Paleo-pedological record in loess deposits in the south of the East European plain, based on Beglitsa-2017 section study

Abstract

Loess-paleosol sequences (LPSs) are one of the main components of the natural environment, which traces how the climate has changed in the past. The article discusses changes in the landscape and climatic conditions from the Middle Pleistocene to the present, identified by the results of the LPS of the Beglitsa-2017 section study. We obtained new data on soil cover change in the Late and Middle Pleistocene in the North-Eastern Azov region based on multi-proxy analysis with high-resolution sampling along the section. The first data on the polygenetic origin of the Salyn interglacial paleosol (MIS 5e) profile which developed according to the Gypsic Calcic Chernozems type in the interglacial optimum, was obtained. Still, in the last stage of soil formation, its type changed to the more arid Gypsic Chernozems (Arenic). During MIS 5c and MIS 5a, the paleosols developed in a more arid climate; their modern analogues may be Gypsic Kastanozems and Calcic Gypsisols, respectively. The period of MIS 3 in the study area is marked by severe cryo-arid conditions, which influenced the formation of incipient Calcic Gypsisols. The profiles of the Middle Pleistocene paleosols in the lower part of the LPS of the Beglitsa-2017 section were subject to gleying processes, which formed specific Gleysols or Stagnosols paleosols. The preliminary age of these paleosols corresponds to MIS 13/15 and 8/9. The MIS 7 paleosols are structurally similar to modern Calcic Kastanozems, currently distributed in the dry steppe zone. Reconstruction of the formation of the LPS paleosol cover in the Beglitsa-2017 section made it possible to trace the trend of changes in climatic conditions in the past. Climate aridity decreases in the interval between MIS 5e and MIS 1, and the maximum drought peaks were recorded in MIS 3 paleosols. Earlier, climate aridization intensified from MIS 13/15 and continued until MIS 7/6. The results will complement our understanding of the soil cover changing over time and will expand the reconstruction of climate change throughout the East European Plain.