Palaeoenvironmental Investigation of Sapropelic Sediments ......Son 6000 y›l esnas›nda çökelmiﬂ olan sapropelik çökelim sonras› sedimentler, foraminiferal faunadaki belirgin

Palaeoenvironmental Investigation of SapropelicSediments from the Marmara Sea: A Biostratigraphic

Approach to Palaeoceanographic History During the LastGlacial–Holocene

ELMAS KIRCI-ELMAS1, OYA ALGAN1, ‹ZVER ÖZKAR-ÖNGEN2, ULRICH STRUCK3,ALEXANDER V. ALTENBACH3, EN‹S K. SAGULAR4 & AT‹KE NAZ‹K5

1 ‹stanbul University, Institute of Marine Sciences and Management, Vefa, TR–34470 ‹stanbul, Turkey(E-mail: [email protected])

2 ‹stanbul University, Engineering Faculty, Department of Geology, Avc›lar, TR–34850 ‹stanbul, Turkey3 Munich Ludwig-Maximilians University, Faculty of Geosciences, Department of Earth and Environmental

Sciences, Richard-Wagner Str. 10, D-80333 Munich, Germany4 Süleyman Demirel University, Faculty of Engineering and Architecture,

Department of Geology, TR–32260 Isparta, Turkey5 Çukurova University, Faculty of Engineering and Architecture, Department of Geology,

Balcal›, TR–01330 Adana, Turkey

Abstract: High-resolution micropalaeontological examination of two cores recovered from the Central Basin of theMarmara Sea distinguishes seven biostratigraphical zones within pre-sapropelic (Pr1 & 2 zones), sapropelic (Sap1& 2 zones) and post-sapropelic (Po1-2-3 zones) sediments. The pre-sapropelic sediments at the basal section ofthe cores reflect the lake stage of the Marmara Sea when it was isolated both from the Black and Mediterraneanseas. First colonization of foraminifers at about 11–10.4 ky BP indicate the beginning of marine conditionsfollowing the entry of Mediterranean waters through the Çanakkale Strait. Sapropelic sediments deposited atabout 10.3–6.2 ky BP were associated with enhanced productivity of the surface waters, as inferred from theconfined abundance of Globigerina bulloides in sapropelic zones. The first stage of the sapropelic deposition startedunder anoxic-close to anoxic bottom water conditions and continued in dysoxic-suboxic conditions, as deduced frombenthic foraminiferal assemblages. Towards the end of the sapropelic deposition, suboxic conditions dominated.The most enriched δ18O values occur within the sapropelic sediments suggesting that a relative freshening of thesurface water must have occurred after deposition of the sapropelic sediments; this observation casts doubt on thepostulated strong Black Sea outflow during their formation.

Post-sapropelic sediments deposited during the last 6 ky BP have been divided into three intervals by distinctdistribution patterns of foraminiferal fauna, possibly indicating relative changes in the Marmara Sea during the LateHolocene. The benthic foraminiferal assemblages in these intervals show that suboxic bottom conditions continuedfrom the last stage of the sapropelic deposition up to the present day.

Key Words: benthic foraminifera, planktic foraminifera, biostratigraphy, sapropel, stable isotopes,palaeoceanography, last glacial–Holocene, Marmara Sea

Marmara Denizi Sapropelik Sedimentlerinin Ortamsal ‹ncelemesi:Son Buzullaflma–Holosen Paleoflinografisine Biyostratigrafik Bir Yaklafl›m

Özet: Marmara Denizi’nin Orta Havzas›’ndan al›nm›fl olan iki karotun yüksek ayr›ml› mikropaleontolojik incelemesi;sapropelik çökelim öncesi (Pr1 & 2 zonlar›), sapropelik (Sap 1 & 2 zonlar›) ve sapropelik çökelim sonras› (Po1-2-3 zonlar›) sedimentler içerisinde yedi biyostratigrafik zon ay›rt etmeye olanak sa¤lam›flt›r. Karotlar›n taban›nda yeralan sapropelik çökelim öncesi sedimentler, Marmara Denizi’nin Akdeniz ve Karadeniz’den izole oldu¤u göl safhas›n›yans›tmaktad›r. Günümüzden yaklafl›k 11000–10400 y›l önce bafllayan ilk foraminifer yerleflimi, Çanakkale Bo¤az›yolu ile giren Akdeniz sular› ile denizel koflullar›n oluflmaya bafllamas›n› gösterir. Günümüzden 10300–6200 y›löncesi zaman aral›¤›nda sapropelik sedimentler çökelmifltir. Globigerina bulloides’in sadece Sapropel zonlar›nda yeralan yüksek bollu¤u, bu sedimentlerin çökeliminin yüzey sular›nda artan birincil üretim ile iliflkili oldu¤unu ortayakoymaktad›r. Sapropelik sedimentlerin bentik foraminifer topluluklar›, sapropelik çökelimin ilk aflamas›n›n anoksik-anoksi¤e yak›n dip suyu koflullar› alt›nda bafllad›¤›n› ve disoksik-suboksik koflullarda devam etti¤ini gösterir.Sapropelik çökelimin sonlar›na do¤ru suboksik koflullar hakimdir. δ18O’ce en zengin de¤erlerin sapropelik

Turkish Journal of Earth Sciences (Turkish J. Earth Sci.), Vol. 17, 2008, pp. 129–168. Copyright ©TÜB‹TAKFirst published online 11 December 2007

129

PALAEOENVIRONMENTS OF SAPROPELIC SEDIMENTS

130

Introduction

Palaeoceanographic significance of sapropel formationshas been well-documented from Middle Miocene to Lateglacial–Holocene deposits in the Mediterranean Sea(Vergnaud-Graezini et al. 1977; Kidd et al. 1978; andalso see papers in Cita et al. 1991 and Rohling & Thunell1999) and in Holocene deposits from the Black Sea(Strakhov 1971; Ross & Degens 1974; Calvert et al.1987; Calvert 1990). The formation of such organic-richdeposits is often attributed to increased primaryproduction, to changes in stratification and/or to thechemistry of the water column leading to anoxia inbottom waters. Sapropel deposition correlates withvariations in the Earth’s orbital parameters which controlthe strength of seasonal monsoon conditions in the NorthAfrican region (Rossignol-Strick et al. 1982; Rossignol-Strick 1983, 1985; Rohling & Hilgen 1991; Lourens etal. 2001). Strong inflows of the less saline nutrient-richBlack Sea waters via the Marmara Sea and its straits werealso shown to be an important factor in formation of theeastern Mediterranean sapropel layers (Ryan 1972;Stanley 1978; Thunell & Lohman 1979; Aksu et al. 1995,1999), whilst a closer freshwater source from the NorthAfrican region (the Nile River) as a cause of deposition ofS1 sapropel has also been considered (Rossignol-Strick1999; Krom et al. 2002).

Sapropelic layers in the Marmara Sea were firstrecognized on the southern shelf (Ça¤atay et al. 1999)and later in the deep basin (Ça¤atay et al. 2000; Aksu etal. 2002a). Radiocarbon ages (14C) for the upper andlower sapropelic layers range from 4.75–3.2, and10.6–6.4 ky BP, respectively. The lower sapropelic layeris therefore synchronous with the youngest sapropel (S1sapropel) of the Mediterranean Sea. Aksu et al. (2002a)identified two sapropel layers in the deep basin: thesapropel M1 corresponding to the lower sapropelic layerin Ça¤atay et al. (2000) and the sapropel M2 depositedbetween 29.5 and 23.5 ky BP. Formation of the

sapropelic layers in the Marmara Sea is considered to beclosely related to nutrient-rich and strong fresh waterinput from the Black Sea at about 11–10 ky BP, whichresulted in a high organic flux to the sea floor andconsequently a strong water stratification (Ça¤atay et al.1999, 2000). These results are supported by additionalmulti-proxy palaeoceanographic data (Aksu et al. 2002a,b; Kaminski et al. 2002; Abrajano et al. 2002; Hiscott &Aksu 2002; Hiscott et al. 2002). However, theseinterpretations related to sea-level changes and associatedwater exchanges between the Black and Mediterraneanseas clash with the Flood Hypothesis introduced by Ryanet al. (1997, 2003). An abrupt Mediterraneantransgression at about 7.15 ky or 8.4 ky BPcatastrophically submerged the low-sea level (lower than– 100 m) shelf area of the Black Sea via the ‹stanbulStrait, decreasing the persistent outflow of the Black Seabeginning at about 11–10 ky BP through the ‹stanbulStrait. In addition, heavy δ18O values and high salinities atthe sea surface indicate that low salinity surface waterfrom the Black Sea was absent during deposition of thesapropelic sediments in the Marmara Sea, as reported ina further study by Sperling et al. (2003).

Previous studies related to the foraminiferal fauna ofthe Marmara Sea sediments are few (Alavi 1988;Hakyemez & Toker 1997; Meriç & Sakınç 1990; Meriç etal. 1995; Ça¤atay et al. 1999, 2000; Aksu et al. 2002a;Sperling et al. 2003). Planktic foraminiferal (Aksu et al.2002a; Sperling et al. 2003) and benthic foraminiferalassemblages in the sapropels (Ça¤atay et al. 1999, 2000;Kaminski et al. 2002) were studied. Although Kaminskiet al. (2002) investigated benthic foraminifers in thesapropels (core MAR98 –12; from Central Basin of theMarmara Sea), no detailed quantitative data were given.Oxygen isotopic composition of foraminiferal tests weregiven only in two studies (Aksu et al. 2002a; Sperling etal. 2003), but led to completely opposite interpretations.Aksu et al. (2002a) identified strong Black Sea outflow

sedimentler içerisinde yer al›fl›, göreceli yüzey suyu tatl›laflmas›n›n sapropelik sedimentlerin çökeliminden sonragerçekleflti¤ini ve çökelimleri esnas›nda Karadeniz’den güçlü su ak›fl› oldu¤u görüflünü flüpheye düflürmektedir.

Son 6000 y›l esnas›nda çökelmifl olan sapropelik çökelim sonras› sedimentler, foraminiferal faunadaki belirginda¤›l›m flekillerine göre üç zona ayr›lm›flt›r. Bu zonlar, muhtemelen Geç Holosen esnas›nda Marmara Denizi’ndegöreceli de¤iflikliklere iflaret etmekte ve sapropelik çökelimin son safhas›ndan günümüze kadar suboksik koflullar›nhakim oldu¤unu göstermektedir.

Anahtar Sözcükler: Bentik foraminifer, planktik foraminifer, biyostratigrafi, sapropel, durayl› izotop,paleoflinografi, Son buzullaflma-Holosen, Marmara Denizi

during deposition of sapropelic layers on the basis ofdepleted oxygen isotopes values. In contrast, Sperling etal. (2003) found enriched oxygen isotopes values withinthe sapropel and interpreted them in terms of theabsence of Black Sea water during deposition.

In this paper we present high-resolutionmicropalaeontological (foraminifera, ostracoda andcalcareous nannofossil) data together with oxygenisotopes from two cores, including sapropelic sedimentsand located in the Central Basin of the Marmara Sea withthe aim of establishing for the first time a localbiostratigraphical scheme from quantitative analysis ofthe benthic and planktic foraminiferal assemblagesthrough the cores. This biostratigraphical scheme andoxygen isotope data are addressed to contribute new datato the palaeoceanographic conditions of the Marmara Seaduring the Last glacial–Holocene interval, with particularattention to the controversial water exchanges betweenthe Black Sea and Mediterranean Sea.

