T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz ... · T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz: Holocene salinity changes in the southwestern Black SeaHOLOCENE SALINITY

T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz: Holocene salinity changes in the southwestern Black Sea 77HOLOCENE SALINITY CHANGES IN THE SOUTHWESTERNBLACK SEA: A RECONSTRUCTION BASED ONDINOFLAGELLATE CYSTS

THOMAS J. VERLEYEKENNETH N. MERTENSSTEPHEN LOUWYEResearch Unit PalaeontologyGhent UniversityKrijgslaan 281/S8 WE13B-9000 GhentBelgiume-mail: [email protected]

HELGE W. ARZGeo Forschungs Zentrum-PotsdamTelegrafenberg14473 PotsdamGermany

Abstract

Dinoflagellate cysts were used as a proxy for reconstructing the salinity variations during the Holocene in the southwestern Black Sea. Theaim of this study was to determine the timing of the reconnection between the Black and Marmara seas. Core GeoB 7625-2, located 50 kmnortheast of the mouth of the Sakarya River, was sampled with a 200-year resolution between 7.42 and 0.52 ka BP. The lower part of thecore was sampled with varying resolution. A distinct change in the dinoflagellate cyst assemblages from freshwater/brackish water tosaltwater was observed between ~ 8.25 and ~ 7.97 ka BP, which is ~ 0.6 ka earlier than observed in other dinoflagellate cyst studies. Thisdiscrepancy may indicate the diachronous salinification of the Black Sea. The freshwater to brackish water assemblage is dominated byPyxidinopsis psilata and Spiniferites cruciformis, while the most important euryhaline species are Lingulodinium machaerophorum andcysts of Pentapharsodinium dalei. The average process length of Lingulodinium machaerophorum was used as a salinity proxy. Bothproxies suggest a gradual reconnection between the Black and Marmara seas, and these findings confirm earlier studies. Peridiniumponticum is restricted to the Black Sea; abundance fluctuations of this species were controlled by salinity variations and changes in nutrientconcentrations. Earlier studies have demonstrated that the 800 to 500 year cycles observed in the sedimentary record are related to theintensity of the discharge of the Sakarya River, and linked to the North Atlantic Oscillations. Cysts of Pentapharsodinium dalei andSpiniferites spp. fluctuated synchronously with the clay layer frequency. The poor preservation of these forms may indicate shelfal transportduring periods of intense river discharge. The variation in relative abundance of heterotrophic species does not correlate with the clay layerfrequency, since upwelling and nutrient supply also influenced their abundances. Lingulodinium machaerophorum shows the highestrelative abundances during periods with reduced river input.

Key words: dinoflagellate cysts; salinity changes; Black Sea; Holocene

Palynology, 33 (2009): 77–100© 2009 by AASP Foundation ISSN 0191-6122

INTRODUCTION

The Black Sea evolved from a freshwater to brackishwater lake into a saline sea due to the reconnection with theMarmara Sea during the Holocene (Mudie et al., 2001;Aksu, Hiscott, Mudie et al., 2002; Aksu, Hiscott, Yasar etal., 2002; Kerey et al., 2004; Marret et al., in press) (Text-Figure 1). The exact timing of the reconnection is a matterof debate. The Marmara Sea–Black Sea reconnection re-

ceived increasing attention after the publication of the“Noah’s Flood Hypothesis” by Ryan et al. (1997), whichpostulated a catastrophic flooding of the Black Sea around7.5 ka BP. This was later changed to 8.4 ka cal BP by Ryanet al. (2003). According to this hypothesis, the sudden inputof saltwater resulted in increased salinity and rapid rise ofthe water level (Ryan and Pitman, 1998). This hypothesiswas challenged by Aksu, Hiscott, Mudie et al. (2002), whohypothesized an outflow of brackish water from the Black

78 PALYNOLOGY, VOLUME 33 — 2009

Sea into the Marmara Sea before sea levels reached theBosphorus sill depth (the “Outflow Hypothesis”). Therehas also been debate on the trajectory of the reconnection(Kerey et al., 2004; Yanko-Hombach et al., 2007). Becausethe location of core GeoB 7625-2 is close to all the sug-gested paths of reconnection (i.e. the Bosphorus and IzmıtGulf–Lake Sapanca–Sakarya Valley waterway), the eventshould be registered earlier in the area studied than in moreremote areas (Text-Figure 1).

Late Quaternary dinoflagellate cysts are important indi-cators of changes in surface water salinity in the Black Sea(Wall and Dale, 1973; Mudie et al., 2001; Mudie et al.,2002; Marret et al., in press). This study aims to reconstructHolocene paleoecological changes in the southwesternBlack Sea by using variations in the dinoflagellate cystassemblages and morphological changes of Lingulodiniummachaerophorum as sea-surface salinity (SSS) indicators.The processes of Lingulodinium machaerophorum are pro-gressively reduced in length or become bulbous in responseto lower salinities (Lewis and Hallett, 1997).

OCEANOGRAPHY AND CLIMATOLOGY

Today, the Black Sea is the largest anoxic marine basinin the world. It is connected to the Marmara Sea via theBosphorus Strait, which in turn is connected by theDardanelles Strait to the Mediterranean Sea. The abyssalplain covers more than 60% of the total surface, and theaverage depth is 1240 m (Ross and Degens, 1974). Thelarge continental shelf in the northwestern Black Seareduces in width in a southerly direction. The flat topog-raphy of the shelf is deeply incised by the Sakarya canyon(Text-Figure 1), where the water depth increases from100 to 1500 m.

The circulation of the surface waters in the Black Sea isdominated by western and eastern gyres, which covervirtually the entire basin (Stanev, 2005). The narrow RimCurrent flows counterclockwise and encloses both gyres.Anticyclonal eddies are present along the coast (Aksu,Hiscott, Yasar et al., 2002). Three distinct water masses aredistinguished. These are a low salinity (17–20 psu), well-

40°34°

B L A C K S E A

30° 40°22°

40°

46°

Aegean Sea

Sakarya RiverMarmara Sea

Sea of Azov

UKRAINE

BULGARIA

TURKEY

RUSSIA

Bosphorus Strait

Dardanelles Strait

N

GeoB 7625-2-400

-1200 -1600

Sakarya River

41°30’

41°0’31°0 32°0’

1

2

2

3

swBSs

M04-2760 GeoB 7622-2

-500

m -100

0 m

-2000 m

GEORGIA

Anatolian Peninsula

25 km 50 km0 km

200 km100 km0 km

Text-Figure 1. Location map of the Black Sea; the inset represents the area of study. 1 - The dotted line indicates a possiblealternative route of the reconnection between the Izmıt Gulf, Lake Sapanca, and Sakarya Valley. 2 - Sakarya Canyon. 3 - Locationof core M02-45 (Marret et al., in press) at a depth of 69 m. The arrow indicates the direction of the inflowing saline water plumeinto the Black Sea. The dashed line represents the current course of the Sakarya River.

