西藏打加错地区念青唐古拉岩群形成构造环境及锆石U-Pb年龄研究  

The structural formation environment and zircon U-Pb chronology of the Nyainqentanglha group in Daggyai,Tibet

作　　者：李生宝 火登三 蔡国华 火久伟 邵小鹏[1] LI Sheng-bao;HUO Deng-san;CAI Guo-hua;HUO Jiu-wei;SHAO Xiao-peng(Third Institute Geologioal and Mineral Exploration of Gansy Provincial Bureau of Geology and Mineral Resources,Lanzhou 730050)

机构地区：[1]甘肃省地矿局第三地质矿产勘查院

出　　处：《矿产勘查》2019年第6期1296-1303,共8页Mineral Exploration

基　　金：中国地质调查局项目(编号:12120113034400)资助

摘　　要：本次在西藏打加错地区发现一套变质程度很高的变质杂岩系,作者拟在详细的野外工作基础上,对该套变质岩进行岩相学、地球化学研究以及SHRIMP锆石U-Pb同位素定年,确定该变质岩为念青唐古拉岩群。同时推断念青唐古拉岩群的形成于大陆边缘火山弧-大洋弧沉积环境,厘定念青唐古拉岩群形成时代为中-新元古代,进而揭示念青唐古拉岩群形成的地质背景和成岩环境。念青唐古拉岩群在该区域的首次发现,推进了前寒武纪古老结晶基底在隆格尔-南木林地区西进的历程,揭开了前寒武系在该区神秘的面纱,具有里程碑意义。A set of metaphorical complex with high degree of metamorphism was found in Dajiacuo region of Tibet.On the basis of detailed field work,the authors intend to study the petrology,geochemistry and U-Pb isotopic dating of SHRIMP zircon,and determine that the metasomatic rock is Nianqing Tanggula rock group.At the same time,it is inferred that the Nianqing Tanggula rock group was formed in the volcanic arc-oceanic arc sedimentary environment on the continental margin,and the formation age of the Nianqing Tanggula rock group was determined to be Middle-Neoproterozoic,and then the geological background and diagenetic environment of the Nianqing Tanggula rock group were revealed.The first discovery of Qingtang Gula Group in this area promoted the westward progress of Precambrian ancient crystallization basement in Longger-Namulin area,and opened the mysterious veil of Precambrian in this area,which is of milestone significance.

关 键 词：西藏 打加错 念青唐古拉岩群 SHRIMP锆石年龄 前寒武基底 

分 类 号：P597[天文地球—地球化学]