2. BLACK SEA STRATIGRAPHY

David A. Ross, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

ABSTRACT

This paper presents some details of the stratigraphic nomenclatureof Black Sea sediments and short summaries of the relevantpaleonotological studies performed on sediments collected duringLeg 42B. Based on these studies, a consistent and generallyacceptable stratigraphy for the drilled Black Sea sediment cannot beestablished at this time.

INTRODUCTION

One of the more complex problems emerging fromthe Black Sea drilling has been the establishment of auniform and consistent stratigraphy for thesedimentary units. There are several reasons for thecomplexity, first of which is the general shortage ofdefinitive paleontological age markers. This is due,among other things, to the relatively short period ofgeological time the cores cover, to the rapidly changingenvironmental conditions that often leave a moredistinctive mark than evolution on the faunal and floralcomposition, to the frequent lack of preservation of thefauna and flora, to the lack of taxonomic knowledge ofmany of the forms, and to reworking and incorporationof older forms into the sediments. Some of these pointsare discussed further in later sections.

The second major reason for the complexity inestablishing a uniform stratigraphy is the general lackof agreement on correlation and time zonation of thesedimentary units. Some authors have used theEuropean Alpine classification; others have used Sovietclassifications based on the Black Sea, Caspian, orCaucasus regions and still others have devised newclassifications of their own. The latter, in a large part,has resulted from major differences of opinion amongscientists who tried to relate their observed sedimentaryunits to a geologic interpretation of the facies and thentie this interpretation to a stratigraphic scheme. Thisdifference of opinion particularly applies to those whoemphasized Sites 379 and 381, as compared to thosewho worked principally on Site 380. Some scientistsunfortunately renumbered or reorganized the originalsedimentary designation (i.e., units) of the samples theystudied.

As one of the Chief Scientists, I waited for thepaleontologists to give me the gospel for the Black Sea.It never came in the definitive form I anticipated, for allor some of the above-mentioned reasons. I had plannedto compare the conflicting views and make a scientific,or if that was not possible, a pontifical decision as to

3Contribution 3811, Woods Hole Oceanographic Institution.

the correct stratigraphy to use. This plan, which seemedse easy while on the secure decks of Glomar Challenger,turned out to be nearly impossible upon return to thereal world. In this manuscript, I have included tablesdepicting some classification schemes, and haveattempted to indicate what seem to be goodcorrelations as well as those areas where complicationbetween sites exists. In the summary article at the endof this volume I have attempted to synthesize thegeneral geological history of the Black Sea during theperiod covered by the drilling results of Leg 42B. Thecareful reader is forwarned: "Caveat emptor."

GENERAL STRATIGRAPHIC SCHEMES FORBLACK SEA SEDIMENTS

Several stratigraphic schemes have been devised forthe Black Sea region, and these can be generallycorrelated with European and U.S. terminology. Tables1A and IB are derived from various compilations, andalthough they might not represent the latest and mostdefinitive word on the stratigraphy of the area, theyshould be useful for most purposes. Table 1A isgenerally more consistent with Europeannomenclature, whereas Table IB from Koreneva andKartashova (this volume) is more typical of Sovietterminology.

Prior to the cruise of Glomar Challenger the surficialBlack Sea sediments had been sampled (by cores) andstudied by numerous investigators. Within the deeperparts of the basin, three main stratigraphic units havebeen recognized, dated, and classified (Degens andRoss, 1974, and articles therein). The stratigraphicposition of these units (Unit 1, at the top, a 30-cm thickCoccolith ooze; Unit 2, a 30-cm-thick sapropel; Unit 3,at the base, a terrigenous mud not completelypenetrated) seems fairly clear (see Table 2). These threeunits are correlative with sediments from Site 379, 380,and 381 (Table 3).

