摘要
地球化学元素不仅反映地球表层沉积物的组成特征,并在分析物源、沉积过程及重建古环境等方面有积极意义。通过野外采样、室内实验,对巴丹吉林沙漠伊和吉格德湖、巴丹湖高大沙山区沉积物地球化学特征进行了分析。结果表明:沙山沉积物元素组成特征和含量略有区域差异;与上部陆壳平均化学组成(UCC)相比,常量元素中仅Si富集,其余均亏损;趋向迎风坡上部剖面,Si、K富集程度相对增加,其他常量元素(除Na)亏损程度增加。常量元素间的关系表明SiO_2影响沙山沉积物的地球化学组成及性质;迎风坡底部剖面沉积物呈现出多源性特征,可能是不同外力作用的结果。两湖区沙山的沙源属局部范围混合的结果,就近供应;干旱气候下沙山沉积物缺少较高等化学风化产生的条件,基本处在大陆风化早期阶段的初期。
Geochemical elements not only reflect the composition characteristics of the earth's surface sediments,but also have positive significance in analysis of material source,sedimentary process,and reconstruction of paleo-environment.Through field investigation and laboratory experiment,this article analyzed the geochemical characteristics of sediments for mega-dunes in Yihejigede Lake and Badain Lake areas of Badain Jaran sand sea.The results showed that the sediment of mega-dunes had the similar composition characteristics and slightly regional differences in element content;Compared with UCC,only Si was enriched for major elements,others was loss;Trending to the upper section in the windward of mega-dune,the relative degree of enrichment for Si and K increased,but the degree of loss for other major element except Na increased;Relationship among major elements demonstrated that SiO_2 played an important role in geochemical composition and properties for mega-dunes;Sediments in the bottom section of windward slope presented a characteristic of multiple material source,this may be affected by different exogenic action,meanwhile,the material source for the mega-dunes in the two lakes areas belonged to local supply as a result of mixture in local scope;The condition of drought climate make it impossible for sediment to get an advanced chemical weathering process,and they stayed in the initial stage of the early stage of continental weathering.
出处
《中国沙漠》
CSCD
北大核心
2017年第1期17-25,共9页
Journal of Desert Research
基金
国家科技支撑计划农村领域科技基础性工作专项(2012BAD16B0303)
中央高校基本科研业务费专项(GK201604011)
国家林业公益性行业科研专项(201304325)
关键词
地球化学元素
化学风化
高大沙山
巴丹吉林沙漠
geochemical elements
chemical weathering
mega-dunes
Badain Jaran Sand Sea
