engleski

Palaeoenvironmental implications from Lower Volga loess - joint magnetic fabric and multi-proxy analyses

Magnetic fabric (MF) investigations complemented by geochemical and grain surface analyses of the understudied and controversial marine isotope stage (MIS) 4 and 3 loess deposits in the Lower Volga region, Russia, show that the material has been transported and deposited by wind and to a large extent experienced post-depositional reworking. Grain surface features suggest that the material was glacially ground and fluvially transported prior to final aeolian deposition as loess. Secondary magnetic fabrics in the loess reveal pedogenic and cryogenic processes and a generally cold environment with brief shifts to warmer climate during both, MIS 4 and 3. Palaeowind reconstructions derived from preserved primary aeolian MF indicate locally influenced north-westerly flow, on a wider scale westerly wind pattern, similar to modern day winter conditions. We suggest that the climate of the last glacial in the Caspian Lowland was cold and dry, with higher wind speeds and less variability during MIS 4 compared to MIS 3.

Anisotropy of magnetic susceptibility ; scanning electron microscopy ; Loess ; Northern Caspian Sea region ; palaeowinds ; post-depositional reworking ; chemical alteration ; palaeoclimate reconstruction

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