Changes in the Ostracod Assemblages of the Northeastern Black Sea Shelf during the Late Pleistocene and Holocene

Abstract

Distribution of 57 ostracod species is investigated in the Quaternary sediment samples from the borehole RBH-16, drilled at the north-eastern Black Sea shelf edge off the town of Anapa. Among them, 52 species of the Caspian type and 5 species of the Mediterranean type were found. Four distinct assemblage zones are identified: the Caspian type one typical for Chaudian basin (Early Neopleistocene) (I) in interval 15.55–14.11 m; the Caspian type one dominating from the Late Pleistocene to the early Holocene (II), according to species composition closed to Khvalynian basin, at the depth 13.4–3.84 m (from 13.6 to 8.7 cal. ka BP), the mixed one of Caspian type and Mediterranean type species (III) in interval 3.84–0.95 m (younger than 8.7 cal. ka BP), and the assemblage with progressively increasing dominance of Mediterranean species (IV) in interval above 0.75 m (after 7.4 cal. ka BP).