Prior to discussing the stratigraphy of oldersediments, a brief summary of the paleontological workis appropriate. It should be emphasized that thepaleontological studies were generally more useful inindicating environmental conditions than in indicating

17

D. A. ROSS

TABLE 1APleistocene Correlation of

European, North American, and Black Sea Areasa

CentralNorthern Europe Alpine Europe North America Black Sea

Post Glacial

Weichselian(glacial)

Eemian(interglacial)

Saalian(Glacial)

Holsteinian(Interglacial)

Elsterian(glacial)

Cromerian(Interglacial)

Menapian(Glacial)

Waalian

Eburion

Tiglian

Pretiglian

Wiirm

Riss/Würm Wisconsin

Riss

Mindel/Riss Sangamonian

Mindel Illinoian

Gunz/Minriel Yarmouthian

Günz

Kansan

New Black SeaOld Black Sea(See Table 2)

New Euxinian(Novo-Euxinian)

Karangat

Post Uzunlarb

Uzunlarb

Old Euxinianb

Holocene

Post Chaudab,c

Danube/Günz(Interglacial)

Biber/Danube(Interglacial)

Aftonian

Nebraskan

GurianAkcagyl

Adapted from van Eysinga, 1975; and other works.

Jouse and Mukhina, this volume, correlate Uzunlar to the Riss, Drevne-Euxinian to theMindel/Riss, and Chauda to the Mindel. Schroeder correlates the Cromerian to the oldEuxinian and the Menapian to the Post Chauda.

Some disagreement here, because some authors prefer the use of Chauda with Cromerian.

the age of the sediment. The major paleontologicalfindings relevant to the Black Sea biostratigraphy aredescribed below.

OstracodesA wide variety of forms were noted, many of which

have been found in stratigraphic sections fromsurrounding basins (Olteanu, this volume), but noPleistocene stratigraphic division was possible. Benson(this volume), looking at a small number of samples,noted that the ostracodes were modern relicts of lateMiocene and Pliocene faunas, whose species underwentlittle change during the Pleistocene. He thought theostracodes could eventually be of some stratigraphicutility when their morphology is better understood.

CoccolithsMost of the coccoliths found by Percival (this

volume) were reworked. The indigenous species couldbe divided into three different types:

(1) An Emiliania huxleyi flora found only in newsurface cores from Site 379 and of late Quaternary age.

(2) A Gephyrocapsa caribbeanica flora present in a100-meter-thick section at top of Sites 379 and 380 andof Quaternary age.

(3) A Braarudosphaera bigelowi flora found in thinhorizons at all three sites, ranging in age from Jurassicto Recent.

None of these were of any significant stratigraphicuse, except that types 1 and 3 indicate brackish marineconditions, whereas 2 is more indicative of normalmarine environments. Bukry, in 1974, examined thepiston cores collected by the 1969 Atlantis II expedition

to the Black Sea, and with the exception of theuppermost sedimentary unit (Unit I), also found mainlyreworked forms.

ForaminifersOnly about one-third of the over 300 samples

examined contained foraminifers; most of them werebenthic (Gheorghian, this volume). The same authorconcludes that the bulk of the foraminifers migratedinto the area from the Mediterranean and adapted tothe reduced salinity in the Black Sea. The generalabsence of planktonic forms is surprising. Gheorghianconcluded that all three sites penetrated Quaternary,Pliocene, and upper Miocene sediments (actually heprobably meant only Sites 380 and 381, since no otherworkers have found Pliocene or Miocene material from Site379).

Spores and PollenSpores and pollen were probably the most

extensively studied paleontological group (Traverse,this volume; Koreneva and Kartashova, this volume).Essentially all the samples studied contained abundantspores and pollen. Traverse also noted a bizarredinoflagellate that flourished when the water freshened.He developed a Steppe-Forest Index for all three sitesusing a ratio of appropriate species of spores andpollen, that serve as a climatic indicator. A high ratioindicates more cool/dry conditions (or Steppeconditions). The modern-day samples have a low ratioof 10%, indicative of warm/wet or Forest conditions.Another ratio called the Marine-Influence Index,compares the amounts of dinoflagellates and acritarchsto dinoflagellates, acritarchs and total pollen; lowvalues suggest non-marine conditions.