.

.

T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz: Holocene salinity changes in the southwestern Black Sea 79

ventilated surface water mass occupying the upper 50 to 90m of the water column, the intermediate suboxic ColdIntermediate Water Mass to a depth of approximately 150m, and a highly saline, anoxic water mass below approxi-mately 150 m (Murray, 1991). The oxic–anoxic boundarycan change by several tens of meters in a few years (Bahret al., 2006). The salinity of the upper water mass is almosthalf that of the Mediterranean Sea because of the intenseriver discharge and the restricted oceanic connection(Yanko-Hombach et al., 2007).

The water exchange between the Black and Marmaraseas occurs via the Strait of Bosphorus as a two-layerwater flow (Latif et al., 1992). The cooler (5–15°C) andless saline (17–20 psu) surface water mass from the BlackSea flows westward (Özsoy et al., 1995; Polat and Tuœrul,1996), and forms a 25–100 m thick surface layer in theBlack, Marmara and Aegean seas (Besiktepe et al., 1994).The bottom current in the Bosphorus is the eastwards-flowing warmer (15–20°C) and more saline (38–39 psu)mixed Marmara Sea and Aegean Sea water (Özsoy et al.,1995; Polat and Tuœrul, 1996). This denser water flowseastwards, cools above the southwestern Black Sea shelf,is diluted by mixing with a cold water layer at about 100m, and sinks below the pycnocline towards the abyssalplain (Özsoy et al., 1995).

According to Cullen and de Menocal (2000), Turkes andErlat (2003), and Felis et al. (2004), the climate on Anatoliais considerably affected by the Arctic Oscillation/NorthAtlantic Oscillation (AO/NAO). The present-day AO/NAO-related precipitation anomalies on Anatolia are negativeduring positive AO/NAO phases, and positive during nega-tive AO/NAO phases (Turkes and Erlat, 2003). Accordingto Lamy et al. (2006), the 800–500 year cycles reflected inthe clay layer frequencies in core GeoB 7625-2 are areflection of the precipitation conditions in Anatolia. TheSSS is positively influenced by the Bosphorus inflow, anddecreases due to precipitation and river inflow (Kara et al.,in press). The surface water temperature (SST) has beencorrelated with the variability of surface air temperature,which is strongly linked to the meridional component of thesurface wind. The latter was in turn correlated to the NAOindex by Kazmin and Zatsepin (2007).

MATERIALS AND METHODS

Gravity core GeoB 7625-2 (41°26.7’N, 31°04.0’E) wascollected during the R/V Meteor Cruise 51–4 in 2001, andis located 50 km northeast of the mouth of the SakaryaRiver in a water depth of 1242 m (Text-Figure 1). The coreis 792 cm long (Jørgensen et al., 2003). The uppermost33.5 cm were not recovered. The site is located on atopographically elevated ridge on the continental slope,

away from the pathways of turbidity currents (Lamy et al.,2006).

Ages obtained by 14C-AMS dating on the nearby coreGeoB 7622-2 (Text-Figure 1) were transferred to the up-permost 624 cm of core GeoB 7625-2 by a visual correla-tion of the distinctive lamination pattern by Lamy et al.(2006) (Text-Figure 2; Table 1). These 14C-AMS dates arefrom well-preserved shells of the larval stage of the shallowmarine mollusc Mytilus galloprovincialis. A well-knownash layer related to the Minoan eruption of Santorini(Guichard et al., 1993) was also recognized by Lamy et al.(2006). The age of the GeoB 7625-2 core top was calculatedusing the method illustrated in Appendix 1. The 14C ages ofthe section below 624 m in core GeoB 7625-2 (725–624cm), were transferred from the nearby core MD04-2760(Text-Figure 1). These 14C dates were measured on gastro-pods and ostracods by Kwiecien et al. (2008), and thecorrelation is based on the calcium record (Text-Figure 3;Table 1).

The Late Glacial to Holocene sediments of the Black Seaare divided into three lithological units (Ross and Degens,1974; Hay et al., 1991) (Text-Figure 2). The oldest Unit 3(base-633 cm) consists of lacustrine clays with sporadiccentimeter-scale laminations. The clays were depositedduring the freshwater/brackish water lake stage of theBlack Sea before ~8.14 ka BP. Unit 2 (633–384 cm) wasdeposited between ~8.14 and 3.05 ka BP and is character-ized by finely laminated sapropelic sediments. The upper-most Unit 1 (above 384 cm) is younger than 3.05 ka BP, andconsists of finely laminated coccolith ooze. Units 1 and 2were deposited under anoxic conditions.

The core was sampled at 200 year intervals from the topof the core (0.52 ka BP) to 622 cm (7.42 ka BP). Additionalsamples at irregular intervals were taken between 625 cm(7.68 ka BP) and 680 cm (10.74 ka BP). Forty nine sampleswith a weight of 1.5 to 3 g were prepared for palynologicalanalysis (Text-Figure 2), using the technique of Louwye etal. (2004). Two or four Lycopodium tablets (batch no.483216, x = 18,583) were added at the start of preparationfor estimating the concentration of palynomorphs in cystsper gram. The treatment involved demineralization withcold hydrochloric acid (6%) and cold hydrofluoric acid(40%) for the removal of carbonates and silicates respec-tively. The remaining organic fraction was then sieved at 20µm on a nylon mesh, and mounted with glycerine jelly. Aminimum of 300 dinoflagellate cysts were counted fromeach sample. Representative dinoflagellate cyst species areillustrated in Plates 1–3. All photomicrographs were takenwith a Zeiss AxioCam MRc5 camera mounted on a ZeissAxioskop 2 Plus microscope. The slides are housed in thecollection of the Research Unit Palaeontology, Ghent Uni-versity, Belgium.

