Pedostratigraphy of the Kuban loess-paleosol sequences

Loess-paleosol series (LPS) are the most significant paleogeographic archive containing information onlandscape and climatic changes during glacial and interglacial epochs. LPS are widespread in Eurasia andstudying them is of great importance for paleoclimatic reconstructions. Our research was carried out in thesouth of the East European Plain, in the Kuban River valley. In this area, loess-paleosol deposits have beenexplored since ۱۹۶۰s (Lebedeva, N.A., ۱۹۶۳), the section near the village of Temizhbekskaya is especiallywell known (Dodonov et al., ۲۰۰۶; Shorkunov, ۲۰۱۱). Our study area is located in a transit position betweenSiberian, Central Asian loesses and loesses of Eastern and Western Europe, however, it is still poorlystudied by modern methods. The research of the LPS in the Kuban River valley is of great meaning forregional chronostratigraphy and study of the patterns of atmospheric transport in the south of the EastEuropean Plain. Currently, one of the urgent tasks in studying the Kuban loess area is to clarify thestratigraphic position of specific loess-paleosol horizons of the section according to the existingchronostratigraphic scheme of the East European Plain (Velichko, Morozova, ۱۹۱۵). In addition, a numberof questions remain unsolved: the number of paleosols, the absolute age of individual horizons, and theinfluence of the evolution of the Kuban River on the change in the sources and the rate of sedimentation.To settle these issues, we carried out field work in the central part of the valley where on the right bank ofthe Kuban river valley a ۴۰ m outcrop was revealed during the survey between Tbilisskaya and Kazanskayavillages (N ۴۵°۲۲'۵۴.۰۵۵" E ۴۰°۱۹'۳۴.۹۶۱"). A ۲۵-meter section was studied in the upper part of the naturaloutcrop. The field study of the Kropotkinsky section included: lithological characteristics of deposits,identification of the stratigraphic units, and description of paleosols, detailed sampling for a set of analyzes(magnetic susceptibility, grain size measurements, micromorphology, OSL and paleomagnetic dating,morphoscopy of sandy quartz grains, etc.). At the moment, the first results have been obtained on thegeneral structure of the units of this section. The upper unit is represented by subaerial deposits consistingof four intervals which correspond to different structure of paleosols and loess horizons separating them(Fig. ۱). Thick layers of alluvial sands lie at the base of the section. The section structure from top to bottomin general looks as follows. The upper part of the section is represented by modern anthropogenic disturbedtypical chernozem underlain by light yellow loess-like loam which is affected in the upper part by modernsoil formation processes.