a gradual drowning of the southwestern black sea shelf evidence for a progressive rather than abrupt holocene reconnection with the eastern mediterranean sea through the marmara sea gateway core m02 45 recovered 9 5 m of a 12 m thick transgressive succession on the sw black sea shelf the underlying transgressive unconformity a deepens toward the shelf edge so that the coresite was never isolated from the open black sea fourteen radiocarbon dates indicate sedimentation from 9 3 ka to the present with only one hiatus at 270 cm depth spanning 4 5 2 5 ka three units are present in the core unit a 0 270 cm burrowed mud with laminated silt beds and mollusc shells of mediterranean affinity accumulation rate 125 cm ky unit b 270 525 cm silty mud with shelly interbeds containing truncatella subcylindrica mytilus galloprovincialis parvicardium exiguum rissoa spp and modiolula phaseolina rate 85 cm ky unit c 525 950 cm burrowed silty mud with graded beds of silt and fine sand and shells of t subcylindrica p exiguum and dreissena polymorpha rate 360 cm ky unit c developed below storm wave base at a time when proponents of a catastrophic flood in the black sea claim that the shelf was subaerially exposed clearly it was not ostracoda of caspian affinity indicate 5 salinity until 7 5 ka dinocysts and foraminifera confirm a low but rising salinity after 8 6 ka an increase of d 34 s from 5 30 through 8 4 7 6 ka is attributed to a first pulse of sulfate rich aegean water into an already high black sea after which this sulfate was quantitatively precipitated as sulfide d 34 s then dropped at 8k a to 20 as dysoxia and water column stratification were established because of the initiation of two way flow through the bosphorus earlier water exchange with the mediterranean was likely impeded by strong black sea outflow which prevented easy access of the aegean water mass r 2006 published by elsevier ltd

glacial hydrologic conditions in the black sea reconstructed using geochemical pore water profiles abstract chloride and 18 o compositions of interstitial water extracted from a long sediment core retrieved from the nw coast of the black sea allowed us to constrain the main hydrologic changes of the back sea during the late pleistocene and holocene prior to its reconnection with the mediterranean sea through the marmara sea at approximately 9000 calendar yr before present 9 ka cal bp the black sea has evolved as a fresh to brackish water lake at the time of reconnection hydrologic changes were drastic bottom water salinities changed from a few psu practical salinity unit to 22 psu since solutes in the interstitial water column within sediments are advected and diffused the measured concentrations do not reflect those of past bottom waters in order to reconstruct these former concentrations we used an advection diffusion model different scenarios of bottom water chloride and 18 o variations were accounted for in this model in order to simulate present day vertical profiles for concentrations of interstitial water in order to compare them to measured ones the comparison suggests that the glacial black sea was a homogeneous freshwater lake with a 18 o of 10 and a salinity of 1 psu modern hydrologic conditions would only have been reached at 2 ka cal bp concomitant with the onset of coccolith rich thin layers that characterize modern basin sediments such delayed salinization over 7000 yr in the basin may have been due to higher precipitation during the early holocene we also simulated the impact of a catastrophic reconnection and a smoother reconnection both salinity scenarios lead to undistinguishable modelled present day profiles indicating that the precise impact of the last reconnection was lost due to the advection diffusion processes

the co evolution of black sea level and composition through the last deglaciation and its paleoclimatic significance abstract the black sea was an inland lake during the last ice age and its sediments are an excellent potential source of information on eurasian climate change showing linkages between regionally and globally recognized millennial scale climate events of the last deglaciation here we detail changes from the last glacial maximum lgm through the transition to an anoxic marginal sea using isotopic strontium and oxygen and trace element sr ca ratios in carbonate shells which record changing input sources and hydrologic conditions in the basin and surrounding region sr isotope records show two prominent peaks between 18 and 16 ka bp cal reflecting anomalous sedimentation associated with meltwater from disintegrating eurasian ice sheets that brought black sea level to its spill point following a sharp drop in sr isotope ratios back toward glacial values two stages of inorganic calcite precipitation accompanied increasing oxygen isotope ratios and steady sr isotope ratios these calcite peaks are separated by an interval in which the geochemical proxies trend back toward glacial values the observed changes reflect negative water balance and lake level decline during relatively warm periods bolling allerod and preboreal and increasing river input less evaporation resulting in higher lake levels during the intervening cold period the younger dryas a final shift to marine values in sr and oxygen isotope ratios at 9 4 ka bp cal corresponds to connection with the global ocean and marks the onset of sedimentation on the black sea continental shelf this date for the marine incursion is earlier than previously suggested based on the appearance of euryhaline fauna and the onset of sapropel formation in the deep basin

