Structure, composition, and depositional environments of recent sediments in the Upper Don River basin inferred from the Korostelevo section

Abstract

The comprehensive investigation of recent sedi ments for the paleogeographic substantiation of detailed stratigraphic Neopleistocene scales, which are widely used in geological mapping and prospect ing, and for understanding general trends in the envi ronment evolution in connection with the expected global climate changes remains a crucial task of the Quaternary geology. In this respect, the study of sedi ments accumulated during long periods is most prom ising. Therefore, the results of the analysis of loess horizons in reference sections of different stratotype areas in the East European Platform, which contain an almost continuous geochronological record of the most significant Neopleistocene paleogeographic events, play a unique role.The thickest (up to 20-25 m thick) and most intri cate Neopleistocene loess sequences are concentrated in the Upper Don basin. The most complete loesssoil sections are observed at the lower levels of Neo gene terraces and in interfluve areas in the central axial Oka-Don Plain. On the adjacent flattened and highly differentiated slopes of the Central Russia, Volga, and Kalach uplifts, cover loams are thin (3-5 m) and locally distributed. Confinement of the region to three different age (early Neopleistocene Oka and Don, middle Neopleistocene Dnieper) glaciation zones substantially affected the structure of subaerial sedi ments.Based on scrutinization of paleosoils and catena regularities in the Korotoyak, Uryv, Kuznetsovka, Moiseevo, and other reference sections with account of the geomorphological, facies stratigraphic, and paleontological data, at least four prolonged stages of intense soil formation interrupted by epochs of litho genesis, morphogenesis, and subaerial and lacustrine sedimentation were defined in the Don moraineDnieper loess interval. According to nomenclature horizons of the integral chronostratigraphic scale for the East European Platform, this interval comprises the Romny, Kamenka, Inzhavino, and Vorona hori zons (Table 1).The recent comprehensive study of several refer ence sections in the Upper Don basin based on differ ent methods of the Quaternary geology, paleogeogra phy, and genetic pedology made it possible to collect, analyze, and summarize the new factual data. They provided new insight into the geological structure of the Neopleistocene sedimentary cover, stratigraphy and depositional environments of recent sediments, and the evolution of the study region.The Don basin proxy is represented by the Koros televo stratotype section (51°50′N, 42°25′E) located in the central (relatively flat and weakly drained) part of the Tambov Plain approximately 40 km away from Uvarovo (Fig. 1). The uniquely complete (>40 m thick) section of the early Pleistocene Don (moraine) and lower-upper Neopleistocene subaerial (sub and supramoraine) sediments is observed in several natural outcrops over 4 km along the right bank of the Vorona River. In this area, the Vorona River erodes a low angle sector of the bedrock bank that was favorable for the accumulation of loess and ...

Micromorphology of the Late and Middle Pleistocene paleosols of the central East European Plain

“…11 shows the geographic distribution of present-day soils of the central East European Plain and reconstructed paleosols attributed to the Mikulino, Kamenka, and Likhvin interglacials. In addition, some data used in the reconstructions were taken from published materials on LPS studied in the sections: Aleksandrovsky Quarry (Sycheva 1998;Sycheva and Sedov 2012;Sycheva et al 2017), Mikhailovka (Agadjanian and Glushankova 2017), Afonino (Dlussky 2007), Likhvin (Lazukov and Chebotareva 1977), as well as sections published by Dlussky (2001), Markov (1977, Yakimenko (1995), Dodonov and Velichko (2003), Glushankova (2008Glushankova ( , 2012, Glushankova and Agadjanian (2015), Bolikhovskaya and Molodkov (2006), Virina et al (2000), a.o.…”