Study Area

The Marmara Sea is a land-locked sea located betweenthe Thrace and Anatolia peninsulas and constitutes anoceanographic link between two large semi-enclosedbasins, the Mediterranean Sea and Black Sea (Figure 1a).It is connected to brackish waters (18–22 psu) Black Seavia the ‹stanbul Strait (the Bosporus) and to normalmarine waters (37.5–38.5 psu) of the Mediterranean Seavia the Çanakkale Strait (Dardanelles). Black Sea watersflowing through the ‹stanbul Strait enter the MarmaraSea as a surface current, whereas Mediterranean Seaflows through the Çanakkale Strait as an undercurrent.These two water bodies cause permanent two-layeredwater stratification (Ünlüata et al. 1990) at about 25 mdepth and form a major feature of the present-dayoceanography of the Marmara Sea. As a result of thiswater stratification and limited vertical mixing of the twowater masses, the dissolved oxygen content of the lowerlayer is depleted and decreases from the Çanakkale Strait(7–10 mg/l) to the ‹stanbul Strait (2.5 to 5.0 mg/l)(Ünlüata et al. 1990). The lower layer is relatively poor inorganic substances compared with the upper layer. TheBlack Sea originating as the upper layer transports 1.5 x106 ton/y of organic carbon to the Marmara Sea. This isfour times higher than that of the lower layer (Polat &Tu¤rul 1995). Production and accumulation of organic

matter in the Marmara Sea are mainly influenced by theorganic-rich upper layer, by the riverine input from southand, to a lesser extend, by the lower layer.

The sea floor of the Marmara Sea presents acomplicated morphological system, including shelves,slopes, ridges and deep basins (Figure 1b). The northernand southern shelves extend to 100 m water depth wherethey are limited by a shelf break. Relatively steep slopes(gradients higher than 7º) are mainly formed at the shelfbreak-basin transition in the northern part, whereasgentle slopes (gradients between 4 and 6º) arecharacteristic of ridge-basin and shelf-ridge transitionalzones in the southern part (Gazio¤lu et al. 2002). Thefour basins, namely Çınarcık (1270 m), Silivri (820 m),Central (1268 m) and Tekirda¤ (1133 m) are separatedby ridges, occurring at water depths between 360 and650 m. Submarine canyons and landslides occur locallyacross the slopes of the Marmara Sea (Gazio¤lu et al.2002). Topographical restrictions (sills) in both straitscontrol the present bottom water circulation and theyplayed important roles during the Late Quaternary sealevel variations. In the ‹stanbul Strait there are two sills:one is located off the northern entrance at about 60 mdepth, and the other is off the southern entrance at about30 m of depth. The sill depth of the Çanakkale Strait isabout 70 m deep. These sills prevented water exchangesbetween the Black Sea and Mediterranean Sea when theglobal sea level was at low stands during glacial periods,until the sea level rising during the interglacial periods.

Material and Methods

Gravity core DM18 and piston core KL40 were collectedfrom the Central Basin of the Marmara Sea during acruise of the R/V MTA Sismik-1 in 1998 and M44/1cruise of the R/V Meteor in 1999, respectively (Figure 1c& Table 1). The cores were lithologically described andsystematically sub-sampled at 2 cm intervals (KL40, Kuhnet al. 2000; DM18, Baflaran 2002).

Dates for the cores are based on the accelerator massspectrometry (AMS) 14C dating method performed at theNSF Arizona AMS Laboratory of Arizona University witha precision of ±41 to ±50 years standard deviation (Table2). A Tephra layer, dated 22 ky BP cal (uncalibrated age:18.05–18.88 ky BP, Pichler & Friedrich 1976; Eriksen etal. 1990 in Wulf et al. 2002) from the Cape RivaEruption of Santorini was used as a further time marker

E. KIRCI-ELMAS ET AL.

131


132

NC

en

tra

lBa

sin

Teki

rda

ğB

asi

n

Str

aito

fÇan

akka

le

(Dar

dane

lles)

Str

ait

ofİs

tan

bu

l(B

osp

ho

rus)

Arm

utlu

Pla

tea

u

İzm

itB

ay

İzn

ikL

ake

Ge

mlik

Ba

yA

rmu

tluP

en

insu

laK

ap

ıda

ğP

en

insu

la

So

uth

ern

Sh

elf

Nor

ther

nS

helf

Prin

ceIs

lan

ds

We

ste

rnR

idg

e

Erd

ek

Ba

y

Sili

vriB

asi

n

Çın

arc

ıkB

asi

n

Ea

ste

rnR

idg

e

25.0

0.

2600

.27

00.

2800

.29

00.

3000

36.0

0

37.0

0

38.0

0

39.0

0

40.0

0

41.0

0M

arm

ara

Sea

AegeanSea

TU

RK

EY

Bla

ck

Se

a

a

b

40

.50

40

.75

41

.00

41

.25

27.20

27.40

27.60

27.80

28.00

28.20

28.40

DM

18

KL

40

Tekir

dağ

Basin

Cen

tralB

asin

Marm

ara

Isla

nd

c

Figu

re 1

.(a

)Lo

catio

n m

ap o

f th

e M

arm

ara

Sea.

(b)

Sub-

bott

om m

orph

olog

ical

imag

e of

the

Mar

mar

a Se

a (f

rom

Gaz

io¤l

u et

al.

2002

). T

he s

tudy

are

a is

enc

lose

d w

ithin

a r

ecta

ngle

. (c

)Lo

catio

n of

the

stu

died

cor

es (

bath

ymet

ry m

ap f

rom

MTA

200

4).

Table 2. Radiocarbon ages of selected levels in the Marmara Sea cores based on uncalibrated AMS 14C measurements (*: from Caner 2005).

Core Depth (cm) Dated material Laboratory number 14C date (yr BP)

DM18 46-48 U. mediterranea + B. striata 1893 ± 37*

DM18 198-200 Planktic foraminifera (mix) AA59214 5096 ± 41

DM18 314-316 G. bulloides AA59215 9277 ± 49

KL40 98-100 Bulk carbonate AA59216 7716 ± 46

KL40 131-133 Bulk carbonate AA59217 9160 ± 50

in core KL40. The radiocarbon dates in this study areexpressed as uncalibrated to compare them withuncalibrated ages published in previous studies (Ça¤atayet al. 2000; Aksu et al. 2002a, b; Kaminski et al. 2002;Hiscott & Aksu 2002; Hiscott et al. 2002) in the studyarea.

Total carbonate and organic carbon (Corg) contents ofthe sediment samples in core KL40 were determined by agasometric-volumetric method (Loring & Rantala 1992)and the Walkey-Blake method (Gaudette et al. 1974;Loring & Rantala 1992). The total carbonate and Corgvalues of core DM18 came from Baflaran (2002).

Foraminiferal analyses were performed at about 10cm intervals in each core. Sapropelic layer in core DM18was studied at about 2–6 cm intervals for foraminiferalanalysis. 10 g of sub-sampled dried sediments weresoaked in 10% H2O2 and then washed on a 0.063 mmsieve. The residue was dried in air and later sieved on a0.125 mm sieve. All the residue of planktonic and benthicforaminiferal specimens were identified and counted ineach fraction coarser than 0.125 mm. The results aregiven as percentages in the graphical illustrations, and asnumbers of specimens per sample in the appendices. Thelower interval (350–901 cm) of core KL40 is not shownin the graphical illustrations and appendix due to absenceof a foraminiferal fauna. Direct comparisons of taxa weremade using a planktonic foraminiferal collection from theEastern Atlantic (Pflaumann & Krasheninnikov 1978) inKiel University and a benthic foraminiferal collection fromNW Africa (Lutze 1980) at Munich Ludwig-Maximilians

University (LMU). Taxonomic concepts of Parker (1962),Bolli & Saunders (1985), Hemleben et al. (1989),Cimerman & Langer (1991), Sgarrella & Moncharmont-Zei (1993), Jones (1994), Loeblich & Tappan (1994),Yassini & Jones (1995), Loeblich & Tappan (1998) andMeriç et al. (2004) were mainly followed foridentification of species. Selected specimens werephotographed using a Leitz-1200 scanning electronmicroscope at LMU, Munich. Ostracodan fauna were alsopicked out and identified at the same samples in the lowerparts of the both cores (between 375 and 400 cms inDM18; between 190 and 890 cms in KL40) where aforaminiferal fauna is absent. Calcareous nannofossilexamination was performed on 16 samples between 53and 871 cms of core KL40. For microscopicdetermination of nannofossils smear-slides wereprepared as outlined in Perch-Nielsen (1985a). Driedsediment samples were scrapped onto a glass slide by aneedle or razor and diluted with distilled water to spreadonto a lam, then covered by a lamella, using Canadabalsam. Nannofossil assemblages were identified under aNikon polarizing microscope with a Sony camera usingthe taxonomic description of Perch-Nielsen (1985a, b)and Martini (1971).

Carbon (δ13C) and oxygen (δ18O) isotopicmeasurements were carried out on the planktonicforaminifera Turborotalita quinqueloba in core DM18 atthe Isotope Geochemistry Laboratory of the LMU,Munich. Sediment samples were soaked in water andwashed through a 0.063 mm sieve. About 100–195


133

Table 1. Location, water depth and length of the studied cores.

Core number Latitude (N) Longitude (E) Water depth (m) Core length (cm)

DM18 40°49.845´ 27°52.626´ 895 424

KL40 40°47.12´ 27°46.31´ 703 901

individuals of the species were selected from the drysieved grain size fraction of 0.125 to 0.250 mm formeasurements. The results were referred to theinternational Vienna-Pee Dee Belemnite standard as ‰deviation.

Results

Lithology and Chronology

The sediments of the studied cores are composedpredominantly of muddy sediments (Figure 2). Theuppermost 70 cm of core DM18 consists of brownish

grey-green mud. Greyish-green mud predominatesbetween 70 and 250 cm. Dark olive green mudinterbedded with a light greyish-green mud layer occursbetween 250 and 342 cm. The lower parts of the coreare composed mainly of light greyish-green mud withintervening yellowish-brown mud.

The uppermost 410 cms of core KL40 are composedof dark olive to olive grey mud with occasional darkcoloured stains and spots (Figure 2). The intervalbetween 410 and 540 cms is represented by a dark grey-blackish grey mud, bounded with a coarse-grained thinlayer (8 cm thick). The lower parts of the cores show


134

0brownish grey - green mud

50

100

150

200

250

300

350

400

greyish - green mud

light grey - green mud interbeddedwith a yellowish - brown mud layer

(wd: - 895 m)

0

50

100

150

200

250

300

350

400

450

500

dark olive (7.5Y4/3) - olive grey(10Y4/2) mud

silt sized ash layer (18 000 y****)600

700

800

900

shell fragment

disturbed surface

dark coloured spot

coarse-grained layer

sand - silt lamina

550

650

750

850

gas bubbles marks

olive black (10Y3/2) mudgrey (10Y5/1) mud

dark grey (N3/1) mud

dark greenish grey (10GY3/1) mud

(wd: - 703 m)

5096 y

9277 y

7716 y

DM18 * KL40 **

grey (N4/4) - greenish grey (7.5GY6/1) mud

dark greenish grey (10GY4/1) mud

greenish grey (7.5GY6/1) mud

grey (N4/1) mud

1893 y***

gypsum crystal

9160 y

dark olive - green mud interbededwith a light grey - green mud layer

Figure 2. Lithological features of the Marmara Sea cores (*: from Baflaran 2002; **: from Kuhn et al. 2000)and uncalibrated AMS 14C dates (***: from Caner 2005) in the cores. ****: uncalibrated date for ashlayer was used from Wulf et al. (2002). The shaded intervals indicate the sapropelic layer.

mainly different tones of green and grey. The ash layerlinked to the Cape Riva event was found (Wulf et al.2002) between 582 and 583 cms in this core.

A sapropelic layer occurs between 232 and 345 cmsin core DM18 and between 111 and 163 cms in coreKL40. The lower boundaries of the sapropelic layer ofboth cores are highlighted by lithological sign, whereasthe upper boundaries do not show any lithological sign.The discrimination is based on Corg content > 1.5%. Atotal of 5 age determinations both from foraminiferalcalcite and bulk carbonate were obtained in two cores(Table 2). Linear interpolated AMS 14C ages obtainedfrom foraminiferal calcite in core DM18 suggest thatsapropelic sediments were deposited between 10.3 and6.2 ky BP, whereas dates from bulk carbonate in coreKL40 suggest that sapropelic sediments were depositedbetween 10 and 8.3 ky BP (Tables 2 & 3). Radiocarbondates from KL40 are in agreement with the lower limit ofthe sapropelic sediments in DM18, but gave slightly olderage for the upper limit, probably due to reworked oldercarbonate. Therefore, DM18 age dates have beenconsidered for the chronology. The age of the sapropeliclayer obtained in this study is in agreement with theprevious findings as shown in the comparison of Table 3.

Total Carbonate and Organic Carbon Contents of theCore Sediments

The total carbonate and Corg contents of the core samplesvary between 2.0 and 37.0% and between 0.2 and3.6%, respectively (Figure 3). The carbonate distributionof core DM18 is practically homogeneous (9.0–13.0%)and displays a peak only in the lower part of the core withthe highest values ranging from 23.0 to 35.0%. In coreKL40, the highest carbonate values (26.0–37.0%) arefound between 191 and 212 cms. The lowest value(2.0%) occurs within the ash layer. The rest of this core

has intermediate carbonate values ranging from 7.0 to14.0%.

A sapropelic layer containing 1.5–3.6% and1.5–2.9% Corg occurs at 232–345 cms in core DM18,and at 111–163 cms in core KL40, respectively. Thissapropelic layer in terms of age and Corg contentcorresponds to a previously defined sapropelic layer (seeÇa¤atay et al. 2000: Lower sapropelic layer; Aksu et al.2002a: sapropel M1; Sperling et al. 2003: S1Marmara;Table 3). The lowest Corg values are observed in sedimentsdeposited below the sapropelic layer, whereasintermediate values occur in sediments overlying thesapropelic layer. The maximum carbonate values of bothof the cores correspond to the level just below thesapropelic layer.

Local Biostratigraphical Division

Throughout the cores, the benthic foraminiferal faunadisplay high diversity compared with the planktonic faunaand is represented by predominantly calcareous forms.However, most of the species have low abundances andsporadic occurrences. Planktonic foraminifera areabundant in spite of low diversity. Neogloboquadrinapachyderma, Globigerina bulloides, Globigerinoides ruberand Turborotalita quinqueloba show significantabundances, whereas the other planktonic foraminiferalspecies are represented only by sporadic occurrences. Theostracoda fauna exhibits low diversity and abundance inthe lower parts of the cores where a foraminiferal faunais absent. The down-core distribution of microfaunashows distinct quantitative patterns and assemblages(Figures 4–10) and hence allows subdivision of thebiostratigraphical zones into three sections: (i) pre-sapropelic sediments (Pr; Pr1-2), (ii) sapropelicsediments (Sap; Sap1-2), (iii) post-sapropelic sediments(Po; Po1-3).


135

Table 3. Comparison of radiocarbon ages calculated for the sapropelic levels found in previous studies.

Ça¤atay et al. Ça¤atay et al. Aksu et al. Sperling et al.(1999) (2000) (2002) (2003) This study

4750–3500 y Upper sapropel Sapropel M1 S1Marmara 10 300–6200 y

4750–3200 y 10 500–6000 y 11 000–7000 y cal

Lower sapropel Sapropel M2

10 600–6400 y 29 500–23 500 y

Pre-sapropelic Sediments (Pr). (Pr) sediments belowthe sapropelic sediments in both cores are characterizedby very rare occurrence of foraminifera (Figures 4–10,Appendices 2 & 3) and by the presence of ostracoda.They are divided into two zones based on the appearanceof foraminifera. The (Pr1) zone is practically barren ofbenthic and planktonic foraminifera, whereas significantnumbers of Bulimina aculeata, B. elongata, B. marginataand Turborotalita quinqueloba occur in the (Pr2) zone incore DM18. This thin (Pr2) zone was not observed in the

upper part of the (Pr) sediments of core KL40 (Figures 7,8 & 10). The nannofossil assemblages of the (Pr1) zonein KL40 (Table 4) includes completely reworked forms ofLate Maastrichtian, Early Paleocene, Late Eocene, EarlyMiocene and Mio–Pliocene age, such as Chiasmolithussolitus, Cribrocentrum reticulatum, Florisphaeraprofunda, Gephyrocapsa cf. caribbeanica, Helicosphaeraeuphratis, Isthmolithus recurvus, Lithraphiditesquadratus, Micula mura, Pseudoemiliania lacunosa,Semihololithus priscus and Zygrhablithus bijugatus.


136

CaCO3 (%)* Corg (%)*

0 20 40

400

300

200

100

0

Dep

th(c

m)

0 1 2 3 4 0 20 40

900

800

700

600

500

400

300

200

100

0

0 1 2 3

CaCO3 (%) Corg (%)

DM18 KL40

Figure 3. Downcore distribution of total carbonate and organic carbon contents of the cores(*: from Baflaran 2002). The shaded intervals indicate the sapropelic layer.


137

E.s

cab

raB

.no

do

sari

aS

iph

ote

xtu

lari

asp

.S

.exc

ava

taS

.dis

tort

aS

.te

nu

isQ

uin

qu

elo

culin

asp

p.

05

10

05

10

05

10

05

100

51

00

51

00

204

00

510

S.s

chlu

mb

erg

eri

M.s

ub

rotu

nd

a

Po

3

Po

2

Po

1

Sa

p2

Pr2

Pr1

Sa

p1

01

530

TB

F0

400

800

400

300

200

1000

Depth(cm)

ma

rin

e

lake

pre

-sa

pro

pe

licse

dim

ent

sP

r1

Pr2

sap

rop

elic

sed

ime

nts

dyso

xic

-su

boxi

cbo

tto

mw

ate

rco

nd

itio

ns

an

oxi

c-cl

ose

toa

nox

icb

ott

om

wa

ter

con

diti

on

sS

ap

1

Sa

p2

po

st-s

ap

rop

elic

sed

ime

nts

Po

1

Po

2

Po

3su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

Figu

re 4

.D

ownc

ore

abun

danc

e of

dom

inan

t be

nthi

c fo

ram

inife

ral s

peci

es in

cor

e D

M18

. TBF

: Tot

al b

enth

ic f

oram

inife

ra p

rese

nted

as

num

bers

/10

g dr

y se

dim

ent.

Spe

cies

freq

uenc

ies

are

in p

erce

nt o

f to

tal.


138

A.t

ub

ulo

saL

en

ticu

lina

spp. N

.pe

reg

rin

aA

.sca

lari

sB

.ala

taG

.su

bg

lob

osa

B.a

cule

ata

B.a

lba

tro

ssi

B.e

lon

ga

taB

.dila

tata

Po

3

Po

2

Po

1

Sa

p2 Pr2

Pr1Sa

p1

05

10

400

300

200

1000

Depth(cm)

05

100

51

00

51

00

50

100

025

50

05

10

01

530

020

40

02

550

ma

rin

e

lake

pre

-sa

pro

pe

licse

dim

en

tsP

r1

Pr2

sap

rope

licse

dim

en

ts

dys

oxi

c-su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

an

oxi

c-cl

ose

toa

no

xic

bo

ttom

wa

ter

con

diti

on

sS

ap1

Sa

p2

po

st-s

ap

rope

licse

dim

en

tsP

o1

Po

2

Po

3su

bo

xic

bo

tto

mw

ate

rco

ndi

tions

Figu

re 5

.D

ownc

ore

abun

danc

e of

dom

inan

t be

nthi

c fo

ram

inife

ral s

peci

es in

cor

e D

M18

. Sp

ecie

s fr

eque

ncie

s ar

e in

per

cent

of

tota

l.


139

B.m

arg

inat

aB

.co

sta

taU

.me

dite

rra

ne

aV

.bra

dya

na

S.b

ullo

ide

sC

.ovo

ide

aGyr

oid

ino

ide

ssp

.H

.bal

thic

aG

.um

bo

nata

Me

lon

issp

p.

Po

3

Po

2

Po

1

Sa

p2

Pr2

Pr1

Sa

p1

02

550

400

300

200

1000

Depth(cm)

05

01

000

204

00

510

05

100

10

200

5010

00

204

00

20

400

51

0

ma

rine

lake

pre

-sa

pro

pe

licse

dim

en

tsP

r1

Pr2

sapr

op

elic

sedi

me

nts

dys

oxi

c-su

bo

xic

bo

ttom

wa

ter

con

diti

ons

ano

xic

-clo

seto

an

oxi

cbo

tto

mw

ate

rco

nd

itio

ns

Sa

p1

Sa

p2p

ost

-sa

pro

pe

licse

dim

ent

sP

o1

Po

2

Po

3s

ubo

xic

bo

tto

mw

ate

rco

nd

itio

ns

Figu

re 6

.D

ownc

ore

abun

danc

e of

dom

inan

t be

nthi

c fo

ram

inife

ral s

peci

es in

cor

e D

M18

. Sp

ecie

s fr

eque

ncie

s ar

e in

per

cent

age

of t

he t

otal

.


140

lake

pre

-sa

pro

pe

licse

dim

en

tsP

r1sa

pro

pe

licse

dim

en

ts

dys

oxi

c-su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

an

oxi

c-cl

ose

toa

no

xic

bo

tto

mw

ate

rco

nd

itio

ns

Sa

p1

Sa

p2

po

st-s

ap

rop

elic

sed

ime

nts

Po

1

Po

2

Po

3su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

S.e

xca

vataQ

uin

qu

elo

culin

asp

p.

S.t

en

uis

S.s

chlu

mb

erg

eri

B.a

lata

B.d

ilata

taB

.str

iatu

la

Po

3

Po

2

Po

1

Sa

p2

Pr1

Sa

p1

02

00

40

0

35

0

30

0

25

0

20

0

15

0

10

0

500

Depth(cm)

01

02

00

51

00

51

00

15

30

05

10

03

06

00

50

10

00

10

20

P.cr

ust

ata

TB

F

Figu

re 7

.D

ownc

ore

abun

danc

e of

dom

inan

t be

nthi

c fo

ram

inife

ral s

peci

es in

cor

e K

L40.