Traverse (this volume) used Site 380 as a standard forcomparison to Sites 379 and 381. Three cool or Steppeperiods termed "Alpha," "Beta," and "Gamma" weredetected at Site 380. These indicate times when theBlack Sea drainage area was dominated by plantsadapted to conditions cooler and drier than today.Four warm periods were detected: "Celia," "Betty,""Anna," and "Pre-Alpha." These seven names werechosen to clearly avoid any confusion with pre-existingPleistocene stratigraphy. At this time there is nodefinitive correlation of these periods to a specificglacial or interglacial period. However, some suggestedcorrelations presented later are based onplaeontological evidence (Tables 5 and 7) or onestimates of sedimentation rates and other criteria(Table 8). Traversed data from the three sites aresummarized in Table 4. Note that the section for Site381 is relatively incomplete compared to Site 380.

The palynological studies of Koreneva andKartashova (this volume) are also of considerableimportance (they studied only Sites 379 and 380). Theysuggest that the lower part of Hole 380A (Cores 33 to80) is of Pliocene age, but they admit that the boundaryis hard to determine. Traverse suggested that theboundary might occur below Core 60 in Hole 38OA,where Artemisia is absent (this form is more typical ofthe colder drier Pleistocene climate). Cores 12-32 ofHole 380A were found by Koreneva and Kartashova to

18

BLACK SEA STRATIGRAPHY

TABLE IBPleistocene Correlation of the Black Sea Chronostratigraphic Units With That of Europe

(from Koroneva and Kastaskova, this volume)

i>>

Sub-

sect

ion

Hol

o-ce

neU

pper

Plei

stoc

ene

Qua

tern

ary

(ant

hrop

ogen

)

Low

er P

leis

toce

ne M

iddl

e Pl

eist

ocen

eE

oplis

toce

nT

hous

ands

of year

s

7-8

23

45

65

90-100

230

300

700

Pliocene

AlpinianStratigraphic

Scale

Würm

Riss-Würm

Riss

Mindel-Riss

Mindel

Günz-Mindel

Günz

Danou- Giinz-Danau

Pliocene

MediterraneanSea

Flandrian

' Grimaldian

(Regression)

Neotirrhenian

Regression

Regression (?)

Paleotyrrhenian

Regression

Sicilian

Emilian

Calabrian

Astian

Subdivision of the Pleistocene in USSR

European Partof the USSR

Holocene

Ostashkian

Mologo-Schexnian

Kalinian

Miculian

Moskovian

Odintsovian

Dneprian

Likhvinian

Okan

BelavezhskianStages

Pliocene

Black Sea

BlackSea

LateEarly

Novo-Euxinian

Surdzh (?)

Post-Karangat

Karangat

Regression

Uzunlar

Late Drevne-Euxinian

Regression

Paleouzumlar

Early Drevne Euxin

Regression

Chauda

Gurian

Kujalnik

be of Gurian age (see Table 5), whereas Cores 7-11(380A) are Chauda in age. If the correlation is correct,it suggests that the "Alpha" glacial period correlateswith the Tiglian or Pretiglian, an age somewhat olderthan others have suggested. They note that Cores 13-15,Hole 379A, and Cores 9-11, Hole 380, are part of thePostuzunlarian layers (Saalian). This implies that the"Gamma" glacial period is correlative to the Riss.Likewise, the "Beta" may correlate with the Mindel orElsterian.

Diatoms

Diatoms were studied in considerable detail bySchrader (this volume) and Jousé and Mukhina (this

volume). These plants are of considerable use becauseof their responsiveness to environmental changes.

For Site 379 both studies note the absence of diatomsbelow Core 29. On one hand, Jousé and Mukhinarecord that the marine species from this site wereeuryhaline forms living in waters of lower salinity,whereas the fresh-water species were halophile formsthat could tolerate some degree of salinity. They dividethe diatoms on this site into four zones:

1) 7, CC to 8, CC—fresh-water assemblage withsome brackish water and sporadic marineforms—relatively cold-water species.

2) 9-2 to 10, CC—marine, moderately warm-waterassemblage with no fresh water forms.

19

D. A. ROSS

TABLE 2Suggested Relationships Between Black Sea Deep-Water Sediment Stratigraphy and Local Black Sea Stratigraphic Sections

Based Primarily Upon In-Shore Molluscan Faunas

Arkhan-Gel'skiy and

Strakhov(1932,1938)

Recent

Beach

Deposits

Old

Black Sea

Beds

New

Euxinian

Sediments

(1961)

New Black Sea

Transgression

(0 - 1300yrB.P.)

Kalamitian

(1300-

3500 yr B.P.)

Bugazian

(3500 -

6000 yr B.P.)

New Euxinian

(6000

9000 yr B.P.)

Markov, Lazukov,and Nikolayv (1965)

New

Black Sea

Beds

Old

Bla

ck S

ea B

eds Upper

Lower

Black Sea -Euxinian Transition

New Euxinian

(Novoeuxinian)

L. A. Nevesskaya(1965)

New

Eux

inia

n St

age

Bla

ck S

ea S

tate

(H

oriz

on)

Recent Beds(Djemenitian)

or

New Black SeaTransgression

Kalamitian

Subhorizon

VityazevkianSubhorizon

BugazianSubhorizon

New

Euxinian

Karkinitian

Sub stage

N. D. Federov(1956,1963)

Eux

inia

n -

Khv

alyn

ian

Hor

izon

B

lack

Sea

Hor

izon

Recent andNymphaean Bedsor Transgression

( 0 - 1500 yr B.P.)

Phanagorian Bedsor RegressionContinental

(1500 - 3200)

New Black Seaor Late EuxineTransgression

(3200 -5200)

Old Black SeaBeds (Beginningof Transgressioncirca 6000 + yr)

New

Euxinian

Beds

(Novoeuxine)

Post-Karangatian

Regressive Series

(Continental)

EuropeanStratigraphy

General

Subatlantic

Subboreal

Atlantic

Boreal

Preboreal

Late Glacial(10000 -13000)

Pleistocene(13000-

23000in our cores

CoreSedi-mentUnits

Unit1

Unit2

Unit3

r

YearsB P.

× 103

1

2

3

4

5

6

7

8

9

10

11

25

Note: Figures in parentheses are estimated ages that were given by the author(s) whose name appears at the top of the table (from Wall and Dale, 1974).

3) 17-1 to 25-1—brackish water and fresh-waterhalophile species assemblage typical of fresh-waterlakes.

4) 25-2 to 29-4—marine and relatively cold-waterassemblage.

They date these units as Novoeuxinian, Karangat,Uzunlar, and Drevne-euxiniar, respectively. Schrader,on the other hand (and it should be noted that bothworkers did not study the same samples nor have

TABLE 3Stratigraphic Correlation of Surface Sediments

Collected by Previous Coring, With SurfaceSediments Collected During Leg 42B Drilling

CoredSediments

Hole Site Site379A 380 380

(Degens and Ross, 1974)

Unit IUnit IIUnit III

l a

2 a

3

Iaa

IbIc

bb1

Not absolutely drilled, but inferred eitherfrom patches of material in recovered sedi-ments, or from previous studies.

3Apparently much of the upper part of thesediments found at Hole 3 79A and Site 380are missing from Site 381.

sufficient and continuous material to make the detailedstudy they probably wanted to do), noted basically fourmarine periods from Site 379, occurring in his Unit II(Cores 8-11), Unit IV (Cores 12-24), and two in Unit V(Cores 24-29). The evaluation by Schrader, and Jouséand Mukhina, of the environmental conditions for Site379, is essentially the same. They use different

TABLE 4Palynological Correlation Between the Three Black Sea Sites

as Determined by Ratios of Spores and Pollen(see Traverse, this volume)

Steppe-ForestIndex Position at Site 379a Position at Site 380a Position at Site 381a

Cores 1-6 (380) Missing

Cores 7-12 Cores 1-6

Cores 13-20 Cores 7-10 (?)

Cores 21-28 Probably missing

Cores 1-13 (380A) Probably missing

Cores 14-35 Cores 11-27

Cores 36-80 Core 28-?

aBased on extrapolation from data presented in site reports; correlations are basedmainly on simple stratigraphic succession, rather than occurrence of key species,and thus could be in error.

