Geochemical features of deluvial-lacustrine sedimentogenesis in the basin of lake Chistoye, Northern Priokhotsk area

Abstract

The results of the geochemical study of loose sediments of the catchment basin and bottom sediments of Lake Chistoye, located in the Northern Priokhotye, showed that the lake was formed at the beginning of the early Holocene about 11200 cal. years ago. Terrigenous sedimentation dominates in it, i. e. the geochemical characteristics of sediments are determined by the particle sizes. Thin grain size sediments have low SiO2, Na2O, K2O, CaO, and Sr contents; and are enriched with Al2O3, TiO2, MgO, Fe2O3, and V. Changes in the nature of sedimentation may be due to climatic reasons and may be associated with cold Bond events. In the Early Holocene, mostly thin silts were deposited in Lake Chistoye. The impulse of “coarse-grained” sediments (140 microns) enriched with silica occurred (9760–9650) and 8810 cal. years ago. A noticeable accumulation of relatively coarse-grained sediments occurred at the very beginning of the Middle Holocene 8540–6920 cal. years ago, as well as 6140 and 4450 cal. years ago. For the Late Holocene, the input of detrital material with increased SiO2 contents was noted in the range of 3470–850 cal. years ago.