BOLETÍN DE LA SOCIEDAD GEOLÓGICA MEXICANA Vol 64, Núm. 2, 2012, P. 189-197 http://dx.doi.org/10.18268/BSGM2012v64n2a4

Paleopedogenesis during the Mikulino interglacial (MIS 5е) in the East-European plain: buried toposequence of the key-section "Alexandrov quarry"

 Paleopedogenesis durante el interglacial Mikulino (MIS 5e) en la llanura de Europa oriental: la toposecuencia sepultada de la sección clave "cantera Alexandrov"

Svetlana Sycheva¹, Sergey Sedov^2,*

¹ Institute of Geography, RAS. Staromonetny 29, Moscow, 119017, Russia
²Instituto de Geología, Universidad Nacional Autónoma de México, México

 ^*This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

The Alexandrovsky quarry exposure (near Kursk, central European Russia) represents one of the most complete and detailed records of paleosols, colluvial sediments and loess for the last glacial-interglacial cycle in Eastern Europe. The buried toposequence of Mikulino (Eemian) paleosols, developed on a gully slope cut in the Dnepr (Riss) loess and overlain by Early Valdai (Würmian) colluvium, was subjected to detailed morphological study. The paleosol on the upper slope is an Albeluvisol that contrasts from the Holocene Chernozem. Analysis of thin sections of the Albeluvisol demonstrated that elluvial features – concentrations of bleached silt in the pores and in the groundmass – dominate not only in E and EB but also in the Bt₁ horizon. They also penetrate into lower Bt₂ and Bt₃ horizons where they combine with illuvial clay pedofeatures. The paleosol profile at the bottom of the gully shows synsedimentary development with several A, AE and E horizons reflecting several phases of geomorphic activity as a response to a complex environmental history during the last interglacial. The shift from dark humus accumulation under grasslands towards forest pedogenesis dominated by clay illuviation and stagnic processes comprised the major trend of the Mikulino (Eemian) soil evolution.

Keywords: Paleopedogenesis, Eemian soil, Mikulino soil, catena, Albeluvisol, last interglacial.