quantitative estimation of holocene surface salinity variation in the black sea using dinoflagellate cyst process length reconstruction of salinity in the holocene black sea has been an ongoing debate over the past four decades here we calibrate summer surface water salinity in the black sea sea of azov and caspian sea with the process length of the dinoflagellate cyst lingulodinium machaerophorum we then apply this calibration to make a regional reconstruction of paleosalinity in the black sea calculated by averaging out process length variation observedatfourcore sites fromtheblack seawithhigh sedimentation rates anddatedbymultiple mollusk shell ages results show averygradual change of salinity from w14 0 91 psu around 9 9 cal ka bp to a minimum w12 3 0 91 psu around 8 5 cal ka bp reaching current salinities ofw17 1 0 91 psu around

compilation of geophysical geochronological and geochemical evidence indicates a rapid mediterranean derived submergence of the black sea s shelf and subsequent substantial salinification in the early holocene abstract our knowledge of rate and processes in which semi enclosed environments alternate from lacustrine to marine is commonly limited because of the paucity of specific proxies for sea level and salinity here we investigate the timing rate and key mechanisms involved in the transformation of the previously isolated black sea lake to the modern partly enclosed marine sea using a suite of geophysical geochemical and geochronological methods cores were collected in transects across shelves of ukraine romania bulgaria and turkey biogenic carbonate from these cores was analyzed for radiocarbon and strontium oxygen and carbon isotopes strontium results indicate that the submergence of the black sea shelf at 9300 calendar years bp was caused by the ingress of mediterranean water and was abrupt taking radiocarbon years are calibrated to calendar years by tuning the oxygen and carbon isotope composition of the mollusk record to that of the u th dated sofular cave stalagmites the match shows a reduction of the lake s prior high reservoir age accompanying the inflow of the mediterranean water in 900 years the salinity reached a threshold that excluded all previous black sea lacustrine fauna these results imply that any substantial postglacial submergence of the black sea shelves did not occur prior to entry of mediterranean water

constraining holocene sea surface conditions in the south western black sea using dinoflagellate cysts this paper presents two dinoflagellate cyst records from the south western shelf of the black sea a new site mar05 13 from the sakarya shelf is described and placed into context with site mar02 45 250 km distant on the thracian shelf the records provide a centennial resolution of surface water conditions in the holocene analysis of the data suggests that the surface salinity of the south western shelf increased in a gradual and progressive manner in the period 11 000 9000 cal a bp the assemblages suggest surface water salinities between 7 13 psu the initial arrival of euryhaline species 8100 cal a bp is linked to the reconnection of the black sea and marmara sea the suggested surface water changes related to the reconnection took approximately 1000 years following this initial change in assemblages a further increase in the number of euryhaline species is noted between 5000 and 4000 cal a bp this is linked to the establishment of more saline surface water conditions close to present day values the record for mar05 13 highlights the complexity of the changes in cyst assemblages during the mid holocene copyright 2012 john wiley sons ltd

an abrupt drowning of the black sea shelf abstract during latest quaternary glaciation the black sea became a giant freshwater lake the surface of this lake drew down to levels more than 100 m below its outlet when the mediterranean rose to the bosporus sill at 7 150 yr bp 1 saltwater poured through this spillway to refill the lake and submerge catastrophically more than 100 000 km2 of its exposed continental shelf the permanent drowning of a vast terrestrial landscape may possibly have accelerated the dispersal of early neolithic foragers and farmers into the interior of europe at that time

early holocene age and provenance of a mid shelf delta lobe south of the strait of bosphorus turkey and its link to vigorous black sea outflow abstract the chronology of an abandoned holocene delta lobe present water depth 40 70 m on the northeastern shelf of the marmara sea south of the strait of bosphorus was revised from the early holocene 11 0 9 7 cal ka to the middle holocene 6 65 3 75 cal ka by eris et al eris k k ryan w b f cagatay m n sancar u lericolais g menot g bard e 2007 the timing and evolution of the post glacial transgression across the sea of marmara shelf south of istanbul marine geology 243 57 76 three independent seismic and multibeam surveys and replotting of navigational fixes for the 1992 1993 vintage survey lines which eris et al correlated to their md04 2750 giant piston core confirm that they misplotted the location of the md04 2750 core site on seismic profiles by a minimum of 200 m because of rapid convergence of seismic reflections in this critical area the assessment of the age of the holocene delta proposed by eris et al is incorrect instead existing and new data allow the age of this delta lobe to be refined to 11 1 10 2 cal ka 200 300 years each using several dated cores and the md04 2750 chronology itself a dense grid of previously unpublished seismic data shows that the lobe emanates from the strait of bosphorus and not from any of the local small streams mineralogy of the very fine sand fraction of the delta excludes the kurbagalidere stream as a source of the detritus as does the composition of detrital hornblendes it is concluded that the early holocene delta lobe indeed records a period of strong black sea outflow as advocated by co authors rnh and aea in 2002 re examination of multibeam imagery from the strait itself provides support for strong southward flow that potentially coincided with accumulation of the delta lobe at the southern exit of the strait

