Acta Geographica Sinica ›› 2021, Vol. 76 ›› Issue (5): 1163-1176.doi: 10.11821/dlxb202105009

• Climate Change and Land Surface Processes • Previous Articles     Next Articles

Dust accumulation processes and palaeoenvironmental significance of loess indicated by grain size in Zhangqiu, Shandong Province

KONG Fanbiao1,2(), CHEN Haitao2,3, XU Shujian2,3(), MIAO Xiaodong2   

  1. 1. School of Geography and Environment, Shandong Normal University, Jinan 250014, China
    2. Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection, College of Resources and Environment, Linyi University, Linyi 276000, Shandong, China
    3. College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, Shandong, China
  • Received:2019-12-16 Revised:2021-03-25 Online:2021-05-25 Published:2021-07-25
  • Contact: XU Shujian E-mail:kongfanbiao92@163.com;xushujian1967@163.com
  • Supported by:
    National Natural Science Foundation of China(41977262);National Natural Science Foundation of China(41472159)

Abstract:

The accumulation processes of loess in Shandong Province record atmospheric circulation changes in eastern China, which is significant in revealing the varied characteristics of East Asian monsoons and palaeoenvironmental change. In this study, the parameterized end-member modelling analysis of grain-size distributions is used to discuss the sedimentary characteristics, transport dynamics and environmental significance for a loess section in Zhangqiu, Shandong Province. The results indicated that: (1) The optically stimulated luminescence (OSL) ages of the Zhangqiu section ranged from 0.26 to 42.24 ka, suggesting that sediments have mostly deposited since the late Pleistocene. (2) The grain size components of the sediments in this section were divided into five end members: EM1 represents the mixed clay component of pedogenesis and transported sediment, EM2 represents the fine silt component transported by the high-altitude westerly wind over long distance, EM3 represents material that settles as floating dust, EM4 is the main material source of the profile, which represents the silt component transported by low-altitude suspension under local wind systems, and EM5 represents short-distance suspended materials under dust storm conditions. Change in the EM5 component is a good indicator of winter monsoon intensity change, and has recorded all climate fluctuation events since the late Pleistocene. (3) According to the climatic proxies such as the grain-size end-member content, low frequency magnetic susceptibility (χlf) and chromaticity (a*), combined with the results of OSL, this effectively indicated the stage change and differences of the sedimentary environment in the Zhangqiu section since the late Pleistocene and reflected the regional response to global climate change.

Key words: loess, end-member modelling analysis of grain-size distributions, dust accumulation, environmental evolution, Shandong Province