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Abstract:
The occurrence of polyhaline, mesohaline and oligohaline diatom, silicoflagellate, ebridian and chrysomonad populations in late Quaternary Black Sea sediments (DSDP Leg 42B) forms the basis for reconstruction of surface water paleosalinities in the Black Sea basin over the last 3 million years. Four major periods with increased salinites are separated by extended freshwater periods. Based on paleosalinites, indicators of trophic freshwater conditions and changes in diatom species diversity, a correlation is made to the northern Europian glacial--interglacial stratigraphy and this correlation is used to place paleoenvironmental events into a chronostratigraphy. The `synchronous' late Quaternary occurrence of sediments rich in organic carbon in both the Eastern Mediterranean and the Black Sea supports this interpretation.Three different stages in the interaction between the Black Sea and the Eastern Mediterranean Sea are defined: Stage A (exchange of freshwater and marine water similar to the present day flux) during the Holocene, Eemian, Holsteinian and Pliocene; Stage B (freshwater conditions with only occasional marine spills) during the Saalian, the Waalian, the Tiglian and the Praetiglian; and Stage C (freshwater conditions with no inflow of marine waters) during the Weichselian, the Elsterian and Eburonian