D.V. NAZAROV (VSEGEI, SPbU), O.A. NIKOLSKAIA, A.S. GLADYSHEVA, I.V. ZHIGMANOVSKIY (VSEGEI), M.V. RUCHKIN (VSEGEI, SPbU), А.V. MERKULJEV (ZIN RAS)

Pleistocene marine formations of the lower Yenissei basin, Arctic Russia: OSL age, facial and paleontological characteristics

New data on geological structures, paleontology and geochronometry of the surficial sedimentary mantle of the lower Yenissei basin have been obtained. The data allow to divide the Upper and Middle Pleistocene marine formations, exposed in river bluffs. The Kheta marine formation has been described on the Bolshaya Kheta River. The formation, sandwiched between two Middle Pleistocene till horizons, has yielded OSL data in range 230–190 ka and is correlated with MIS 7. The Kheta fauna contains a characteristic Pleistocene mollusk Cyrtodaria jenisseae Sachs, 1951, which extinct before the Late Pleistocene. The Kheta marine formation is overlain by the Taz till which is covered by marine silt and sand with boreal mollusk fauna and OSL age 130–100 ka. The latter is correlated with MIS 5e and covered by the Upper Pleistocene glacial complex in the Bolshaya Kheta basin. This marine formation composes a well­pronounced terrace in the Tanama basin. The marine terrace can be traced throughout the region, north of the Bolshaya Kheta basin.
Keywords: Middle and Late Pleistocene, Bivalvia Cyrtodaria jenisseae, Arctic, West Siberia, stratigraphy, correlation.