Celia(Forest)

Gamma(Steppe)

Betty(Forest)

Beta(Steppe)

Anna(Forest)

Alpha(Steppe)'re-Alpha

Cores 1-9

Cores 10-21

Cores 24-34 (?)

Cores 35-41 (?)

Cores 42-55

Cores 53-61

Cores 62-68 (?)

20

BLACK SEA STRATIGRAPHY

TABLE 5Correlations as Determined by Spore and Pollen Studies of Koreneva and Kartashova (this volume)

New Euxinian

Surozhskie (?)

Post-Karangatian

Karangatian

Postuzunlarian

Uzunlarian

Dreve-euxinian(late)

Paleouzunlarian-Dreve-euxinian

(early)

Regressivelayers

Chauda

Gurian

Pliocene

Hole 379

top

-

Cores 4-10.5

Cores 10.6-12.1

Cores 13-15

Cores 16-20

Cores 21-42

Cores 43-54

Cores 55-66

Cores 67-68

Hole 380

top

Core 2

Cores 3-6 (?)

Core 7

Cores 9-11

Coresllcc-19(?)

Cores 19 (?)-32

Cores 33-37

Cores 38-40

Hole 380A

Cores 2-7

Cores 7-11

Cores 12-32

Cores 33-80

Remarks

Temperate, cool

Warming and moisteningof climate

Alternation of forestand steppe vegetation

Warm, temperate flora

Cold

Temperate-warm

Temperate-cold

Temperate-warm

Temperate-cold

Temperate-warm

Temperate-cold

Temperate-warmSubtropical

numbering systems for the sedimentologic units, butcorrelation between their data is possible by using corenumbers.

For Site 380 Schrader describes nine units, with threemarine episodes in Site 380 (also three smallexcursions), and also three in Hole 38OA (the upper twoof which are similar to the lower two of Site380).Correlations between the two holes, generallyaccepted by most workers involved with Leg 42B, are:

Hole 380A, Core 1 to Hole 380, Core 36Hole 380A, Core 3 to Hole 380,Core 39.

According to Schrader, the marine episodes coincidewith Traversed pollen curve where this ratio indicateswarm water. However, Traverse and Schrader do notagree on the correlations between Sites 379 and 380.Jousé and Mukhina note three major marine phases atSite 380 which are essentially the same as that noted bySchrader. The former authors date the Pliocene at thebase of Core 31, Hole 38OA, and the start of thePontian at Core 55-3, Hole 380A. They distinguish sixmajor diatom assemblages for the site.

For Site 381, Schrader defines nine units and twomarine phases (near the surface and Cores 35-38). Jouséand Mukhina noted the latter phase and divide the site intothree units.

The authors attempt correlations between the sites.Schrader makes 18 correlations, principally based onspecies variations due to environmental changes (Table6). Correlations 5-11 and 13-14 do not fit withTraverse's correlations based on spore and pollen data(Table 4). Jousé and Mukhina's correlations are basedon their eight diatoms units. They have also assigneddates to these units, using various paleontological andsedimentological criteria (see Table 7). Schrader alsoassigns ages to the sediments, but he generally usessedimentation rates since he feels that no adequatefresh-water diatom stratigraphy is available. I find it

extremely difficult to compare the two works becauseof the differences in nomenclature, i.e., the Waalian orDanube/Ginz can be correlative with the Chauda inone classification (Table 1A) and with the Gurian inanother (Table IB). Unfortunately, there are alsoconsiderable differences in the stratigraphy of Jouséand Mukhina (Table 7) and Koreneva and Kartashova(Table 5).

MolluscaSeveral samples containing mollusca were studied by

Nevesskaya (this volume). She notes the generalabsence of shell remains and, where found, therelatively large percentage of juvenile forms (actuallyonly fragments of larger forms were found), andattributed this to the unsatisfactory environmentalconditions for benthic life. She is able to give someages, and notes that Cores 0-5 from Site 380 (in the"Celia" episode) contains juvenile shells of Dreissenarostriformis and Monodacna caspia which are typicalNeoeuxinian brackish water mollusks. In Core 4 shefinds juvenile shells of Bittium reticulatum, acharacteristic species of both the upper Holocene andthe Karangatian horizon. Sample 36 (Site 380 and inthe "Anna" episode) has remains of Dreissena andDidacna (?) which can have Paleoeuxinian(Drevneeuxinian) age. These ages are slightly differentthan those of Kareneva and Kartashova (this volumeand Table 5).