¸


De

pth

(cm

)

100

200

300

400

500

600

680

Lithological units of

Core GeoB 7625-2

3.05 ka BP

Interpolated ages

50

150

250

350

450

550

650

14 C-AMS ages BP

1.170 ka BP ± 35

measured on GeoB 7622 and

MD04-2760transferred

to GeoB 7625-2

2.095 ka BP ± 30

2.385 ka BP ± 35

3.080 ka BP ± 35

Santorini ash layer3595 ka BP

4.605 ka BP ± 55

5.715 ka BP ± 25

6.590 ka BP ± 70 7.625 ka BP ± 55

8.505 ka BP ± 458.910 ka BP ± 45

Sa

mp

le

po

sitio

ns

UNIT 1

Finely laminated

coccolith ooze

8.14 ka BP

UNIT 2

Finely laminated

sapropelic

sediments

UNIT 3

Lacustrine clays with sporadic

centimeter-scale laminations

The morphological variation of Lingulodiniummachaerophorum was studied by measuring the threelongest processes on 50 cysts per sample. The longestprocesses are chosen for three reasons. Firstly, the longerprocesses reflect unobstructed growth during formationof the cyst. Secondly, since only a restricted number ofprocesses are measurable per cyst, it is necessary to havea consistent approach by choosing the longest processes.Thirdly, the largest variation is obtained by choosing the

longest processes, and this provides a more accurateproxy.

Lingulodinium machaerophorum var. clavatum is a spe-cies with bulbous processes indicative of low salinities(Lewis and Hallett, 1997). The Lingulodiniummachaerophorum var. clavatum:total Lingulodiniummachaerophorum ratio is used herein as a proxy for salinityvariation, by comparison of the trend to the process lengthvariation of Lingulodinium machaerophorum.

The taxonomy used follows Rochon et al. (1999) andFensome and Williams (2004), and the forms recognizedare listed in Appendix 2. Spiniferites ramosus sensu latoincludes Spiniferites bulloideus and Spiniferites delicatus.Spiniferites belerius is grouped with Spiniferitesmembranaceus sensu lato (Plate 3, fig. 9). Selenopemphixquanta sensu lato includes cysts of Protoperidinium nu-dum (Plate 1, fig. 9); in the dinoflagellate cyst counts theyare shown separately as Selenopemphix quanta sensustricto and cysts of Protoperidinium nudum respectively(Table 2).

RESULTS

Relative Abundance Data and Zonation

Thirty-nine dinoflagellate cyst species were identified incore GeoB 7625-2, including the organic membrane of thecalcareous dinoflagellate Scrippsiella trifida (Plate 2, fig. 9;Table 2). Pyxidinopsis psilata (Plate 3, fig. 3) and Spiniferitescruciformis (Plate 3, figs. 7, 8) are the most commonspecies in the freshwater/brackish water stage of the BlackSea before the reconnection. After the reconnection, thedinoflagellate cyst assemblages are dominated byLingulodinium machaerophorum (Plate 3, figs. 4, 5) andcysts of Pentapharsodinium dalei, together with high num-bers of Peridinium ponticum and Spiniferites spp.Peridinium ponticum (Plate 1, fig. 4) is restricted to theBlack Sea. The dinoflagellate cyst absolute abundances arehigh in zone 3 between 5.93 and 3.35 ka BP (> 100,000cysts/gram of sediment), with a distinctive peak of morethan 800,000 cysts/gram of sediment between 5.93 and5.66 ka BP. This interval is dominated by Lingulodiniummachaerophorum (> 90%) (Text-Figure 4). Before 6.8 kaBP and after 3.35 ka BP, the dinoflagellate cyst concentra-tion fluctuated by around 50,000 cysts/gram of sediment(Text-Figure 4). Five dinoflagellate cyst assemblage zonescan be distinguished (Text-Figures 3, 4).

Zone 1 comprises samples 680 to 632, and was depos-ited between 10.74 and 8.08 ka BP (Text-Figure 5). Theupper boundary is marked by a rapid decrease of therelative abundances of the freshwater/brackish water taxa(Text-Figure 4). Zone 1 is characterized by a low species

Text-Figure 2. The Holocene lithological units representedin core GeoB 7625-2.


diversity of less than 10 taxa dominated by freshwater/brackish water species (Text-Figure 6). The most abun-dant species is Pyxidinopsis psilata, with a relative abun-dance of 92% at the base of the core and 35% at the upperboundary. The freshwater/brackish water speciesSpiniferites cruciformis (see Kouli et al., 2001) has arelative abundance of 3% at the base of the core at 680 cm(10.74 ka BP), and of 25% at the top of the zone (632 cm,8.08 ka BP). Zone 1 is the only interval in which theprotoperidiniod cyst Selenopemphix nephroides (Plate 2,fig. 1) was found (< 3%). Other rare (< 1%) species in thisinterval are Brigantedinium spp. (includingBrigantedinium cariacoense, Brigantedinium simplex, andround brown cysts), Lingulodinium machaerophorum,and Tectatodinium pellitum (Plate 3, fig. 6). Spiniferitesspp. have a relative abundance of less than 1% throughoutmost of the zone, except in the uppermost samples, wherehigh proportions (30%) are present.

Zone 2, between 630 and 591 cm, was deposited between7.97 and 6.03 ka BP (Text-Figure 5). The upper boundaryis defined by the marked increase of Lingulodiniummachaerophorum. Zone 2 is dominated by cysts ofPentapharsodinium dalei, Spiniferites membranaceus sensulato, and Spiniferites ramosus sensu lato. These species

have maxima of 31%, 25%, and 30% respectively.Spiniferites bentorii occurs in low numbers (< 5%) andSpiniferites mirabilis has a lowest occurrence at 610 cm.Spiniferites spp. indet. comprises poorly-preserved speci-mens, and has a maximum relative abundance of 58% inthis zone. The relative abundance of Lingulodiniummachaerophorum fluctuated between 4 and 34%. Therelative abundance of the brackish water speciesPyxidinopsis psilata is 4% at the base of Zone 2 (630 cm;7.97 ka BP), and is reduced to less than 2% higher in thecore. Spiniferites cruciformis has a relative abundance of2% at the base of Zone 2, and of < 1% throughout theremainder of the zone. The heterotrophic species are repre-sented by Brigantedinium spp., Dubridinium caperatum(Plate 1, fig. 5), and Gymnodinium nolleri/microreticulatum(Plate 1, fig. 8). Peridinium ponticum is present sporadi-cally.

