【作者】 谢静； 吴福元； 丁仲礼；

【Author】 XIE Jing,WU FuYuan and DING ZhongLi 1.Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China 2.Graduate University of Chinese Academy of Sciences,Beijing 100049,China

【机构】 中国科学院地质与地球物理研究所； 中国科学院研究生院；

【摘要】 通过对浑善达克沙地末次冰盛期（LGM）以来沙样的碎屑锆石原位U-Pb年龄和Hf同位素组成的分析,并与周围可能源区的岩石年龄和Hf同位素组成进行对比,发现浑善达克沙样的U-Pb年龄主要可以分为3组（2.6～2.3Ga,2.2～1.6Ga和显生宙100～500Ma）。其中较老的两组和具有负ε_Hf（T）值的显生宙锆石可能来源于华北克拉通北部的燕山褶皱带,而具有正ε_Hf（T）值的显生宙锆石可能来源于中亚造山带东部。现代沙和LGM沙具有相同的锆石U-Pb年龄谱和ε_Hf（T）组成特征。同时,与蒙古中南部和塔里木中部沙样进行对比,发现蒙古中南部沙样主要来源于中亚造山带的显生宙高山,而塔克拉玛干沙漠在锆石U-Pb年龄和Hf同位素组成上与浑善达克沙地存在较大的差异,表明西部的大沙漠对东部沙地的贡献很小。更多还原

【Abstract】 Detrital zircon compositions of in-situ U-Pb ages and Hf isotope were measured for sand samples since the Last Glacial Maxim（LGM） from the Hunshandake sandland,and compared with surrounding potential source areas.We found that U-Pb age spectra of samples from the Hunshandake sandland can be mainly divided into three groups（2.6～2.3Ga,2.2～1.6Ga and Phanerozoic age 100～500Ma）.The older two groups and some Phanerozoic zircons with negativeε_Hf（T） values maybe were derived from the Yanshan Fold Belt in the northern part of the North China Craton,and other Phanerozoic zircons with positiveε_Hf（T） values may originated from the eastern part of the Central Asian Orogenic Belt.The present sands have the similar composition characteristics of zircon U-Pb age spectra andε_Hf（T） values with the LGM sands.Meanwhile,comparing with the sand samples from central-southern Mongolia and central Tarim,we found that the sand samples of central-southern Mongolia mainly come from Phanerozoic high mountains of the Central Asian Orogenic Belt,however,much difference of zircon U-Pb ages and Hf isotopes occurs between the samples of the Hunshandake and Taklimakan deserts,indicating that the material of the western large desert contributes little to the eastern sandland.更多还原