Magnetic StratigraphyMagnetic studies on selected samples from Sites 379

and 380 (Hailwood and Hamilton, this volume) havebeen helpful in establishing some minimal and maximaldates. The Brunhes/Matuyama magnetic epochboundary (with an age of 700,000 years) can betentatively assigned to a depth between 145 and 175

21

D. A. ROSS

Hole379A

4

9

Hole380

1

4

8

Hole380A

-

Hole381

-

11

16 15

TABLE 6Stratigraphic Correlations Between Sites Based Primarily on First or Last Occurrences of Diatom Species

Correlation

Abundance peak of Stephanodiscus astraea(correlates with Unit 2 from piston cores - seeTable 3)

Abrupt decrease in S. hantzschü

Increase in abundance of S. hantzschü

Peak abundance of Cyclotella caspia, associated withThalassiosira marine species, Chaetoceros speciesand absence of Hermesinum adriaticum

Decrease in abundance of S. astraea and varietiesand S. robustus

Abundance peak of S. astraea and varieties andS. robustus, and one abundance peak of Actino-cyclus normanii and Cyclotella caspia

Abundance peak of S. astraea and S. robustus

Last abundant occurrence of A. normannii associatedwith Hermesinum adriaticum

First abundant occurrence of A. normanniiassociated with H. adriaticum

Decrease in abundance of A. normannii, increasedS. astraea and its varieties

Abundance peak of A. normannii and noH. adriaticum

Last occurrence of freshwater diatoms in the lowerBlack Sea section

Abundance peak within the range of Melosiragranulata var. angustissima f. curvata, and occurrenceof S. omarensis and S. -Cyclotella

Last common occurrence of S. carconensis(triangulate type)

First common occurrence of S. carconensis(triangulate type)

Last common occurrence of S. binderianus typea. Thalassiosira aff. lineata

First common occurrence of S. binderianus type a,also the range of Coscinodiscus (?) stokesianus inHole 38OA (Cores 54 to 51) and in Hole 381 (Cores34-32), the range of Cyclotella operculata

Last common occurrence of Actinocyclus ehrenbergii,slightly below common occurrence ofSynedra indica

18(tentative)22 (top)

24

25

29

29

31

35

36

39

39

-

-

1

3

3(?)

-

-

1 (Sec. 3)

3

32 (or 34) 19

38

40

42

44

47

22

26

28 (middle part)

30

32 (bottom)

55 (top) 35 (top)

meters at Site 379. For Site 380, Core 51 (Hole 380A about800 m) a minimum age of 0.7 m.y. and a maximum age of 2.4m.y. is estimated (the latter value seems closer to the correctvalue). These values do not contradict the possible stratig-raphies of Tables 4 and 5, but the maximum age of 2.4 m.y. isstretching Hsü's middle to lower Pliocene estimate for 380Unit IVb (Table 8). A more detailed investigation should beattempted to define better the magnetic boundaries.

Stratigraphic Correlation Between Sites

Several of the shipboard scientists met in May of1976 in an attempt to correlate the sedimentary unitsdescribed at Sites 379, 380, and 381. The tentativecorrelations and ages of these sediments are shown inTable 8. Note especially the use of Roman numerals forSite 380. Further description of the units can be found

in the individual site chapters. Site 380 was describedprincipally by Ken Hsü, whereas Sites 379 and 381 weredescribed principally by Egon Degens and PeterStoffers. An attempt to assign an age to the Black Seasediments (by Degens and Stoffers) is also presented onTable 8. These ages are based on estimates ofsedimentation rates, changes in the depositionalenvironment and its correlation with neighboringgeological events, some paleontological information,and intuition. Again, a careful appraisal of the relevantchapters in this volume should be made by theinterested reader. Probably the major differencebetween the two classifications is that Stoffers andDegens assign an age to the glacial and interglacialevents where Hsü uses the glacial and interglacialdesignations from the pollen and spore work of