Zone 3 comprises samples 587 to 410, and was depos-ited between 5.93 and 3.23 ka BP (Text-Figure 5).Lingulodinium machaerophorum dominates this zone withmaximum relative abundance values of 70 to 90%. Therelative abundance of the cysts of Pentapharsodiniumdalei reaches a maximum of 57% at 564 cm (5.37 ka BP).The fluctuations of the relative abundance of this species

Core Depth (cm) Remarks14C-AMS Age, years BP ± Error, years

0 interpolated age based on correlation with GeoB 7622-2 523a

46 age from correlation with GeoB 7622-2 1170 ± 35




466.2 Santorini ash layer 3595b

537.5 age from correlation with GeoB 7622-2 4605 ± 55




639.5 age from correlation with MD04-2760 8505 ± 45


686 age from correlation with MD04-2760 11105 ± 60


a age calculated using the method illustrated in Appendix 1.

b age after Hammer et al. (1987).

Table 1. Age control points used for the construction of the age model of GeoB 7625-2. Above 624 cm, 14C dates were measuredon core GeoB 7622-2 and transferred to GeoB 7625-2 by a detailed visual inspection of the lamination pattern by Lamy et al.

(2006). Below 624 cm, 14C dates were measured on core MD04-2760 by Kwiecien et al. (2008) and transferred toGeoB 7625-2 based on the calcium record of both cores.


are perfectly asynchronous with the relative abundancevariations of Lingulodinium machaerophorum. Spiniferitesmembranaceus sensu lato occurs in abundances of < 10%,and is the most abundant species of Spiniferites.Operculodinium centrocarpum sensu Wall and Dale (1966)and Spiniferites mirabilis become a persistent part of thedinoflagellate cyst assemblage, although their relativeabundances remain low (< 4% and ≤ 2% respectively).The cysts of the heterotrophic species Polykrikos kofoidii/schwartzii (2–4%) and Brigantedinium spp. (≤ 10%) arepresent throughout the zone. Dubridinium caperatum wasrecorded sporadically (0–5%), while Gymnodinium nolleri/microreticulatum is rare. Notable at a depth of 539 cm(4.66 ka BP) in Zone 3 are the almost simultaneous lowestoccurrences of the peridinioid species Peridiniumponticum, and the protoperidinioid species cysts of

Protoperidinium stellatum (Plate 1, fig. 1), Selenopemphixquanta sensu lato, and Xandarodinium xanthum (Plate 2,fig. 4). Peridinium ponticum has a maximum of 12% at503 cm (4.12 ka BP), while the other species occur in lowrelative abundances of less than 3%.

Zone 4 comprises samples 392 to 302 (3.11–2.45 ka BP)(Text-Figure 5), and its lower boundary is defined by thedistinct increase of Scrippsiella trifida (Text-Figure 4).This species dominates this zone with a highest value ofmore than 30%. The intervals of decreasing numbers ofScrippsiella trifida are characterized by relative increasesof the cysts of Pentapharsodinium dalei. Lingulodiniummachaerophorum is less abundant in comparison to Zone3, and its relative abundance fluctuates between 20 and30%. The relative abundances of Spiniferites species arehigher than in Zone 3. Peridinium ponticum, cysts of

5 5 0 5 7 5 6 0 0 6 2 5 6 5 0 6 7 5 7 0 0 7 2 5 7 5 0

2 0 0

6 0 0

1 0 0 0

1 4 0 0

1 8 0 0

2 2 0 0

Cal

cium

(cp

s)

3 00 3 5 0 4 00 4 5 0 5 00 5 5 0 6 00 6 5 0 7 00 7 5 0

6

1 8

3 0

4 2

5 4

6 6

Com

posi

te C

alci

um/1

000

depth (cm) in core MD04-2760

depth (cm) in core GeoB 7625-2

MD04-2760

GeoB 7625-2

Text-Figure 3. Calcium-record of the cores MD04-2760 (Kwiecien et al., 2008) and GeoB 7625-2 used for the correlation betweenboth cores to transfer the 14C age control points from the former to the latter core. The points of correlation on core GeoB 7625-2 correspond with 725.0, 715.5, 686.0, 649.5, and 639.5 cm.


0

50

10

0

15

0

20

0

25

0

30

0

35

0

40

0

45

0

50

0

55

0

60

0

65

0

Depth (cm)

Zo

ne

1

Zo

ne

3

Zo

ne

2

Zo

ne

4

Zo

ne

5

010

0

Pyx

idin

opsi

s ps

ilata

04

Sel

enop

emph

ix n

ephr

oide

s

04 0

Spi

nife

rites

cru

cifo

rmis

form

1-4

06

Spi

nife

rites

ben

torii

03 0

Spi

nife

rites

mem

bran

aceu

s se

nsu

lato

04

Spi

nife

rites

mira

bilis

sen

su la

to

04 0

Spi

nife

rites

ram

osus

sen

su la

to

06 0

Spi

nife

rites

spp

. ind

eter

min

ate

05 0

1 00

Ling

ulod

iniu

m m

acha

erop

horu

m

06

Cys

t of P

olyk

rikos

sch

war

tzii

/ kof

oidi

i

04

Cys

t of P

roto

perid

iniu

m s

tella

tum

02

Sel

enop

emph

ix q

uant

a se

nsu

lato

02

Xan

daro

dini

um x

anth

um

04 0

Scr

ipps

iella

trifi

da

030

Per

idin

ium

pon

ticum

02 0

Brig

ante

dini

um s

pp.

06

Dub

ridin

ium

cap

erat

um

01 6

Gym

nodi

nium

nol

leri/

mic

rore

ticul

atum

06

Ope

rcul

odin

ium

cen

troca

rpum

sen

su W

all &

Dal

e 196

6

030

60

Cys

ts o

f Pen

taph

arso

dini

um d

alei

050

010

0 01 5

0 0

Dino

flage

llate

cysts

/gra

m (x

1000

)

Zo

ne

1Z

on

e 2

Zo

ne

3 -

5Z

on

e 4

Zo

ne

5O

the

rs

Zona

tion

Tex

t-Fi

gure

4.

Rel

ativ

e ab

unda

nces

of

sele

cted

din

ofla

gella

te c

ysts

in c

ore

Geo

B 7

625-

2. T

he s

peci

es a

re g

roup

ed a

ccor

ding

to th

e zo

ne o

f w

hich

they

are

cha

ract

eris

tic.

The

con

cent

ratio

n (e

xpre

ssed

in c

ysts

/gra

m) i

s al

so s

how

n. T

he z

onat

ion

1–5

on th

e ri

ght s

ide

repr

esen

ts th

e di

nofl

agel

late

cys

t zon

es b

ased

on

sim

ple

visu

al in

spec

tion.


