DISTINCTIVE FEATURES OF SEDIMENTATION IN THE TALAYA GROUP OF GLACIAL LAKES, KOLYMA HIGHLANDS, DURING THE LATE NEOPLEISTOCENE–HOLOCENE: GEOCHEMICAL EVIDENCE

A group of Talaya lakes (Gryazevoe, Schuch’e, Goluboe, Nalimnoe are located in the east of the Maimandzhinsky Mountains (Kolyma Highlands). The lakes are of glacial origin. They were formed during the Late Neopleistocene-Early Holocene. Geochemical characteristics of lake sediments, tephra, deluvial deposits, and bedrock were obtained. Based on the analysis of the distribution of major elements, SiO2/TiO2, Fe2O3/TiO2, Fe2O3/MnO, SiO2/Al2O3, SiO2/MgO, SiO2/Fe2O3 ratios, ICV, CIA indices, and principal component analysis data, geochemical zones reflecting various sedimentation conditions have been established in sediments. The intervals of biogenic, terrigenous and chemogenic (autigenic) accumulation were revealed. Autigenic iron–containing minerals are represented by sulfides (pyrite, pyrrhotite). Clastic minerals are titanomagnetics, magnetites, and ilmenites. The dependence of the ratios of elements and indices on the grain size of granulometric fractions of deluvium has been studied, the relationship between the geochemical characteristics of lake sediments and deluvial deposits has been established. The main stages of lake development have been reconstructed. A comprehensive characterization of the sediments of the transition interval from the Late Neopleistocene to the Holocene was obtained.