Revised chronostratigraphy and palaeoenvironmental record of loess-palaeosol sequences in the Azov Sea region of Russia since the late Pleistocene

Loess-palaeosol sequences are the most intensively studied terrestrial archives used for the reconstruction of late Pleistocene environmental and climatic changes in the Sea of Azov region, southwest Russia. Here we present a revised luminescence-based chronostratigraphy and a multi-proxy record of late Pleistocene environmental dynamics of the most complete and representative loess-palaeosol sequences (Beglitsa and Chumbur-Kosa sections) from the Azov Sea region. We propose a new chronostratigraphy following the Chinese and Danubean loess stratigraphy models that refines the subdivision of the last interglacial palaeosol (S1) in two Azov Sea sites, resolves the uncertainty of the stratigraphic position of the weakly developed paleosol (L1SSm) in Beglitsa section, and allows direct correlation of the Azov Sea sections with those in the Danube Basin and the Chinese Loess Plateau. More importantly, it adds important data to better constrain local and regional chronostratigraphic correlations, and facilitates the interpretation of climatic connections and possible forcing mechanisms responsible for the climatic trend among these regions. In addition, a general succession of environmental dynamics is reconstructed from these two vital sections, which is broadly consistent with other loess records in the Dnieper Lowland and Lower Danube Basin, demonstrating similar climatic trends in these regions at glacial-interglacial time scales. However, differences in details were also identified, especially for palaeosols developed during the last interglacial period, and the cause of these dissimilarities between loess records appears complex.

Furthermore, our results have important implications for the chronostratigraphic representativeness of Beglitsa as a key loess section and the reconstruction of the temporal and spatial evolution of late Pleistocene palaeoclimate in the Sea of Azov region.