察尔汗盐湖沙漠沙丘沉积物粒度特征分析

Grain Size Characteristics of Sediments from Typical Sand Dunes in Chaerhan Salt Lake

在对柴达木盆地沙漠地区两次野外实地调查的基础上,选取察尔汗盐湖沙漠盛行风向沿线的线形沙丘和新月形沙丘沉积物样品进行了粒度特征分析。结果表明,研究区沙区沙粒度组成以细沙和中沙占优,粉沙和黏土含量明显,粒度变化遵循沿盛行风向粒径变细的规律;粒度参数特征表现出沉积物平均粒径较国内其他沙漠偏粗,分选较差,呈正偏—近对称形分布,线形沙丘成熟度比新月形沙丘偏高;沉积物累计概率曲线特征指示研究区沙区沙的沉积环境以跃移搬运为主,存在明显的悬移搬运和微弱的滚动搬运。

Based on the two field studies in Qaidam Basin Desert, sediments of linear dune and barchans dune that are distributed along the prevailing wind in Chaerhan Salt Lake were collected as samples. Then, the grain size of the selected samples was analyzed. The results showed that fine and medium sand was dominant in the sand, sandy clay and fine silt was also detected in a large quantity. The grain size changed from coarse to fine along the prevailing wind. Moreover, the grain size parameters implied that the mean diameter of the samples was higher than those collected from the other deserts in China, which indicated a higher maturity values of linear dune over those of barchans dune. Finally, the cumulative frequency curve demonstrated that the sandy area under research was primarily deposited by saltation and suspension population.