Employing a highly-sensitive synchrotron XRF technique for obtaining multielement geochemical records: the first continuous ~10-kyr record from a remote Caucasus Mountains lake
- Alexei GRACHEV
- Alexei GRACHEV (Institute of Geography RAS)
- Mr. Fedor DARIN (Budker Institute of Nuclear Physics SB RAS)
- Dr. Iakov RAKSHUN (Budker Institute of Nuclear Physics)
- Dr. Andrey DARIN (Sobolev Institute of Geology and Mineralogy SB RAS)
- Mr. Dmitry SOROKOLETOV (Budker Institute of Nuclear Physics SB RAS)
- Dr. Ivan KALUGIN (Sobolev Institute of Geology and Mineralogy SB RAS)
- Dr. Tatiana MARKOVICH (Sobolev Institute of Geology and Mineralogy)
- Dr. Olga SOLOMINA (Institute of Geography RAS)
Lake sediments offer valuable highly-resolved continuous records of past climatic and environmental changes. Temporal coverage of these records typically constitutes centuries to millennia. Over past decades many indicators have been explored in the sediments and used as proxies for past climatic and environmental conditions. One powerful technique for paleoreconstructions, that has been perfected at the Siberian Synchrotron and Terahertz Radiation Centre, SSTRC (by A. V. Darin, I. V. Rakshun, and others) is based on employing synchrotron radiation. The technique (described in detail previously by A. V. Darin et al.) supplies essentially continuous (resolution up to 20 μm) profiles of over 20 elements along the vertical axis of the sediment core. Employing a synchrotron beam allows to significantly extend the possibilities of the ordinary XRF analysis. In this work, we present the first continuous geochemical record for the Holocene for the Caucasus region from a remote lake in the Caucasus Mountains (Lake Khuko, 43°56′N 39°48′W). Specially prepared samples from the ~2-meter sediment core were scanned at the X-ray Fluorescent Elemental Analysis station at the SSTRC at the 23-keV energy. The increment step during the overview scanning was set to 250 μm. The full interpretation of the new record will be possible only when the geochemistry data will be combined with other indicators (pollen, organic matter content, etc.). Here we present the data on selected elements (Br, Sr, etc.) displaying the most distinctive patterns, signifying the past changes in climate and environment.
This work was supported by the Russian Foundation for Basic Research (Project leader: O. N. Solomina, grant No. 17-05-01170).