DATING THE LOWER KHVALYNIAN SEDIMENTS OF THE MANYCH DEPRESSION

The Early Khvalynian transgression developed in the Caspian basin at the end of the Late Pleistocene. As soon as its waters exceeded the height of the watershed with the Azov-Black Sea basin the Early Khvalynian Strait was opened. The main link of this strait was the Manych depression - a vast depression in the south of the European Russia.

Despite the long history of the study of the region, the opinions of researchers regarding the age of the deposits of the Early Khvalyn Strait differ. The functioning time of the strait was not been unambiguously correlated with the global chronostratigraphic scheme until now.

Here we present the results of optically stimulated luminescence (OSL) dating of the Lower Khvalynian deposits exposed in the coastal outcrop of the western tip of Levy Island in the central part of the Manych depression. In total, nine datings were obtained: six of them characterize the aquatic stages of the territory evolution, three - subaerial. Biostratigraphic analysis of the malacofauna confirmed the belonging of the marine sediments exposed in the section of the Levyi Island to the Early Khvalynian transgression of the Caspian Sea. The salinity of waters is estimated at 10-11 ‰.

The age of the Early Khvalynian paleo-strait deposits corresponds to the epoch of degradation of the Late Valdai (Ostashkov) glaciation stage (MIS 2, dates 16400±1100, 15800±1000, 16800±1000, 14700±1000, and 13800±900 years). Subaerial sedimentation began in the central part of the Manych depression no later than 9200±800 years ago.