Late Pleistocene sedimentation in the Northern Caspian Lowland during the Early Khvalynian transgression

Abstract

Early Khvalynian basin was one of the largest in the history of the Caspian Sea during the Pleistocene. Six lithofacies (LF1-LF6) with two subfacies (LF2a-LF2b) are recognized in lower khvalynian deposits in the Lower Volga Region (the Northern Caspian Lowland). The chocolate clay deposition in the Lower Volga region corresponds to an interval between 16.4-12.7 cal ka BP. According to radiocarbon dates, the age of the Early Khvalynian stage in the Lower Volga Region is varying between 20-12.6 cal ka BP. The most density of the radiocarbon dates is between 14.1-13.5 ka ago. The interval between 14.5-14.1 ka ago is characterized by the absence of mollusc shells and deposition of massive chocolate clay. Comparison radiocarbon data of mollusc shells and lithofacies characteristics of khvalynian sediments reveal a certain pattern with the main late Pleistocene climatic events and allow us to reconstruct the depositional history during LGM to Younger Dryas at the Lower Volga Region.