末次盛冰期和全新世大暖期浑善达克沙地边界的变化  

CHANGES OF THE BORDER OF OTINDAG SAND FIELD(NORTHERN CHINA) DURING THE LAST GLACIAL MAXIMUM AND HOLOCENE OPTIMUM

作　　者：周亚利[1] 鹿化煜[2] 张小艳[1] 弋双文[2] 

机构地区：[1]陕西师范大学旅游与环境学院,西安710062 [2]南京大学地理与海洋科学学院地貌过程与环境实验室,南京210093

出　　处：《第四纪研究》2013年第2期228-242,共15页Quaternary Sciences

基　　金：国家自然科学基金项目(批准号:4093010和41030637);全球变化研究国家重大科学研究计划项目(批准号:2010CB950204);中国博士后科学基金项目(批准号:2011M501443和2012T50795);陕西省科技计划项目(批准号:2011JM5014)共同资助

摘　　要：本文在浑善达克沙地选取34个代表性沙丘-砂黄土剖面,利用光释光测年技术确定地层年龄,在野外考察、风沙动力学分析以及气候替代性指标测试的基础上,结合前人的研究,确定了浑善达克沙地在末次盛冰期和全新世大暖期的范围:在末次盛冰期时,流沙南界到达镶黄旗-正镶白旗-正蓝旗-多伦一线,较现代沙地南界偏南约40km,沙地面积扩张约1.39×10~4km^2,扩张了37%;在9~5ka时段的全新世大暖期,沙地普遍发育灰黑色砂质古土壤,植被覆盖良好,沙丘固定,流沙南界向北退缩约200km。末次盛冰期和全新世大暖期浑善达克沙地空间格局的变迁受控于东亚季风强度和有效湿度共同影响。Desert and sand field are results of arid and semi-arid climate in Northern China. Their formation and evolution are mainly controlled by the global climate change, which also lead the changes of desert margins during the Late Quaternary. Previous studies have been controversial ：in the direction and amplitude of desert/sand field borders migrations. In addition, specific location of the borders in the climate extremes is not well understood. Otindag sand field is located in the east of the Inner Mongolia Plateau. It lies between 112° 22＇ - 117° 57＇N and 41° 56＇ 44° 24＇E with a total area of 3.71 × 104kin2. The south margin of sand field can reach northern foot of Yinshan Mountains,as while as the east boundary is at the west edge of Daxing＇anling Mountains. The low hills and ridges distribute in the east-south part of sand field. Shiraz Mulun River connects Otindag and Horqin sand field in Hexigten Banner which lies the east boundary of Otindag sand field. The sand, sandy-loess and sandy-soil sequences from Otindag sand field can be used as indicators to determine changes in the position of the sand field border. In this study,34 representative dune and sandy loess profiles are collected throughout the sand field. The stratigraphy sequences of the selected 34 profiles consist of aeolian dune deposit overlying bright yellow （white） lacustrine sand, red-brown soil sediment and bedrock. The depths of deposits shift from 2m to 10m. Based on the equivalent dose and dose rate,the chronology of aeolian deposition is obtained, which region from 19.36ka to 0. 15ka in. Otindag sand field and its southern edge area. Most of the last glacial sand age are 15 ~ 13ka,while the sandy soil were developed in 9 -5ka period. Combination of particle size, magnetic susceptibility and ignition loss used as the climatic proxies, sand and sandy soil can be confirmed the existence which demonstrate the expansion and narrow of sand field respectively,reflect the climate and boundary changes during the Last Glacial Max

关 键 词：浑善达克沙地 末次盛冰期 全新世大暖期 沙地边界 

分 类 号：P941.73[天文地球—自然地理学] P597.3