holocene paleoecology and paleoceanography of the southwestern black sea shelf revealed by ostracod assemblages abstract the holocene replacement of ponto caspian ostracod assemblages by mediterranean species is studied in two long composite cores m02 45 a composite of cores m02 45p m02 45 t and m05 03p and m05 50 a composite of cores m05 50p and m05 51g acquired at sites 69 m and 91 m deep on the southwestern black sea shelf composite core m02 45 was collected from the middle shelf and composite core m05 50 was acquired on the distal fringe of the eastern levee of a saline underflow channel emanating from the strait of bosphorus sixteen radiocarbon dates in m02 45 and nine in m05 50 are used to construct age models which show recovery of sediments as old as 12 915 cal yr bp m02 45 site and 12 010 cal yr bp m05 50 site a total of 45 ostracod species are identified in the two cores from 12 000 to 7425 cal yr bp the ostracod assemblage is dominated by ponto caspian species mainly loxoconcha sublepida l lepida and tyrrhenocythere amnicola donetziensis from 7425 to 6315 cal yr bp the assemblage consists of nearly equal abundances of mediterranean species cytheroma variabilis in m02 45 sagmatocythere littoralis in m05 50 and the ponto caspian species after 6315 cal yr bp to the tops of the cores the assemblage is dominated by mediterranean species including palmoconcha agilis carinocythereis carinata hiltermannicythere rubra and pterygocythereis jonesii cluster analysis further subdivides the stratigraphic succession into six bioecozones with different ostracod assemblages the changes in the ostracod assemblages from one bioecozone to the next indicate that progressive environmental changes took place on the southwestern black sea shelf from at least 7500 cal yr bp to the present the first hint of changing conditions at 7500 cal yr bp lags the initial reconnection to the mediterranean sea through the strait of bosphorus by 2000 yr demonstrating that black sea salinity increased slowly and took that long to reach values tolerable to marine ostracod immigrants widespread colonization by mediterranean species took even longer 3000 years from the time of the initial reconnection

corrigendum to a gradual drowning of the southwestern black sea shelf evidence for a progressive rather than abrupt holocene reconnection with the eastern mediterranean sea through the marmara sea gateway quaternary international 167 168 2007 19 34 on page 24 in table 1 several species identi cations listed are incorrect we attribute this to our limited experience prior to 2006 withbrackish to fresh water molluscs of the black sea and caspian sea well illustrated recent articles orlova et al 2005 gelembiuk et al 2006 wesselingh 2007 internet sites e g www gastropods com and helpful advice from william ryan columbia university haveallowed us to correct the errors for six shells with radiocarbon laboratory numbers to 11438 to 11439 to 11440 to 11441 to 11007and to 11443 the revised shell identi cations respectively are the bivalves monodacna pontica didacna praetrigonoides didacna spp dreissena rostiformis d rostiformis and the gastropod theodoxus spp in the description of unit c on pages 25 and 26 references to par vicardium exiguum and dreissena polymorpha should be replaced by monodacna pontica didacna spp dreissena polymorpha andd rostiformis references

holocene biostratigraphy and paleoenvironmental changes in the black sea based on calcareous nannoplankton in this study detailed micropaleontological analyses were carried out on 270 samples from eight piston cores collected in the black sea the primary goal was to elucidate the late quaternary evolution of the black sea specifically to refine its biostratigraphy and to explore the holocene paleoenvironmental changes three intervals were recognized in all the cores studied irrespective of whether they were from the basin or the shelf these intervals are characterized from old to young by the spotty occurrence the presence and the local acme of emiliania huxleyi respectively moreover the species braarudosphaera bigelowii is in contrast to the younger units absent in the oldest unit the co occurrence of the two marine species e huxleyi and b bigelowii suggests a shift from fresh brackish water to low salinity marine conditions in the black sea the spotty and very rare occurrence of e huxleyi in the lowermost unit is reported here for the first time two hypotheses are suggested the presence of reworked specimens from eemian outcrops or the presence of low salinity waters also during the lacustrine phase of the basin another feature observed in almost all the cores is the presence of a multi lamina aragonite level in the upper part of the ecozone 3 which functions as a marker for basin wide correlations the parallel study of water samples and surficial sediment assemblages demonstrates the presence of syracosphaera lamina in the surface water samples and its absence in the sediments suggesting dissolution in the water column on the other hand the occurrence of b bigelowii in all cores and its near absence in water and in recent sediment samples suggest a change in water conditions during recent times

high resolution sr isotopic evolution of black sea water during the holocene implications for reconnection with the global ocean abstract the 10 m thick holocene succession at core site m02 45 41 41 17 n 28 19 08 e 69 m water depth has key advantages for investigation of the sr isotopic evolution of the holocene black sea earlier studies have focussed on thinner successions and coquinas at the m02 45 site augmented by nearby core m05 03p 87sr 86sr determinations on mollusc shells extracted at mostly 10 20 cm depth increments provide a temporal resolution mostly

