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

was the black sea catastrophically flooded in the early holocene abstract a catastrophic flooding of the black sea basin was proposed to have occurred during its reconnection to the ocean in the early holocene possible cultural consequences of the flood include the migration of neolithic farmers from around the black sea towards central europe as well as the creation of flood myths stratigraphic and paleo geomorphologic information from danube delta aided by radiocarbon ages on articulated mollusks constrain the level in the black sea before the marine reconnection to ca 30 m below the present sea level rather than 80 m or lower if the flood occurred at all the sea level increase and the flooded area during the reconnection were significantly smaller than previously proposed

on the interpretation of century millennium scale variations of the black sea level during the first quarter of the holocene abstract analysis and synthesis of different paleo evidence has enabled a qualitatively new outline of the holocene history of the black sea bs in the early holocene the sea level rise was complicated by a series of transgressions and regressions the question of their origin remains open because there are no clear stable links of the bs level anomalies and palaeohydrological phases with the calendar of climatic anomalies tectonically induced vertical motions may also be a source of discrepancies of different eustatic curves neglecting the water exchange via the bosphorus strait at the beginning of the holocene we can propose the mechanism of occurrence of large transgressive regressive stages of the bs the model of the bs level dynamics is interpreted as stochastic from this perspective it is a langevin equation that incorporates the action of river runoff precipitation and evaporation as random white noise under these conditions the fast anomalies of the water regime are accumulated by the bs undergoing random walk this mechanism could be responsible for the appearance of secular millennium scale large irregular fluctuations of the bs level that do not correlate with known climatic events however such hypothetical bs level anomalies could not have occurred in the presence of a large water discharge value via the bosphorus strait because intensive water exchange between the bs and the sea of marmara was a very effective spin down process destroying bs level anomalies and prohibiting the development of large scale anomalies lasting a few centuries or furthermore a few thousand years therefore the theoretical analysis showed that the empirical data are controversial observed bs level fluctuations during the first quarter of the holocene and large water discharge value via the bosphorus sill could not occur simultaneously the magnitude and occurrence of bs level fluctuations and features of the bs sea of marmara interaction require further specification based on geological and geochronological evidence

holocene marine transgression in the black sea new evidence from the northwestern black sea shelf abstract for two decades the timing and rate of holocene marine transgression and the level of the black sea prior to the transgression has been the focus of many geological palaeoecological and archaeological studies the potential importance of confirming or rejecting the catastrophic flood hypothesis by refining the chronology of the marine transgression and determining the water level of the early holocene black sea neoeuxinian lake is the aim of many ongoing black sea palaeoecological studies in this report we review previous studies and present new data on the early holocene marine transgression obtained from multidisciplinary studies of several cores from different parts of the black sea core 342 from the edge of the dniester paleovalley on nw shelf is particularly important because it provides wood and leaf material from several peat and muddy peat beds each up to 10 cm thick inter layered in a coastal succession with mud clay and shell coquina ams ages for wood fragments and sedge leaves in the peat layers provide critical new data for calibrating and re tuning of previously published shell and bulk detrital peat ages our multi disciplinary study of geological material recovered from different shelf areas of the black sea refines the chronology of the marine transgression and clarifies conflicting interpretations of the water level and salinity of the neoeuxinian lake prior to the initial mediterranean inflow imi and transgression of mediterranean water in the holocene we find that 1 the level of the late neoeuxinan lake prior to the early holocene mediterranean transgression stood around 40 m bsl but not 100 m or more as suggested by advocates of catastrophic rapid prominent flooding of the black sea by mediterranean water 2 at all times the neoeuxinan lake was brackish with salinity not less that 7 psu 3 by 8 9 ka bp the black sea shelf was already submerged by the mediterranean transgression an increase in salinity took place over 3600 years with rate of the marine water incursion being estimated in the order of 0 05 cm 1 7 cm a 1 4 the combined data set of sedimentological characteristics and microfossil data establish that the holocene marine transgression was of a gradual progressive nature in the early holocene

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

abrupt changes of temperature and water chemistry in the late pleistocene and early holocene black sea new mg ca sr ca and published stable oxygen isotope and 87sr 86sr data obtained on ostracods from gravity cores located on the northwestern black sea slope were used to infer changes in the black sea hydrology and water chemistry for the period between 30 to 8 ka b p calibrated radiocarbon years the period prior to 16 5 ka b p was characterized by stable conditions in all records until a distinct drop in 18o values combined with a sharp increase in 87sr 86sr occurred between 16 5 and 14 8 ka b p this event is attributed to an increased runoff from the northern drainage area of the black sea between heinrich event 1 and the onset of the bolling warm period while the mg ca and sr ca records remained rather unaffected by this inflow they show an abrupt rise with the onset of the bolling allerod warm period this rise was caused by calcite precipitation in the surface water which led to a sudden increase of the sr ca and mg ca ratios of the black sea water the stable oxygen isotopes also start to increase around 15 ka b p although in a more gradual manner due to isotopically enriched meteoric precipitation while sr ca remains constant during the following interval of the younger dryas cold period a decrease in the mg ca ratio implies that the intermediate water masses of the black sea temporarily cooled by 1 2 c during the younger dryas the 87sr 86sr values drop after the cessation of the water inflow at 15 ka b p to a lower level until the younger dryas where they reach values similar to those observed during the last glacial maximum this might point to a potential outflow to the mediterranean sea via the sea of marmara during this period the inflow of mediterranean water started around 9 3 ka b p which is clearly detectable in the abruptly increasing mg ca sr ca and 87sr 86sr values the accompanying increase in the 18o record is less pronounced and would fit to an inflow lasting 100 a

a new system for acquisition and processing of very high resolution seismic reflection data a new digital seismic data acquisition system and accompanying software have been developed by ifremer to replace the analog equipment commonly used in very high resolution less than 1 m shallow marine seismic reflection surveys the acquisition part based on a hewlett packard 9000 microcomputer is capable of sampling rates of up to 15 khz for one channel signal processing and image processing can be performed either during the survey by the acquisition computer or after the survey with a software system that runs on a sun workstation the system has been developed for the specific requirements of coastal studies understanding of the sediment layers in such studies requires a vertical resolution of around 1 m in the top 10 m of sediment this system has been successfully used for the study of subtidal sand waves off the cherbourg peninsula france the results which revealed the internal structure of sand waves from about 3 m to 8 m high correlated well with synthetic seismograms that were create

