New Data on Late Quaternary Sedimentation in High-Mountain Khikushka Lake (Eastern Sayan): The Role of Climatic and Volcanic Factors

• Published in: Doklady earth sciences Vol. 501; no. 1; pp. 938 - 944
• Main Authors: Solotchin, P. A., Kuzmin, M. I., Solotchina, E. P., Bezrukova, E.V., Strakhovenko, V. D., Shchetnikov, A. A., Zhdanova, A. N.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2021; Springer; Springer Nature B.V
• Subjects: Analysis; Analytical methods; Basins (Geology); Catchment area; Chlorite; Clay; Earth and Environmental Science; Earth Sciences; Electron microscopy; Feldspars; Fluorescence; Freshwater; Freshwater lakes; Glacial lakes; Glacier fluctuations; Glaciers; Grain size; Holocene; Illite; Illites; Infrared analysis; Infrared spectroscopy; Inland water environment; Kaolinite; Lacustrine sedimentation; Lacustrine sediments; Lake basins; Lake deposits; Lake sediments; Lakes; Lithology; Mathematical models; Mica; Mineralogy; Minerals; Mountains; Muscovite; Pleistocene; Quaternary; Recent sediments; Scanning electron microscopy; Sediment; Sedimentation; Sedimentation & deposition; Sediments; Silicates; Smectite; Smectites; Spectroscopy; Vermiculite; Volcanic activity; Volcanism; Volcanoes; Water levels; X ray fluorescence analysis; X-ray diffraction; X-ray fluorescence; X-ray spectroscopy; lacustrine sediments; volcanic activity; Late Pleistocene; clay minerals; Holocene; paleoclimate; Eastern Sayan; modeling of XRD patterns
• ISSN: 1028-334X; 1531-8354
• DOI: 10.1134/S1028334X21110155

We present the results of a comprehensive study of Late Pleistocene–Holocene sediments from Khikushka Lake located in the high-mountain Zhom-Bolok volcanic area (East Sayan Mountains). The lake is freshwater, endorheic, and of glacial origin; the age of sediments is ~13.8 ka. The sediments have been studied by X-ray diffractometry (XRD), IR spectroscopy, laser grain-size analysis, scanning electron microscopy, X-ray fluorescence analysis, and AMS dating. Detailed mineralogical studies of the Khikushka Lake sediments have been conducted for the first time. It is shown that feldspars, quartz, phyllosilicates, and amphibole prevail in them. Mathematical modeling of complex XRD patterns allowed us to identify chlorite, illite, illite–smectite, chlorite–smectite, muscovite, vermiculite, and kaolinite among layered silicates. The quantitative ratios of these minerals change significantly from the Pleistocene to the Holocene. Despite the close proximity of the volcanoes and multistage Late Quaternary eruptions in the Zhom-Bolok area, only indirect indications of the presence of pyroclastic material were found in the lacustrine sediments studied. Based on the mineralogical, crystallochemical, lithological, and geochemical studies, five evolutionary stages of the Khikushka Lake basin have been identified. Sedimentation in this basin occurred under the influence of both climatic (glacier activity, lake level fluctuations, lake bioproductivity) and geological (composition of rocks within the catchment, Late Quaternary volcanism) factors.