Chronology of the Karangat Transgression of the Black Sea by Luminescence Dating

Abstract

At the beginning of the Late Pleistocene within the modern Azov-Black Sea basin the Karangat transgression developed synchronously with the interglacial transgression of the world ocean. Based on the analysis of faunal complexes, the basin was characterized as the warmest and deepest basin of the Late Pleistocene with water salinity much higher than the salinity of the modern Black Sea. The most complete sequence of transgression sediments was found in the Eltigen section, located on the western coast of the Kerch Strait. The section has been examined several times. However, due to the large extent, facies variability of the section and the lack of geochronological data, there is still no consensus on how the deposits in the section correlate, to what number of phases of the Karangat transgression they correspond to, and what their age is. The aim of this work is to obtain the chronology of sedimentation of the southern (Tobechik) part of the Eltigen stratotype section, which is considered by most researchers to be the deposits of the first phase of the Karangat transgression. Seventeen luminescence dates were obtained for quartz (OSL) and feldspar (pIRIR290): nine from lagoon-marine and coastal-marine deposits and eight from the overlying loess-soil layer. Biostratigraphic analysis of the malacofauna confirmed the belonging of the marine deposits of the Karangat transgression of the Black Sea discovered in the section. The results of OSL dating showed that in the southern part of the Eltigen section, three cycles of lagoon-coastal-marine sedimentation are distinguished in the intervals of 135–130 ka years ago (MIS 6–MIS5e), 130–115 ka years ago (MIS 5e) and 115–95 ka years ago (MIS 5d-c). The accumulation of the upper subaerial strata began no earlier than 95 ka years ago.