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| Preliminary Study on the Geochemical Features of Sediments from Different Geomorphic Units of the Eastern Kumtagh Desert |
| Liu Benli1, Qu Jianjun1, Yang Gensheng1, Niu Qinghe1, An Zhishan1, Gao Yanhong2 |
1. Key Laboratory of Desert and Desertification/Dunhuang Gobi and Desert Ecology and Environment Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
2. Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China |
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Abstract A geochemical study was conducted on the sediments from the east Kumtagh Desert and its nearby geomorphic units, including desert, gobi, oasis, wetland, wadi, et al. The contents of major and trace elements were compared with the upper continental crust's average value (UCC), and the Ba-Sr ratio and chemical index of alteration (CIA) of each sample were analyzed. Preliminary results show a weak weathering level for all the samples, despite the significant differences among the sediments from different environments. The sediments from sandy land and vegetated land at the northeast corner of the Kumtagh Desert share similar geochemical features, indicating a same source-area of the North Mountain. Sands at the east of the desert have similar element components and Ba-Sr ratio and the chemical characteristics change gradually from north to south, indicating an aeolian mixture effect by the north winds. Potential sources of the desert sands include the alluvial deposits from the south Altyn Tagh Mountain, the gobi area to the east, and the wadis. The gobi area between the desert and the Dunhuang Oasis suffers from weak weathering, whereas chemical features of sediments at various locations are similar to their nearby potential source areas. Sand elements at the west Mingsha Megadune differ from the Kumtagn Desert clearly but are alike to the deposits in the Danghe River, thus the Danghe River is the most likely provenance of the Mingsha Megadune.
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Received: 26 August 2013
Published: 20 September 2014
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2014, Vol. 34 
