ИСТИНА

The cyclic climate fluctuations in the Pleistocene are estimated by researchers to be reflected in the structure of loess-paleosol series: during warm interglacial and interstadial epochs, the role of biogenic sedimentation increased and soils were formed; during cold epochs, when there was a significant expansion of the permafrost, loess horizons accumulated and frost fractures were formed. These judgments are based on the results of analysis of wedge-shaped structures, as well as numerous data from spore-pollen, micro-faunal and other types of analysis. There are also notions, based mainly on the analysis of the particle size distribution of loess, of a very cold environment during their formation and a significant development of cryogenic weathering at that time. Loess deposits in the Northern Caspian Sea region play a significant role in understanding continental scale palaeoclimate systems in Eurasia during the Pleistocene. In contrast to the wellstudied loess areas of Europe, Central and East Asia, loess in the Northern Caspian lowland has received very little research attention. Despite this lack of attention, its geographical position and the lack of other palaeoenvironmental data from continental deposits in the region (Koltringer et al., 2020) make it an important ‘missing link’ for developing a full understanding of Eurasian palaeoclimate and wind systems.