High-resolution analysis of the Likhvin loess-paleosol sequence (the central part of the East European Plain, Russia)

Studies of the loess-paleosol sequence of the center of the East European Plain have a long history. Previously, samples from loess-soil sections were taken for paleoreconstruction of climate and environment with low resolution, usually 1-2 samples per stratigraphic unit. This led to an unclear interpretation of the processes of soil formation and deposition of loess material. Our article discusses the LPS of the Likhvin stratotype section. High-resolution analysis was applied, which will allow us to trace in detail the history of the formation of the paleosol cover from the Middle Pleistocene to the present. A total of 245 bulk samples were taken from sections Likhvin-1/18 and Likhvin-2/18 and analyzed using laboratory analytics (the particle-size distribution, magnetic susceptibility, the loss on ignition values, total organic carbon, pH). Nine samples were taken for OSL dating and two samples for AMS dating to determine the age of the deposits. The micromorphological characteristics were described in detail for paleosols. The Salyn interglacial paleosol (MIS 5e) appeared to be comparable to the modern Retisols in its macro- and micromorphology and physical and chemical characteristics. As to the Krutitsa interstadial paleosol (identified formerly with MIS 5c in the sequence), our results suggest its belonging to MIS 5a. The modern prairie soils - Folic Cambisols - may be considered as its modern analogue. During the MIS 3, the Bryansk paleosol developed. The paleosol is polygenetic; in cooling, its main type (Cambisol) changed to Gleysol and finally became Cryosol. The paleosol described as belonging to MIS 7 displays all the characteristics of the Early Kamenka interglacial paleosol and develops the characteristics of Luvisols (Cutanic) type, its analogues being found in Latvia, Poland, and Hungary. There is a level of soil-formation above the Early Kamenka interglacial paleosol corresponding to the Romny paleosol (MIS 6) in its stratigraphic position. The latter statement is difficult to assert with confidence; it is not improbable that the level presents the Late Kamenka interstadial paleosol, also attributable to MIS 6.

Automated summary

The study of the loess-paleosol sequence in the center of the East European Plain has a long history, with a focus on the high-resolution analysis of the LPS at the Likhvin stratotype section. Through detailed analysis, the study reveals the history of paleosol formation from the Middle Pleistocene to the present, identifying distinct characteristics of paleosols from different periods. The findings suggest similarities between ancient paleosols and modern soils, as well as potential reclassification of certain paleosols to different stages in the Pleistocene.