TBF

: Tot

al b

enth

ic f

oram

inife

ra p

rese

nted

as

num

bers

/10

g dr

y se

dim

ent.

Spe

cies

freq

uenc

ies

are

in p

erce

nt o

f to

tal.

The

low

er in

terv

al (

350–

901

cm)

of t

he c

ore

is n

ot s

how

n du

e to

abs

ence

of

a fo

ram

inife

ral f

auna

.


141

B.c

ost

ata

U.m

edite

rranea V

.bra

dya

na

H.b

alth

ica

Melo

nis

spp.

C.o

void

ea

Gyr

oid

inoid

es

sp.

Po3

Po2

Po1

Sap2

Pr1

Sap1

010

20

350

300

250

200

150

100500

Derinlik(cm)

025

50

025

50

05

10

025

50

05

10

015

30

020

40

B.m

arg

inata

lake

pre

-sa

pro

pe

licse

dim

en

tsP

r1d

yso

xic-

sub

oxi

cb

ott

om

wa

ter

con

diti

on

sa

no

xic-

clo

seto

an

oxi

cb

ott

om

wa

ter

con

diti

on

s

sap

rop

elic

sed

ime

nts

Sa

p1

Sa

p2

po

st-s

ap

rop

elic

sed

ime

nts

Po

1

Po

2

Po

3su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

Figu

re 8

.D

ownc

ore

abun

danc

e of

dom

inan

t be

nthi

c fo

ram

inife

ral s

peci

es in

cor

e K

L40.

Spe

cies

fre

quen

cies

are

in p

erce

nt o

f to

tal.

The

low

er in

terv

al (

350–

901

cm)

of t

he c

ore

is n

ot s

how

n du

e to

abs

ence

of

a fo

ram

inife

ral f

auna

.


142

ma

rin

e

lake

pre

-sa

pro

pe

licse

dim

en

tsP

r1

Pr2

sap

rop

elic

sed

ime

nts

dys

oxi

c-su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

an

oxi

c-cl

ose

toa

no

xic

bo

tto

mw

ate

rco

nd

itio

ns

Sa

p1

Sa

p2

po

st-s

ap

rop

elic

sed

ime

nts

Po

1

Po

2

Po

3su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

TP

FG

.bullo

ides

G.r

uber

N.p

ach

y.(d

ex)

T.quin

quelo

ba

N.p

ach

y.(s

in)

Po3

Po2

Po1

Sap2

Pr2

Pr1S

ap1

-0.5

0.5

1.5

400

300

200

1000

Depth(cm)

-4-3

-2-1

01500

3000

010

20

025

50

050

100

010

20

050

100

no

dat

a

�18O

(‰)

�13

C(‰

)

Figu

re 9

.δ1

8 O a

nd δ

13C

reco

rds

of p

lank

tic f

oram

inife

ra T

urbo

rota

lita

quin

quel

oba

and

abun

danc

es o

f do

min

ant

plan

ktic

for

amin

ifera

l spe

cies

in c

ore

DM

18.

TPF:

Tot

al p

lank

toni

cfo

ram

inife

ra p

rese

nted

as

num

bers

/10

g dr

y se

dim

ent.

Spe

cies

fre

quen

cies

are

in p

erce

nt o

f th

e to

tal.

δ18 O

(‰

)δ1

3 C (

‰)


143

lake

Pr1

dys

oxi

c-su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

an

oxi

c-cl

ose

toa

no

xic

bo

tto

mw

ate

rco

nd

itio

ns

Sa

p1

Sa

p2

Po

1

Po

2

Po

3su

bo

xic

bo

tto

mw

ate

rco

nd

itio

ns

TP

FN

.pa

chy.

(de

x)N

.pa

chy.

(sin

)T.

qu

inq

ue

lob

aG

.bu

lloid

es

G.r

ub

er

Po

3

Po

2

Po

1

Sa

p2

Pr1

Sa

p1

0700

1400

350

300

250

200

150

100

500

Depth(cm)

020

40

05

10

030

60

05

10

050

100

sapro

pelic

sedim

ents

post

-sapro

pelic

sedim

ents

pre

-sapro

pelic

sedim

ents

Figu

re 1

0.D

ownc

ore

abun

danc

e of

dom

inan

t pl

ankt

ic f

oram

inife

ral

spec

ies

in c

ore

KL4

0. T

PF:

Tota

l pl

ankt

ic f

oram

inife

ra p

rese

nted

as

num

bers

/10

g dr

y se

dim

ent.

Spe

cies

fre

quen

cies

are

in

perc

ent

of t

otal

. Th

e lo

wer

int

erva

l (3

50–9

01 c

m)

of t

he c

ore

is n

otsh

own

due

to a

bsen

ce o

f fo

ram

inife

ral f

auna

.

However, typical marine Late Pleistocene records werenot observed. The ostracoda fauna in this zone includesspecies with thin and fragile carapaces such as Candonacandida, Candona sp., Darwinula sp. and Leptocytherelacertosa in DM18 and Callistocythere littoralis,Callistocythere sp., Candona candida, Candona sp.,Candona (Pseudocandona) sp., Heterocypris sp.,Leptocythere castanea, L. lacertosa, L. psammophila,Loxoconcha rhomboidea and Tyrrhenocythere amnicola inKL40. The most common and dominant species isCandona candida. This species is one of the best-knownbenthic freshwater cypridoids. The maximum toleratedsalinity for Candona candida reported in the literature is5.77‰ (Meisch 2000). Other ostracod species, such asCallistocythere littoralis, Callistocythere sp., Darwinulasp., Heterocypris sp., Leptocythere castanea, L. lacertosa,L. psammophila, Loxoconcha rhomboidea andTyrrhenocythere amnicola have sporadic occurrences; atpresent they generally live in oligohaline (0.5–5‰) andmesohaline (5–18‰) environments (van Morkhoven1963; Guillaume et al. 1985; Besonen 1997).

Sapropelic Sediments (Sap). (Sap) sediments, definedby the Corg value >1.5% (Figure 3) include two zones,based on abundance and distribution pattern offoraminiferal fauna (Figures 4–10, Appendices 2 & 3).The lower parts of the (Sap) contain only a few benthicspecies (Sap1 zone). The (Sap2) zone is characterized byrelatively abundant benthic foraminiferal assemblages,dominated by infaunal life-style-taxa, such as Brizalinaalata, B. dilatata, Bulimina costata, B. marginata, Hyalineabalthica and Chilostomella ovoidea. The transition fromthe (Sap) sediments to the (Po) sediments ischaracterized by a sharp decrease in total benthicforaminifera (TBF) (Figures 4 & 7). The planktonicforaminiferal fauna of the (Sap) sediments are dominatedby cold-water assemblages, including abundantly shallow-dwellers Turborotalita quinqueloba (Bé 1977; Hemlebenet al. 1989; Ottens 1992; Stangeew 2001), Globigerinabulloides and subordinately specimen ofNeogloboquadrina pachyderma (Figures 9 & 10). The(Sap1) zone includes low TPF consisting mainly ofGlobigerina bulloides and Turborotalita quinqueloba. In


144

NANNOFOSSILS

53-5

5

73-7

5

83-8

5

93-9

5

101-

103

191-

193

311-

313

391-

393

403-

406

519-

521

549-

551

589-

591

629-

631

809-

811

829-

831

869-

871

Braarudosphaera bigelowii (Gran & Braarud) rR RF FC FC RCalcidiscus leptoporus (Murray & Blackman) - r - - rCalciosolenia murrayi Gran - - - - rCoronosphaera mediterranea (Lohmann) RF F FC F RFCoccolithus pelagicus (Wallich) RF RF F RF RFCrenalithus doronicoides (Black & Barnes) r - r - rDictyococcites antarcticus Haq RF rR R R rDictyococcites productus (Kamptner) RF R RF R FEmiliania huxleyi (Lohmann) FC FC C FC CGephyrocapsa ericsonii McIntyre & Bé FC FC FC FC FGephyrocapsa muellerae Bréhéret R R r rR rRGephyrocapsa oceanica Kamptner - - r r RHelicosphaera carteri (Wallich) R r R F RFHelicosphaera hyalina (Gaarder) RF R F F FHelicosphaera wallichii (Lohmann) RF R F F FSyracosphaera pulchra Lohmann r R R RF rThoracosphaera spp. RF R r rR RUmbellosphaera irregularis Paasche - - r - rUmbilicosphaera sibogae (Weber-van Bosse) r r - r r +Reworked Nannofossils (ratio in the samples) 35% 20% 30% 30% 35%

BIOZONE NN21 E. huxleyi Zone

Depth (cm)

100% extrabasinal nannofossil assemblages

reworked fromUpper Maastrichtian, Lower Paleocene,

Upper Eocene, Lower Miocene and Mio -Pliocene sedimentary rock sources

Explanation: r 1 specimen in per 100 area rR 2 specimen in per 100 area R 3 - 5 specimen in per 100 area RF 6 - 9 specimen in per 100 area F 10 - 15 specimen in per 100 area FC 16 - 50 specimen in per 100 area C 51 - 100 specimen in per 100 area

Table 4. General characteristics of the nannofossils assemblages in the studied levels of core KL40.

the (Sap2) zone the occurrence of Neogloboquadrinapachyderma increases according to the TPF value. Thehighest abundance of Globigerina bulloides is observedonly in the (Sap) layer.

Post-sapropelic Sediments (Po). Due to the differentsedimentation rates the thicknesses of the (Po) intervalare ~230 cms in core DM18 and ~100 cms in core KL40.The (Po) sediments are characterized by high abundanceof TPF which displays some maxima, up to 2500specimen/10 g (Figures 9 & 10). Considering both theTBF and TPF distributions, three zones can be identified(Po1, Po2, Po3; Figures 4–10). The TBF and the speciesrichness start to increase in (Po1); the assemblage isrepresented mainly by Sigmoilinita tenuis, Brizalinadilatata, Bulimina costata, B. marginata, and by minornumbers of Quinqueloculina spp., Spiroloculina excavata,Neolenticulina peregrina, Amphicoryna scalaris, Melonisspp. and Chilostomella ovoidea (Figures 4–8). TBFdecreases in the (Po2) zone, but diversity remains nearlythe same (average number of species in the Po1 zone=14; average number of species in the Po2 zone= 12). Theoccurrences of Sigmoilinita tenuis, Brizalina dilatata,Bulimina costata and B. marginata decrease, whileChilostomella ovoidea and other benthic species continueto occur sporadically with low abundance. The (Po3) zoneincludes the top parts of the cores; it shows the highestTBF and the most diverse benthic foraminiferal fauna (27species, Figures 4–8). The most dominant taxa areBulimina costata and Uvigerina mediterranea togetherwith subordinate numbers of Spiroloculina excavata,Quinqueloculina spp., Miliolinella subrotunda, Sigmoilinitatenuis, Sigmoilopsis schlumbergeri, Lenticulina sp.,Brizalina alata, B. dilatata, Bulimina marginata, Melonisspp., Chilostomella ovoidea and some agglutinated formssuch as Eggerella scabra, Bigenerina nodosaria,Pseudoclavulina crustata, Sigmoilopsis schlumbergeri,Siphotextularia sp. and Textularia spp.

