基于CMB模型的巴丹吉林沙漠沙源区分析  

Analysis of sand source for Badain Jaran Desert based on CMB model

作　　者：宁凯 王乃昂[3,4] 李卓仑[3,4] 杨振京[1,2] 毕志伟 王奕心[3,4] 王攀[1,2] 孙杰 NING Kai;WANG Naiang;LI Zhuolun;YANG Zhenjing;BI Zhiwei;WANG Yixin;WANG Pan;SUN Jie(Key Laboratory of Quaternary Chronology and Hydro-Environmental Evolution,Chinese Academy of Geological Sciences,Shijiazhuang 050061,Hebei,China;Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,Hebei,China;College of Earth and Environmental Sciences,Lanzhou University,Lanzhou 730000,Gansu,China;Research Center for Glacier and Desert,Lanzhou University,Lanzhou 730000,Gansu,China)

机构地区：[1]中国地质科学院第四纪年代学与水文环境演变重点实验室,河北石家庄050061 [2]中国地质科学院水文地质环境地质研究所,河北石家庄050061 [3]兰州大学资源环境学院,甘肃兰州730000 [4]兰州大学冰川与沙漠研究中心,甘肃兰州730000

出　　处：《干旱区地理》2021年第2期389-399,共11页Arid Land Geography

基　　金：中国地质科学院水文地质环境地质研究所基本科研业务费项目(SK202012);中央高校基本科研业务费项目(lzujbky-2018-it82);国家自然科学基金(41871021)资助。

摘　　要：沙漠因其高反照率、低比热容的下垫面以及粉尘高输出率的特征对全球和区域环境有重要的作用。作为具有高大沙山的第二大流动性沙漠,其物质来源一直是地球科学研究热点。通过对巴丹吉林沙漠及周边地区表层沉积物进行矿物分析,在此基础上对巴丹吉林沙漠的可能物源区进行分析,进一步利用化学质量平衡(CMB)模型探讨了各物源区对巴丹吉林沙漠的贡献率。结果表明:巴丹吉林沙漠的表层沉积物中主要矿物包括相对比较稳定钠长石、钙长石、歪长石、黑云母、斜顽辉石、透辉石、铁辉石、微斜长石、白云母、正长石、石英和榍石以及不具区域代表性的斜绿泥石、石膏、角闪石、方解石、岩盐;主要物源区包括沙漠湖积平原沙、洪积平原沙、现代湖泊沉积物、外源沙和岩石风化壳;其中岩石风化壳和现代湖泊沉积物属于就地起沙,基本只影响其周边区域,来自沙漠北部的冲洪积沙和来自沙漠西北的外源沙是沙漠的主要物源。这与中国东部沙漠以湖泊沉积就地起沙有明显不同,可能和沙漠的发育过程、地质历史时期湖泊退缩规模和气候环境状况有关。Desert ecosystems play an important role in global and regional environments due to their high albedo,low specific heat capacity,and high dust output.As the second largest mobile desert in China,the source of sediment in the Badain Jaran Desert has always been a subject of interest in earth science research.In this paper,the composition of surface sediments collected from the Badain Jaran Desert and surrounding areas were analyzed to identify their provenance,and the chemical mass balance model was used to estimate the contribution rates of source or sources.The results show that the main minerals in the surface sediments of the Badain Jaran Desert include relatively stable albite,albite,anorthite,anorthoclase,biotite,clinoenstatite,enstatite,microcline,muscovite,orthoclase,quartz,titanite,and non-regionally representative clinochlore,gypsum,hornblende,calcite,and halite,and the main provenances include desert lacustrine plain sands,alluvial plain sands,modern lake sediments,exogenous sands,and weathered rock crusts.The weathered rock crusts and modern lake sediments belong to in situ sanding and thus only affects the surrounding area.Alluvial sand from north of the desert and exogenous sand from the northwest are the main sources of the Badain Jaran Desert sands.These are very different from the desert sediments in the eastern parts of China which are attributed to lake sedimentation and may be related to the evolution of the desert,the scale of retreat of lakes in the region throughout geological history,and the climate and environmental conditions.

关 键 词：矿物 风成沙 CMB模型 物源分析 巴丹吉林沙漠 

分 类 号：P931.3[天文地球—自然地理学]