SCIENTIA GEOGRAPHICA SINICA ›› 2023, Vol. 43 ›› Issue (4): 745-753.doi: 10.13249/j.cnki.sgs.2023.04.018

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Impact of sediment physicochemical characteristics on the genesis of clay dunes in the Suhongtu Basin

Hu Fangen1(), Zhang Deguo2()   

  1. 1. Department of Geography, Yichun Univesity, Yichun 336000, Jiangxi, China
    2. School of Earth Sciences, Zhejiang University, Hangzhou 310027, Zhejiang, China
  • Received:2022-02-20 Revised:2022-06-12 Online:2023-04-30 Published:2023-04-20
  • Contact: Zhang Deguo E-mail:hufg1112@jxycu.edu.cn;dgzhang@zju.edu.cn
  • Supported by:
    National Key Research and Development Program of China(2019YFE0124900);National Natural Science Foundation of China(41771022);National Natural Science Foundation of China(41801009);Natural Science Foundation of Jiangxi Province(20224BAB203032)

Abstract:

Clay dune is a special aeolian landform, study on its formation mechanism, development and evolution process are of great significance for enriching the knowledge of diversity of aeolian landscape and strengthening the understanding of aeolian geomorphic process. In this article, grain size and soluble salts of the clay dunes surface sand, crust and lacustrine sediments were determined to discuss its material sources, formation mechanism. The results show that: 1) The grain size composition of the surface sand of the clay dunes in the Suhongtu Basin is dominated by silt, and the clay component is relatively high, the grain-size frequency curve shows obvious bimodal distribution characteristics, and the mean grain-size is about 6.01 Φ, which is significantly different from those typical desert dune sand; 2) The surface sand of clay dunes and lacustrine sediments have roughly similar particle size distribution, reflecting that the lacustrine sediments are the main material source of clay dunes in the Suhongtu Basin; 3) Clay dunes are transported and accumulated as sand-sized aggregates of clay minerals by wind, which are formed by the efflorescence of salts or by the mechanical disintegration of sun-cracked crust and mud curls; 4) The differences in grain size composition, sand source and climatic conditions are the main reasons for the significant differences in morphology, mobility and sedimentary structure of clay dunes in different areas; 5) Raked red clay dunes can form by a moving barchan dune in east-west direction for bedforms growing in the bed instability mode combined with an extension arm in the southwesterly direction for dunes growing in the fingering mode.

Key words: clay dunes, grain-size, soluble salt, the Suhongtu Basin

CLC Number: 

  • P931.3