Grain-size cycles in Salawusu River valley since 150 ka BP |
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| Authors: | ZHANG Yu-hong LI Bao-sheng JIN He-ling David Dian ZHANG YAN Mun-cun ZHU Yi-zhi YAO Chun-xia |
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| Institution: | 1. State Key Lab of Loess and Quaternary Geology, Institute of Earth Environment, CAS, Xi’an 710061, China|
2. Dept. of Geography, South China Normal University, Guangzhou 510631, China|
3. Cold and Arid Regions Environmental and Engineering Research Institute, CAS, Lanzhou 730000, China|
4. Dept. of Geography and Geology, Hong Kong University|
5. Dept. of Hydraulic Engineering, Tsinghua University, Beijing 100084, China |
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| Abstract: | The palaeo-mobile dune sands and fluvio-lacustrine facies with palaeosols in Milanggouwan stratigraphic section of the Salawusu River valley situated at the southeast of the Mu Us Desert experienced abundant remarkable alternative changes of coarse and fine rhythms in grainsize since 150 ka BP, and the grain-size parameters — Mz,σ, Sk, Kg and SC/D also respond to the situation of multi-fluctuational alternations between peak and valley values. Simultaneity the grainsize eigenvalues — Φ5, F16, Φ25, Φ50, Φ75, Φ84 and Φ95 are respondingly manifested as greatly cadent jumpiness. Hereby, the Milanggouwan section can be divided into 27 grain-size coarse and fine sedimentary cycles, which can be regarded as a real and integreted record of climate-geological process of desert vicissitude resulted from the alternative evolvement of the ancient winter and summer monsoons of East Asia since 150 ka BP. |
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| Keywords: | Salawusu River valley Milanggouwan section 150 ka BP grain-size palaeoclimate cycles |
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