浙江舟山群岛首次发现二叠纪变质岩  

The first discovery of Permian metamorphic rocks in Zhoushan Islands,Zhejiang Province

作　　者：姜杨[1] 邢光福[1] 袁强 赵希林[1] 段政[1] 董学发 

机构地区：[1]中国地质调查局南京地质调查中心,江苏南京210016 [2]浙江地质调查院,浙江杭州311203

出　　处：《地质通报》2016年第7期1046-1055,共10页Geological Bulletin of China

基　　金：中国地质调查局项目(编号:DD20160037;12120113070800;12120114005801)

摘　　要：浙江舟山群岛大衢岛及周边若干小岛出露少量变质岩系,包括斜长角闪岩、片麻岩、片岩、大理岩等,以往被归为陈蔡岩群。LAICP-MS锆石U-Pb测年结果表明,黑云斜长片麻岩变质新生锆石或岩浆锆石的变质边年龄在260~270Ma之间,大理岩的变质年龄为261.1±1.3Ma,侵入变质岩的未变形伟晶岩脉年龄为258.0±1.6Ma,表明该套变质岩系的变质时代约为260Ma,不能归入加里东期变质的陈蔡岩群。这是在华南东北缘地区首次发现二叠纪变质岩,为探讨华南东吴运动和全球海西运动,甚至泛大陆的重建提供了重要新信息。Abstrace：There are some metaphoric rocks such as amphibolite, genesis, schist and marble exposed in Daqu Island of Zhoushan Is-lands, Zhejiang Province. In the past, they are assigned to Chencai Formation. Nevertheless, new LA-ICP-MS zircon U-Pb analysis yielded the ages of metamorphic neogenic zircon and metamorphic rim in biotite-plagioclase gneiss ranging from 260Ma to 270Ma, whereas the metamorphic age of marble and the formation age of undeformed pegmatite veins which intruded into metamorphic rocks are 261.1 ± 1.3Ma and 258.0 ± 1.6Ma respectively, indicating that the metamorphic age of the rocks in Daqu Island is^260Ma. This is the first reported Permian metamorphic rock on the northeastern margin of South China Block, which may provide some im-portant new information for Dongwu movement in South China, global Hercynian movement and even the Pangaea reconstruction.

关 键 词：变质岩 二叠纪 LA-ICP-MS锆石U-PB年龄 舟山群岛 

分 类 号：P534.46[天文地球—古生物学与地层学] P588.3[天文地球—地质学]