RESULTS OF STUDYING THE PLEISTOCENE IN THE VILGORT SECTION (CHERDYN DISTRICT, PERM TERRITORY)

Abstract

Link for citation: Plyusnin A.V., Sulima A.I., Marinov V.A., Vdovichenko S.I., SamodurovS.A. Results of studying the Pleistocene in the Vilgort section (Cherdyn district, Perm territory). Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 5, рр.148-158.In Rus. The relevance. The study of glacial deposits, which is one of the main components of most continental sedimentary formations of all ages, makes it possible to identify the features of its structure and formation, as well as to establish the facies-genetic confinement. This is especially true for Quaternary geology, since makes it possible to carry out stratigraphic comparisons and identify paleogeographic settings for the formation of deposits. This paper presents the results of a comprehensive lithological and biostratigraphic study of the Vilgort section of the Kolva river valley, Cherdyn district of the Perm Territory. The main aim of the research is to study the geological section and substantiation of the age of the Mesozoic deposits according to the fauna complex. Objects: continental deposits of the Middle Pleistocene, exposed in the right side of the river Kolva. The deposits of this region are poorly studied. References are sown in the literature about the Mesozoic fauna found in the Vilgort section. Methods: geomapping, layered lithological description, layer-by-layer sampling, biostratigraphic studies. Results. These studies made it possible to carry out a detailed layer-by-layer description and stratigraphic subdivision of the Vilgort section. The Permian carbonate deposits are overlain by eluvial-deluvial deposits of the Likhvin horizon, they are overlain first by lacustrine-glacial, and then by glacial deposits of the Dnieper horizon of the middle Pleistocene with erratic blocks of Mesozoic repeatedly redeposited terrigenous rocks. Due to the neotectonic activity of the right-bank block part of the Vilgort area, which underwent uplift in the Late Pleistocene, most of the Upper Pleistocene deposits were eroded, which explains the stratigraphic unconformity, when modern deposits lie on glacial deposits of the Middle Pleistocene. According to the results of micropaleontological studies, foraminifers were identified from samples taken in the fifth layer: the Middle Volgian substage of the Volgian stage (sample 1); distributed in the interval of the Ryazanian Stage of the Lower Cretaceous (sample 3) and the middle and upper substages of the Volgian Stage (sample 4).