Regarding the planktonic foraminifera, the TPF valuestarts to increase within the (Po1) zone and the faunainclude predominantly Turborotalita quinqueloba andNeogloboquadrina pachyderma (Figures 9 & 10).Abundant Globigerinoides ruber defines zone (Po2). TPFstarts to decrease in the (Po3) zone and is represented byTurborotalita quinqueloba, with lesser numbers ofNeogloboquadrina pachyderma (both dextral and sinistralmorphotypes).

(Po) sediments also include nannofossils. NN21Emiliania huxleyi Interval Zone (Martini 1971) wereidentified (Table 4 & Plate I). Emiliania huxleyi isaccompanied by Braarudosphaera bigelowii, Coccolithuspelagicus, Coronosphaera mediterranea, Dictyococcitesantarcticus, D. productus, Gephyrocapsa ericsonii, G.muellerae, G. oceanica, Helicosphaera carteri, H. hyalina,H. wallichii, Syracosphaera pulchra, Thoracosphaera spp.and Umbilicosphaera sibogae. However, the presence ofBraarudosphaera bigelowii, Helicosphaera carteri, H.hyalina and H. wallichii within the zone is conspicuous. Inaddition, approximately 20–35% of reworked formsconsisting of Cretaceous, Early or Late Tertiary speciesoccur at this level of the core. The abundance of Emilianiahuxleyi and the absence of Pontosphaera indooceanicaindicate that these levels were deposited during theHolocene.

Stable Isotope Records

The δ13C and δ18O records of planktonic foraminiferaTurborotalita quinqueloba in core DM18 extend from thetop to 328 cms (within the [Sap] layer). The δ13C andδ18O values range from -3.18 to -1.92‰ and from 1.28to -0.20‰, respectively (Figure 9). The higher δ18Ovalues (between 1.28 and 0.54‰) occur within the (Sap)layer. The transition from the (Sap) sediments to the (Po)sediments is marked by a sharp decrease in δ18O valueswith 0.95‰ depletion. The most depleted values areobserved within the (Po) sediments, where it is possibleto distinguish three patterns towards the top of the core:(i) between 226 and 158 cms, δ18O value increases from0.08‰ to 0.51‰; (ii) between 158 and 58 cms, δ18Ovalues display fluctuations from -0.20 to 0.55‰; (iii) inthe uppermost part of the core, δ18O values fluctuatebetween 0.45 and 0.85 ‰. Although there is nostatistically strong correlation between isotopes and TBF;TPF values along the core and the biostratigraphic zoneboundaries correspond to major changes in isotopedistributions (Figure 9).

Discussion

Lake Stage and Initial Colonisation–Pre-sapropelicDeposition

Cores DM18 and KL40 recovered from the Central Basinof the Marmara Sea record the last lowstand stage of theMarmara Sea. The lower parts of the cores (Pr1 zone,


145

Figures 4–10) are nearly totally barren of benthic andplanktonic foraminifera. The (Pr1) zone between 170and 901 cms in KL40 includes mixed/old nannofossilsalthough characteristic Late Pleistocene forms were notobserved (Table 4). Very rare occurrences of marinefauna and flora and the presence of fresh-brackish waterostracods in the (Pr1) zone denote the lake stage of theMarmara Sea when it was isolated from the Black Sea andthe Aegean Sea during Last-glacial time when sea levelwas below the sill depth of the Çanakkale Strait. Theseresults are in agreement with Stanley & Blanpied (1980),Ça¤atay et al. (2000), Aksu et al. (2002a) and Kaminskiet al. (2002). The salinity of the Marmara Lake must havebeen much lower than that of the Mediterranean waters,as inferred from oligohaline and mesohaline ostracodaspecies recorded in the (Pr1) zone. Thus sudden waterstratification is likely expected to occur during theinvasion of Mediterranean waters. The first colonizationof foraminiferal species such as Bulimina aculeata, B.elongata, B. marginata and Turborotalita quinquelobaoccurs at about 11–10.4 ky BP in core DM18 based onthe interpolated 14C ages (Pr2 zone: from 345 to 370cms, Figures 5, 6 & 9). These assemblages denote thestart of marine conditions and record salineMediterranean Sea water inflow through the ÇanakkaleStrait before the sapropelic deposition. TheMediterranean influence at shallower sites (~550 and110 m water depths) is recorded by Turborotalitaquinqueloba, Fursenkoina together with subordinatenumbers of Brizalina and Bulimina species and Aubignynaperlucida, Cassidulina carinata, Fursenkoina acuta andHaynesina depressula, respectively (Aksu et al. 2002a;Kaminski et al. 2002).

Sapropelic Deposition

The benthic foraminiferal assemblage of the (Sap)interval allows determination of the oxygen level ofbottom water during deposition of the sapropelicsediments in the Marmara Sea. The lower part of thesapropelic layer (Sap1 zone) is almost barren of benthicforaminifera indicating that the first stage of sapropelicdeposition started under anoxic-close to anoxic bottomwater conditions (Figures 4–8). The first appearance ofspecies such as Brizalina alata, B. dilatata, Buliminacostata, B. marginata, Hyalinea balthica and Chilostomellaovoidea in the (Sap2) zone is indicative of dysoxic andsuboxic environments. On the basis of test morphology

(Kaiho 1991, 1994), the genera Brizalina andChilostomella are considered dysoxic indicators and somespecies of the genera Bulimina are suboxic indicators(Aksu et al. 2002a). Considering the microhabitat,Brizalina alata, B. dilatata and Chilostomella ovoidea aredeep infaunal species (Jorissen 1999a; Kitazato et al.2000), whereas Bulimina costata, B. marginata andHyalinea balthica are infaunal, shallow-deep infaunal andshallow infaunal, respectively (Rathburn et al. 1996;Jorissen et al. 1998; Jorissen 1999a, b; Schmiedl et al.2000). Selected species of deep-infaunal taxa can livedown to 10 cms depth in sediments (Jorissen 1999b) andcan tolerate very low oxygen conditions (Jorissen1999a). In this case, it is likely that the deep infaunal taxaare more resistant to low oxygen conditions compared toshallow-infaunal taxa because of the decreasing dissolved-oxygen content downward in sediments resulting fromorganic degradation. Combining the test morphology andmicrohabitat, we assume that Brizalina alata, B. dilatata,Bulimina marginata and Chilostomella ovoidea are dysoxicindicators, whereas Bulimina costata and Hyalineabalthica are suboxic indicators. These assemblages in(Sap2) zone show that anoxic-close to anoxic bottomwater conditions in the initial stage of the sapropelicdeposition must have changed to dysoxic-suboxicconditions in the (Sap2) zone (Figures 4–8). Near the topof the (Sap2) zone, the maximum abundance ofGyroidinoides, which is an indicator of suboxic conditions(Kaiho 1994), clearly indicates establishment of suboxicconditions in the bottom waters (Figures 6 & 8). At thesame level, the frequency of dysoxic species becomes lessabundant. This might be related to the decreasing organicmatter input as indicated by the decreasing Corg content(Figure 3). Some benthic foraminifera are highlyresponsive to organic flux changes and cannot surviveunder constantly reduced food availability (Altenbach &Sarnthein 1989; Gupta 1999; Jian et al. 1999; De Rijk etal. 2000; Kitazato et al. 2000; Wollenburg & Kuhnt2000).

The significant occurrence of Globigerina bulloides inthe (Sap1-2) zones can testify to enhanced productivity inthe surface waters of the Marmara Sea during sapropelicdeposition as previously shown by Rohling et al. (1997)and Sperling et al. (2003). Its absence and/or presencewith

the sapropel interval was also reported by Aksu et al.(2002a) and Sperling et al. (2003), but not interpretedas a sign of enhanced productivity during deposition ofthe sapropel by Aksu et al. (2002a).

The δ18O records of Turborotalita quinqueloba displaythe most enriched δ18O values ranging from 1.28 to0.54‰ and occur within the (Sap1-2) zones in coreDM18 (Figure 9). The δ18O value sharply decreases at theboundary between the (Sap) and (Po) sediments. Thistrend suggests that a relative freshening of the surfacewaters occurred after deposition of the (Sap) sediments.If Black Sea waters had strongly outflowed into theMarmara Sea at about 11–10 ky BP the δ18O valueswithin the sapropelic layer should be depleted. However,the sapropelic layer displays the most enriched δ18Ovalues. The distribution patterns of δ18O and Corg contentsbetween the (Sap) and (Po) sediments suggest that thesurface waters of the Marmara Sea were relatively salineduring deposition of the sapropelic sediments and theremust have been a relative freshening after the sapropelicdeposition. Turborotalita quinqueloba lives mostly in thephotic zone and bears symbionts (Hemleben et al. 1989).On the other hand, considering that the habitat of thisspecies reflects the deeper layer, but not the surfacewater layer (Carstens et al. 1997; Niebler et al. 1999), itis possible that a relatively thin surface layer withbrackish water from the Black Sea might have existed.However abruptly depleted δ18O values of this species atthe end of the sapropelic deposition clearly indicate theincreasing brackish water inflow after deposition of thesapropelic sediments. This view contrasts with previousconclusions concerning formation of the sapropelic layersin the Marmara Sea (Ça¤atay et al. 2000; Aksu et al.2002a). Multi-proxy data from core sediments in theMarmara Sea and Black Sea shelf areas indicate that theBlack Sea strongly outflowed into the Marmara Sea atabout 11–10 ky BP causing a strong water stratificationthat initiated sapropelic deposition (Aksu et al. 2002a, b).In addition, the formation of a delta located at thesouthern exit of the ‹stanbul Strait has been related to thepresence of strong and persistent outflow of the BlackSea (Aksu et al. 2002a; Hiscott et al. 2002; Kaminski etal. 2002).

In these studies, depleted δ18O from the plankticforaminiferal tests and the planktonic foraminiferaltransfer functions have been considered as signatures ofa significantly reduced surface water salinity and

temperature during the sapropel deposition interval.Although the same planktonic foraminifera have beenused in our study, an opposite isotopic data trend wasfound. This contradiction remains partially unexplained.On the other hand, deltaic deposition at the southern exitof the ‹stanbul Strait was evidently linked to local riveractivity (the Kurba¤alı stream) with east–west-prograding parasequences located on the eastern side ofthe ‹stanbul Strait and not to the strong outflow of theBlack Sea (Gökaflan et al. 2005).

On the other hand, our isotopic data support theresults of Sperling et al. (2003). These latter authorspointed out that the Black Sea is not a major factor forthe formation of organic-rich sediments in the MarmaraSea on the basis of the heavy δ18O values recorded on T.quinqeeloba of the sapropelic sediments. Consequently;absence or presence (regarding the habitat of T.quinqueloba) of thin Black Sea-originating low salinitysurface waters declining with strong Black Sea outflow atabout 11–10 ky BP. The main conditions for sapropelicdeposition must be the enhanced productivity at thesurface waters as shown by high abundances ofGlobigerina bulloides. Water stratification and/or bottomwater anoxia for preserving the sapropelic sedimentsmight be produced by stratification between salineMediterranean waters and Marmara Lake watersfollowing the connection with the Mediterranean Sea viathe Çanakkale Strait.

