REFERENCE EOPLEISTOCENE-LOWER NEOPLEISTOCENE SECTION OF THE SOUTH TRANSURALS REGION

Abstract

The paper presents the results of long-term complex investigation of lacustrine and fluvial-lacustrine sediments in the Baturino coal quarry (Chelyabinsk district, south Transurals region). Three units, the Chumlyak (lower Eopleistocene), Sarykul' (upper Eopleistocene-lower Neopleistocene),and Baturino (lower Eopleistocene) formations characterize cycles of lacustrine sedimentation. Each of the units begins with basal inequigranular dusty sands that enclose gravel and pebbles and represent alluvium of steppe rivers. They are crowned by laminated to massive lacustrine clays with buried soil at the top. Lithological and mineral characteristics of studied sediments are described. Sediments enclose fossil remains of vertebrates, mollusks, ostracods, and spores-pollen complexes, which reliably depict their stratification. The Chumlyak Formation and lower part of the Sarykul' Formation are correlated with the Matuyama Chron, whereas the upper part of the Sarykul' Formation and Baturino Formation correspond to the Brunhes Chron. In terms of paleogeography, basal layers of the Chumlyak and Baturino formations were deposited during the inetrglacials, and their upper clayey layers accumulated under cold conditions of glacials. Sedimentation terminated in cryoxerothermic phases of glaciations, as it is evident from cryogenic wedges in the topmost parts of formations.