CollectHomepage AdvertisementContact usMessage

Arid Land Geography ›› 2024, Vol. 47 ›› Issue (4): 588-598.doi: 10.12118/j.issn.1000-6060.2023.374

• Climate Change and Surface Process • Previous Articles     Next Articles

Grain size characteristics and environmental significance of different types of dune surface sediments in the Dinggye area, southern Xizang

GONG Yifu(), PAN Meihui(), LI Na, HAO Zewen, CHEN Yougui, LI Chenlu   

  1. Collage of Geography and Environment Science, Northwest Normal University, Lanzhou 730070, Gansu, China
  • Received:2023-07-20 Revised:2023-09-03 Online:2024-04-25 Published:2024-05-17
  • Contact: PAN Meihui E-mail:2021222909@nwnu.edu.cn;panmh@nwnu.edu.cn

Abstract:

To explore the environmental significance of grain size characteristics, modern dunes in the Dinggye area of Xizang, China were sampled to analyze the grain size characteristics of surface sediments from different types of dunes. The results are as follows: (1) The grain size composition was similar between mobile and climbing dunes, and the grain size composition differed significantly between nebkha and the two dune types. The surface sediments of mobile and climbing dunes were dominated by fine and medium sands, whereas those of nebkha were dominated by very fine sand, fine sand, and powdery sands. (2) The grain size parameters of these dunes showed different trends, with the surface sediments of mobile and climbing dunes well sorted, nearly symmetrical, and moderately sharp, and those of nebkha moderately sorted, positively skewed, and very sharp. (3) The frequency distribution curves of mobile and climbing dunes are nearly symmetrical and single-peaked, whereas those of nebkha are bimodal; the differences in the probability accumulation curves of the surface sediments of these dunes are more obvious. (4) The deposition environment of the surface sediments of these dunes is mainly dominated by wind-formed deposition, with a few river deposits. (5) A comparison of particle size characteristics of the surface sediments of these dunes shows that the differences in particle size characteristics are mainly because of the joint action of sand source, vegetation cover, and wind conditions.

Key words: dunes, surface sediments, grain-size characteristics, environmental significance, Dinggye area