Post-sapropelic Deposition

The (Po) sediments reflect depositional conditions duringthe last ~6 ky BP in the Marmara Sea. The benthicforaminiferal assemblages of the (Po1-3) zones showthat suboxic bottom conditions continued from the laststage of sapropelic deposition up to the present day.Although Miliolids are generally considered indicators ofoxic conditions (Kaiho 1994), their occurrences arelimited only to small forms (

present-day. At present-day condition, nutrient-rich,brackish Black Sea waters constitute the upper layer ofthe Marmara Sea. However, sapropelic sediments do notoccur and the enhanced food dependent speciesGlobigerina bulloides occurs in only minor amounts,which weakens the low-salinity, nutrient rich water-source view of sapropelic deposition. Globigerinoidesruber, indicating warm waters, occurs in maximumabundance only in the (Po2) zone and disappears in theupper parts of the cores, indicating an intermittent shortterm change. Planktonic foraminifera generally decreasein the (Po3) zone in the uppermost part of the cores.Biostratigraphical zones in post-sapropelic sedimentsprobably reflect variations in sea level and/or local climaticconditions.

Conclusions

The core sediments from the Marmara Sea includevarious biostratigraphical zones that are characterized bytheir TBF, TPF and distinct assemblages in eachdepositional section. The pre-sapropelic sediments reflectthe lake stage of an isolated Marmara Sea and also thebeginning of marine conditions through the ÇanakkaleStrait at about 11 ky BP. Benthic foraminiferalassemblages of the sapropelic sediments show that theinitial stage of the sapropelic sedimentation occurredunder anoxic-close to anoxic bottom water conditions at10.3 ky BP and continued into dysoxic-suboxicconditions. The leading conditions for sapropelicdeposition inferred from the confined abundance ofGlobigerina bulloides within the sapropelic sedimentswere enhanced by primary productivity of the surfacewaters of the Marmara Sea. The most enriched δ18Ovalues within the sapropelic sediments and the most

depleted values within the post sapropelic sedimentssuggest that relative freshening of the surface watersmust have occurred after deposition of the sapropelicsediments, but not during their deposition in theMarmara Sea. This finding implies the presence of only athin Black Sea flow into the Marmara Sea duringsapropelic deposition. Termination of sapropelicdeposition at about 6.2 ky BP together with the mostdepleted isotope signals in post-sapropelic sedimentssuggest that a Black Sea outflow, probably similar to thepresent-day, had been established. Benthic foraminiferalassemblages within the (Po1-3) zones show that suboxicbottom conditions continued from the last stage of thesapropelic layer up to the present. Three zones in post-sapropelic sediments imply small variations during theestablishment of present-day oceanographical conditions.Further studies will be necessary for a betterunderstanding of these changes.

Acknowledgements

We thank the scientists, technicians, captains and crewson board the R/V Sismik-1 of the General Directorate ofthe Mineral Research and Exploration (MTA) and R/VMeteor of Federal Republic of Germany for their experthelp during the collection of cores. Special thanks are dueto Uwe Pflaumann (Kiel University), who supplied thecomparitive material for description of the planktonicforaminifera. We are also grateful to useful commentsmade by the referees Romana Melis and JoachimSchoenfeld for improving the earlier version of thismanuscript. This research was supported by the ResearchFoundation of ‹stanbul University (Project no: T-179/06032003). John D. Piper edited the English of finaltext.


148

References

ABRAJANO, T., AKSU, A.E., HISCOTT, R.N. & MUDIE, P.J. 2002. Aspects ofcarbon isotope biochemistry of late Quaternary sediments fromthe Marmara Sea and Black Sea. Marine Geology 190, 151–165.

AKSU, A.E., YAfiAR, D., MUDIE, P.J. & GILLESPIE, H. 1995. Late glacial-Holocene paleoclimatic and paleoceanographic evolution of theAegean Sea: micropaleontological and stable isotopic evidence.Marine Micropaleontology 25, 1–28.

AKSU, A.E., HISCOTT, R.N. & YAfiAR, D. 1999. Oscillating Quaternarywater levels of the Marmara Sea and vigorous outflow into theAegean Sea from the Marmara Sea-Black Sea drainage corridor.Marine Geology 153, 275–302.

AKSU, A.E., HISCOTT, R.N., KAMINSKI, M.A., MUDIE, P.J., GILLESPIE, H.,ABRAJANO, T. & YAfiAR, D. 2002a. Last glacial–Holocenepalaeoceanography of the Black Sea and Marmara Sea: stableisotopic, foraminiferal and coccolith evidence. Marine Geology190, 119–149.

AKSU, A.E., HISCOTT, R.N., MUDIE, P.J., ROCHON, A., KAMINSKI, M.A.,ABRAJANO, T. & YAfiAR, D. 2002b. Persistent Holocene outflowfrom the Black Sea to the eastern Mediterranean contradictsNoah’s Flood hypothesis. GSA Today 12, 4–10.

ALAVI, S.N. 1988. Late Holocene deep-sea benthic foraminifera from theSea of Marmara. Marine Micropaleontology 13, 213–237.


149

ALTENBACH, A.V. & SARNTHEIN, M. 1989. Productivity record in benthicforaminifera. In: BERGER, W.H., SMETACEK, V.S. & WEFER, G. (eds),Productivity of the Oceans, Present and Past. Dahlem-Konferenzen, John Wiley and Sons, New York, 255–269.

BAfiARAN, S. 2002. Marmara Denizi’nde Kütle Hareketi Kökenli DepolarınSedimentolojik Özellikleri [Sedimentological Characteristics ofMass Movement Deposits from the Marmara Sea]. MSc Thesis,‹stanbul University, Institute of Marine Sciences and Management,‹stanbul, Turkey [in Turkish with English abstract, unpublished].

BATSCH, A.I.G.C. 1791. Sechs Kupfertafeln mit Conchylien desSeesandes, gezeichnet und gestochen von A.J.G.K. Batsch, Jena.

BÈ, A.W.H. 1977. An ecological, zoogeographic and taxonomic rewievof recent planktonic foraminifera. In: RAMSAY, A.T.S. (ed), OceanicMicropaleontology. Academic Press, New York, 1–100.

BERTHOıS, L. & LE CALVEZ, Y. 1959. Deuxième contribution à l’étude de lasédimentation dans le golfe de Gascogne. Reveu TraveauxInstitute Pêches Maritimes 23, 325–376.

BESONEN, M.R. 1997. The Middle and Late Holocene Geology andLandscape Evolution of the Lower Archeron River Valley, Epirus,Greece. MSc Thesis, The University of Minnesota [unpublished].

BOLLI, H.M. & SAUNDERS, J.B. 1985. Oligocene to Holocene low latitudeplanktic foraminifera. In: BOLLI, H.M., SAUNDERS, J.B. & PERCH-NIELSEN, K. (ed), Plankton Stratigraphy. Cambridge UniversityPress, Cambridge, 155–262.

BRADY, H.B. 1879. Notes on some reticularian Rhizopoda of theChallenger Expedition. Part 2. Additions to the knowledge ofporcellaneous and hyaline types. Quarterly Journal ofMicroscopical Science, New Series 19, 261–299.

BRADY, H.M. 1881. Notes on some of the reticularian Rhizopoda of theChallanger Expedition. Part III. 1. Classification. 2. Further noteson new species. 3. Note on Biloculina mud. Quarterly Journal ofMicroscopical Science, New Series 21, 31–71.

BROTZEN, F. 1936. Foraminiferen aus dem schwedischen unterstenSenon von Eriksdal in Schonen. Arsbok Sveriges GeologiskaUndersökning 30, 1–206.

CALVERT, S.E. 1990. Geochemistry and origin of the Holocene sapropelin the Black Sea. In: ITTEKKOT, V. (ed), Facts of ModernBiogeochemistry. Springer-Verlag, Berlin, 327–353.

CALVERT, S.E., VOGEL, J.S. & SOUTHON, J.R. 1987. Carbon accumulationrates and origin of the Holocene sapropel in the Black Sea.Geology 15, 918–921.

CANER, H. 2005. Late Quaternary climate changes shown bypalynological records fom the Marmara Sea. 1st Plenary Meetingand Field Trip of Project IGCP-521 Black Sea-MediterraneanCorridor During the Last 30 ky: Sea Level Change and HumanAdaptation (2005-2009), Extended Abstracts, 8–15 October2005, ‹stanbul, 26–28.

CARSTENS, J., HEBBELN, D. & WEFER, G. 1997. Distribution of planktonicforaminifera at the ice margin in the Arctic (Fram Strait). MarineMicropaleontology 29, 257–269.

CIMERMAN, F. & LANGER, M.R. 1991. Mediterranean Foraminifera.Slovenska Akademija Znanossti in Umetnosti, Ljubljana.

CITA, M.B., DE LANGE, G.J. & OLAUSSON, E. 1991. Anoxic basins andsapropel deposition in the Eastern Mediterranean: Past andpresent. Marine Geology 100, 1–4.

CUSHMAN, J.A. 1922a. Foraminifera of the Atlantic Ocean: Part 3-Textulariidae. Bulletin of the United States National Museum 104,1–143.

CUSHMAN, J.A. 1922b. Shallow-water foraminifera of the TortugasRegion. Publications of the Carnegie Institution of Washington,no. 311, Department of Marine Biology 17, 1–85.

CUSHMAN, J.A. 1923. The Foraminifera of the Atlantic Ocean: Part4–Lagenidae. Bulletin of the United States National Museum 104,1–228.

CUSHMAN, J.A. 1924. Samoan foraminifera. Publications of the CarnegieInstitution of Washington, no. 342, Department of MarineBiology 21, 1–75.

CUSHMAN, J.A. 1936. New genera and species of the familiesVerneuilinidae and Valvulinidae and of the subfamily Virgulininae.Special Publications Cushman Laboratory for ForaminiferalResearch 6, 1–71.

CUSHMAN, J.A. & EDWARDS, P.G. 1937. Astrononion a new genus of theforaminifera, and its species. Contributions from the CushmanLaboratory for Foraminiferal Research 13, 29–36.

CZJZEK, J. 1848. Beitrag zur Kenntniss der fossilen Foraminiferen desWiener Beckens. Haidinger’s NaturwissenschaftlicheAbhandlungen, Wien 2, 137–150.

ÇA⁄ATAY, M.N., ALGAN, O., SAKıNÇ, M., EASTOE, C.J., EGESEL, L., BALKıS, N.,ONGAN, D. & CANER, H. 1999. A mid-late Holocene sapropelicsediment unit from the southern Marmara Sea shelf and itspalaeoceanographic significance. Quaternary Science Reviews 18,531–540.

ÇA⁄ATAY, M.N., GÖRÜR, N., ALGAN, O., EASTOE, C., TCHAPALYGA, A., ONGAN,D., KUHN, T. & KUfiÇU, ‹. 2000. Late Glacial-Holocenepalaeoceanography of the Sea of Marmara: timing of connectionswith the Mediterranean and Black seas. Marine Geology 167,191–206.

DE RIJK, S., JORISSEN, F.J., ROHLING, E.J. & TROELSTRA, S.R. 2000. Organicflux control on bathymetric zonation of Mediterranean benthicforaminifera. Marine Geology 40, 151–166.

EGGER, J.G. 1893. Foraminiferen aus Meeresgrundproben, gelothet von1874 bis 1876 von S.M.Sch.Gazelle. Abhandlungen derBayerischen Akademie der Wissenschaften Mathematisch-Physik18, 193–458.

