Abstract
Abstract. Borisoglebsk Upland is considered an example of a secondary upland plain in the marginal zone of the last Middle Pleistocene glaciation. Moraine hills and kames were reworked by glaciofluvial processes and incised by small fluvial forms later. Its postglacial surface drift cover is regularly defined as an undivided complex of mantle loams of dominantly subaerial origin with characteristic cryogenic features and remnants of paleosols. However, some previous studies suggest that lake sedimentation played an important role in the postglacial history of the Borisoglebsk Upland. This paper presents results of a detailed investigation of postglacial sedimentary cover of the eastern part of the Borisoglebsk Upland aimed to reconstruct the co-evolution of surface deposits, soil cover and geomorphic landscapes since degradation of the last Middle Pleistocene glaciation about 150 ka (MIS-6). The study is essentially based on a comprehensive lithological, pedological and geocryological description of postglacial deposits in cores (hand or machine-driven) and open sections, systematic sampling for grain size analysis and selective sampling for 14C absolute dating and monoliths structural examination. The results indicate that most of the surface drifts in this feature consists of stratified lacustrine deposits. Their Late Pleistocene age is stratigraphically confined by the underlying paleosols and incorporated peats of the Mikulino interglacial age (MIS-5) and several organic-rich layers within the lake sequence 14C dated to the Middle Valdai interstadial (MIS-3). Overlying mantle loams and colluvial deposits with cryogenic features and low organic matter content those facially substitute lacustrine sediments were attributed to the Late Valdai stadial (MIS-2). After the Mid-Holocene stabilization, relatively thin colluvial cover identified by the increased amount of organic matter also deposited. We conclude that lacustrine sedimentation is the primary Late Pleistocene agent that transformed the initial glacial topography and most characteristic type of lithodynamics of the eastern Borisoglebsk Upland.
Highlights
The eastern part of the Borisoglebsk Upland is located near the Nero Lake in Central European Russia and has long been an attraction for paleogeographers and archeologists who conduct research to reconstruct the natural environment and human settling histories
The present paper provides new insights regarding the lithology, paleopedology and relic cryogenic deformation of the Late Pleistocene surface drifts located on the eastern macroslope of the Borisoglebsk Upland
The interfluve topography of the eastern Borisoglebsk Upland is comprised of two types of hill structures with strikingly different morphology
Summary
The eastern part of the Borisoglebsk Upland is located near the Nero Lake in Central European Russia and has long been an attraction for paleogeographers and archeologists who conduct research to reconstruct the natural environment and human settling histories. Little is known about the formation of interfluve areas and smaller elements of the fluvial network This region is regarded as a secondary upland plain in the marginal zone of the last Middle Pleistocene glaciation (Moscow Age, MIS-6) (Semenov et al, 1972; Astakhov et al, 2016). Not exceeding a depth of 2–3 m, they are reported across several parts of European Russia and Europe and are correlated with loesses of the southerly regions (Velichko et al, 2006) Many researchers propose this feature is predominantly of subaerial origin formed under periglacial conditions that included a combination of aeolian, cryogenic and shallow pool sedimentation processes (Makeev et al, 2017). Detailed information on its origin is an important key to further elucidate evolution of the geomorphic landscape
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