22

BLACK SEA STRATIGRAPHY

TABLE 7Correlations, Ages, and Biostratigraphy of Black Sea Sites

(adapted from Jous^and Mukhina, this volume)

Units

I

II

III

IV

V

VI

VII A

VII B

VII C

VII D

VIII

Cores

Piston Cores

379A380

379A380

379A380

379A380380A381

379A380381

380A381

380A381

380A381

380A381380A381

1.4-6, CC0, CC-5.3

7CC-11.35.3-11, CC

11.3-25.111-33, CC

25.1-30.233, CC-

1.1-3.41.2-4, CC

30.2-?3.4-31, CC

4,CC-19.5

31.CC-40.419.5-26.3

40.4-45, CC26.3-28.6

45,CC-50.128.6-32.2

50.1-54.132.2-34.554.1-34.5-

Age

Holocene

Novoeuxinian

Karangat

Uzunlar andPaleouzunlar

Drevneeuxinian

Chauda

Pliocene

Pontian(Messinian)

Comments

Marine diatoms

Deficient in diatoms

Marine diatoms at bottom of section, becomingfresh towards top

Mainly fresh-water forms with some brackish and fresh-water species; changing climate conditions

Mostly marine species

Mainly terrigenous with no diatoms

Fresh-water diatoms; lake conditions; four diatomzones are noted

Marine

Traverse (this volume). The differences can perhapsbetter be seen by examining the different stratigraphicsections (Figures la, lb). Unfortunately the workers ofSite 379 and 381 revised the number system for Site 380,making meaningful comparisons difficult. A summaryof the stratigraphic information is given in Ross (thisvolume.)

SUMMARY

A unique and completely acceptable stratigraphy forthe drilled Black Sea sediments has not been achieved.This is principally due to different time scales used byvarious authors, absence of definitive paleontologicalage markers, and differences in opinion among authors.Thus, appropriate care must be taken in discussingspecific aspects of Black Sea stratigraphy. Otherwise,environmental changes of the Black Sea are welldocumented and generally correlative among thevarious studies.

ACKNOWLEDGMENTThis manuscript was reviewed by Drs. Bil Haq and Frank

Manheim. The author was supported during the writing ofthis manuscript by a contract with the Office of NavalResearch.

REFERENCESArkhangel'skiy, A.D. and Strakhov, N.M., 1932.

Geologicheskoye istoriya Chernogo morya (Geologicalhistory of Black Sea): Moskov. Obshch. IspytateleyPiriody Byull., Otdel. Geol. v. 10., p. 3-104.

, 1938. Geologicheskoye stroyeniye i istoriyarazvitiya Chernogo morya (Geological structure and

history of evolution of Black Sea): Akad. Nauk SSSR Izv.,226 p.

Bukry, D., 1974. Coccoli ths as Paleosal ini tyIndicators—evidence from Black Sea. In Degens, E.T.,and Ross, D.A., (Eds.) The Black Sea—geology,chemistry, and biology: Am. Assoc. Petrol. Geol. Mem.20, p. 353-363.

Degens, E.T. and Ross, D.A. (Eds.), 1974. The BlackSea—geology, chemistry, and biology: Am. Assoc. Petrol.Geol. Mem. 20, 633 p.

Federov, P.V., 1956. O sovremennoi epokhe vgeologicheskom istorii Chernogo morya (Modern epoch ingeological history of Black Sea): Akad. Nauk SSSRDoklady, v. 110, p. 839-841.

, 1963. Stratigrafiya obetvertichnykh oslosheniiKrymskogo-Kavkazkogo poberzh'ya i nekotorye voprosygeologicheskoy istorii Chernogo morya (Stratigraphy ofQuaternary sediments on coast of Crimea and Caucasusand some other problems connected with the geologicalhistory of the Black Sea): Akad. Nauk SSSR Geol. Inst.Trudy, v. 88, p. 7-159; National Lending Library RTSNo. 2572, 245 p.