further evidence of abrupt holocene drowning of the black sea shelf a 1999 survey of the black sea continental shelf off the north central turkish seaport of sinop using a side scan sonar small remotely operated vehicles and a series of dredge lowerings located inspected and sampled an exposed high energy paleoshoreline at a depth of 155 m radiocarbon dating of mollusk shells collected from this ancient beach revealed that the marine flooding of the black sea took place between 7460 and 6820 yr b p all ages are reported in radiocarbon years not calendar years without correction for reservoir age or dendro calibration changing it from a lacustrine to marine environment this relic surface remained in contact with the bottom waters of the black sea for a long period of time before being draped by a thin layer of sapropel mud wood samples recovered from this same location were very well preserved and yielded dates as old as 3580 yr b p q 2000 elsevier science b v all rights reserved

development and structural architecture of the eastern black sea the cenozoic sedimentary fill of the eastern black sea figure 1 is up to 10 km in thickness its bedding is almost horizontal with the the exception of basin flanks the eastern black sea basin is separated from the cenozoic sorokin and tuapse troughs by the buried shatsky and tetyaev ridges which have mesozoic and paleocene eocene sedimentary cover figure 2

late pleistocene holocene sea level dynamics in the caspian and black seas data synthesis and paradoxical interpretations abstract different multidisciplinary data concerning the paleodynamics of sea level variations in the caspian and black seas are controversial in some aspects there are at least three paradoxes that are discussed in the paper the paradox no 1 relates to the early and late khvalynian transgressions that occurred in the cs during the second part of mis 3 35 25 ka bp and the late glacial epoch 17 12 ka bp respectively it is unclear what the main source or sources of water were that caused them paradox no 2 emerges from the comparison of climate events and transgressive regressive cycles in the caspian sea and the black sea it implies that large sea level anomalies occurred in accordance with global climate changes because they are influenced by climate variations however other not so long lived sea level fluctuations are poorly correlated with climate events the question is why climatically induced sea level changes did not follow climatic variations paradox no 3 concerns the contradiction between the massive water discharge from the black sea into the sea of marmara via the bosphorus strait and the black sea level fluctuations in the latest pleistocene holocene that could not exist simultaneously it is shown that paradox no 2 has been solved at least on conceptual level solutions to paradoxes no 1 and no 3 are still lacking further geological and geochronological evidence as well as climate simulation are required formulation of solutions for these paradoxes should make a major contribution not only to the problems of the caspian and black seas paleogeography but also provide help in explaining the reasons for inadequate simulation of regional climate changes this is important in the context of the development of models for future climate prediction

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

multicentennial scale hydrological changes in the black sea and northern red sea during the holocene and the arctic north atlantic oscillation 1 paleoenvironmental proxy data for ocean properties eolian sediment input and continental rainfall based on high resolution analyses of sediment cores from the southwestern black sea and the northernmost gulf of aqaba were used to infer hydroclimatic changes in northern anatolia and the northern red sea region during the last 7500 years pronounced and coherent multicentennial variations in these records reveal patterns that strongly resemble modern temperature and rainfall anomalies related to the arctic oscillation north atlantic oscillation ao nao these patterns suggest a prominent role of ao nao like atmospheric variability during the holocene beyond interannual to interdecadal timescales most likely originating from solar output changes

the timing and evolution of the post glacial transgression across the sea of marmara shelf south of istanbul high resolution reflection seismic profiles with core analyses of sedimentary sequence near the sea of marmara som entrance to the strait of istanbul soi bosphorus provide detailed record of sealevel changes since the late glacial maximum lgm the sequence is deposited over the lgm erosional surface at a maximum depth of 105 m it includes seven seismic units that can be confidently correlated with 14c dated sedimentary units in the cores unit 6 represents levee deposits of the paleo soi channel that was deposited by a black sea outflow during 11 2 10 6 kyr bp the reflection surfaces at base of unit 5 and 4 correspond to wave cut terraces at 71and 63 m respectively and are estimated to be 10 6 and 9 8 kyr bp the seismic unit 2 overlaying a mud drape unit 3 comprises deltaic sediments that was deposited during 6 400 3200 yr 14c bp isopach map and

late glacial to holocene climate and sedimentation history in the nw black sea abstract gravity cores from the continental slope in the northwestern black sea were studied using high resolution stable isotope grain size and xrf scanning data the measurements provide a 30 000 years ams 14c dated record of variations in the hydrological regime of the black sea and give insight into changing paleoenvironments in the surrounding areas stable climatic conditions during the last glacial maximum were followed by a series of meltwater pulses most likely originating from the scandinavian ice sheet between 18 000 and 15 500 yr bp 1 this meltwater input rose the level of the caspian sea to a point that caspian water could spill into the black sea via the manych depression north of the caucasian mountains high frequency oscillations in the xrf data during this period suggest a probable link to the arctic climate regime later during the bolling allerod and the early holocene prevailing high temperatures led to authigenic calcite precipitation through increased phytoplankton activity interrupted by the younger dryas and the 8200 yr bp cold event with dominant clastic sedimentation

late glacial to holocene paleoenvironmental evolution of the black sea reconstructed with stable oxygen isotope records obtained on ostracod shells high resolution stable oxygen isotope d 18 o on ostracod shells xrf scanning and bulk grain size data obtained on a transect of 6 gravity cores from the continental slope in the northwestern black sea give new insight into the hydrological evolution of the black sea since the last glacial maximum lgm stable climatic conditions during the lgm were followed by a series of meltwater pulses between 18 and 15 5 kyr bp that resulted in temporary isotopic depletion of the black sea waters subsequently steadily increasing d 18 o values in all cores are mainly caused by isotopically enriched precipitation at the onset of the allerod bolling warm period a comparison of the major trends in d 18 o at different water depths suggests evaporation driven deep water formation since 14 5 kyr bp while the two shallowest cores from 168 and 465 m water depth were under the influence of increased warming in the upper water column since 14 5 and 12 5 kyr bp respectively the core from 168 m depth seems to be additionally influenced by freshwater input of the danube this core provides a high resolution record from the younger dryas allerod boundary and suggests that a nao like climate mode was governing the interannual variability in the run off of the danube which implies that this climate mode has been a persistent climatic feature over central europe the inflow of saline mediterranean waters occurs between 9 and 8 kyr bp where a merging of all d 18 o records signals an initial homogenisation of the water column

