Reconstruction of the Late Quaternary climate of Oka Plateau (East Sayan) based on sedimentary record from high-mountain freshwater lake

Authors

  • Solotchin P.A. 1
  • Solotchina E.P. 1
  • Bezrukova E.V. 2
  • Shchetnikov A.A. 2, 3
  • Zhdanova A.N. 1
  • 1 V.S. Sobolev Institute of Geology and Mineralogy, Siberian Branch of the Russian Academy of Sciences, pr. Koptyuga, 3, Novosibirsk, 630090, Russia
    2 A.P. Vinogradov Institute of Geochemistry, Siberian Branch of the Russian Academy of Sciences, Favorskogo str., 1a, Irkutsk, 664033, Russia
    3 Institute of the Earth’s Crust, Siberian Branch of the Russian Academy of Sciences, Lermontova str.,128, Irkutsk, 664033, Russia

DOI:

https://doi.org/10.31951/2658-3518-2024-A-4-670

Keywords:

lacustrine sediments, layered silicates, modeling of XRD patterns, Holocene, paleoclimate, East Sayan

Abstract

We present the results of a comprehensive study of Holocene sediments from high-mountain Lake Sagan-Nur located in East Sayan. The lake is freshwater and has glacial origin. The sediments have been studied by X-ray diffractometry (XRD), IR spectroscopy, laser grain-size analysis, X-ray fluorescence analysis, AMS (14С) and 210Pb dating. The mineral composition of lake bottom sediments is dominated by phyllosilicates, quartz and feldspars. The method of mathematical modeling of their complex XRD profiles was used for correct identification of layered silicates. It has been established that the structural characteristics and quantitative ratios of these minerals change in response to climate changes in the region. The study of sediments composition and, especially, the precision mineralogical-crystallochemical analysis of layered silicates allowed us to reconstruct the climatic conditions of sedimentation.

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Published

2024-08-26

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Articles