northern north sea benthic ostracoda modern distribution and palaeoenvironmental significance the ostracod faunas of the northern north sea exhibit a depth related distribution that is controlled by substrate and hydrographic conditions four biofacies are defined on the basis of total live dead counts sandy substrates shallower than 110 m are characterized by robertsonites tuberculatus and cytheropteron latissimum these species are replaced by acanthocythereis dunelmensis and palmenella limicola on sandy muds in the fladen ground 110 150 m muellerina abyssicola dominates from 175 250 m in the norwegian channel giving way to krithe praetexta at greater depths on soft bottom substrates the results are compared with data from the skagerrak and the western european shelf area temperature ranges for the commonest taxa show that north sea faunas contain endemic western european species temperature range on average 2 20 c some southern species 5 26 c and taxa that range to high latitudes 2 to 14 c southern species are confined to the southern and western margins of the north sea

modelling the provenance of detritus flushed through the strait of bosphorus turkey during early holocene outflow from the black sea to the world ocean abstract source to sink tracing of very fine sand supplied to a controversial lower holocene deltaic lobe in the northeastern marmara sea was undertaken using sem backscatter mapping and quantitative mineral liberation analysis of very fine sand fractions forty two samples from the kurbagalidere goksu golden horn and riva watersheds and from oligo miocene outcrops along the southwestern black sea coast show that each of these potential sources has a distinct mineralogical fingerprint comparison with 11 samples from the lower holocene delta and 19 samples from the overlying mud drape show that no single source can account for the mineral proportions in the sand fractions of these depositional sinks but a mixed provenance provides good matches for the deltaic lobe quantitative mixing based on 250 000 monte carlo simulations suggests 50 contribution from oligo miocene successions of the southwestern black sea coast and inner shelf 20 contribution from the goksu stream and minor contributions from other sources including the kurbagalidere stream this balance of source contributions continued to supply the holocene mud drape until 6 cal ka after which local sources became more important it is hypothesized that unconsolidated sediment from a number of watersheds was parked along the coast of the neoeuxine lake and in the paleo bosphorus valley during the mis 2 lowstand a rising neoeuxine lake possibly swollen by glacial outburst floods from the altay region of central asia flushed 0 5 km 3 of this sediment through the strait of bosphorus to the deltaic lobe and permitted it to rapidly advance into the marmara sea which at that time was rising 1 m each 100 yr provenance of the lower portion of the holocene mud drape is consistent with continued black sea outflow throughout the deposition of sapropel m1 in the marmara sea

the holocene history of the ne black sea and surrounding areas an integrated record of marine and terrestrial palaeoenvironmental change here we present an almost complete and integrated holocene record of marine and terrestrial palaeoenvironmental change from the ne shelf of the black sea a dinoflagellate cyst record used to recon

deltas south of the bosphorus strait record persistent black sea outflow to the marmara sea since 10 ka at the southern exit of the bosphorus strait in the northeastern marmara sea high resolution seismic profiles reveal two lobate progradational delta lobes in modern water depths of v40 65 m the younger delta was active from v10 to 9 ka based on radiocarbon dates of equivalent prodelta deposits and the elevation of its topset to foreset transition the topset to foreset transition climbs in the seaward direction because the delta prograded into a rising sea low abundances of marine fauna and flora in the 10 9 ka interval support a deltaic interpretation there are no rivers in the area that could have fed the delta instead all evidence points to the strait itself as the source of sediment and water when this outflow was strongest v10 6 6 0 ka sapropels accumulated in basinal areas of both the aegean and marmara seas benthic foraminiferal and dinoflagellate cyst data from contemporary deposits elsewhere in the marmara sea point to the continual presence through the holocene of a surface layer of brackish water that we ascribe to this same outflow from the black sea through the bosphorus strait by v9 1 8 5 ka two layer flow developed in the bosphorus strait as global sea level continued to rise and the sediment supply to the younger delta was cut off because the outflowing black sea water ceased to be in contact with the floor of the strait the older delta lobe lies below a prominent lowstand unconformity and is tentatively interpreted to have formed from v29 5 to 23 5 ka oxygen isotopic stage 3 when the marmara sea stood at v355 m and a second sapropel accumulated in deep basinal areas crown copyright 2002 elsevier science b v all rights reserved