a post younger dryas black sea regression identified from sequence stratigraphy correlated to core analysis and dating the north western black sea shelf is the widest continental shelf of the black sea where the danube delta prodelta system includes important records on the black sea water level fluctuations this study integrates newly acquired high resolution single channel seismic reflection profiles and calypso piston cores recovered along a transect extending from the danube delta deep into its deep sea fan the correlated results provide information on the late quaternary architecture of the danube black sea shelf and on the role of global glacio eustatic fluctuations on the building of the danube delta prodelta the sedimentary sequences in the black sea are strongly affected by water level changes for the whole duration of late glacial holocene period the level of the black sea was controlled by the regional climate modifications rather than the global eustatic changes the seismic sequences recognized on a very high resolution seismic profile were dated by two calypso piston cores based on the obtained data during the last glacial maximum the black sea was a land locked lake with the level below 120 m in the course of the deglaciation the lake level rose up to 40 m which is confirmed by occurrence of the prodelta lobes formed after the rise in water level originated from the melt water following the younger dryas 11 000 8500 c 14 bp there occurred a new level lowering to the level of 100 m identified by the forced regression deposits recorded on the romanian shelf this last lowstand previously recognized by a pronounced shoreline with a characteristic beach profile and a belt of coastal dunes is also indicated by the prodelta at 100 m depth all these coastal features as well as the incised anastomosed channel system remained preserved on the shelf resulting from a rapid ultimate transgression starting immediately after 8500 c 14 bp c 2010 elsevier ltd and inqua all rights reserved

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

small scale seismic stratigraphy and paleogeographical evolution of the continental shelf facing the se elba island northern tyrrhenian sea italy abstract approximately 200 naut mi of high resolution single channel seismic reflection profiles from the se elba continental shelf were analyzed the analysis included a detailed three dimensional reconstruction of the upper 100 m of shelf sediments six depositional sequences were identified with an average thickness of less than 10 m these sequences were bounded by unconformities which were mostly erosional and which extended over the entire area commonly used exploration seismology methods were applied they included an analysis of the configurations of reflectors inside each sequence and their terminations against the basal unconformity the lower five sequences experienced a similar history they appear to represent coastal environments which developed at more than 100 m below the present sea level during pleistocene sea level changes the uppermost sequence was correlated with the muddy shelf sedimentation of the present highstand the recurrent distribution in the five lower seismic sequences can be explained by the fact that during rises of sea level sedimentation was largely controlled by local paleogeography and paleotopography during such periods the investigated area was located at the apex of a wide gulf connecting elba island to the mainland in this area progradations were mostly controlled by the slope of the paleocoast that is by the structural constraint represented by the monte calamita headland p the paleoenvironmental interpretation for the upper sequences was largely substantiated by seafloor cores cores were collected from relict transgressive littoral deposits below a mud interval related to the present eustatic environment

stratal architecture of western mediterranean margins as the result of the stacking of quaternary lowstand deposits below glacio eustatic fluctuation base level abstract through a comparison of high resolution seismic stratigraphy of seven western mediterranean margins similarities and differences in stratigraphic architecture were highlighted and a hierarchy of controlling factors was established the areas are northwestern alboran ebro and northern catalonia in the spanish margin rho ne in the french margin and tuscany latium and calabria in the italian tyrrhenian margin despite their different tectonic physiographic and depositional setting the seismic facies and growth pattern of the middle late pleistocene deposits are comparable the margins are in fact the result of the stacking of lowstand systems tracts of 4th order depositional sequences bounded by polygenetic unconforniities on the shelf and condensed sections on the upper slope this lowstand nature results from the high frequency 100 ka high amplitude 100 m asymmetry falling 65 of the time and stationariness between 10 and 120 m with respect to the present of the glacio eustatic sea level curve if eustasy directly controls the types of deposits making up the margins tectonism conditions their growth pattern as it is the only factor accounting for similarities and differences in the external geometry stratal pattern and distribution of the middle late pleistocene depositional sequences an evolutionary model for the quaternary growth of young passive continental margins is proposed in this model tectonics determines the degree of preservation of lowstand deposits because it conditions the accommodation space left below the erosional profile produced by each glacio eustatic cycle thus some of the sequence stratigraphy principles widely used to set up the model have been modified and adjusted to take into consideration the peculiar nature of quaternary glacio eustasy

dynamics of the coastal north black sea area in late pleistocene and holocene and early human dispersal abstract based on detailed surveys the reconstructions of coastal and marine environments of the north western black sea shelf were carried out for the time spans of ca 25 18 12 10 7 and 7 4 ka bp during the great part of late pleistocene and early holocene the black sea remained a land locked basin of the caspian type which became colonised by early modern humans starting from ca 40 ka the subsequent evolution of coastal landscapes was generally conditioned by the gradual rise of sea level and increasing temperature and precipitation resulting in the formation of coastal wetland landscapes which became the main source of late palaeolithic and mesolithic subsistence the initial indications of farming activities are coeval with the kalamitian stage being conditioned by the increased temperature and precipitation combined with the formation of fertile soils under altithermal conditions the data fail to indicate a catastrophic breakthrough of mediterranean water that could have had any effect on the subsistence or migrations of early farming communities

organic matter production and preservation and evolution of anoxia in the holocene black sea dating of sediments collected in gravity cores during leg 1 of the 1988 r v knorr expedition to the black sea suggests that the onset of water column anoxia at 7 5 ka was virtually synchronous across the basin over a depth range of 200 2250 m a finely laminated organic carbon oc rich sapropel unit ii was produced as a result of this anoxia the trigger for increased oc production and development of anoxia was the spillover of saline waters through the bosporus that probably began at 9 0 ka and peaked between 7 0 and 5 5 ka this spillover enhanced vertical mixing and nutrient cycling and caused a short term 2 3 kyr burst in surface water productivity during the early part of unit ii deposition continued incursion of saline waters enhanced vertical stability and inhibited mixing of nutrients into surface waters thus limiting primary production and decreasing the oc flux to sediments beginning 5 5 ka concentration accumulation rate and degree of preservation of organic matter all decreased in the upper part of unit ii as a result of decreasing productivity but anoxia persisted throughout most of the water column the end of unit ii sapropel deposition was synchronous across the black sea as the result of the first blooms of the coccolith emiliania huxleyi which presumably marked an increase in surface water salinity above 11 and the beginning of unit i deposition the high coccolith carbonate fluxes that occurred during deposition of unit i diluted the oc concentration in the sediments but oc accumulation rates are about the same as those in upper part of unit ii