EHRENBERG, C.G. 1861. Elemente des tiefen Meeresgrundes imMexikanischen Golfstrome bei Florida; über dieTiefgrund–Verhältnisse des Oceans am Eingange der Davisstrasseund bei Island. Monatsbericht der Königlichen PreussischenAkademie der Wissenschaften zu Berlin 1861, 275–315.

EMILIANI, C. 1949. Studio micropaleontologico di una serie calabriana.Rivista Italiana di Paleontologia y Stratraphiae 55, 1–17.

ERIKSEN, U., FRIEDRICH, W.L., BUCHARDT, B., TAUBER, H. & THOMSON, M.S.1990. The Stronghyle Caldera: geological, palaeontological andstable isotope evidence from radiocarbon dated stromatolitesfrom Santorini. In: HARDY, D.A., KELLER, J., GALANOPOULOS, V.P.,FLEMMING, N.C. & DRUITT, T.H. (eds), Thera and the Aegean WorldIII. Santorini, Greece, 139–150.

FICHTEL, L. VON & MOLL, J.P.C. VON, 1798. Testacea microscopica, aliaqueminuta ex generibus Argonatua et Nautilus, ad naturam picta etdescripta (Microscopische und andere klein Schalthiere aus dengeschlechtern Argonaute und Schiffer). Vienna, Camesina.

FORNASINI, C. 1900. Intorno ad alcuni esemplari di foraminiferi Adriatici.Memorie della Reale Academia della Scienza dell’Istituto diBolognia, Sezzione dell Scienze Naturali, Serie 5, 357–402.

GAUDETTE, H., FLıGHT, W., TONES, L. & FOLGER, D. 1974. An inexpensivetitration method for the determination of organic carbon in recentsediments. Journal of Sedimentary Petrology 44, 249–253.

GAZ‹O⁄LU, C., GÖKAfiAN, E., ALGAN, O., YÜCEL, Z., TOK, B. & DO⁄AN, E.2002. Morphologic features of the Marmara Sea from multi-beam data. Marine Geology 190, 397–420.

GÖKAfiAN, E., ALGAN, O., TUR, H., MER‹Ç, E., TÜRKER, A. & fi‹MfiEK, M.2005. Delta formation at the southern entrance of ‹stanbul Strait(Marmara Sea, Turkey): a new interpretation based on high-resolution seismic stratigraphy. Geo-Marine Letters 25,370–377.

GUıLLAUME, M.C., PEYPOUQUET, J.P. & TETART, J. 1985. Quaternaire etactuel. In: OERTLı, H.J. (ed), Atlas des Ostracodes de France.Bulletin Centres Recherches Exploration et Production, Elf-Aquitaine, Mémoir 9, 337–377.

GUPTA, A.K. 1999. Latest Pliocene through Holocene paleoceanographyof the eastern Indian Ocean: benthic foraminiferal evidence.Marine Geology 161, 63–73.

HAKYEMEZ, A. & TOKER, V. 1997. Marmara Denizi güney selfinde güncelplanktonik foraminifera da¤ılımı [Distribution of recent planktonicforaminifera on the southern shelf of the Sea of Marmara].Yerbilimleri (GEOSOUND) 30, 191–203 (in Turkish with Englishabstract).

HEMLEBEN, C., SPıNDLER, M. & ANDERSON, O.R. 1989. Modern PlanktonicForaminifera. Springer-Verlag, New York.

HERON-ALLEN, E. & EARLAND, A. 1913. Clare Island Survey: Part 64-Foraminifera. Proceedings of the Royal Irish Academy 31, 1–188.

HERON-ALLEN, E. & EARLAND, A. 1930. The foraminifera of the Plymouthdistrict. I. Journal of the Royal Microscopical Society 3, 46–84.

HISCOTT, R.N. & AKSU, A.E. 2002. Late Quaternary history of theMarmara Sea and Black Sea from high-resolution seismic andgravity-core studies. Marine Geology 190, 261–282.

HISCOTT, R.N., AKSU, A.E., YAfiAR, D., KAMINSKI, M.A., MUDIE, P.J.,KOSTYLEV, V.E., MACDONALD, J.C., ‹fiLER, F.I. & LORD, A.R. 2002.Deltas south of the Bosphorus Strait record persistent Black Seaoutflow to the Marmara Sea since ~ 10 ka. Marine Geology 190,95–118.

HOFKER, J. 1932. Notizen über die Foraminiferen des Golfes von Neapel,III-Die Foraminiferenfauna der Ammontatura. Estratto dellaPubblicazioni Stazione Zoologica di Napoli 12, 61–144.

HOFKER, J. 1956. Foraminifera dentata: foraminifera of Santa Cruz andThatch Island, Virginia Archipelago, West Indies. Spolia ZoologicaMusei Hauniensis 15, 1–237.

HÖGLUND, H. 1947. Foraminifera in the Gullmar Fjord and the Skagerak.Zoologiska Bidrag Från Uppsala 26, 1–328.

JıAN, Z., WANG, L., KıENAST, M., SARNTHEıN, M., KUHNT, W., LıN, H. &WANG, P. 1999. Benthic foraminiferal paleoceanography of theSouth China Sea over the last 40000 years. Marine Geology 156,159–186.

JONES, R.W. 1994. The Challenger Foraminifera. Oxford UniversityPress, Oxford.

JORISSEN, F.J. 1999a. Benthic foraminiferal successions across LateQuaternary Mediterranean sapropels. Marine Geology 153,91–101.

JORISSEN, F.J. 1999b. Benthic foraminiferal microhabitats below thesediment-water interface. In: SEN GUPTA, B.K. (ed.), ModernForaminifera. Kluwer Academic Publishers, 161–199.

JORISSEN, F.J., WITTLING, I., PEYPOUQUET, J.P., RABOUILLE, C. & RELEXANS,J.C. 1998. Live benthic foraminiferal faunas off Cape Blanch, NWAfrica; Community structure and microhabitats. Deep-SeaResearch 45, 2157–2188.

KAIHO, K. 1991. Global changes of Paleogene aerobic/anaerobic benthicforaminifera and deep sea circulation. Palaeogeography,Palaeoclimatology, Palaeoecology 83, 65–85.

KAIHO, K. 1994. Benthic foraminiferal dissolved-oxygen index anddissolved-oxygen levels in the modern ocean. Geology 22,719–722.

KAMINSKI, M.A., AKSU, A., BOX, M., HISCOTT, R.N., FILIPESCU, S. & AL-SALAMEEN, M. 2002. Late glacial to Holocene benthic foraminiferain the Marmara Sea: implications for Black Sea-Mediterranean Seaconnections following the last deglaciation. Marine Geology 190,165–202.

KIDD, R.B., CITA, M.B. & RYAN, W.B.F. 1978. Stratigraphy of easternMediterranean sapropel sequences recovered during DSDP Leg42A and their paleoenvironmental significance. Initial Reports ofthe Deep Sea Drilling Project 42, 421–443.

KITAZATO, H., SHIRAYAMA, Y., NAKATSUKA, T., FUJIWARA, S., SHIMANAGA, M.,KATO, Y., OKADA, Y., KANDA, J., MASUZAWA, T. & SUZUKI, K. 2000.Seasonal phytodetritus deposition and responces of bathyalbenthic foraminiferal populations in Sagami Bay, Japan:preliminary results from Project Sagami 1996-1999. MarineMicropaleontology 40, 135–149.

KROM, M.D., STANLEY, J.D., CLIFF, R.A. & WOODWARD, J.C. 2002. NileRiver sediments fluctuations over the past 7000 yr and their keyrole in sapropel development. Geology 30, 71–74.

KRUIT, C. 1955. Sediments of the Rhône delta: 1 – Grain size andmicrofauna. Verhandelingen van het Koninklijk Nederlandsgeolgisch minjbouwkundig, Geology Series 15, 357–514.

KUHN, T., RICHTER, S. & ALGAN, O. 2000. Core descriptions. In: PATZOLD,J., HALBACH, P.E., HEMPEL, G. & WEIKERT, H. (eds), ÖstlichesMittelmeer-Nördliches Rotes Meer 1999. Cruise no. 44, 22January–16 May, METEOR-Berrichte, Universitat Hamburg,37–39.

LINNÉ, C. 1758. Systema Naturae, 10th Edition, Volume 1. Holmiae(Stockholm): L. Salvii, 1–824.

LOEBLıCH, A.R. & TAPPAN, H. 1988. Foraminiferal Genera and TheirClassification. New York, Van Nostrand Reinhold Company.

LOEBLıCH, A.R.JR. & TAPPAN, H. 1994. Foraminifera of the Sahul Shelfand Timor Sea. Cushman Foundation for Foraminiferal Research,Special Publication no. 31, Los Angeles.

LORING, D.H. & RANTALA, R.T.T. 1992. Manual for the geochemicalanalyses of marine sediments and suspended particulate matter.Earth-Science Reviews 32, 235–283.

LOURENS, L.J., WEHAUSEN, R. & BRUMSACK, H.J. 2001. Geologicalconstraints on tidal dissipation and dynamical ellipticity of theEarth over the past three million years. Nature 409, 1029–1033.

LUTZE, G.F. 1980. Depth distribution of benthic foraminifera on thecontinental margin off NW Africa. Meteor Forschungs-ErgebnisseC32, 31–80.

MARTINI, E. 1971. Standard Tertiary and Quaternary calcareousnannoplankton zonation. In: FARINACCI, A. (ed), Proceedings II.Planktonic Conference, Roma, 1970, 739–785.


150

MEISCH, C. 2000. Freshwater Ostracoda of Western and Central Europe.In: SCHWOERBEL, J. & ZWICK, P. (eds.), Suesswasserfauna vonMitteleuropa. Spektrum Akademischer Verlag, Heidelberg, 8,1–522.

MER‹Ç, E. & SAKıNÇ, M. 1990. Foraminifera. In: MER‹Ç, E. (ed), ‹stanbulBo¤azı Güneyi ve Haliç’in Geç Kuvaterner (Holosen) Dip Tortulları[Late Quaternary (Holocene) Bottom Sediments of the SouthernBosphorus and Golden Horn]. ‹.T.Ü. Vakfı, ‹stanbul, 13–41 [inTurkish].

MER‹Ç, E., YANKO, V. & AVfiAR, N. 1995. ‹zmit Körfezi (Hersek Burnu-Kaba Burun) Kuvaterner istifinin Foraminifer Faunası[Foraminiferal fauna of the Quaternary sequence in the Gulf of‹zmit (Hersek Burnu-Kaba Burun)]. In: MER‹Ç, E. (ed), ‹zmitKörfezi Kuvaterner ‹stifi [Quaternary Sequence in the Gulf of‹zmit]. Deniz Harp Okulu Komutanlı¤ı Basımevi, ‹zmit, 103–151[in Turkish].

MER‹Ç, E., AVfiAR, N. & BERG‹N, F. 2004. Benthic Foraminifera of EasternEagean Sea (Turkey) Systematics and Autoecology. TurkishMarine Research Foundation, ‹stanbul, Turkey.

MONTAGU, G. 1803. Testacea Britannica, or Natural History of BritishShells, Marine, Land and Fresh Water, Including the Most Minute.Romsey, England: J.S. Hollis.

MTA 2004. Bathymetry of the Marmara Sea. General Directorate ofMineral Research and Exploration (MTA) of Turkey Publication.