black sea lake reservoir age evolution since the last glacial hydrologic and climatic implications abstract chronologies of sediments that document the last glacial history of the black sea lake are hampered by issues relating to reservoir age regulated by basin hydrology reservoir ages represent a tool that could potentially be used to better understand the response of black sea lake hydrology to climate change therefore deciphering reservoir age evolution is crucial both for better constraining the basin chronological framework and for providing new insights into our understanding of black sea lake hydrology by tuning a meaningful new high resolution geochemical dataset obtained from core md04 2790 to a climate reference record here we propose a reliable chronology spanning the last 32 kyr bp the chronology is compared to a large ams radiocarbon dataset n 51 pairs of calendar and radiocarbon ages allowed us to compute reservoir ages and to then reconstruct a high resolution quantitative reservoir age record for the last glacial history of the black sea lake the main factor controlling reservoir ages in lakes is the hard water effect hwe which is regulated by basin hydrology therefore changes in the reconstructed reservoir age record have been qualitatively interpreted in terms of the hydrologic responses of the black sea lake to climate change our results allowed us to determine periods of complete isolation or outflow for the black sea lake during heinrich event 2 he2 and during the last glacial maximum lgm the basin was strictly isolated whereas prior to he2 and during he1 it outflowed into the marmara sea following the onset of the bolling allerod factors other than the hwe are thought to have influenced the reservoir age preventing conclusive interpretations we also determined an undocumented to date phase of black sea lake stratification during the full glacial he2 and lgm our results indicate that reservoir age is a powerful tool for investigating and better understanding past hydrologic changes in lakes and inland seas

holocene sea level oscillations and environmental changes on the eastern black sea shelf abstract a multi proxy study of four sediment cores from the eastern caucasian black sea shelf revealed five transgressive regressive cycles overprinted on the general trend of glacioeustatic sea level rise during the last 11 000 14c yr these cycles are well represented in micro and macrofossil assemblages sedimentation rates and grain size variations the oldest recovered sediments were deposited in the neoeuxinian semi freshwater basin 10 500 9000 14c yr bp and contain a caspian type mollusk fauna dominated by dreissena rostriformis low 18o and 13c values are measured on this species the first appearance of marine mollusks and ostracodes from the mediterranean is established in this part of the black sea at 8200 14c yr bp i e about 1000 2000 yr later than the appearance of marine microfossils in the deeper part of the sea the early holocene bugazian to vityazevian condensed section of shell and shelly mud sediments with at least two hiatuses represent a high energy shelf edge facies it contains a transitional assemblage representing a mixture of caspian and mediterranean fauna this pattern suggests a dual flow regime via the bosphorus after 8200 14c yr bp caspian species disappear and oligohaline species decrease in abundance during the vityazevian prekalamitian cycle later during the middle to late holocene low sea level stands are characterized by shell layers whereas silty mud with various mollusk and ostracode assemblages rapidly accumulated during transgressions restricted mud accumulation as well as benthic faunal composition and abundance suggest high energy and well ventilated bottom water during low sea level stands a trend of 18o enrichment in mollusk shells points to an increase in bottom water salinity during the vityazevian to kalamitian transgressions 7000 to 5700 14c yr bp due to a more open connection with the mediterranean while a pronounced increase in polyhaline species abundance is established during the kalamitian to djemetean transgressions 6400 to 2700 14c yr bp however the composition of the faunal assemblage indicates that bottom water salinity never exceeded modern values of 18 20 psu

modern and holocene sublittoral ostracod assemblages crustacea from the caspian sea a unique brackish deep water environment abstract we present a reconnaissance study of sublittoral ostracods from a number of caspian sea core tops collected during a joint french russian scientific cruise in 1994 cores from between 13 and 875 m water depth the modern ostracods show little depth restriction and this reflects the hydrography of the caspian sea which maintains relatively constant conditions 5 c 13 salinity below 50 m throughout the year we also present the ostracod faunal record from a 10 m core of laminated sediments recovered from the central caspian basin at a water depth of 475 m which we believe shows repetitive quasi cyclic changes in bottom water conditions over approximately the last 14 15 000 years with a major change at about the late glacial to holocene transition the faunal record from this core illustrates the potential of these sediments for reconstructing environmental changes in the caspian region during the late quaternary to holocene the continuous occurrence of in situ benthic meiofauna throughout the core also indicates that the bottom water must have remained ventilated throughout this period although variability in the faunal assemblages may reflect long and short term changes in the strength of ventilation

the search for graves over the decades grave markers in old cemeteries have been lost geophysical exploration can sometimes locate the unmarked burials the two techniques which may be best for this search are a ground penetrating radar survey and a soil conductivity survey a ground penetrating radar survey with its capability for estimating the depth and shape of buried objects is particularly suitable with an electromagnetic induction survey the disturbed soil in the grave shaft can sometimes be detected as a change in electrical conductivity both of these surveys also can locate large metal objects these surveys have limitations at some sites the radar cannot profile deeply enough at others the soil strata are so complex that graves cannot be distinguished a conductivity survey can be degraded by metallic trash and other small objects in the topsoil it can give the best results where the earth is distinctly stratified results from nine surveys are illustrated here the sites are all in the u s a and the gra