the late holocene evolution of the black sea a critical view on the so called phanagorian regression abstract throughout its geologic history the black sea experienced major sea level changes accompanied by severe environmental modifications including geomorphologic reshaping the most spectacular changes were driven by the quaternary glaciations and deglaciations that reflect responses to milankovitch cycles of 100 and 20 ky periodicity major sea level changes were also considered for a shorter and more recent cyclicity the concept of the phanagorian re and transgression cycle supposedly with a minimum sea level stand of 5 6 m below its present position in the middle of the 1st millennium bc was established in 1963 by fedorov for the black sea region it was based on archaeological and palaeogeographical research conducted around the ancient greek colonies of the cimmerian bosporus in particular at the name giving site of phanagoria where underwater prospection had revealed the presence of a large number of submerged relics of the classical greek era analyses of sediment cores as well as 14c dated fossil coastal bars in the western and southern parts of taman peninsula show that contemporary coastal bars are related to different sea levels the dissymmetry can reach up to 6 m around 500 bc this and more evidence from drill cores confirms that on taman peninsula many of the apparent sea level changes are tectonically induced the subsidence may have been initiated by the release of gas from mud volcanoes inherited along anticline axes other observations around the black sea confirm that submerged archaeological sites correspond to areas where subsidence has taken places while the so called holocene highstand said to have been located above the present day sea level is associated with uplift areas triggered by the ongoing caucasus orogeny recent oceanographic research carried out in the black sea area shows that since the black sea was reconnected with the mediterranean sea i e 7500 14c bp at the latest both marine water bodies have been in equilibrium this fact and arguments from archaeology history hydrodynamics etc lead us to question the existence of the phanagorian regression it is important to note that none of the sea level curves established for the eastern mediterranean shows a comparable regression transgression cycle of several metres during the 1st millennium bc

young danube delta documents stable black sea level since the middle holocene morphodynamic paleogeographic and archaeological implications new radiocarbon and optical dates show that the holocene danube delta started to build out of a black sea embayment 5200 yr ago delta lobe development phases differ by as much as 5 k y from previously proposed ages the new chronology allows for a better understanding of the danube delta paleogeography includ ing the demise of istria the main ancient greek roman city in the region prior reconstructions of sea level in the black sea inferred fluctuations to 15 m in range however stratigraphy of beach ridg es in the delta shows that the relative black sea level for the past 5 k y was stable in the danube delta region within 2 m and 1 5 of the current level hydroisostatic effects related to a proposed catastrophic reconnection of the black sea to the world ocean in the early holocene may have been responsible for the sea level reaching the highstand earlier than estimated by models the new sea level data suggest that submergence at several ancient settle ments around the black sea may be better explained by local fac tors such as subsidence rather than by basin wide sea level fluctuations

postglacial connection of the black sea to the mediterranean and its relation to the timing of sapropel formation the opening of the connection between the mediterranean and black seas as sea level rose above the bosporus sill has long been associated with the formation of the most recent holocene sapropel deposit s1 in the eastern mediterranean but the mechanism has remained elusive we present a model for the opening of the black sea based on hydraulics arguments which demonstrates that increased freshwater flux out of the black sea began 500 1000 years after sea level reached sill depth and that the timescale for the increased freshwater flux that drained the freshwater reservoir of the black sea is about 2500 3500 years we argue that the increased freshwater discharge out of the black sea would lead to decreased deep water formation and higher productivity in the surface waters in the eastern mediterranean two conditions generally associated with sapropel formation the delay in increased freshwater flux after the opening of the black sea and the period of increased freshwater discharge appear to match the onset and duration of sapropel deposits in the eastern mediterranean

black sea impact on the formation of eastern mediterranean sapropel s1 evidence from the marmara sea abstract water exchange between the black sea and the mediterranean sea has been a major focus of the paleohydrography of the eastern mediterranean glacial melt water released from the black sea is a potential factor in the formation of sapropel s1 an organic rich sediment layer that accumulated during the early holocene a high resolution study done on sediments from the marmara sea the gateway between the mediterranean and the black sea sheds light on the holocene exchange processes past sea surface temperature and sea surface salinity sss were derived from stable oxygen isotope ratios 18o of foraminiferal calcite and alkenone unsaturation ratios uk 37 heavy 18o values and high sss in the marmara sea suggest absence of low salinity water from the black sea during s1 the comparison with data from the levantine basin and southern aegean sea outlines gradients of freshening in the eastern mediterranean sea whereby the major sources of freshwater were closer to the levantine basin it is thus concluded that the black sea was not a major freshwater source contributing to formation of s1 given the absence of a low salinity layer the deposition of organic rich sediments corresponding to s1 in the marmara sea is likely the result of the global transgression and the concomitant re organization of biogeochemical cycles leading to enhanced productivity as shown by globigerina bulloides

observations of mediterranean flow into the black sea mediterranean sea water inflow into the black sea is investigated using acoustic and oceanographic data obtained in the black sea exit region the path of mediterranean water and the resulting spreading on the continental shelf are observed with multibeam echo sounding swath bottom bathymetry measurements high resolution echo sounding images and conductivity temperature depth profiles it is found that the saline mediterranean water is reduced by 6 practical salinity units as it flows and spreads on the shelf before reaching the continental slope where it sinks to a depth appropriate to its density temporal and spatial variability in the flow and their relation to atmospheric and sea level changes are documented it is shown that blockage of the mediterranean undercurrent occurs when the estimated black sea water transport exceeds 25 103 m3 s 1 which corresponds to a relative sea level difference greater than 40 cm mediterranean flow into the black sea is a high reynolds low richardson number flow resulting in a turbulent bottom boundary layer measurements of the path averaged turbulent kinetic energy dissipation rate give values ranging from 1 10 6 to 1 10 4 w kg 1

