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JOURNAL OF DESERT RESEARCH ›› 2017, Vol. 37 ›› Issue (2): 228-236.DOI: 10.7522/j.issn.1000-694X.2016.00096

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The Modern Processes of Atmospheric Dust Recorded by Sediments from Gonghai Lake, Shanxi, China

Chen Shengqian, Wang Xin, Chen Jianhui, Liu Jianbao, Wang Zongli, Qiang Mingrui, Chen Fahu   

  1. College of Earth and Environmental Sciences/MOE Key Laboratory of Western China's Environmental Systems, Lanzhou University, Lanzhou 730000, China
  • Received:2016-06-16 Revised:2016-07-13 Online:2017-03-20 Published:2017-03-20

Abstract:

Lacustrine dust record is one of important documents for studying the evolution history of reginal dust, while the study of modern deposition processes of dust is the key basis to quantitatively extract dust signal from lake sediments. In the present paper, we analyzed the grain-size distributions of lacustrine sediments from Gonghai Lake and different types of modern surface deposits from the catchment. In addition, we further quantitatively separated grain-size components of sedimentary core from Gonghai Lake. The results indicate that lacustrine sediments from Gonghai Lake during the Holocene are mainly composed of clay (<2 μm), fine silt (2-19 μm) and coarse silt (19-78 μm), and the grain-size distribution of the coarse silt is similar with that of the isolated quartz particles in the sediments, coarse component of loess and modern atmospheric dust. Moreover, the surface of lacustrine quartz particles is characterized by typical aeolian features. Hence we conclude that the variation of coarse silt component in lake sediments from Gonghai Lake can be used to indicate the evolution of atmospheric dust, which is consistent with the knowledge that coarse silt component of lake sediments could be regarded as the main component of dust storm. In addition, the mean grain size of ice-trapped aeolian dust from lake-ice surface of Gonghai Lake decreases from northwest to southeast, and this direction is consistent with prevailing wind direction of winter monsoon, thus further indicating that the content of coarse silt component in sediments from Gonghai Lake can represent the variation of East Asian winter monsoon. Therefore, it is suggested that the coarse silt component of sediments from Gonghai Lake can be used to reconstruct the variation of atmospheric dust and the possible evolution history of East Asian winter monsoon during the Holocene.

Key words: lake sediments, dust, modern processes, grain size, coarse silt component

CLC Number: