Two cores (67 and 105 cm) of high mountain Lake Khindiktykol (Tuva) bottom sediments were sampling by a hummer gravity corer from depths of 64,7 m in the middle of the lake and of 31,3 m in the small bay. The upper 170 mm of each core was studied by scanning micro-XRF with synchrotron radiation (µXRF-SR). The analysis was carried out at the experimental station "Elemental analysis" in the joined Research Center SSTRC. Experimental conditions: excitation energy 23 keV, dimensions of the exciting radiation beam 1.5 mm in height and 10 mm in width of the sample. The scanning step was 2 mm in height of the sample. The distributions of more than 20 rock-forming and trace elements over the core depth were obtained. The distribution of Ti, Mn, Fe, Ni, Ga, Y in both cores coincides well. This suggests one source of terrigenous material and similar sedimentation rates. Large discrepancies are visible in the distribution of Ca, As, Br, Sr, Mo. These elements are characteristic of carbonates and biogenic material. The obtained data indicate differences in the sources of matter entering the bottom sediments in different parts of the lake. Additional lithological and geochemical studies are required when choosing bottom sediments will be used to climatic reconstructions.
This work was financially supported by the RSF project. № 20-17-00110. The work was done at the joined Research Center SSTRC on the basis of the VEPP-4 - VEPP-2000 complex at BINP SB RAS, using equipment supported by project RFMEFI62119X0022.