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中国沙漠 ›› 2018, Vol. 38 ›› Issue (1): 68-75.DOI: 10.7522/j.issn.1000-694X.2017.00090

• 沙漠与沙漠化 • 上一篇    下一篇

柴达木盆地察尔汗盐湖北侧沙丘黏性沉积物特征

李超, 董治宝, 陈国祥, 杨军怀, 石唯康   

  1. 陕西师范大学 地理科学与旅游学院/地理学国家级实验教学示范中心, 陕西 西安 710062
  • 收稿日期:2017-10-01 修回日期:2017-11-28 出版日期:2018-01-20 发布日期:2018-01-20
  • 作者简介:李超(1989-),男,河北藁城人,博士研究生,从事风沙物理与风沙地貌学研究。E-mail:lichao256237@outlook.com
  • 基金资助:
    中央高校基本科研业务费专项资金项目(GK201704015,2017TS026)

Characteristics of the Cohesive Sediment on the Sand Dune in the North of Chalhan Salt Lake in Qaidam Basin, China

Li Chao, Dong Zhibao, Chen Guoxiang, Yang Junhuai, Shi Weikang   

  1. School of Geography and Tourism/National Experimental Teaching Demonstration Center of Geography Science, Shaanxi Normal University, Xi'an 710062, China
  • Received:2017-10-01 Revised:2017-11-28 Online:2018-01-20 Published:2018-01-20

摘要: 柴达木盆地察尔汗盐湖周边黏性沉积物被认为是单风向风况条件下线形沙丘和新月形沙丘两类沙丘共存的主要原因。为进一步探究察尔汗盐湖周边沙丘黏性沉积物特征,实地调查采集并测量了察尔汗盐湖北侧新月形沙丘/线形沙丘和丘间地沉积物的粒度特征、盐分含量和纵剖面水分含量变化,以期为明确黏性沉积物对沙丘地貌形成演化影响的研究提供参考。结果表明:丘间地沉积物平均粒径最大约为2.39 Φ,新月形沙丘沉积物(2.41 Φ)略粗于线形沙丘(2.54 Φ)。沉积物以细沙为主(84%),中沙和极细沙含量都很少,丘间地中沙含量略高(18%)。区内沉积物都表现出极好的分选性,线形沙丘沉积物略优于新月形沙丘;丘间地沉积物的可溶性盐含量最高平均约为6.88%,线形沙丘(平均2.78%)明显高于新月形沙丘(平均0.80%);丘间地沉积物水分含量最高,在30 cm深垂直范围内约为1.93%。新月形沙丘沉积物水分含量(平均0.12%)在1 m深垂直范围内明显低于线形沙丘(平均0.55%)。除黏性沉积物(盐、粉沙和黏土)外,沉积物水分含量的空间差异也是引起沙丘形态发生变化的重要环境要素。

关键词: 黏性沉积物, 察尔汗盐湖, 线形沙丘, 新月形沙丘

Abstract: The coexistence of barchan dune and linear dune under unidirectional wind had been thought to be coursed by the difference of cohesive sediment content around the Chalhan Salt Lake in the Qaidam Basin. In order to investigate the characteristics of the cohesive sediment, field investigations had been carried out to explore the particle size characteristics of the sediment, salt content of the dune samples and the moisture content. This study will provide further information for the study of the influence of cohesive sediment on the formation and evolution of dune landforms. The results show that the average particle size of the interdune sediment is the thickest which is approximately 2.39 Φ. Particle size of the barchan dune sediment is a little thicker than the linear dune sediment, but there is no significant difference. In the study area, the main part of the sediment particle size distribution is the fine sand (about 84%), there are fewer content of middle sand and very fine sand, and the content of middle sand in the interdune sediment is slightly higher. All of the sediments show excellent grain sorting, and the linear dune sediment is slightly better than the barchan dune. The salt content of interdune sediment is the highest (about 6.88%). The salt content in the linear dunes is higher than that in the barchan dunes. The moisture content of the interdune sediments is the highest, which is about 1.93% in the deep vertical range of 30 cm. Moisture content in the barchan dune (about 0.12%) is significantly lower than that of the linear dunes (0.55%) in the depth of 1 meters. The spatial difference of sediment water content is also an important environmental factor of dune shape changes besides the cohesive sediment (salt, silt and clay).

Key words: cohesive sediment, Chalhan Salt Lake, linear dune, barchan dune

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