compositional trends through the holocene mud succession of the southwestern black sea shelf implications for sedimentary provenance and water level history abstract cores mar02 45 and mar05 03 were raised from 68 69 m water depth on the sw black sea shelf and indicate transgression and submergence beneath several tens of metres of water before 11 0 cal ka those who postulate a black sea lowstand below 100 m until the approximately 9 1 cal ka reconnection with the world ocean have suggested that sites like mar02 45 and mar05 03 must have been located in perched lakes on what is now the modern shelf however the silt and clay fraction mineralogy of samples from mar02 45 provides no evidence for a shift in provenance at 9 1 cal ka with earlier input from local rivers and later input from a broader region sedimentary abundances of sc fe co ce la th and y also show no significant downcore trends these elements likely reside in aluminosilicate mineral grains shed from terrestrial sources so negligible downcore variation suggests long term continuity in the composition of the detrital supply more critically the volume of pre 9 1 cal ka sediment around the mar02 45 and mar05 03 sites is 25 times the expected yield from local rivers over a 5000 year period so other more substantial sources are required the predominant silt size of the recovered sediments the configuration of late holocene currents in the western black sea and analogies with dispersal systems elsewhere suggest that the bulk of the fine grained muds at these sites likely came from the danube and kamchiya drainage basins where thick deposits of unconsolidated pleistocene loess have been strongly dissected to reach core sites on the sw black sea shelf this material must have been advected from the danube and kamchiya deltas by unobstructed marine currents only thin event beds tempestites of fine sand and silt in the lower part of cores mar02 45 and mar05 03 are interpreted to have a local source in the strandja mountains of thrace comparison of the palynology of surface samples from the danube delta and its associated coastal lagoons with the pre 9 1 cal ka sediments of core mar02 45 confirms that the hypothesis of deposition in a perched ancient lake is untenable

seismic stratigraphy of late quaternary deposits from the southwestern black sea shelf evidence for non catastrophic variations in sea level during the last 10 000 yr abstract detailed interpretation of single channel seismic reflection and huntec deep tow boomer and sparker profiles demonstrates that the southwestern black sea shelf formed by a protracted shelf edge progradation since the miocene pliocene five seismic stratigraphic units are recognized unit 1 represents the last phase of the progradational history and was deposited during the last glacial lowstand and holocene it is divided into four subunits subunit 1a is interpreted as a lowstand systems tract 1b and 1c are interpreted as a transgressive systems tract and subunit 1d is interpreted as a highstand systems tract the lowstand systems tract deposits consist of overlapping and seaward prograding shelf edge wedges deposited during the lowstand and the subsequent initial rise of sea level these shelf edge wedges are best developed along the westernmost and easternmost segments of the study area off the mouths of rivers the transgressive systems tract deposits consist of a set of shingled shore parallel back stepping parasequences deposited during a phase of relatively rapid sea level rise and include a number of prograded sediment bodies including barrier islands beach deposits and thin veneers of seismically transparent muds showing onlap onto the flanks of older sedimentary features a number of radiocarbon dates from gravity cores show that the sedimentary architecture of unit 1 contain a detailed sedimentary record for the post glacial sea level rise along the southwestern black sea shelf these data do not support the catastrophic refilling of the black sea by waters from the mediterranean sea at 7 1 ka postulated by ryan pitman major shimkus maskalenko jones dimitrov gorur sakinc yuce mar geol 138 1997 119 126 ryan pitman touchstone book 1999 319 pp and ballard coleman rosenberg mar geol 170 2000 253 261

holocene sedimentation in the southwestern black sea interplay between riverine supply coastal eddies of the rim current surface and internal waves and saline underflow through the strait of bosphorus abstract an extensive grid of high resolution huntec deep tow seismic reflection profiles 9150 line km complemented by 72 gravity cores and 25 piston cores reveals that the sedimentary architecture of the southwestern black sea above a prominent shelf crossing unconformity is characterized by three allostratigraphic units allounits 1b 1c 1d separated by two regional unconformities and their correlative conformities 1 and 2 a fourth allounit 1a occurs as patchy remnants between the unconformity and a deeper pleistocene erosional unconformity 0 the chronology is established using 56 radiocarbon dates in five key piston cores the unconformity developed as a ravinement surface during the transgression associated with the transition from the last glacial maximum to holocene thus defines the base of the holocene successions allounit 1b is bounded at its base and top by the and 1 unconformities correlative conformities it was deposited between 12 5 and 7 4 cal ka and shows a notably patchy but widespread distribution across the southwestern shelf allounit 1c is bounded at its base and top by the 1 and 2 unconformities correlative conformities it was deposited between 7 4 and 5 3 cal ka allounit 1d accumulated above the 2 unconformity correlative conformity and was deposited since 5 3 cal ka interpretation of radiometrically dated cores and several detailed regional maps reveal that the widespread occurrence of 12 5 7 4 cal ka deposits allounit 1b across the middle and outer shelf provides no possibility for a holocene evaporative drawdown to a lowstand elevation of 120 m at 9 4 cal ka as suggested by yanchilina et al 2017 instead the volume of detritus in allounit 1b can only be explained if base level was sufficiently high to allow major distant rivers in bulgaria and romania e g kamchiya danube to contribute mud through long distance marine transport along a submerged shelf there is no evidence in any cores which sample allounit 1b that the sites were located in limans rather than on a transgressed shelf which had been flooded by post glacial meltwater and enhanced river runoff as the climate became more humid in the early holocene a prolonged stillstand at the spill depth controlled by the sill in the strait of bosphorus is confirmed by the elevation of a drowned recurved spit downdrift from cape emine bulgaria the development of the subaqueous unconformities correlative conformities 1 and 2 was facilitated by storm induced wave erosion transport bypass and erosion under the rim current and its anticyclonic eddies and possibly breaking internal waves volumetrics based on isopach maps and pre industrial sediment discharge rates of various rivers entering the western and southwestern black sea suggest that the total sediment yields of bulgarian and turkish rivers can only account for 13 14 of the total holocene succession allounits 1b 1d and that major input from the danube river via along shelf long distance transport must have occurred through the entire holocene

