Correlation of the zonal schemes in the Quaternary sediments of the Bulgarian Black Sea shelf according to molluscs and ostracods

Abstract

The Candona Ostracod Zone corresponds the Uppr Chaudinian where the Dreissena Molluscan Zone is indicated. The Didacna-Dreissena-Abra Molluscan Concurrent-range-zones corresponding to the Cryptocyprideis Ostracod Zone are indicated respectively in the Middle Pleistocene, Old Euxinian and Uzenlarian Stages. The sequence of the molluscan and ostracod zones in the inner shelf has been broken by a barren zone which corresponds to the continental sediments, deposited in the early New Euxinian. The Loxoconcha Ostracod Zone corresponds to the Upper Euxinian Dreissena Molluscan Concurrent-range-zone. The Hydrobia-Monodacna Molluscan Zone together with the Mytilus Zone comprise the sediments of the Old Chernomorian. The intervals occupied by the Cyprideis Ostracod Zone correspond to these molluscan zones. The Falunia-Loxoconcha Ostracod Zone comprises the area occupied by the Spisula Molluscan Zone including also the upper parts of the Mytilus Molluscan Zone. -from Authors