| Инд. авторы: | Kalugin I., Darin A., Tretyakov G., Rogozin D., Kholodova L., Maksimova N. |
| Заглавие: | Geochemical signals of paleoclimate in the varved clastic and carbonate lake sediments |
| Библ. ссылка: | Kalugin I., Darin A., Tretyakov G., Rogozin D., Kholodova L., Maksimova N. Geochemical signals of paleoclimate in the varved clastic and carbonate lake sediments // International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM. - 2013. - P.643-650. - ISBN 9786197105032. - ISSN 1314-2704. |
| Внешние системы: | DOI: 10.5593/SGEM2013/BD4/S19.018; РИНЦ: 21908113; SCOPUS: 2-s2.0-84892594120; |
| Реферат: | eng: Geochemical study of bottom sediments from several Siberian and Mongolian lakes (Teletskoye, Kucherla, Baikal, Arachlei, Telmen, and Shira) allows reconstructing of environmental parameters such as air temperature, precipitation, lake level, runoff, tree ring growth index, pressure, wind direction and others on annual scale. The new approach to study sediment records appeared due to automatic technique for scanning microanalysis of cores in situ. X-ray fluorescence analysis on synchrotron radiation (XRF SR) in the Institute of Nuclear Physics, Novosibirsk was adapted. More than 35 elements with step of measurement > 0.05 mm along fresh opened cores and in solid preparates were determined. Variations of several microelements content appeared to be well correlated with environmental parameters, which were used as a geochemical proxies for statistical treatment and modeling. Elements composing organic component of sediments (Br, I, U) are correlative with mean annual temperature variations because of changes vegetation productivity content in catchment and in waterbody. And elements from clastic mineral part (Rb, Sr, Ti, Y, Zr) reflect annual precipitation, runoff and the proportion of the unweathered terrestrial fraction. X-ray density (XRD) indicates water yield regime and sediment flux. Clastic varves are well-known all over the world, they are formed in glacial and non-glacial lakes, for example, Kucherla, Teletskoe lakes in Altai a.o. Analysis shows graded structure from lower mid-grained material (silt) to upper fine-grained part as usual. The last one contains more weathered (clay) material with a touch of organics. Correspondingly Rb and Br content increase, but XRD, Ti, Sr, Zr and other clastic components decrease upward. Carbonate varves are presented in saline lakes Telmen, Shira and other. Carbonate matter, as Ca, Mg and Sr content, evidences seasonal and long-term salinity fluctuation connected with lake level and aridity. Equilibrium thermodynamic modeling allows to quantify the atmosphere - water - sediment - pore solution system for saline lakes. Computer physicochemical simulation adapted for natural rock-water-gas multisystem of Shira lake is executed by 'Selector' software, which used method of thermodynamic potentials minimization under local equilibrium state. For example, estimated salinity effect on Sr concentration proves positive correlation between strontianite content and evaporation/ice cover periods. Time series of lithological-geochemical indicators of climate change, based on counting of annual layers and isotope dating, are calibrated by hydrometeorological data to obtain the functions of variability for relevant parameters beyond instrumental and tree ring limits in the past. © SGEM2013 All Rights Reserved by the International Multidisciplinary Scientific GeoConference SGEM. |
| Ключевые слова: | microXRF; Paleoclimate; Seasonality; Varves; Geochemical proxies; Micro-XRF; Paleoclimates; Seasonality; Varves; Carbonation; Catchments; Climate change; Computer simulation; Computer software; Exhibitions; Forestry; Geochemistry; Glacial geology; Isotopes; Lakes; Lithology; Nuclear physics; Rubidium; Runoff; Saline water; Strontium; Titanium; Trees (mathematics); Zirconium; Sediments; Carbonation; Climates; Computer Programs; Exhibitions; Forestry; Geochemistry; Isotopes; Lakes; Rubidium; Runoff; Sediments; Simulation; Strontium; Titanium; Uranium; Zirconium; Geochemical proxy; Uranium; |
| Издано: | 2013 |
| Физ. характеристика: | с.643-650 |
| Конференция: | Название: 13th International Multidisciplinary Scientific Geoconference and EXPO, SGEM 2013 Даты проведения: 2013-06-16 - 2013-06-22 |