INGRESSION OF THE KARANGATIAN SEA INTO THE MANYCH DEPRESSION (LATE PLEISTOCENE)

Abstract

The work presents the results of paleogeographic study, including facies-lithological, malacofaunistic and luminescence analyses, of three boreholes core drilled in the central part of the Manych Depression, which made it possible to determine the time and stages of the existence of the Karangatian ingressive bay in the Manych Depression, and to correlate the latter with phases of the Karangatian transgression identified earlier on the basis of luminescence dating. Based on the results of the study it was found that: 1) the Karangatian Sea penetrated into the Manych Depression during the second phase of transgression in the time interval of ~120-110 ka years ago (MIS 5e-d). The salinity of the bay in the area of the modern Manych-Gudilo Lake reached 20-22‰; 2) the inflow of water of the Hyrcanian transgression of the Caspian into the bay in the central part of the Manych Depression took place 110-105 ka years ago, which corresponds to the third phase of the Karangatian transgression (MIS 5c). The brackish Caspian waters desalinated the Karangatian Bay in the area of the modern Manych-Gudilo Lake down to 14‰ and below; 3) the waters of the Karangatian Sea finally left the Manych Depression about 105 ka years ago (MIS 5c).