Stages of Development of the Ryshkovo Pedolithocomplex as an Alternation of Favorable and Extreme Conditions in the Mikulino Interglacial (MIS-5e).

In 2011, in the Aleksandrov quarry (Kursk oblast, Russia), the Ryshkovo pedolithocomplex of the Mikulino (Eemian) Interglacial (MIS-5e) was studied. It includes three to four soil profiles separated by humified pedosediments. The lower soil is an eroded gray forest soil, the two middle soils ones are meadow soils at the bottom of the ravine and a soddy-podzolic soil on the paleoslope, and the upper soil is an underdeveloped soil with elements of forest pedogenesis. Morphological, physicochemical, and microbiomorphic studies of the pedolithocomplexes on the slope and in the bottom of the buried coastal ravine filled with colluvial and alluvial–colluvial sediments made it possible to reconstruct at least three pedogenic and four morpholithogenic stages in MIS-5e, which significantly detailed the event history of the interglacial. In the profile of the Ryshkovo pedolithocomplex, the buried humus horizon of the lower gray forest soil is clearly visible reflecting warmer climatic conditions of the first half of the last completed interglacial in comparison with its second half. Soil formation in trans-accumulative landscapes was repeatedly interrupted by erosion–accumulation processes, which reflects the instability (rhythmicity) of the climatic situation during the Mikulino interglacial and correlates well with detailed records from other geological archives. [ABSTRACT FROM AUTHOR]