NATLAND, M.L. 1938. New species of foraminifera from off the WestCoast of North America and from the later Tertiary of the LosAngeles Basin. University of California, Scripps Institution ofOceanography Bulletin, Technical Series 4, 137–163.

NıEBLER, H.S., HUBBERTEN, H.W. & GERSONDE, R. 1999. Oxygen isotopevalues of planktic foraminifera: a tool for the reconstruction ofsurface water stratification. In: FıSCHER, G. & WEFER, G. (eds), Useof Proxies in Paleoceanography. Springer-Verlag, Berlin,165–189.

ORBıGNY, A.D.’ 1826. Tableau méthodique de la classe des Céphalopodes.Annales des Sciences Naturelles 7, 245–314.

ORBıGNY, A.D’ 1839a. Foraminifères. In: DE LA SAGRA, R. (ed), HistoirePhysique, Politique et Naturelle de l’île de Cuba. Paris, ArthusBertrand, 1–224,

ORBıGNY, A.D’ 1839b. Foraminifères. In: BARKER-WEBB, P. & BERTHELOT,S. (ed), Histoire Naturelle des îles Canaries. Zoologie, Paris,Bethune, 119–146.

ORBıGNY, A.D’ 1839c. Voyage dans l`Amérique méridionale-Foraminifères. Paris and Strasbourg: P. Bertrand.

ORBıGNY, A.D’ 1846. Foraminifères fossiles du bassin tertiaire de Wienne(Autriche). Paris: Gide et Comp.

ORBıGNY, A.D’ 1852. Prodrome de Paléontologie StratigraphiqueUniverselle des Animaux Mollusques et Rayonnés, TableAlphabetique et Synonomique des Genres et des Especes. Paris: V.Masson.

OTTENS, J.J. 1992. Spatial dynamics of planktic foraminifera in theNortheast Atlantic. In: OTTENS, J.J. (ed), Planktonic Foraminiferaas Indicators of Ocean Environments in the Northeastern Atlantic.Academisch Proefschrift, Vrije Universiteit te Amsterdam,109–147.

PARKER, F.L. 1958. Eastern Mediterranean foraminifera, Sediment coresfrom the Mediterranean and Red Sea. Reports of the SwedishDeep-Sea Expedition 8, 219–283.

PARKER, F.L. 1962. Planktonic foraminiferal species in Pacific sediments.Micropaleontology 8, 219–254.

PERCH-NıELSEN, K. 1985a. Mesozoic calcareous nannofossils. In: BOLLı,H.M., SAUNDERS, J.B. & PERCH-NıELSEN, K. (eds), PlanktonStratigraphy. Cambridge Earth Science Series, 329–426.

PERCH-NIELSEN, K. 1985b. Cenozoic calcareous nannofossils. In: BOLLI,H.M., SAUNDERS, J.B. & PERCH-NIELSEN, K. (eds), PlanktonStratigraphy. Cambridge Earth Science Series, 427–554.

PERCONıG, E. 1954. Note paleontologicha sulla zona costiere di Agrigento(Sicilia). Contributi di Scienze Geologiche 3, 91–98.

PFLAUMANN, U. & KRASHENINNIKOV, V.A. 1978. Quaternary stratigraphyand planktonic foraminifera of the eastern Atlantic, DSDP, Leg41. Initial Reports of the Deep Sea Drilling Project, Supplement tovolumes 38, 39, 40, and 41, 883–911.

PHLEGER, F.B. & PARKER, F.L. 1951. Ecology of foraminifera, nortwestGulf of Mexico. Pt. II. Foraminifera species. Memoirs of theGeological Society of America 46, 1–64.

PICHLER, H. & FRIEDRIC, W. 1976. Radiocarbon dates of Santorinivolcanics. Nature 262, 373–374.

POLAT, Ç. & TU⁄RUL, S. 1995. Nutrient and organic carbon exchangesbetween the Black and Marmara Seas through the BosphorusStrait. Continental Shelf Research 15, 1115–1132.

RATHBURN, A.E., CORLISS, B.H., TAPPA, K.D. & LOHMANN, K.C. 1996.Comparisons of the ecology and stable isotopic compositions ofliving (stained) benthic foraminifera from the Sulu and SouthChina Seas. Deep-Sea Research 43, 1617–1646.

REUSS, A.E. 1850. Neue Foraminiferen aus den Schichten desösterreichischen Tertiärbeckens. Denkschriften der KaiserlichenAkademie der Wissenschaften, Mathematisch-Naturwissenschaftliche Classe 1, 365–390.

REUSS, A.E. 1851. Uber die fossilen Foraminiferen und Entomostraceender Septarienthone der Umgegend von Berlin. Zeitschrift derDeutschen Geologischen Gesellschaft, Berlin 3, 49–91.

ROHLING, E.J. & HILGEN, F.J. 1991. The eastern Mediterranean climate attimes of sapropel formation: a review. Geologie en Mijnbouw 70,253–264.

ROHLING, E.J., JORISSEN, F.J. & DE STIGTER, H.C. 1997. 200 Yearinterruption of Holocene sapropel formation in the easternMediterranean. Journal of Micropaleontology 16, 97–108.

ROHLING, E.J. & THUNELL, R.C. 1999. Five decades of Mediterraneanpalaeoclimate and sapropel studies. Marine Geology 153, 7–10.

ROSS, D.A. & DEGENS, E.T. 1974. Recent sediments of the Black Sea. In:DEGENS, E.T. & ROSS, D.A. (eds), The Black Sea-Geology,Chemistry, and Biology. American Association of PetroleumGeologists, Memoir 20, 183–189.

ROSSIGNOL-STRICK, M. 1983. African monsoons, an immediate climateresponse to orbital insolation. Nature 304, 46–49.

ROSSIGNOL-STRICK, M. 1985. Mediterranaean Quaternary sapropels, andimmediate response of the African monsoon to variation ofinsolation. Palaeogeography, Palaeoclimatology, Palaeoecology49, 237–263.

ROSSIGNOL-STRICK, M. 1999. The Holocene climatic optimum and pollenrecords of sapropel 1 in the eastern Mediterranean, 9000–6000BP. Quaternary Science Reviews 18, 515–530.

ROSSIGNOL-STRICK, M., NESTEROFF, W., OLIVE, P. & VERGNAUD-GRAZZINI, C.1982. After the deluge: Mediterranean stagnation and sapropelformation. Nature 295, 105–110.


151

RÖGL, F. & BOLLI, H.M. 1973. Holocene to Pleistocene planktonicforaminifera of Leg 15, Site 147 (Cariaco Basin (Trench),Caribbean Sea) and their climatic interpretation. Initial Reports ofthe Deep Sea Drilling Project 15, 553–615.

RYAN, W.B.F. 1972. The stratigraphy of late Quaternary sediments inthe eastern Mediterranean. In: STANLEY, D.J. (ed), TheMediterranean Sea: a Natural Laboratory. Dowden, Hutchinsonand Ross, Stroudsbourg, PA, 149–169.

RYAN, W.B.F., PITMAN, W.C., MAJOR, C.O., SHIMKUS, K., MOSKALENKO, V.,JONES, G.A., DIMITROV, P., GÖRÜR, N., SAKıNÇ, M. & YÜCE, H. 1997.An abrupt drowning of the Black Sea shelf. Marine Geology 138,119–126.

RYAN, W.B.F., MAJOR, C.O., LERICOLAIS, G. & GOLDSTEIN, S.L. 2003.Catastrophic flooding of the Black Sea. Annual Review of Earthand Planetary Sciences 31, 525–554.

SAIDOVA, KH. M. 1975. Bentosnye Foraminifery Tikhogo Okeana. InstitutOkeanologii P.P. Shirshova, Akademiya Nauk SSSR, Moscow.

SCHRÖTER, J.S. 1783. Einleitung in die Conchylienkenntniss nach Linné.Halle: J.J. Gebauer.

SEGUENZA, G. 1862a. Prime ricerche intorno ai Rhizopodi fossili delleargille Pleistoceniche dei dintorni di Catania. Atti AccademiaGioenia Scienze Naturali 18, 85–126.

SEGUENZA, G. 1862b. Dei terreni Terziarii del distretto di Messina; ParteII – Descrizione dei foraminiferi monotalamici delle marneMioceniche del distretto di Messina. Messina: T. Capra.

SCHLUMBERGER, C. 1891. Révision des Biloculines des grands fonds.Mémoires de la Société Zoologique de France 4, 509–511.

SCHMIEDL, G., DE BOVÉE, F., BUSCAIL, R., CHARRIÈRE, B., HEMLEBEN, C.,MEDERNACH, L. & PICON, P. 2000. Trophic control of benthicforaminiferal abundance and microhabitat in the bathyal Gulf oflions, western Mediterranean Sea. Marine Micropaleontology 40,167–188.

SCHWAGER, C. 1866. Fossile Foraminiferen von Kar Nikobar, Reise derÖsterreichischen Fregatte Novara um die Erde in den Jahren1857, 1858 1859 unter den Befehlen des Commodore B. VonWüllerstorf-Urbair. Geologischer Theil, GeologischeBeobachtungen, no. 2, Paläontologische Mittheilungen.

SGARRELLA, F. & MONCHARMONT-ZEI, M. 1993. Benthic Foraminifera of theGulf of Naples (Italy): systematics and autoecology. Bollettinodella Società Paleontologica Italiana 32, 145–264.

SILVESTRI, A. 1898. Foraminiferi Pliocenici della Provincia di Siena. ParteII, Memorie dell’Accademia Pontificia dei Nuovi Lincei 15,155–381.

SILVESTRI, A. 1903. Dimorfismo e nomenclature d’una Spiroplecta. Altrenotizie sulla struttura Siphogenerina columerralis. Atti dellaPontifica Accademia Romana dei Nuovi Lincei 56, 59–66.

SILVESTRI, A. 1904. Ricerche strutturali su alcune forme dei Trubi diBonfornello (Palermo). Memorie della Pontificia AccademiaRomana dei Nuovi Lincei 22, 235–276.

SPERLING, M., SCHMIEDL, G., HEMLEBEN, CH., EMEIS, K.C., ERLENKEUSER, H.& GROOTES, P.M. 2003. Black Sea impact on the formation ofeastern Mediterranean sapropel S1? Evidence from the MarmaraSea. Palaeogeography, Palaeoclimatology, Palaeoecology 190,9–21.

STANGEEW, E. 2001. Distribution and Isotopic Composition of LivingPlanktic Foraminifera N. pachyderma (Sinistral) and T.quinqueloba in the High Latitude North Atlantic. PhD Thesis, KielUniversity [unpublished].

STANLEY, D.J. 1978. Ionian Sea sapropel distribution and late Quaternarypaleoceanography in the eastern Mediterranean. Nature 274,149–152.

STANLEY, D.J. & BLANPIED, C. 1980. Late Quaternary water exchangebetween the eastern Mediterranean and the Black Sea. Nature266, 537–541.

STRAKHOV, N.M. 1971. Geochemical evolution of the Black Sea in theHolocene. Lithology and Mineral Resources 3, 263–274.

THIES, A. 1991. Die Benthos-Foraminiferen im E

Documents

Palaeoenvironmental Investigation of Sapropelic Sediments ......Son 6000 y›l esnas›nda çökelmiﬂ olan sapropelik çökelim sonras› sedimentler, foraminiferal faunadaki belirgin