华南双桥山群和河上镇群凝灰岩中的锆石SHRIMP U-Pb年龄--对江南新元古代造山带演化的制约  

SHRIMP U-Pb zircon dating of tuff in the Shuangqiaoshan and Heshangzhen groups in South China——constraints on the evolution of the Jiangnan Neoproterozoic orogenic belt

作　　者：高林志[1] 杨明桂[2] 丁孝忠[1] 刘燕学[1] 刘训[1] 凌联海[3] 张传恒[4] 

机构地区：[1]中国地质科学院地质研究所,北京100037 [2]江西省地质矿产勘查开发局,江西南昌330002 [3]江西省地质调查研究院,江西南昌330201 [4]中国地质大学(北京),北京100083

出　　处：《地质通报》2008年第10期1744-1751,共8页Geological Bulletin of China

基　　金：中国地质调查局项目(编号:1212010611508);科技部基础专项(编号:2006FY120300-1)联合资助

摘　　要：通过西澳科庭大学离子探针中心的远程测试,在双桥山群横涌组和安乐林组斑脱岩中获得大量锆石,其SHRIMP U-Pb加权平均年龄为831Ma±5Ma(横涌组)、829Ma±5Ma(安乐林组),在河上镇群上墅组中获得加权平均年龄767Ma±5Ma。锆石SHRIMP U-Pb年龄表明华南地区广为发育的双桥山群应归入新元古界,该年龄为标定双桥山群在地层柱中的位置提供了准确的年代学依据。A large number of zircons were obtained from three samples of bentonite in the Hengyong and Anleling formations of the Shuanqishan Group and Heshangzhen Group. They yielded weighted mean ^206Pb/^238U ages of 831 ± 5 Ma for the Hengyong Formation, 829 ± 5 Ma for the Anleling Formation and 767 ± 5 Ma for the Shangshu Formation of the Heshangzhen Group by the sensitive high-resolution ion microprobe at the SHRIMP center, Curtin University, Western Australia. These ages show that the widespread Shuangqiaoshan and Heshangzhen groups should be assigned to the Neoproterozoic and provide an accurate chronostratigraphic evidence for the determination of the location of the Shuanqishan Group in the stratigraphic column.

关 键 词：华南 双桥山群 锆石SHRIMP U-PB年龄 新元古代 

分 类 号：P534.3[天文地球—古生物学与地层学] P597-3[天文地球—地质学]