河西走廊及其毗邻地区地表物沉积元素特征  

Elemental Compositions of Surface Deposits in Hexi Corridor and Its Adjacent Areas, Northwestern China

作　　者：王立强 王亲[2] 

机构地区：[1]广东省地质局719地质大队,广东肇庆526000 [2]兰州大学西部环境教育部重点实验室,甘肃兰州730000

出　　处：《西北地质》2013年第2期69-80,共12页Northwestern Geology

基　　金：国家自然科学基金项目(批注号:40721061;40671192);教育部"新世纪优秀人才支持计划";"111计划"

摘　　要：笔者分析了河西走廊及其毗邻地区的戈壁(石漠)、河流平原(石羊河与黑河流域)、沙漠(腾格里和巴丹吉林)以及祁连山北麓等地表沉积物的元素组成,并对研究区不同地表类型沉积物和洛川黄土的元素组成进行对比。结果表明:研究区不同地表类型松散堆积物之间地球化学特征具有较好的一致性,可能来自于祁连山的高山作用过程,即从祁连山至沉积尾闾的物质搬运导致研究区物源趋于一致;洛川黄土和研究区微量元素以及特征元素配分模式吻合较为良好,暗示了黄土高原的粉尘物质源区可能主要为河西走廊及其毗邻地区的戈壁、河流平原以及沙漠;细粒物质在祁连山向河西走廊的搬运过程中,物质经过一定程度的风力和水力分选,造成粗颗粒物质富集。因此,戈壁、河流平原和沙漠地表细粒物质风化指数较祁连山坡麓沉积物偏低。其中,腾格里和巴丹吉林沙漠又经受风力作用,中值粒径最大、风化指数最低。Elemental compositions of surface deposits, collected from the gobi （rock desert）, river plain （alluvium of Shiyang River and Heihe River）, desert （Tengger and Badain Jaran） and northern piedmont of Qilian Mountains in the Hexi Corridor and its adjacent areas, were analyzed. Meanwhile, elemental composition between the Luochuan loess and the different types of surface sediments in the study region were also compared. The results showed that geochemical features of incompact deposits among different types of surface in the researched area, which may come from the altiplanation of Qilian Mountains, are aligned fairly well. Namely, it was the process of material transportaion from Qilian Mountains to sediment coccyx that caused the provenance consistency in the study area. The distribution patterns of trace element and feature element in the Hexi Corridor and its adjacent areas are in good agreement with that of Luochuan loess, implying that gobi, river plain （alluvial fan） and desert in the study area are likely to be the dust sources of loess deposits on the Loess Plateau. In the course of moving from Qilian Mountains to the Hexi Corridor, detrital particles are enriched with coarsegrained components, due to a certain degree of sorting by hydrological and windy agents. As a result, weathering indices of surface deposits in the Hexi piedmont of Qilian Mountains. Because of the stronger wind desert , the median particle diameter of dune sand there is lowest indices of chemical weathering. Corridor are lower than that in the erosion in Tengger and Badain Jaran the coarsest , which results in the

关 键 词：河西走廊 粉尘源区 高山作用过程 元素配分 

分 类 号：P66[天文地球—地质学]