danube river sediment input and its interaction with the north western black sea abstract the influence of the river danube is determinant to the sedimentation of the north western and western black sea area after 1970 following the building of the iron gates dam the danube river sediment discharge diminished to 30 40 of its previous value after a 12 000 year evolution marked by active progradation the danube delta has become mainly inactive over the last few decades partly due to interventions of man made origin the deficit of sediment influx has led to the intense erosional processes of the deltaic littoral on the black sea north western shelf two main areas with contrasting sedimentary processes have been identified the internal danube sediment fed shelf and the external sediment starved shelf the modern highstand sedimentary history of the north western black sea deep area is marked by the cessation of the danube deep sea fan active development the main depositional units within the north western black sea are described

tephra from the minoan eruption of santorini in sediments of the black sea the explosive eruption of santorini volcano in the aegean sea about 3 300 years ago is of considerable archaeological and volcanological significance1 5 here we report the discovery of tephra from this minoan event in laminated sediments of the black sea this finding provides constraints on the distribution of debris from the eruption we estimate a minimum fallout area of 2 l06 km2 extending from the black sea in the north to the southeastern mediterranean sea the main dispersal axis trends through southern turkey in agreement with other studies of minoan tephra6 7 the tephra deposits should provide a useful reference horizon for assessing the chronology of black sea sediments which has been much debated8 15

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

corrigendum to a holocene dinocyst record of a two step transformation of the neoeuxinian brackish water lake into the black sea

the timing of the black sea flood event insights from modeling of glacial isostatic adjustment abstract we present a suite of gravitationally self consistent predictions of sea level change since last glacial maximum lgm in the vicinity of the bosphorus and dardanelles straits that combine signals associated with glacial isostatic adjustment gia and the flooding of the black sea our predictions are tuned to fit a relative sea level rsl record at the island of samothrace in the north aegean sea and they include realistic 3 d variations in viscoelastic structure including lateral variations in mantle viscosity and the elastic thickness of the lithosphere as well as weak plate boundary zones we demonstrate that 3 d earth structure and the magnitude of the flood event which depends on the pre flood level of the lake both have significant impact on the predicted rsl change at the location of the bosphorus sill and therefore on the inferred timing of the marine incursion we summarize our results in a plot showing the predicted rsl change at the bosphorus sill as a function of the timing of the flood event for different flood magnitudes up to 100 m these results suggest for example that a flood event at 9 ka implies that the elevation of the sill was lowered through erosion by 14 21 m during and after the flood in contrast a flood event at 7 ka suggests erosion of 24 31 m at the sill since the flood more generally our results will be useful for future research aimed at constraining the details of this controversial and widely debated geological event

constraints on black sea outflow to the sea of marmara during the last glacial interglacial transition new cores from the upper continental slope off romania in the western black sea provide a continuous high resolution record of sedimentation rates clay mineralogy calcium carbonate content and stable isotopes of oxygen and carbon over the last 20 000 yr in the western black sea these records all indicate major changes occurring at 15 000 12 800 8400 and 7100 yr before present these results are interpreted to reflect an evolving balance between water supplied by melting glacial ice and other river runoff and water removed by evaporation and outflow the marked retreat of the fennoscandian and alpine ice between 15 000 and 14 000 yr is recorded by an increase in clays indicative of northern provenance in black sea sediments a short return toward glacial values in all the measured series occurs during the younger dryas cold period the timing of the first marine inflow to the black sea is dependent on the sill depths of the bosporus and dardanelles channels the depth of the latter is known to be 80 5 m which is consistent with first evidence of marine inundation in the sea of marmara around 12 000 yr the bedrock gorge of the bosporus reaches depths in excess of 100 m relative to present sea level though it is now filled with sediments to depths as shallow as 32 m two scenarios are developed for the connection of the black sea with the sea of marmara one is based on a deep bosporus sill depth effectively equivalent to the dardanelles and the other is based on a shallow bosporus sill less than 35 m in the deep sill scenario the black sea s surface rises in tandem with the sea of marmara once the latter connected with the aegean sea and black sea outflow remains continuous with inflowing marine water gradually displacing the freshwater in the deep basin the increase in the 18 o of mollusk shells at 12 800 yr and the simultaneous appearance of inorganic calcite with low 18 o is compatible with such an early marine water influx causing periodic weak stratification of the water column in the shallow sill scenario the black sea level is decoupled from world sea level and experiences rise and fall depending on the regional water budget until water from the rising sea of marmara breaches the shallow sill in this case the oxygen isotope trend and the inorganic calcite precipitation is caused by increased evaporation in the basin and the other changes in sediment properties reflect climate driven river runoff variations within the black sea watershed the presence of saline ponds on the black sea shelf circa 9600 yr support such evaporative drawdown but a sensitive geochemical indicator of marine water one that is not subject to temperature salinity or biological fractionation is required to resolve whether the sill was deep or shallow

is the abrupt drowning of the black sea shelf at 7150yrbp a myth abstract sedimentological and chronostratigraphic studies of the coastal plain sediments of the black sea near the sakarya river turkey and seismic stratigraphic survey of the shelf sediments off this river s mouth were carried out the results indicate that just prior to its flooding by the mediterranean waters at about 7200 yr bp the black sea was a fresh water lake emptying its waters into the sea of marmara the water level of this lake was about 18 m lower than the present sea level but above the 35 m sill depth of the bosphorus this finding contradicts with ryan et al 1997a ryan et al 1997b hypothesis that the black sea lake water level was more than 100 m below the sill depth of the bosphorus and that the drowning of the black sea shelf at 7150 yr bp was abrupt

wind shear effects on radiatively and evaporatively driven stratocumulus tops abstractdirect numerical simulations resolving meter and submeter scales in the cloud top region of stratocumulus are used to investigate the interactions between a mean vertical wind shear and in

calibration of the c 14 timescale over the past 30 000 years using mass spectrometric u th ages from barbados corals uranium thorium ages obtained by mass spectrometry from corals raised off the island of barbados confirm the high precision of this technique over at least the past 30 000 years comparison of the u th ages with 14c ages obtained on the holocene samples shows that the u th ages are accurate because they accord with the dendrochronological calibration before 9 000 yr bp the 14c ages are systematically younger than the u th ages with a maximum difference of 3 500 yr at 20 000 yrbp the u th technique thus provides a way of calibrating the radiocarbon timescale beyond the range of dendrochronological calibration