catastrophic flooding of the black sea abstract decades of seabed mapping reflection profiling and seabed sampling reveal that throughout the past two million years the black sea was predominantly a freshwater lake interrupted only briefly by saltwater invasions coincident with global sea level highstand when the exterior ocean lay below the relatively shallow sill of the bosporus outlet the black sea operated in two modes as in the neighboring caspian sea a cold climate mode corresponded with an expanded lake and a warm climate mode with a shrunken lake thus during much of the cold glacial quaternary the expanded black sea s lake spilled into to the marmara sea and from there to the mediterranean however in the warm climate mode after receiving a vast volume of ice sheet meltwater the shoreline of the shrinking lake contracted to the outer shelf and on a few occasions even beyond the shelf edge if the confluence of a falling interior lake and a rising global ocean persisted to the moment when the rising ocean penetrated across

origin migration pathways and paleoenvironmental significance of holocene ostracod records from the northeastern black sea shelf micropaleontological studies of the black sea including ostracod records have suggested that early holocene salinity values were between 5 and 10 practical salinity units psu contrasting with present values of 18 22 psu however more precise paleoenvironmental reconstructions based on ostracod assemblages require additional information related to their modern ecological affinities this study uses modern species information collected from samples with living fauna to interpret the fossil holocene assemblages of two sediment cores ak 2575 and ak 521 collected from the northeastern outer shelf of the black sea a total of 37 ostracod species are recorded in the fossil assemblages with 2 related to freshwater oligohaline environments 23 from caspian type environments and 12 from environments similar to the mediterranean three distinct assemblage zones are identified from the caspian type dominating in the early holocene up to 7 4 cal ka bp a mixed assemblage of caspian type and mediterranean type from 7 4 to 6 8 cal ka bp and a progressive dominance of mediterranean species from 6 8 cal ka bp it is very likely that the dominant control of ostracod species occurrence during the period up to 6 8 cal ka bp is salinity a range of factors including temperature biotope and sedimentation rates influenced the species distribution over the last 6 8 cal ka bp

