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Abstract: Core M02-45 recovered 9.5m of a ∼12m-thick transgressive succession on the SW Black Sea shelf. The underlying transgressive unconformity, α, deepens toward the shelf edge, so that the coresite was never isolated from the open Black Sea. Fourteen radiocarbon dates indicate sedimentation from ∼9.3ka to the present, with only one hiatus at ∼270cm depth spanning ∼4.5–2.5ka. Three units are present in the core: Unit A (0–270cm)=burrowed mud with laminated silt beds and mollusc shells of Mediterranean affinity (accumulation rate ∼125cm/ky); Unit B (270–525cm)=silty mud with shelly interbeds containing Truncatella subcylindrica, Mytilus galloprovincialis, Parvicardium exiguum, Rissoa spp. and Modiolula phaseolina (rate ∼85cm/ky); Unit C (525–950cm)=burrowed silty mud with graded beds of silt and fine sand, and shells of T. subcylindrica, P. exiguum and Dreissena polymorpha (rate ∼360cm/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 ∼7.5ka. Dinocysts and foraminifera confirm a low but rising salinity after ∼8.6ka. An increase of δ 34S from ∼5–30‰ through 8.4–7.6ka 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. δ 34S then dropped at ∼8ka 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. [Copyright &y& Elsevier]

Abstract: An exceptionally high-resolution and species-rich dinoflagellate cyst record from core M02-45 collected from the southwestern Black Sea shelf provides strong evidence of a gradual reconnection between the Black (BS) and Mediterranean (MS) seas at the beginning of the Holocene. Two main assemblages, one dominated by brackish species, Spiniferites cruciformis and Pyxidinopsis psilata, and freshwater algae, and a subsequent one, characterised by euryhaline species (Lingulodinium machaerophorum, Brigantedinium spp., Protoperidinium ponticum), document a progressive change in sea-surface conditions from low saline (∼7–12psu) to present-day conditions. A first major pulse of marine waters is recorded at around 8.46ka BP, with a maximum of L. machaerophorum. The occurrence of this species from the bottom of the core, dated at 9.3ka BP, supports the hypothesis that water levels were already high on the southwestern shelf by that time. Fully present-day conditions are recorded at around 5.6ka BP, when brackish species and morphotypes of S. belerius, S. bentorii and L. machaerophorum disappeared. Arrivals of Mediterranean species (Operculodinium centrocarpum and S. mirabilis) are observed simultaneously in the southwest and southeast region of the BS at around 7ka BP. Despite a different protocol for palynomorph preparation and presentation of data, previous studies from the northern shelf also document the arrival of euryhaline species at 7ka BP, and marine influence prior to that time. The history of harmful algal blooms (HABs) shows a correlation with warmer mid-Holocene temperatures, followed by a succession of introductions possibly associated with early Greek exploration, then merchant shipping. [Copyright &y& Elsevier]