Comparative analysis of geochemical signatures for sources of Cenozoic sedimentary deposits laterally to South Baikal

Abstract

Geochemical signatures of Oligocene and Miocene sedimentary deposits from the Khoygot Paleovalley of Vitim Plateau changed successively over time that reflected change in sources of terrigenic material in the context of the migratory nature of the development of the river network. Geochemical signatures of Eocene-Miocene sedimentary deposits from the eastern (Mishikha-Klyuevka) and western (Osinovka) paleovalleys of the Tankhoy tectonic step of South Baikal were uniform that indicates long-term intake of sedimentary material from a common source. Composition of sedimentary material from paleovalleys of the Tankhoy step was controlled by a limited catchment. After the early Pliocene structural reorganization, geochemical signatures of sedimentary deposits from the eastern part of the Tankhoy tectonic step became similar to those of the Pliocene-Quaternary alluvium frpm the Proto-Manzurka valley of the opposite (north-western) coast of Lake Baikal. It is assumed that the common source of Pliocene-Quaternary sedimentary material was located in Jurassic (Pra-Manzurka) and Upper Jurassic-Lower Cretaceous (eastern part of the Tankhoy tectonic step) sedimentary rocks, disintegrated and eroded on the uplifts of the Primorsky and Khamar-Daban ranges.