Table 2. Numbers of dinoflagellate cysts and other palynomorphs counted.

Calibrated weight dry sample (R2 = 0.95)


Table 2 (continued).



De

pth

(cm

)

100

200

300

400

500

600

680

Zonations of

Core GeoB 7625-2

Zonations of Core M02-45

(Marret et al., in press)

2.282 ka BP

3.106 ka BP

6.031 ka BP

2.5 ka BP

4.5 ka BP

5.7 ka BP

7.0 ka BP

ZONE 5

Lingulodinium machaerophorum,

cysts of Pentapharsodinium dalei,

Peridinium ponticum,

Brigantedinium spp.,

Gymnodinium nolleri/microreticulatum

ZONE 4

Scrippsiella trifida, cysts of

Pentapharsodinium dalei,


Spiniferites membranaceus sensu lato

ZONE 3


cysts of Pentapharsodinium dalei,

Brigantedinium spp.,

Peridinium ponticum,

Spiniferites species (mainly

Spiniferites membranaceus sensu lato

Cymathiosphaera globulosa

ZONE 1P. psilata, S. cruciformis forma 1-4, Brigantedinium spp., S. nephroides,

L. machaerophorum + Pediastrum spp.

ZONE 3


Operculodinium centrocarpum,

Spiniferites spp.,

Gymnodinium catenatum/nolleri,

Peridinium ponticum

ZONE 3


O. centrocarpum, Spiniferites spp. ind.,

G. catenatum/nolleri, P. ponticum

ZONE 2

Lingulodinium machaerophorum and

morphotypes, Spiniferites belerius,

Spiniferites bentorii morphotypes

ZONE 1

Pyxidinopsis psilata, Spiniferites

cruciformis, small occurence of


Spiniferites spp.,

Brigantedinium spp., Pediastrum,

Botryococcus

7.6 ka BP

Interpolated ages

50

150

250

350

450

550

650

14C dating points

1.170 ka BP ± 35

measured on GeoB 7622

and MD04-2760and transferred to GeoB 7625-2

2.095 ka BP ± 30

2.385 ka BP ± 35

3.080 ka BP ± 35

Santorini ash layer3595 ka BP

4.605 ka BP ± 55

5.715 ka BP ± 25

6.590 ka BP ± 70 7.625 ka BP ± 55

Depth

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7.560 ka BP ± 60

0.730 ka BP ± 40

2.400 ka BP ± 60

5.190 ka BP ± 50

5.900 ka BP ± 60

8.380 ka BP ± 70

8.570 ka BP ± 70

HIATUS

8.505 ka BP ± 458.910 ka BP ± 45

8.250 ka BP (start transition zone)

7.966 ka BP (end transition zone)

Sa

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tions

ZONE 2Spiniferites species, cysts of P. dalei

8.250 ka BP

Text-Figure 5. A comparison of the biostratigraphy of core GeoB 7625-2 with core M02-45 (Marret et al., in press). The shadedarea represents the transition zone from freshwater/brackish to marine conditions, and starts with the decline of the brackishassemblage and ends almost when marine conditions were achieved. The dashed line indicates the transition zone in core GeoB7625-2 transferred to core M02-45.

1 Cyst of Protoperidinium stellatum, high focus, slide515, B36/4.

2 Lejeunecysta marieae, combined high foci, dorsal view,slide 302, B48/3.

3 Islandinium spp. indeterminate, high focus, orientationuncertain, slide 464(2), C41/0.

4 Peridinium ponticum, combined high foci, dorsal view,slide 88, D23/0.

5 Dubridinium caperatum, high focus, lateral view, slide347, H25/3.

PLATE 1

The photomicrographs were taken using transmitted light. The scale bar represents 10 µm, and the slide numbers and England Findercoordinates are quoted for each specimen.

6 Echinidinium delicatum, optical section, slide 155,E45/0.

7 Echinidinium sp. 1, high focus, orientation uncertain,slide 325, H20/2.

8 Gymnodinium nolleri/microreticulatum, high focus,slide 610, C27/0.

9 Cyst of Protoperidinium nudum, optical section, com-bined photomicrographs, slide 88, F20/4.

T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz: Holocene salinity changes in the southwestern Black Sea 89Plate 1


Protoperidinium stellatum, Quinquecuspis concreta,Selenopemphix quanta sensu lato, and Xandarodiniumxanthum occur sporadically. Brigantedinium spp. andPolykrikos kofoidii/schwartzii (Plate 2, fig. 2) form a per-sistent, but minor part of the dinoflagellate cyst assem-blage.

Zone 5 is the uppermost zone (261.5–0 cm), and itsboundaries are dated as 2.32 and 0.52 ka BP (Text-Figure5). The dinoflagellate cyst assemblage of Zone 5 is char-acterized by three dominant species: Lingulodiniummachaerophorum, cysts of Pentapharsodinium dalei andPeridinium ponticum. Their relative abundances displaylarge fluctuations. Scrippsiella trifida represents < 5% ofthe assemblage. Spiniferites membranaceus sensu lato hashighest relative abundances of 10%. Operculodiniumcentrocarpum sensu Wall and Dale (1966) occurs in smallnumbers. The heterotrophic species Brigantedinium spp.,cysts of Polykrikos kofoidii/schwartzii, and cysts ofProtoperidinium stellatum are persistently present al-though in low numbers. Gymnodinium nolleri/microreticulatum displays two prominent peaks of 9%and 11%, followed by rapid declines to < 1%. Diplopeltasymmetrica sp. 1 (Plate 2, fig. 5), Diplopelta symmetricasp. 2 (Plate 2, fig. 6), Echinidinium delicatum (Plate 1, fig.6), Echinidinium transparantum, Lejeunecysta marieae(Plate 1, fig. 2), Selenopemphix quanta sensu lato andXandarodinium xanthum were recorded sporadically inZone 5.

BIOSTRATIGRAPHIC CORRELATION

The biozonation proposed by Marret et al. (in press) forCore M02-45 (piston core M02-45P and trigger-weightcore M02-45TWC) (Text-Figure 5) can be correlated withthe biozonation presented herein (Text-Figure 5). Thedinoflagellate cyst assemblages in both cores are similar.Pyxidinopsis psilata and Spiniferites cruciformis domi-

nate the dinoflagellate cyst assemblages before the incur-sion of saline waters while Lingulodinium machaero-phorum dominated after the inflow of saline waters. Thetransitional Zone 2 dominated by Spiniferites was ob-served in both cores between the freshwater/brackishwater interval and the dominance of Lingulodiniummachaerophorum. According to the interpolated 14C-AMS ages, the decline of the freshwater/brackish waterdinoflagellate cysts started at 7.6 ka BP in Core M02-45,and the assemblage was marine at ~7.0 ka BP ± 60 years.In core GeoB 7625-2, the decline of the freshwater/brackish dinoflagellate cyst assemblage started at 8.25 kaBP. The dinoflagellate cyst association in core GeoB7625-2 was almost fully marine (95%) at 7.97 ka BP (630cm) (Text-Figures 4, 5).

