e s s i v e

water

bodies

116

spilling ensuing

over major

into

lagoonal

p h o s p h a t e event

phosphatic

skeletons

phosphorus

also i n h i b i t s

allows

the f o r m a t i o n

carbonates,

such

Evidence

settings. in Zones

of P r o t o h e r t z i n a , the f o r m a t i o n

of low M g - c a l c i t e

for s e q u e n t i a l

deposition

and c a l c i t e

s h o u l d be c a r e f u l l y

examined.

a s e q u e n c e of b i o m i n e r a l -- a p a t i t e

of c a l c i u m tion,

across

II,

of calcite, skeletons

for the

a s s o c i a t e d w i t h the

Hyolithellus

and ethers. its r e m o v a l

(Simkiss

of s u l p h a t e - b l a c k

1964)

e.g.

precipitation

organic This

transgression,

with

have b r o u g h t

-- a r a g o n i t e

is almost

in a b r i n e

w h i c h c o u l d have d e v e l o p e d d i a c h r o n o u s l y

Since in turn and

dolomite, boundary about

-- high Mg

the p r e d i c t e d order

of d e c r e a s i n g

supersatura-

t h r o u g h the c o u r s e

'biomineralisation

a series of s h a l l o w c o a s t a l

shale,

the P r e c a m b r i a n - C a m b r i a n

Such a p a t t e r n could

events:

-- low Mg calcite.

carbonate

the C a m b r i a n across

I and

account

as those of t r i l o b i t e s .

phosphate-aragonite

calcite

This may p a r t l y

fronts'

of

passing

habitats.

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1t7

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