Markov, K.K., Lazukov, G.I. and Nikolayev, V.A., 1965.The Quaternary Period (Glacial period-Antropogenperiod), v. 1: The Territory of the USSR: Moscow(Moskov. Univ.), 371 p.

Nevesskaya, L.A., 1965. Pozdnechetvertichnyedvustvorchatye mollyuski Chernogo morya, ikhsistematika i ekologiya (Late Quaternary bivalve molluscsof the Black Sea, their systematics and ecology): Akad.Nauk SSSR Paleont. Inst. Trudy, v. 105. p. 1-390.

Nevesskii, Ye.N., 1961. O poslelednikovoi transgressiiChernogo morya, Akad. Nauk SSSR Doklady, v. 137,no. 3, p. 667-670; Engl. transl., 1962, Post-glacialtransgression of the Black Sea: Am. Geol. Inst., v. 137,p. 317-320.

23

D. A. ROSS;

van Eysinga, F.W.B., 1975. Geological time table, 3rd Ed.:Netherlands (Elsevier Pubi Co.)

Wall, D. and Dale, B., 1974. Dinoflagellates in lateQuaternary deep-water sediments of Black Sea. In Degens,

E.T., and Ross, D.A., (Eds.), The Black Sea—geology,chemistry, and biology: Am. Assoc. Petrol. Geol. Mem.20, p. 364-380.

TABLE 8Tentative Correlation of Sites 379, 380, and 381

Based on Post-Cruise Meeting

Hsü(380)

Ia and Ib

I c

ld

h

h

k)II

II & III

III

III

IVa

ivb

ivc

IVd,e&Va

IVd

vb

ive + v a

>vb

Stoffers and Degens(379 and 381)

1 & 2 (379)

3 (379)

4&5 (379)

6 (379)

7(379)

8 (379)

9 & Deeper(379)

9 (379)

2 (381)

Part of 9 (379) and2(381)

3(381)

4(381)

5 (381)

6(381)

6,7,8

Uncored ZeoliteInterval

9

789

Tentative Age(see text)

Holocene

Weichselian/Würm

Eemian/Riss—Würm Interglacial

Saalian/Riss (Stoffers and Degens)Glacial and Interglacial (Hsü)

Holsteinian (Stoffers and Degens)Interglacial B (Hsü)

Elster/Mendel (Stoffers and Degens)Glacial B (Hsü)

About 800,000 (Stoffers and Degens)

Plio/Quat (Hsü)

Eburon (cold period about1.7 × 106 - Stoffers and Degens)

Alpha (glacial - about 2 × 106

Hsü)

Tiglian (2.2 X 106 base - Stoffers andDegens) U. Pliocene (Hsü)

Pretiglian (Stoffers and Degens)M.—L. Pliocene (Hsü)

(About 2.6 X 106 or younger< (Stoffers and Degens)v L. Pliocene (Hsü)

Pliocene (or possibly older - Stoffersand Degens)

L. Miocene (Hsü)

Pliocene? (Stoffers and Degens)

Miocene (Hsü)

(4-5 X 106 (Stoffers and Degens)

24

BLACK SEA STRATIGRAPHY

100

200

300

400

500

600

700

800

900

1000

1080

SITE381

1+7

SITE380/380A

1+2

STRATIGRAPHYOF LEG 42B

A u

-t- -X. - / . -i

. . . . u. ..-L.

"I Z. ^ .Z

SITE379

1+2

1074 m

TERRIGENOUS

CLAY VARVES

SAND LAYERS (Loess)

DIATOMS

NANNOS

MICRITE (Seekreide)

DOLOMITE

SIDERITE

ARAGONITE

ZEOLITES

BRECCIA

CARBONATE (Ca.-Mg.)FREE INTERVALS

SHELL HASH

Figure la. Stratigraphic section from Stoffers et al., this volume.

25

D. A. ROSS

SITE 381 SITE 380 SITE 379

100

200

300

400

•B 500a.

600

700

800

900

1000-

Seekreide (Lacustrine Chalk)

T. D.1075 m

Figure lb. Stratigraphic section from Hsü, this volume.

26