Morphological Variation of Process Lengths ofLingulodinium machaerophorum

The three longest processes of 50 Lingulodiniummachaerophorum specimens in 37 samples were mea-sured. However, poor preservation or low abundance hin-dered measurements in certain samples. A total of 4,778processes were measured. The changes in process lengthvariation show some fluctuations (Text-Figure 6). Theprocess length increased gradually to 14.4 µm at 503 cm(4.12 ka BP). After this, the process length variation rangedbetween 13–16 µm, except for two reductions at 2.78 ka BP(347 cm) and 1.32 ka BP (64 cm).

The average process length is 13.15 µm, while theaverage body diameter is 47.41 µm. There is no significantrelationship between variation in body diameter and pro-cess length. The size-frequency spectrum of all measure-ments shows a unimodal curve, centered around an averageof 13.15 µm (Text-Figure 7), which suggests that thevariations in the sediment are linked to variations in processlength of a single morphotype of Lingulodinium

1 Selenopemphix nephroides, combination of low focuson dorsal side and optical section, slide 640, J51/3.

2 Cyst of Polykrikos kofoidii, combination of high focusand optical section, lateral view, slide 1, C34/2.

3 Cochlodinium spp., combination of high and opticalfocus, orientation uncertain, slide 88, J24/0.

4 Xandarodinium xanthum, combined high foci, orienta-tion uncertain, slide 302, C34/2.

5 Diplopelta symmetrica sp. 1, optical section, slide 1,F31/2-4.

PLATE 2


6 Diplopelta symmetrica sp. 2, optical section, slide166, D41/2.

7 Type A, combined high focus to optical section,orientation uncertain, slide 464, D34/2.

8 Type B, high focus, orientation uncertain, slide 640,D22/3.

9 Scrippsiella trifida, optical section, slide 370(2),E22/4.


1 Hexasterias problematica, combination of high focuson pylome and optical section, slide 370(2), F20/4.

2 ?Cobricosphaeridinium spiniferum, combined highfocus, orientations uncertain, slide 613(2), A24/0.

3 Pyxidinopsis psilata, low focus, dorsal view, slide 680,J29/2.

4 Lingulodinium machaerophorum var. clavatum, opti-cal section, slide 112, H18/1.

5 Lingulodinium machaerophorum, combined high fo-cus and optical section, slide 464(2), B46/4.

Rel

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0,6

PLATE 3


6 Tectatodinium pellitum, combined high focus and opti-cal section, dorso–lateral view, slide 591, C36/2.

7 Spiniferites cruciformis, high focus, dorsal view, slide680, L47/0.

8 Spiniferites cruciformis, low focus, ventral view, slide680, L47/0.

9 Spiniferites membranaceus, combined photomicro-graphs of optical section, slide 539, C32/0.

←

Text-Figure 6 . The variation in the relative abundance ofLingulodinium machaerophorum, the relative abundancesof heterotrophic species, the Shannon-Wiener diversityindex, the relative abundances of Peridinium ponticum,the ‘Lingulodinium machaerophorum var. clavatum/Lingulodinium machaerophorum var. clavatum +Lingulodinium machaerophorum s.s.’ ratio (L. mach var.clav/L. mach), and the Lingulodinium machaerophorumprocess lengths. The few badly preserved Lingulodiniummachaerophorum specimens at 660 and 680 cm areprobably not in situ, and their process length measure-ments should not be considered as representative (indi-cated by a dashed line).

machaerophorum. Another method of assessing the reli-ability of process length as a salinity proxy is to compare theLingulodinium machaerophorum var. clavatum (Plate 3,fig. 4) versus Lingulodinium machaerophorum ratio withthe curve of the process lengths. Since the morphotype

Lingulodinium machaerophorum var. clavatum is moreabundant in less saline (> 7–10) waters (Lewis and Hallet,1997), a higher ratio during periods of smaller processes isexpected, which is actually the case (Text-Figure 6).

DISCUSSION

The Black Sea–Mediterranean Sea Reconnectionfrom a Dinoflagellate Cyst Perspective

This high resolution dinoflagellate cyst study on coreGeoB 7625-2 enabled an assessment of the timing ofenvironmental changes in the surface waters of the south-western Black Sea during the Holocene to be made. Fivemajor successions of dinoflagellate cyst associations aredistinguished, and all are related to changes in surfacewater conditions. The lowermost Zone 1 occurs from thebase of the core to 8.08 ka BP (632 cm) (Text-Figure 5), andis characterized by the stenohaline, freshwater/brackishwater to freshwater taxa Pyxidinopsis psilata and Spiniferitescruciformis (Text-Figure 4). The low relative abundancesof Lingulodinium machaerophorum with short processes at


and before 8.25 ka BP (635 cm) assumes that the salinitylevel of the Black Sea was between 7 and 12 psu before thetime of reconnection. The limit of 12 psu corresponds to theupper limit of the modern distribution of Spiniferitescruciformis in the Caspian Sea (Marret et al., 2004; Leroyet al., 2007), and Pyxidinopsis psilata in the Baltic Sea (Yuand Berglund, 2007). The decreasing relative abundance ofPyxidinopsis psilata through Zone 1, together with anincrease in Spiniferites cruciformis, is interesting. An ex-planation of this is problematic. The occurrence ofPyxidinopsis psilata in the Baltic Sea may be an indicationof colder conditions. This species also occurs in low num-bers in the Caspian Sea (Marret et al., 2004). The decreas-ing relative abundance of Pyxidinopsis psilata could there-fore be a result of slow warming during the Early Holocene(Kraft, 1971). The appearance of Operculodiniumcentrocarpum sensu Wall and Dale (1966) and Spiniferitesspp. indet. at 8.25 ka BP (635 cm) may be the result of theinitial reconnection between the Black and Marmara seaswhich indicates a changing environment. A prominentchange in the dinoflagellate cyst assemblages was ob-served at 8.08 ka BP (632 cm), where 60% of the assem-blage consists of the freshwater/brackish water speciesPyxidinopsis psilata and Spiniferites cruciformis. At thistime, 30% of the assemblage consisted of Spiniferites spp.(exclusive of Spiniferites cruciformis), while at 7.97 ka BP(630 cm) their relative abundances increased to 87%. Thisis an indication of environmental change and possibly

unstable conditions caused by the onset of the reconnectionof the Black and Marmara seas. The short and membranousprocesses of the Spiniferites species, together with the shortprocess length of Lingulodinium machaerophorum (6.9–5.4 µm), are indicators of a low salinity environment at thistime (Lewis and Hallett, 1997; Ellegaard, 2000). Theintrusion of saline waters led to a decline of the freshwater/brackish assemblage, which disappeared almost completelyat 7.8 ka BP (627 cm).

