Dating for Jifanggou metamorphic complex in central Jilin and its tectonic implications  

作　　者：WANG Zhongcheng LU Xiaoping ZHAO Juan TAO Junyu CHEN Mingjian 

机构地区：[1]The First Geological Survey of Jilin Province, Changchun 130033, China [2]Regional Geology and Mineral Resources Survey of Jilin Province, Changchun 130022, China [3]Nuclear Industry Geological Bureau of Jilin Province, Changchun 130062, China

出　　处：《Global Geology》2017年第4期200-207,共8页世界地质（英文版）

基　　金：Supported by projects of China Geological Survey(Nos.DD20160049,12120114029101)

摘　　要：Based on the results of four regional geological surveys of 1: 50000 including Shulan County map in Jilin,taking Shulan area as the study area,the authors re-delineated the rock type assemblages,e.g. metamorphic rhyolite,metamorphic tuffaceous breccia lava,sericite-quartz schist and tremolite altered rock,etc.,and the structural contacts between them. With the help of in-situ LA-ICP-MS U-Pb dating for zircons,it is concluded that the zircon crystallization ages of the metamorphic rhyolite,the metamorphic andesitic tuff breccia lava and the tremolite altered rock are 339. 1 ± 1. 3 Ma( n = 27,MSWD = 0. 78),351. 8 ± 1. 7 Ma( n = 21,MSWD = 0.82),and 362.0±1.8 Ma( n = 43,MSWD = 2.2) respectively. The metamorphic complex is actually a set of tectonic melange which comprises the rocks in different types,sources,times,or tectonic settings,and was formed by tectonism.Based on the results of four regional geological surveys of 1: 50000 including Shulan County map in Jilin,taking Shulan area as the study area,the authors re-delineated the rock type assemblages,e.g. metamorphic rhyolite,metamorphic tuffaceous breccia lava,sericite-quartz schist and tremolite altered rock,etc.,and the structural contacts between them. With the help of in-situ LA-ICP-MS U-Pb dating for zircons,it is concluded that the zircon crystallization ages of the metamorphic rhyolite,the metamorphic andesitic tuff breccia lava and the tremolite altered rock are 339. 1 ± 1. 3 Ma( n = 27,MSWD = 0. 78),351. 8 ± 1. 7 Ma( n = 21,MSWD = 0.82),and 362.0±1.8 Ma( n = 43,MSWD = 2.2) respectively. The metamorphic complex is actually a set of tectonic melange which comprises the rocks in different types,sources,times,or tectonic settings,and was formed by tectonism.

关 键 词：CENTRAL Jilin Jifanggou METAMORPHIC complex ZIRCON LA-ICP-MS U-PB age tectonic MELANGE 

分 类 号：P588.3[天文地球—岩石学] P597.3[天文地球—地质学]