巴丹吉林沙漠湖相沉积的探地雷达图像及光释光年代学证据  

Ground Penetrating Radar Images and Optically Stimulated Luminescence Dating for Lacustrine Deposition of the Badain Jaran Desert

作　　者：白旸[1] 王乃昂[1] 何瑞霞[2] 李景满[1] 赖忠平[3] 

机构地区：[1]兰州大学资源环境学院/干旱区水循环与水资源研究中心,甘肃兰州730000 [2]中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室,甘肃兰州730000 [3]中国科学院青海盐湖研究所盐湖资源与化学重点实验室,青海西宁810008

出　　处：《中国沙漠》2011年第4期842-847,共6页Journal of Desert Research

基　　金：国家自然科学基金项目(50879033;41001116);高等学校博士点专项基金项目(20090211110025);兰州大学中央高校基本科研业务费专项资金项目(lzujbky-2010-221);冻土工程国家重点实验室自主研究项目(YOSF106001)共同资助

摘　　要：应用探地雷达对巴丹吉林沙漠南部高大沙丘下伏地层进行了探测,在探地雷达剖面沿线采集湖相沉积样品进行光释光测年。对探地雷达数据进行了处理与图像解译,探地雷达反射波与沉积相有相关关系,根据探地雷达数据与沉积信息重建沙丘下伏结构与沉积环境。研究发现,巴丹吉林沙漠南部该测区下伏地形平坦,流沙覆盖区的风成沙是覆盖在古湖相沉积层之上的。样品光释光测年结果反映,在MIS 5e阶段和MIS3阶段,巴丹吉林沙漠南部存在大湖期或高湖面,之后湖相沉积物或钙质胶结层与风成沙因不同的干湿环境而交替叠积;局部流沙覆盖区甚至在距今7ka前后还存在有浅湖-沼泽环境。质言之,在巴丹吉林沙漠高大沙丘的形成过程中,气候的多次波动是主要因素之一。This paper presents underlying stratifications under the dunes in the south of the Badain Jaran Desert using ground-penetrating radar（GPR）.The GPR data was processed and analyzed.Dune structures,sedimentary environment and geomorphological evolution were reconstructed by GPR data and sedimentological data.Field survey result and GPR images showed that the underlying topography was found to be underlain by platform topography in the southeast of the Badain Jaran Desert,and aeolian sand most covered on ancient lacustrine deposit layers.The GPR profile and optically stimulated luminescence（OSL） dating results represented that in the stages of MIS 5e and MIS 3,there existed last great lake periods or high lake levels in south desert,and then lacustrine deposit or calcareous cementation layers alternately deposited with aeolian sand,and shallow lakes and swamps even existed around 7 ka in parts of the study area covered by drifting sands.Consequently,the multiplex geomorphology in the Badain Jaran Desert is the result of global climatic undulation,which is not the only factor to the mega-dunes.

关 键 词：下伏地层 湖相沉积 探地雷达 光释光测年 巴丹吉林沙漠 气候波动 

分 类 号：P539.4[天文地球—古生物学与地层学]