察尔汗盐湖北侧沙丘沉积物颗粒微结构特征  

Surface Texture of Quartz Grains from Dune Sediments of Northern Qarhan Salt Lake of China

作　　者：陈国祥 董治宝 李超 肖巍强 杨军怀 石唯康 张岳敏 Chen Guoxiang;Dong Zhibao;Li Chao;Xiao Weiqiang;Yang Junhuai;Shi Weikang;Zhang Yuemin(School of Geography and Tourism/National Experimental Teaching Demonstration Center of Geography Science,Shaanxi Normal University,Xi＇an 710062,China)

机构地区：[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

出　　处：《中国沙漠》2018年第5期954-962,共9页Journal of Desert Research

基　　金：国家自然科学基金项目(41401310);中央高校基本科研业务费专项(GK201604011)

摘　　要：利用扫描电镜对比分析了柴达木盆地察尔汗盐湖北侧线形沙丘和新月形沙丘沉积物颗粒的表面显微特征。结果表明:柴达木盆地察尔汗盐湖北侧线形沙丘和新月形沙丘沉积物石英颗粒表面具有明显的风成特征。颗粒以次棱角状为主,普遍发育典型的碟形撞击坑、麻坑和新月形撞击坑;察尔汗盐湖北侧沙丘沉积物以物理分解和机械搬运作用为主,化学风化作用较低,反映了当时干旱炎热的沉积环境;贝壳状断口、平行擦痕及V形坑的存在表明柴达木盆地沙丘沉积物前期曾受到冰川或流水的作用,推断出柴达木盆地周围高山的剥蚀产物或察尔汗盐湖的湖相沉积物可能是察尔汗盐湖北侧沙丘沉积物的来源之一。Surface texture characteristic of quartz grains from linear dunes and barchan dunes in northern Qarhan Salt Lake of Qaidam Basin was compared and analyzed by scanning electron microscopy （SEM）. The results show that the quartz grains from linear dunes and barchan dunes in northern Qarhan Salt Lake of Qaidam Basin are mainly sub-angular shape, and massively developed dish-shaped impact scars, crescent-shaped impact scars, which suggests typical features of aeolian environment. The sediments in northern Qarhan Salt Lake are dominated by physical decomposition and mechanical action while the chemical weathering plays a small role, which reflects the arid and hot sedimentary environment at that time. The existence of conchoidal breakages, parallel striations and V-shaped pits indicate that the sedi- ments in the Qaidam Basin have been subjected to glaciation or flowing water. It can be inferred that the erosion products from the mountains around the Qaidam Basin or sediments from Qarhan Salt Lake may be one of the sources of dune sediments in northern Qarhan Salt Lake.

关 键 词：表面微结构 线形沙丘 新月形沙丘 沉积物 柴达木盆地 

分 类 号：P931.3[天文地球—自然地理学]