Possible Diachroneity in theSalinification of the Black Sea

These findings indicate that the transition from a fresh-water/brackish water to a marine assemblage started after8.25 ka BP at a core depth of 635 cm (Text-Figure 5). Thefreshwater/brackish water assemblage in M02-45 started todecline at 7.6 ka BP, and this implies diachroneity in thesalinification of the Black Sea of ~0.6 ka. However, acomparison of 14C dates based on gastropods, mollusks, orostracods can imply significant uncertainty. Despite thispossible error, the dinoflagellate cyst associations werefully marine at 630 cm, 6 cm below the lowermost 14Cdating on mollusks of 7.625 ka BP at 624 cm. Since thedecline of the freshwater/brackish water association in coreGeoB 7625-2 starts between 635 and 632 cm, thediachroneity in the salinification of the Black Sea was a realphenomenon. This does not support a catastrophic

0

100

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2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Process length (µm)

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Text-Figure 7. The size-frequency spectrum of all Lingulodinium machaerophorum process length measurements, showing aunimodal curve centered around the average of 13.15 µm.


reconnection (Ryan et al., 1997; 2003) which implies arapid and synchronous salinity increase. The reason for anearlier salinification, and a possible shorter transition pe-riod, could be the direct influence of the eastward-flowingsaline plume from the Bosphorus entrance (Text-Figure 1).This earlier salinification in the present area of study wouldbe independent of the pathway of the reconnection, i.e.through the Bosphorus Strait or through the Sakarya Rivervalley. A reconnection through the Sakarya valley water-way would obviously result in an earlier salinification,given the nearby location of the area of study (Text-Figure1). A reconnection through the Bosphorus would also resultin an earlier effect on the area of study because of theeastward-flowing salinity plume, which flows above thesouthwestern Black Sea shelf and sinks to the abyssal plainnear the Sakarya Canyon (Özsoy et al., 1995).

The average process length of Lingulodiniummachaerophorum can be related to SSS variations (e.g.Lewis and Hallett, 1997). The findings herein confirmthese observations. A non-catastrophic reconnection is alsosupported by the observed process length of Lingulodiniummachaerophorum, which increased gradually from 8.25 to4.12 ka BP (635 to 503 cm respectively) (Text-Figure 6).

Dinoflagellate Cyst Assemblages and River Dynamicsduring the Holocene after the Reconnection

The variation of the relative abundances of cysts ofPentapharsodinium dalei and Spiniferites shows similarfluctuations with the clay layer frequency values. The latterfluctuations are, according to Lamy et al. (2006), related tothe precipitation regime in Anatolia (Text-Figure 8). Pre-cipitation is high during periods with a negative AO/NAOindex, and this results in a stronger river discharge andhigher clay layer frequency values. The aforementionedspecies mostly have highest relative abundances duringthese periods. One exception occurs at 3.35 ka BP (Text-Figure 8). Here, the poor preservation of the cysts ofPentapharsodinium dalei and Spiniferites spp., togetherwith their synchronous fluctuations with the clay layerfrequency curve, suggest that the fluctuations resulted fromtransport from the shelf into the depositional area. Therelative abundances of cysts of heterotrophic species werenot synchronous with clay layer frequencies, which indi-cates that the signal could result from a combined river and/or upwelling induced supply of micronutrients.

Periods of high relative abundances of Lingulodiniummachaerophorum match with low relative abundances ofcysts of Pentapharsodinium dalei and Spiniferites spp.Possibly, more turbulent conditions caused by an increas-ing amount of freshwater from the Sakarya River couldhave lead to a decrease in the relative abundances of

Lingulodinium machaerophorum. The highest relative abun-dances of this species were recorded during periods of lowriver input (Text-Figure 8). The higher dinoflagellate cystconcentrations during periods of lower river discharge arenot necessarily related to higher productivity, but can alsobe induced by a lower terrigenous input. For example theextremely high absolute abundances of Lingulodiniummachaerophorum between 5.93 and 5.66 ka BP (587–576cm) are most likely exaggerated because of the low terrig-enous input by river discharge, indicated by the low claylayer frequency (Text-Figure 8).

Influence of the Sakarya River Discharge on Salinity

There is no unequivocal relation between the salinityvalues estimated from Lingulodinium machaerophorumprocess lengths and the river discharge, as deduced fromthe clay layer frequencies (Text-Figure 8). This indicatesthat salinity in this area was not only controlled by the riverinput, but also by oceanographic changes such as variableinput of Mediterranean waters through the Bosphorus. It isfurthermore highly probable that the clay layer frequencyrecord might be influenced by onshore tectonic activitysuch as earthquakes and landslides.

Peridinium ponticumRelative Abundances and Salinity

The relative abundance of Peridinium ponticum, whichaccording to Dale (1996) could be considered as a possiblebrackish water cyst, increased up-section and fluctuated(Text-Figure 6). These fluctuations are synchronous withthe Lingulodinium machaerophorum process length varia-tions, related to changes in salinity. A remarkable observa-tion is the more pronounced amplitude of the Peridiniumponticum fluctuations compared to this process lengthvariation. Since Peridinium ponticum is heterotrophic,nutrient availability in the upper waters also influences itsabundance. For example, the maximum peak of Peridiniumponticum at 4.12 ka BP (503 cm) occurred during a periodof high salinity and a high clay layer frequency togetherwith a high nutrient input by river discharge (Text-Figures6, 8).

Peridinium ponticum relative abundances were highwhen both the clay layer frequencies (= nutrient input) andthe process lengths of Lingulodinium machaerophorumwere high. The fluctuations are less obvious when the claylayer frequencies were low during a salinity optimum.When the clay layer frequency record shows high valuesduring a period of decreasing salinity, Peridinium ponticumwas virtually absent, which might indicate that salinityplays a major role in the abundance of this species.


