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干旱区地理 ›› 2014, Vol. 37 ›› Issue (5): 892-900.

• 地表过程研究 • 上一篇    下一篇

巴丹吉林沙漠东南部末次间冰期环境演变:来自粒度、光释光(OSL)及14C测年的证据

范小露1,田明中1,刘斯文2   

  1. 1    中国地质大学(北京)地球科学与资源学院, 北京    100083;    2    国家地质实验测试中心, 北京    100037
  • 收稿日期:2013-10-10 修回日期:2014-01-21 出版日期:2014-09-25
  • 通讯作者: 刘斯文. Email:siwenzliu@126.com
  • 作者简介:范小露(1987-),女,博士研究生,第四纪地质学专业,主要从事第四纪地质环境及旅游地学研究. Email:atsunnyshore@126.com
  • 基金资助:

    国家地质实验测试中心,基本科研业务费项目(2013CSJ02)

Environmental change of southeastern Badain Jaran Desert during the last interglacial: evidences from the grain-size analysis,optically stimulated luminescence and radiocarbon dating

FAN Xiao-lu1,TIAN Ming-zhong1,LIU Si-wen2   

  1. 1   School of Earth Science and Resource, China University of Geosciences, Beijing  100083, China;2   National Research Center of Geoanalysis, Beijing  100037, China
  • Received:2013-10-10 Revised:2014-01-21 Online:2014-09-25

摘要: 巴丹吉林沙漠是中国第三大沙漠,分布着数百个大大小小的湖泊。为了探明巴丹吉林沙漠东南缘的古气候环境变迁,选取代表性的巴润宝日陶勒盖沉积露头作为研究对象,结合现代湖泊岩芯,采用C-M图、粒度频率曲线、粒度频率累计曲线、粒度参数和粒度组成等粒度特征分析方法,并结合光释光和14C年代数据,对巴丹吉林沙漠东南缘的巴润宝日陶勒盖剖面进行了研究。结果表明:粒度特征能够很好的反映研究区古环境的变化。分析表明,巴润宝日陶勒盖剖面为湖泊沉积物,其露头可能是巴润宝日陶勒盖湖泊连续发育的大湖泊的一个滨湖高地或者湖心岛;末次间冰期巴丹吉林沙漠发育有规模大于今天的湖泊,并且经历了MIS 5a和5c的暖期和MIS 5b的冷期,与末次间冰期西北地区的研究成果对比,结果是一致的;粒度频率曲线和粒度频率累计曲线的特征表明,BRGH剖面沉积物很可能就是沙漠的基底,这对于理解沙漠的形成时代和机理具有重要的意义。

关键词: 末次间冰期, 古气候环境, 粒度特征, 巴润宝日陶勒盖, 巴丹吉林沙漠

Abstract: Badain Jaran Desert is the third largest desert of China and also is the only desert in which megadunes distribute densely. The desert also develops hundreds of large and small lakes. The paleoclimatic and paleoenvironmental researches on the lake sediments are of significance for the further study on the formation mechanism of Badain Jaran Desert,etc. As the research object in this paper,Barunbaoritaolegai profile is the relatively typical one amomg these sedimentary outcrops which are located in the southeast of the Badain Jaran Desert. In previous studies,researchers had presumed the age of the sediment to the early Pleistocene. However,the detailed research on sedimentary outcrop has not been done. To ascertain paleoenvironmental evolution of southeast edge of the Badain Jaran Desert,this paper selects the representative Barunbaoritaolegai outcrop deposits as the research object. By combining modern lakes core and using the analysis methods of C-M figure,the frequency curve,the cumulative frequency curve,grain-size parameter,grain composition,and combing the results of OSL and 14C dating data,the authors carry out research on the Barunbaoritaolegai profile. Results show that combined with chronological data,the grain-size characteristics can reflect the change of the ancient environment in the study area well. According to the graph of the ages and grain-size parameters of Barunbaoritaolegai,the paleoenvironmental evolution which is reco- rded by the profile can be divided into three stages: the stage of the warm and wet climate during 106~93.65 ka BP,the stage of the dry and cold climate during 93.65~87.93 ka BP and the stage of the warm and wet climate during 87.93~81.98 ka BP. The comparative analysis of the C-M graph between Barunbaoritaolegai profile and modern lakes core indicates that the Barunbaoritaolegai profile belongs to the lacustrine deposit. The Barunbaoritaolegai outcrop is most probably a lakeside highland or an island in a lake which came from the continuous development of Barunbaoritaolegai lake. In addition,the analysis result indicates that the Badain Jaran Desert had developed lakes which are larger than today's during the last interglacial period,that the lake had experienced the warm periods of MIS 5a and 5c and cold period of MIS 5b,and that the results are consistent with those of the northwestern region in the last interglacial northwest. Furthermore,by the analysis on the characteristics of frequency curve and cumulative frequency curve,the authors find a breakthrough clue,that is the Barunbaoritaolegai profile deposits are likely to be the basement of the desert,which is of great importance for investigating the age and the formation mechanism of Badain Jaran Desert.

Key words: the last interglacial period, paleoclimate environment, characteristics of grain-size, Barunbaoritaolegai, Badain Jaran Desert

中图分类号: 

  • P532