Chronology of Khvalynian Stage of the Caspian Sea according to radiocarbon dating

Abstract

The paper analyzes 234 radiocarbon dates of the Khvalynian deposits obtained by researchers over more than 50 years of studying the Caspian region. Most of the dates were obtained from shell material, including endemic species of mollusks of the genus Didacna that lived in the early and late Khvalynian basins of the Caspian Sea. The radiocarbon coverage of the Khvalynian stage is in the range of 468.3 cal. ka BP. The most ancient dates were obtained from the Khvalynian deposits of the Caspian Sea. The largest number of dates falls within the interval of 1712.5 cal. ka BP. The development of the early Khvalynian transgression began 4035 cal. ka BP. During 2518 cal. ka BP the coastline of the early Khvalynian basin reached levels above 05 m asl, and the level of 2022 m asl developed in the range of 1713.5 cal. ka BP. After 12.5 cal. ka BP the sea level was falling probably leading to the development of Enotaevkian regression. The Upper Khvalynian deposits dated between 118.5 cal. ka BP probably correspond to the development of the late Khvalynian transgression. The age interval for the development of the maximum phase (4548 m asl) of the Early Khvalynian transgression has not been determined according to the currently available data.