controversy over the great flood hypotheses in the black sea in light of geological paleontological and archaeological evidence abstract legends describing a great flood are found in the narratives of several world religions and the biblical account of noah s flood is the surviving heir to several versions of the ancient mesopotamian flood myth recently the story of the biblical deluge was connected to the black sea together with the suggestion that the story s pre mesopotamian origins might be found in the pontic basin ryan w b f pitman iii w c 1998 noah s flood the new scientific discoveries about the event that changed history simon and schuster new york based on the significance of this flood epic in the judeo christian tradition popular interest surged following publication of the idea currently two great flood scenarios have been proposed for the black sea 1 an early holocene event caused by catastrophic mediterranean inflow at 7 2 ky bp initial hypothesis of ryan et al 1997 an abrupt drowning of the black sea shelf marine geology 138 119 126 or 8 4 ky bp modified hypothesis of ryan et al 2003 catastrophic flooding of the black sea annual review of earth and planetary science 31 525 554 and 2 a late pleistocene event brought on by caspian influx between 16 and 13 ky bp chepalyga a l 2003 late glacial great flood in the black sea and caspian sea gsa annual meeting and exposition 2 5 november 2003 seattle usa p 460 both hypotheses claim that the massive inundations of the black sea basin and ensuing large scale environmental changes had a profound impact on prehistoric human societies of the surrounding areas and both propose that the event formed the basis for the biblical great flood legend this paper attempts to determine whether the preponderance of existing evidence sustains support for these great floods in the evolution of the black sea based upon established geological and paleontological data it finds that the late pleistocene inundation was intense and substantial whereas the early holocene sea level rise was not between 16 and 13 ky bp the late neoeuxinian lake the late pleistocene water body in the pontic basin pre dating the black sea increased rapidly from 14 to 50 m below the present level of the black sea then rose gradually to 20 m by about 11 ky bp at 11 10 ky bp the younger dryas it dropped to 50 m when the black sea re connected with the sea of marmara at about 9 5 ky bp inflowing mediterranean water increased the black sea level very gradually up to 20 m and in so doing it raised the salinity of the basin and brought in the first wave of mediterranean immigrants these data indicate no major drawdown of the black sea after the younger dryas and they do not provide evidence for any catastrophic flooding of the black sea in the early holocene in addition available archaeological and paleoenvironmental evidence from the pontic region reveal no recognizable changes in population dynamics between 14 and 6 ky bp that could be linked to an inundation of large magnitude dolukhanov p shilik k 2006 environment sea level changes and human migrations in the northern pontic area during late pleistocene and holocene times in yanko hombach v gilbert a s panin n dolukhanov p m eds the black sea flood question changes in coastline climate and human settlement springer dordrecht pp 297 318 stanko v n 2006 fluctuations in the level of the black sea and mesolithic settlement of the northern pontic area in yanko hombach v gilbert a s panin n dolukhanov p m eds the black sea flood question changes in coastline climate and human settlement springer dordrecht pp 371 385 more specifically mesolithic and early neolithic archaeological data in southeastern europe and ukraine give no indications of shifts in human subsistence or other behavior at the time of the proposed catastrophic flood in the early holocene anthony d 2006 pontic caspian mesolithic and early neolithic societies at the time of the black sea flood a small audience and small effects in yanko hombach v gilbert a s panin n dolukhanov p m eds the black sea flood question changes in coastline climate and human settlement springer dordrecht pp 345 370 dergachev and dolukhanov 2006 the neolithization of the north pontic area and the balkans in the context of the black sea floods in yanko hombach v gilbert a s panin n dolukhanov p m eds the black sea flood question changes in coastline climate and human settlement springer dordrecht pp 489 514

widespread overspill from a saline density current channel and its interaction with topography on the south west black sea shelf seaward of the bosphorus strait the south west black sea shelf is dominated by the world s largest channel network maintained by a quasi continuous saline ca 35 31 psu underflow calculations indicate that 85 of the initial discharge of ca 104 m3s 1 spills overbank before the shelf edge this paper documents interaction of the overspill with sea bed topography using multibeam bathymetry echo sounder images of the water column conductivity temperature depth profiles and sediment cores overbank spill is widespread particularly through crevasse channels and on the middle shelf where confinement by channel banks is negligible towards the outer shelf the wind driven rim current advects mud along the shelf contributing to levee successions and deposition on stoss sides of elongate transverse ridges echo sounder profiles reveal metre scale eddies over megaflutes and breaking lee waves and internal hydraulic jumps over ridges megaflutes reach 600 m long and 7 m deep yet form where the underflow outside the flute is no thicker than ca 2 to 5 m two types of elongate seaward facing ridges are recognized type 1 ridges 2 to 5 m high consist of bivalve rich muddy sand in low angle 3 5 to 6 cross sets created by the underflow type 2 ridges ca 5 m high have crests up to 2 km long and a buried wedge shaped foundation the ridge core comprised of facies similar to type 1 ridges these ridge cores are blanketed on the landward side by stratified muds and are capped by obliquely oriented ribs supporting a diverse benthic community this facies distribution is interpreted to result from stoss side and lee side velocity and turbulence fluctuations induced by internal hydraulic jumps and breaking lee waves in overspilling portions of the underflow experimental results published by w h snyder and co workers effectively explain ridge evolution and flow across the ridges and therefore can be applied with confidence to less easily studied deep marine settings swept by turbidity currents

establishment of euxinic conditions in the holocene black sea the paleoenvironmental evolution of the black sea is closely linked to the ingression of mediterranean seawater over the bosporus sill after the last glacial maximum we have reconstructed the temporal and spatial development of the black sea suboxic chemocline which divides oxic surface water from anoxic sulfi dic euxinic deep water by combining high resolution geochemical records of bulk parameters carbonate total organic carbon sulfur trace metals cu mo v and an isotopic proxy 56 fe from seven sediment cores in the black sea we generated a single composite geochemical core log that serves as a reference archive for the entire basin our proxy records refl ect the changing depositional and redox conditions of the black sea and permit us to estimate the infl ow budget of mediterranean seawater throughout the holocene our data indicate a gradual rise of the chemocline until ca 5 3 ka when suboxic waters fl ooded the shelf for the fi rst time trace metal and isotopic inventories document one major descent of the chemocline since the onset of brackish marine conditions before the present stable situation was established