geochemistry of the black sea during the last 15 kyr a protracted evolution of its hydrography and ecology the black sea is a 2200 m deep anoxic marine sea connected to the mediterranean sea via the dardanelles strait marmara sea and the 3 km wide 35 m deep bosphorus strait the biogeochemistry of sediment from the anatolia slope has recorded changes to the hydrography leading up to and following the input of mediterranean water at 9 4 ka 103 yr bp when global sea level rose to the level of the bosphorus sill and high salinity water from the mediterranean began to spill into the then brackish lake the water initially mixed little with the lake water but cascaded to the bottom where it remained essentially isolated for ca 1 6 kyr the time required to fill the basin from the bottom up at its present input rate the accumulation of mo in the sea floor sediments a proxy of bottom water anoxia increased sharply 8 6 ka when bacterial respiration in the bottom water advanced to so42 reduction by the oxidation of organic detritus that settled out of the photic zone its accumulation remained elevated to 5 6 ka when it decreased 60 only to again increase slightly at 2 0 ka the accumulation of corg a proxy of primary productivity increased 3 to 4 fold at 7 8 ka when upward mixing of the high salinity bottom water replaced the then thin veneer of the brackish photic zone in less than 50 yrs from that time onward the accumulation of corg mo and additional trace metals have reflected the hydrography of the basin and bosphorus strait controlled largely by climate

testing the physical oceanographic implications of the suggested sudden black sea infill 8400 years ago 1 we apply a shock capturing numerical model based on the single layer shallow water equations to an idealized geometry of the black sea and the sea of marmara in order to test the implications of a suggested sudden black sea infill 8400 years ago the model resolves the two dimensional flow upstream and downstream of the hydraulic jump provoked by the cascade of water from the sea of marmara into the black sea which would occur during a sudden black sea infill the modeled flow downstream of the hydraulic jump in the black sea would consist of a jet that is in part constrained by bathymetric contours guided by the bosporus canyon the modeled jet reaches depths of up to 2000 m and could explain the origin of the sediment waves observed at this depth at a late stage of the infill the modeled jet is attached to the coast and might account for the course of a submerged channel at the mouth of the bosporus the preservation of continuous barrier washover lagoonal fill systems occurring on the black sea shelf is however not easily reconcilable with the large flows over the southwest black sea shelf predicted by the model intensified flow in the upstream basin sea of marmara is restricted to the immediate vicinity of the bosporus suggesting that a sudden reconnection need not have disturbed sediments in the wider sea of marmara

anatomy of a compound delta from the post glacial transgressive record in the adriatic sea abstract on the mediterranean continental shelves the post glacial transgressive succession is a complex picture composed of seaward progradations related to sea level stillstands and or increased sediment supply to the coasts and minor flooding surfaces associated with phases of enhanced rates of sea level rise among late pleistocene examples major mid shelf progradations have been related to the short term climatic reversal of the younger dryas event a period during which the combination of increased sediment supply from rivers and reduced rates of sea level rise promoted the formation of progradations up to tens meter thick while the documentation of coastal and subaqueous progradations recording the younger dryas interval is widely reported in literature the model of compound progradation within transgressive deposits has not yet been proposed here we present the documentation of a deltaic system where both delta front sands and related fine grained subaqueous progradations prodeltaic to shallow marine have been preserved the paleo gargano compound delta pgcd formed offshore the modern gargano promontory southern adriatic sea and is composed of a coastal coarse grained delta of reduced thickness and a muddy subaqueous clinoform up to 30 m thick the pgcd probably the first worldwide documentation of a compound delta within the transgressive record provides the opportunity to investigate the processes controlling the formation of a compound delta system during an overall sea level rise and the factors that allowed its preservation the finding of the pgcd provides the opportunity for a comparison with modern worldwide compound systems

oscillating quaternary water levels of the marmara sea and vigorous outflow into the aegean sea from the marmara sea black sea drainage corridor abstract detailed interpretation of single channel air gun and deep tow boomer profiles demonstrates that the marmara sea turkey experienced small amplitude 70 m fluctuations in sea level during the later quaternary limited in magnitude by the sill depth of the strait of dardanelles moderate subsidence along the southern shelf and quaternary glacio eustatic sea level variations created several stacked deltaic successions separated by major shelf crossing unconformities which developed during the transitions from global glacial to interglacial periods near the strait of dardanelles a series of sand prone deposits are identified beneath an uppermost holocene transparent mud drape the sandy deposits thicken into mounds with the morphology and cross sectional geometries of barrier islands sand waves and current generated marine bars all cross stratification indicates unidirectional flow towards the dardanelles prior to the deposition of the transparent drape which began 7000 years bp in strong support of the notion that the marmara sea flowed westwards into the aegean sea through the dardanelles at times of deglaciation in northern europe the global sea level curve shows that at 11 000 and 9500 years bp sea level rose to the sill depths of the straits of dardanelles and bosphorus respectively the effect from 11 000 to 9500 years bp was seawater incursion into the marmara sea drowning and formation of algal serpulid bioherms atop lowstand barrier islands and transgression of shelves and lowstand deltas at 9500 years bp glacial meltwater temporarily stored in the black sea lake developed into a vigorous southward flow toward the aegean sea forming west directed sandy bedforms in the western marmara sea and initiating deposition of sapropel s1 in the aegean sea this strong outflow persisted until 7000 years bp after which a mud drape began to accumulate in the marmara sea and euryhaline mediterranean mollusks successfully migrated into a progressively more saline black sea where sapropel deposition began most eastern mediterranean sapropels from s1 to s11 appear to correlate with periods of rising sea level and breaching or near breaching of the bosphorus sill these events are believed to coincide with times of vigorous outflow of low salinity fresh surface waters transiting the black sea marmara sea corridor and ultimately derived from melting of northern european ice sheets

