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中国沙漠 ›› 2014, Vol. 34 ›› Issue (5): 1194-1199.DOI: 10.7522/j.issn.1000-694X.2013.00364

• 沙漠与沙漠化 • 上一篇    下一篇

库姆塔格沙漠东部复杂地貌地表沉积物化学元素组成初步研究

柳本立1, 屈建军1, 杨根生1, 牛清河1, 安志山1, 高艳红2   

  1. 1. 中国科学院寒区旱区环境与工程研究所 沙漠与沙漠化重点实验室/敦煌戈壁荒漠生态与环境研究站, 甘肃 兰州 730000;
    2. 中国科学院寒区旱区环境与工程研究所 寒旱区陆面过程与气候变化重点实验室, 甘肃 兰州 730000
  • 收稿日期:2013-08-26 修回日期:2013-11-12 出版日期:2014-09-20 发布日期:2014-09-20
  • 作者简介:柳本立(1986-),男,河南漯河人,助理研究员,主要从事风沙地貌和风沙工程研究。Email:liubenli@lzb.ac.cn
  • 基金资助:
    国家自然科学基金项目(41201003);中国科学院寒旱区陆面过程与气候变化重点实验室开放基金项目(LPCC201301);中国科学院寒区旱区环境与工程研究所青年基金项目资助

Preliminary Study on the Geochemical Features of Sediments from Different Geomorphic Units of the Eastern Kumtagh Desert

Liu Benli1, Qu Jianjun1, Yang Gensheng1, Niu Qinghe1, An Zhishan1, Gao Yanhong2   

  1. 1. Key Laboratory of Desert and Desertification/Dunhuang Gobi and Desert Ecology and Environment Research Station, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China;
    2. Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2013-08-26 Revised:2013-11-12 Online:2014-09-20 Published:2014-09-20

摘要: 通过对库姆塔格沙漠东部的沙漠、戈壁、绿洲、湿地、干河床等地貌单元地表沉积物化学元素的分析,研究了不同类型沉积物常量、微量元素的UCC标准值、Ba-Sr含量比值、化学蚀变指数等特征。结果表明:各类型沉积物的元素特征差异显著,但都处于低等风化阶段。库姆塔格沙漠东北端的平沙地、灌丛沙地与北侧戈壁地表沉积物元素特征相近,物源是北山;沙漠东缘沙物质有相近的主元素含量和Ba-Sr含量比值,化学风化特征和Fe、Mg含量自北向南呈现渐变趋势,表明受到偏北风的搬运混合作用,其可能的物源包括南部阿尔金山洪冲积物、东侧的干河床和戈壁。沙漠与敦煌绿洲间的戈壁地带化学风化微弱,区域差异不明显,但不同部位沙物质的元素含量有近源性。鸣沙山西侧的沙物质元素不同于库姆塔格沙漠,而与之相近的党河漫滩相近,因此其最有可能的物源是党河。

关键词: 库姆塔格沙漠, 化学元素, 风化, 物质来源

Abstract: A geochemical study was conducted on the sediments from the east Kumtagh Desert and its nearby geomorphic units, including desert, gobi, oasis, wetland, wadi, et al. The contents of major and trace elements were compared with the upper continental crust's average value (UCC), and the Ba-Sr ratio and chemical index of alteration (CIA) of each sample were analyzed. Preliminary results show a weak weathering level for all the samples, despite the significant differences among the sediments from different environments. The sediments from sandy land and vegetated land at the northeast corner of the Kumtagh Desert share similar geochemical features, indicating a same source-area of the North Mountain. Sands at the east of the desert have similar element components and Ba-Sr ratio and the chemical characteristics change gradually from north to south, indicating an aeolian mixture effect by the north winds. Potential sources of the desert sands include the alluvial deposits from the south Altyn Tagh Mountain, the gobi area to the east, and the wadis. The gobi area between the desert and the Dunhuang Oasis suffers from weak weathering, whereas chemical features of sediments at various locations are similar to their nearby potential source areas. Sand elements at the west Mingsha Megadune differ from the Kumtagn Desert clearly but are alike to the deposits in the Danghe River, thus the Danghe River is the most likely provenance of the Mingsha Megadune.

Key words: Kumtagh Desert, geochemical elements, weathering, material source

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