The Neopleistocene of the Oka–Don Periglacial-Loess Province: Stratigraphy, Paleogeography, Correlation

As a result of complex interdisciplinary studies, the existence of much more complex glacial-interglacial climatic rhythms than previously thought was revealed in the Neopleistocene history of the Oka–Don Loess Province. We have established nine warm epochs (seven interglacials, two interstadials, including the Holocene) and eight interglacial epochs or cooling periods over the last 0.7–0.8 m.y. The sequence of the development of the ice sheets and the interglacial periods in the Early and Middle Neopleistocene is significantly revised. In the Early Neopleistocene, another glacial-interglacial macrocycle was identified in the interval between MIS 15 and MIS 12. In the Middle Neopleistocene, an alternation of three macrocycles was established instead of two previously identified ones. The concept of landscape and climatic changes within interglacial epochs has become more complex. The paleopedological materials on the Ilyinka, Muchkap, Kamenka and Mikulino interglacials indicate the existence of several phases within them, corresponding to two or more optima. It is shown that the Muchkap interglacial was the most humid and heat-provided thermochron in the series of interglacial epochs. The evolution of interglacial pedogenesis and the natural environment over the last ~780 000 years has been traced. The main climatic trend that determined the development of the natural environment and the evolution of landscapes in the geological history of the Oka–Don Loess Province was the directed cooling from the Early Pleistocene Interglacial epoch to the Late Pleistocene epoch. A similar trend toward increasing severity and continentality of the climate is observed for the glacial epochs. The interregional correlation of deposits and events of the Neopleistocene in glacial and periglacial regions in the Don, Dnieper, Volga, and Kama basins was performed.