Geochemical Features of the Talus–Lacustrine Sedimentogenesis in the Chistoye Lake Basin, Northern Okhotsk Region

The results of the geochemical study of loose sediments of the catchment basin and bottom sediments of Lake Chistoye located in the Northern Okhotsk region showed that the lake was formed at the beginning of the Early Holocene about 11200 cal. years BP. It is dominated by terrigenous sedimentation, i.e. the geochemical characteristics of sediments are controlled by the grain size. Fine-grained sediments have low SiO₂, Na₂O, K₂O, CaO, Sr contents and are enriched in Al₂O₃, TiO₂, MgO, Fe₂O₃, and V. Changes in the sedimentation nature are likely caused by climatic reasons and may be associated with the cold Bond events. In the Early Holocene, mostly thin silts were deposit in Lake Chistoye. The pulses of “coarse-grained” sediments (>140 μm) enriched with silica occurred (9760–9650) and 8810 cal years BP. Relatively coarse-grained sediments were mainly accumulated at the very beginning of the Middle Holocene 8540–6920 cal years BP, as well as 6140 and 4450 cal years BP. In the Late Holocene, the input of detrital material with increased SiO₂ contents was noted in the range of 3470–850 cal. years BP.