CONCLUSIONS

The high resolution dinoflagellate cyst record enablesthe determination of the first marine intrusion caused by

the reconnection of the Black and Marmara seas. Thedinoflagellate cyst assemblages indicate a marked changefrom freshwater/brackish water to more saline conditions,starting after 8.25 ka BP. At 7.97 ka BP, the dinoflagellatecyst assemblages off the mouth of the Sakarya Riverconsist almost exclusively of marine or euryhaline spe-cies. Because of the limited knowledge of the freshwater/brackish water taxa Pyxidinopsis psilata and Spiniferitescruciformis, the exact conditions during the freshwater/brackish water stage of the Black Sea before thereconnection cannot be elucidated at present. The limitedoccurrence of Lingulodinium machaerophorum beforethe reconnection, and the current environmental charac-teristics of Pyxidinopsis psilata and Spiniferitescruciformis suggest a salinity between 7 and 12 psu.

The diachroneity of the salinification of the Black Seaand the process length variation of Lingulodiniummachaerophorum point to a non-catastrophic reconnection,contrasting with the Noah’s Flood Hypothesis of Ryan etal. (1997; 2003). The earlier and shorter duration of thetransition from freshwater/brackish water to more salineconditions in the area of study compared to the area westof the Bosphorus entrance (Marret et al., in press), prob-ably resulted from a direct influence of the saline plumein this area. Relative abundances of Peridinium ponticumfluctuated synchronously with the Lingulodiniummachaerophorum process length variation. The abun-dance of Peridinium ponticum was therefore related tosalinity, although the amount of available nutrients alsoplayed an important role in its concentration. Periods withlow river input were characterized by abundantLingulodinium machaerophorum, whereas periods with ahigher terrigenous input were marked by increasing abun-dances of cysts of Pentapharsodinium dalei andSpiniferites spp. The preservation of the latter forms, incomparison with other dinoflagellate cysts, indicate thatthis is at least partly the result of transport from the shelf.

ACKNOWLEDGMENTS

Financial support to the first author was provided by theInstitute for the Encouragement of Innovation throughScience and Technology in Flanders. Fabienne Marret,Jens Matthiessen, and Karin Zonneveld are thanked forstimulating discussions on the morphology of some spe-cies. Sharon Schillewaert measured the process lengths ofLingulodinium machaerophorum in a number of samples.Technical assistance by Sabine Vancauwenberghe is ac-knowledged. The constructive reviews by Barrie Dale(Oslo University) and an anonymous reviewer are muchappreciated and greatly improved the manuscript.

Text-Figure 8. Detrended curves (real values minus thecorresponding estimated value by linear regression)which represent variations in the Lingulodiniummachaeorophorum process lengths, the relative abun-dances of Lingulodinium machaerophorum, the rela-tive abundances of heterotrophic species, the relativeabundances of cysts of Pentapharsodinium dalei, therelative abundances of Spiniferites species, the relativeabundances of cysts of Pentapharsodinium dalei +Spiniferites species and the clay layer frequencies mea-sured by Lamy et al. (2006). The clay layer frequencieswere calculated for 200-year intervals shifted in 50-year steps along the record. The resulting frequencycurve was detrended by subtracting a 1,000-year mov-ing average (Lamy et al., 2006).

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APPENDIX 2. The dinoflagellate cysts recorded in this study with author citations listed alphabetically within 6 major groupings.

APPENDIX 1. Method used to calculate the age of the core top of core GeoB 7625-2.

PERIDINIOIDSPeridinium ponticum Wall & Dale 1973Cyst of Pentapharsodinium dalei Indelicato & Loeblich III

1986Scrippsiella trifida Lewis 1991 ex Head 1996

PROTOPERIDINIOIDSBrigantedinium cariacoense (Wall 1967) Lentin & Will-

iams 1993Brigantedinium simplex (Wall 1965) Lentin & Williams

1993Brigantedinium spp. of Reid (1977)Diplopelta symmetrica Pavillard 1993 (Dale et al. 1993)Dubridinium caperatum Reid 1977Echinidinium delicatum Zonneveld 1997Echinidinium transparantum Zonneveld 1997Islandinium spp. indeterminate of Head (2001)Lejeunecysta marieae Harland et al. 1991Cyst of Protoperidinium nudum (Meunier 1919) Balech

1974Cyst of Protoperidinium stellatum (Wall in Wall & Dale

1968) Rochon et al. 1999Quinquecuspis concreta (Reid 1977) Harland 1977Selenopemphix nephroides (Benedek 1972) Benedek &

Sarjeant 1981Selenopemphix quanta (Bradford 1975) Matsuoka 1985Trinovantedinium applanatum (Bradford 1977) Bujak &

Davies 1983Votadinium calvum Reid 1977Xandarodinium xanthum Reid 1977

GYMNODINIOIDSCochlodinium sp. indeterminateGymnodinium nolleri/microreticulatum Ellegaard &

Moestrup 1999/Bolch et al. 1999

POLYKRIKOIDSCyst of Polykrikos kofoidii Chatton 1914Cyst of Polykrikos schwartzii Bütschli 1873

GONYAULACOIDSAchomosphaera spp. of Evitt (1963)Ataxiodinium choane Reid 1974Lingulodinium machaerophorum Wall 1967Operculodinium centrocarpum sensu Wall and Dale (1966)Operculodinuim israelianum (Rossignol 1962) Wall 1967Operculodinium sp. cf. O. janduchenei Head et al. 1989Pyxidinopsis psilata Wall & Dale 1973Pyxidinopsis reticulata (McMinn & Sun 1994) Marret & de

Vernal 1997Spiniferites belerius Reid 1974Spiniferites bentorii (Rossignol 1964) Wall & Dale 1970Spiniferites cruciformis Wall & Dale 1973Spiniferites elongatus sensu lato of Reid (1974)Spiniferites membranaceus (Rossignol 1964) Sarjeant 1970Spiniferites mirabilis (Rossignol 1967) Sarjeant 1970Spiniferites ramosus (Ehrenberg, 1838) Mantell 1854Tectatodinium pellitum Wall 1967

GONIODOMACOIDSTuberculodinium vancampoae (Rossignol 1962) Wall 1967

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T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz ... · T.J. Verleye, K.N. Mertens, S. Louwye and H.W. Arz: Holocene salinity changes in the southwestern Black SeaHOLOCENE SALINITY