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Journal of Desert Research ›› 2022, Vol. 42 ›› Issue (3): 51-62.DOI: 10.7522/j.issn.1000-694X.2021.00166

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Environmental changes recorded by aeolian deposits in the coasts of China

Hong Jia1(), Zhiyan Sun1, Jinming Xie2, Jie Chen1, Yinghua Zheng3, Mingrui Qiang1()   

  1. 1.School of Geography,South China Normal University,Guangzhou 510631,China
    2.College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,China
    3.MOE Engineering Research Center of Desertification and Blown-Sand Control,Beijing Normal University,Beijing 100875,China
  • Received:2021-09-07 Revised:2021-10-27 Online:2022-05-20 Published:2022-06-01
  • Contact: Mingrui Qiang

Abstract:

The coasts are the critical zones in which complex interactions among the land, ocean and atmosphere are intensive. The coastal aeolian deposits are a product in the dynamic environments, and therefore are good archives for studying evolution of coastal environments and changes in sea level. There are mainly three types of aeolian deposits along the coasts of China, i.e., the “Old Red Sand”, aeolianites and sand dunes. This paper reviews the sedimentary characteristics of aeolian deposits by comparing the material composition and stratigraphic variability of different types of aeolian deposits that have been reported formerly. In this study, we selected the aeolian deposits sections dated by absolutely dating, used probability density function to analyze the distribution characteristics of the ages of aeolian deposits, investigated the history of aeolian activity on various timescales, and discussed key factors affecting coastal aeolian deposition along the coasts of China. The results show that aeolian activity on a glacial-interglacial scale were mainly recorded by the “Old Red Sand”. At around 120 ka BP and 73-55 ka BP, aeolian activity was mainly related to abundant sediment supply, originated from continental shelfs due to decline in sea level and strong winter monsoon circulation; whereas at around 105 ka BP and 80 ka BP, aeolian activity was ascribed to abundant sediment supply due to intensified runoffs resulted from enhanced monsoonal circulation and/or enhanced seasonality of monsoon climate. The decrease in the intensity of aeolian activity since 55 ka BP most likely reflected changes in preservation environments of sedimentation record, and most coastal aeolian deposits during the last glacial were inundated below the modern sea level, which does not mean that actual coastal aeolian activity weakened at that time. Aeolian activity recorded by sand dune deposits mainly occurred in the past 3 000 years, which may be related to the strengthened winter monsoon during the late Holocene. Our results may have been helpful for further understanding of key processes affecting coastal aeolian depositions and environmental changes as inferred from them.

Key words: coastal aeolian deposits, age control, aeolian activity, sedimentary processes, environmental changes

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