evolution of the danube deep sea fan since the last glacial maximum new insights into black sea water level fluctuations abstract the danube deep sea fan nw black sea is one of the most developed deep sea sediment depositional systems in europe although the morphology and the architecture have been widely described in the past years little is known about the stratigraphy of this depositional system for the late quaternary this results from the lack of significant stratigraphic markers the scarcity of radiocarbon ages and the difficulty in constraining reservoir ages recent robust quantification of reservoir ages has allowed the construction of a new stratigraphic framework for the black sea from the end of the last glacial period to the holocene thus giving the opportunity to correlate sedimentological and geochemical features previously described on the nw black sea margin with climatic events identified in the northern hemisphere based on this approach we propose an improved chrono lithostratigraphic framework for the danube deep sea fan channel levees since the last glacial maximum we show that the danube deep sea fan was active during the last glacial maximum until the younger dryas early holocene transition ca 11 700 cal a bp when the turbidite activity abruptly terminated in the whole system throughout this period the danube river was the main source of the deep depositional system except between ca 17 200 cal a bp and 15 700 300 cal a bp at that time the deposition of red turbidites in the deep basin concomitant with the deposition of the so called red layers onto the continental shelf and the upper slope emphasises the direct impact of the increased meltwater runoff of the dnieper river as far as the danube deep sea fan some significant changes in the location of the depocentre of the danube deep sea fan occurred through time the main change in depocentre location occurred at ca 28 000 cal a bp with the northward avulsion leading to the formation of the middle channel although the middle and northern channel became the preferential turbidite depocentres after this event the deposition of turbidites has persisted in the southern channel levee until 14 700 cal a bp indicating that the southern channel was definitely not abandoned after the upstream northward avulsion unsurprisingly water level fluctuations and river sediment flux acted as the main forcings on the evolution of the danube deep sea fan based on these results and on the morphology of the danube canyon we propose that i lowstand conditions 110 m prevailed during the last glacial maximum and possibly between 15 700 300 cal a bp and 14 700 cal a bp ii water level ranged from 110 and 70 m between 14 700 and 11 700 cal a bp and iii water level ranged from 70 and 30 m from 11 700 cal a bp and until the reconnection of the black sea lake with the global ocean at ca 9000 cal a bp

radiocarbon dating of danube delta deposits abstract the holocene history of the danube delta has been studied using 14c analyses of faunal material the principal phases of development include 1 initial letea caroarman spit 11 700 9800 yr b p in its central part 8800 5500 yr b p in its southern part 2 sf gheorghe i delta 8900 7200 yr b p 3 sulina delta 7200 2000 yr b p and 4 sf gheorghe ii delta chilia delta 2000 yr b p present other smaller scale features have also been dated including secondary deltas cosna and sinoe deltas and littoral bars age determinations carried out on whole samples were erratic and it was found that individual species had to be separated and dated in all cases the older dates were of transported material whereas the younger dates gave the true age of the formation

last glacial holocene paleoceanography of the black sea and marmara sea stable isotopic foraminiferal and coccolith evidence multi proxy data and radiocarbon dates from several key cores from the black sea and marmara sea document a complex paleoceanographic history for the last v30 000 yr the marmara sea was isolated from both the black sea and the aegean sea during glacial periods when global sea level lowering subaerially exposed the shallow sills at the straits of bosphorus and dardanelles i e lake stage and reconnected through both straits during interglacial periods when rise of global sea level breached the shallow sills i e gateway stage micropaleontological data show that during the lake stage the surface water masses in both the marmara sea and black sea became notably brackish however during the gateway stages there was a low salinity surface layer and normal marine water mass beneath two sapropel layers are identified in the marmara sea cores sapropels m2 and m1 were deposited between v29 5 and 23 5 ka and v10 5 and 6 0 ka respectively micropaleontological and stable isotopic data show that the surface water salinities were reduced considerably during the deposition of both sapropel layers m2 and m1 and calculation using planktonic foraminiferal transfer functions shows that sea surface temperatures were notably lower during these intervals the presence of fauna and flora with black sea affinities and the absence of mediterranean fauna and flora in sapropels m1 and m2 strongly suggest that communication existed with the black sea during these times a benthic foraminiferal oxygen index shows that the onset of suboxic conditions in the marmara sea rapidly followed the establishment of fully marine conditions at v11 10 5 ka and are attributed to black sea outflow into the marmara sea since 10 5 ka these suboxic conditions have persisted to the present the data discussed in this paper are completely at odds with the flood hypothesis of ryan et al 1997 and ryan and pitman 1999 crown copyright 2002 elsevier science b v all rights reserved

black sea marmara sea quaternary connections new data from the bosphorus istanbul turkey abstract previous studies concluded that the bosphorus strait was formed during the quaternary by fluvial incision of a valley between the black sea to the north and the marmara sea in the south hitherto however few details of the evolution of this connection have been elucidated from the sediments deposited within the bosphorus itself we report here details of sedimentological and palaeontological evidence relating to this history obtained from five boreholes drilled into the unconsolidated sediment fill in the north central sector of the bosphorus together with nearby geophysical profiles the quaternary fill of this part of the bosphorus comprises two major facies associations yellow arkosic sands dominate the lower facies association a these are assigned a middle to late pleistocene age and the contained faunas have a lagoonal to lacustrine character and a black sea provenance paratethyan affinities the abruptly succeeding units of facies association b comprise fining and coarsening upwards units of coarse to fine shelly and clayey sands that alternate with shell bearing green clays these sediments were formed in a range of marine and coastal settings and biostratigraphic evidence and absolute dating demonstrate the mid late holocene age of this upper unit initially brackish faunal assemblages in this upper unit show an upward increase in marine and mediterranean affinities integrating these new data with previously published observations from coeval deposits in the southern bosphorus and izmit bay ne marmara sea we conclude that during the late pleistocene and early holocene a topographic barrier existed in the south central sector of the bosphorus on both sides of which estuarine and lagoonal sediments accumulated with distinctive black sea and mediterranean faunas during a significant rise in sea level between 7000 and 5300 years ago this barrier was finally submerged permitting interchange of marine waters between the mediterranean and the black sea and creating the present oceanographic situation this evolution conflicts with the cataclysmic role of the bosphorus in the early holocene as postulated in the catastrophic flood hypothesis of ryan et al mar geol 138 1997 119 126 annu rev earth planet sci 31 2003 525 554 it also contrasts with the history recorded from the gulf of izmit where intermittent connection between these two bodies of water throughout much of the quaternary is evident

on the origin of the bosphorus abstract the palaeozoic upper cretaceous basement palaeomorphology of the bosphorus the strait of istanbul bears the evidence of a valley of a palaeostream running to the black sea in the north a palaeobasin deeper than 160 m opening to the sea of marmara in the south and a barrier between these two features this suggest that the northern part of the bosphorus was formed mainly by fluvial activity whereas the southern part developed as a basin by faulting the recent sediment thickness exceeds 130 m in the basin indicating that the southern part of the bosphorus was once essentially depositional rather than an erosional the present form of the bosphorus was established in holocene time by the connection of the basin in the south with the stream in the north the barrier and the stream valley in the north have been deepened by erosion and faulting to form a strait connecting the black sea and the mediterranean

the black sea basins structure and history new model based on new deep penetration regional seismic data part 1 basins structure and fill abstract this work is based upon results of interpretation of about 8872 km long regional seismic lines acquired in 2011 within the international project geology without limits in the black sea the seismic lines cover nearly the entire black sea basins including russia turkey ukraine romania and bulgaria sectors a new map of acoustic basement relief and a new tectonic structure scheme are constructed for the black sea basins the basement of the black sea includes areas with oceanic crust and areas with highly rifted continental crust a chain of buried seamounts which were interpreted as submarine volcanoes of late cretaceous santonian to campanian age has been identified to the north of the turkish coast on the shatsky ridge probable volcanoes of albian age have also been recognized synorogenic turbidite sequences of paleocene eocene and oligocene ages have been mapped in the cenozoic numerous compressional and transpressional structures were formed in different parts of the black sea basin during the pleistocene quaternary turbidites mass transport deposits and leveed channels were formed in the distal part of the danube delta

seasonal interannual and mesoscale variability of the black sea upper layer circulation derived from altimeter data 1 topex poseidon and ers altimeter data comprising the period from may 1992 to may 1999 are assimilated into a shallow water model for providing a dynamically consistent interpretation of the sea surface height variations and estimation of the temporal and spatial characteristics of the upper layer circulation in the black sea these 7 year long observations offer a new capability for interpretation of major transient and quasi permanent features of the upper layer circulation the instantaneous flow fields involve a complex eddy dominated system with different types of structural organizations in which the eddies and the gyres of the interior cyclonic cell interact continuously among themselves and with meanders and filaments of the rim current the circulation possesses a distinct seasonal cycle whose major characteristic features repeat every year with some year to year variability an organized two gyre winter circulation system disintegrates gradually into a series of interconnecting eddies in the summer and autumn months which are also characterized by more pronounced and complex mesoscale activity in the peripheral flow system our analyses suggest a revised schematic circulation picture of the major quasi permanent and recurrent elements of the black sea

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

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

lithospheric thickness estimation beneath northwestern south america from an s wave receiver function analysis we make use of the s to p receiver function technique beneath colombia and neighboring regions to make a first order approximation of the depth of the lithosphere asthenosphere boundary lab and therefore of lithospheric thickness a deconvolution technique was used to calculate the receiver functions and after a moveout correction and a time depth conversion lab depths for different tectonic regions of northwestern south america were obtained results are typically between 65 and 110 km consistent with previous estimates around the world and other regions in south america lithospheric thickness beneath an oceanic island in the caribbean is 80 km whereas for the ecuador colombia trench it is 65 km and around 100 km for the panama arc the transition to the continent is associated with an increase in lab depth where it can reach 110 km with no significant differences among terranes and or tectonic blocks

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

the modern po delta system lobe switching and asymmetric prodelta growth the modern po delta system comprising five main delta lobes has been investigated by integrating vhr seismic surveys recorded offshore from water depths as shallow as 5 m to the toe of the prodelta in about 30 m with accurate historical cartography extending back several centuries previous studies give sedimentological and geochronological information from precisely positioned sediment cores this combined historical and stratigraphic reconstruction of the modern po prodelta allows volumetric reconstructions indicating an average sediment load of 9 4 10 6 ty r 1 for po di pila and po di goro gnocca lobes this estimate is remarkably consistent with the total sediment load of 11 5 10 6 ty r 1 available for parts of the last century from a gauge station at the apex of the delta plain in pontelagoscuro these integrated stratigraphic studies allow to explain the key characters of the po delta system a the marked asymmetry of the whole delta prodelta system reflecting prevailing sediment dispersal to the south of each individual delta outlet b the shoreparallel overlapping of successive prodelta lobes fed by distinct river outlets of ever changing relative importance c the delta outlets being artificially forced in a fixed position so that natural avulsion is prevented and delta lobes undergo headland retreat leaving a marked erosion on the prodelta d the presence of prodelta lobes showing widespread bcut and fillq features ranging from 100 to 300 m and depths up to 4 5 m filled with massive silt to very fine sand offshore of short lived very active distributary channels e g po di tolle lobe and suggesting that in some particular interval short lived episodes of submarine erosion are induced by catastrophic increases in river discharge of natural origin or induced by human maintenance the seismic stratigraphy of the modern po delta documents that markedly distinct prodelta architectures form when a newly activated lobe is located updrift north in this case or downdrift south of the one that is retreating in the first case the abandoned lobe becomes sheltered by the new rapidly advancing one in the opposite case the retreating lobe is updrift and a substantial portion of the sediment is cannibalized and transported to the new lobe downdrift d 2005 elsevier b v all rights reserved

north atlantic control on precipitation pattern in the eastern mediterranean black sea region during the last glacial based on proxy records from western black sea cores we provide a comprehensive study of climate change during the last glacial maximum and late glacial period in the black sea region for the first time we present a record of relative changes in precipitation for nw anatolia based on variations in the terrigenous supply expressed as detrital carbonate concentration the good correspondence between reconstructed rainfall intensity in nw anatolia and past western mediterranean sea surface temperatures ssts implies that during the glacial period the precipitation variability was controlled like today by mediterranean cyclonic disturbances periods of reduced precipitation correlate well with low ssts in the mediterranean related to heinrich events h1 and h2 stable oxygen isotopes and lithological and mineralogical data point to a significant modification in the dominant freshwater sediment source concomitant to the meltwater inflow after 16 4 cal ka bp this change implies intensification of the northern sediment source and with other records from the mediterranean region consistently suggests a reorganization of the atmospheric circulation pattern affecting the hydrology of the european continent the early deglacial northward retreat of both atmospheric and oceanic polar fronts was responsible for the warming in the mediterranean region leading simultaneously to more humid conditions in central and northern europe