On the Possibility of Constructing a Quantitative Paleoreconstruction of the Altai Mountains Climate Based on Scanning SR-XRF Data on the Bottom Sediments of Lower Multa

Bottom sediments in mountain lakes archive regional and global environmental changes, including those related to climate change. For fresh highland lakes of the Altai region, the main sources of bottom-sediment material are terrigenous demolition and organics of allochthonous and autochthonous origin. Changes in air temperature and amount of atmospheric precipitation modulate the elemental composition of bottom sediments determined by the ratio of incoming terrigenous and organic material. Analysis of variations in the elemental composition by the core depth of bottom sediments can provide information on changes in the region’s main climatic parameters over past millennia with high detail determined by the spatial (sequential–temporal) resolution of the analytical method. The method of scanning synchrotron-radiation-induced X-ray fluorescence analysis (SR-XRF) is used for climatic reconstruction of high time resolution, which allows one to obtain a continuous series of elemental composition according to core depth with required spatial resolution. The article presents the results of studying a core of bottom sediments from Multa Lakes (Altai) using analytical microstratigraphy techniques, including scanning SR-XRF. A transfer function was constructed that relates the chemical composition of dated core intervals for the 1940–2015 time period with regional instrumental meteorological observations. The possibility of creating quantitative climate reconstructions based on data from scanning SR-XRF is shown.