新疆伊吾地区晚石炭世石英闪长岩LA-ICP-MS锆石U-Pb年龄及其地质意义  

LA-ICP-MS zircon U-Pb age of Late Carboniferous quartz diorite in Yiwu area of Xinjiang and its geological significance

作　　者：马俊强 杨峻[3] 张凯 潘杨辉[3] 程柏林 杨晓君 MA Junqiang;YANG Jun;ZHANG Kai;PAN Yanghui;CHENG Bolin;YANG Xiaojun(College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,Sichuan China;Sichuan Chuan He Geology Engineering,Chengdu 610052,Sichuan,China;Sichuan Institute of Nuclear Geology,Chengdu 610052,Sichuan,China)

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]四川川核地质工程有限公司,四川成都610052 [3]四川省核工业地质调查院,四川成都610052

出　　处：《地质通报》2019年第10期1637-1646,共10页Geological Bulletin of China

基　　金：新疆自治区中央返还两权价款基金项目《新疆伊吾县1∶5万K46E003022、K46E003023、K46E003024三幅区域地质矿产调查》(编号:T15-1-LQ06)

摘　　要：新疆伊吾地区晚石炭世侵入岩产于天山-兴蒙造山系谢米斯台-库兰卡兹干古生代复合岛弧带的东段。用LA-ICP-MS技术测得伊吾地区石英闪长岩中锆石206Pb/238U年龄为312.4±1.5Ma(MSWD=0.18,n=30),属晚石炭世。岩石化学资料表明,伊吾地区晚石炭世侵入岩为准铝质高钾钙碱性岩系,轻稀土元素富集,重稀土元素平坦,具中等程度的负Eu异常。微量元素中富集轻稀土元素及Ba、Th等大离子亲石元素,而相对亏损Nb、Ti、P元素,P元素较强亏损可能与磷灰石分离结晶作用有关,元素地球化学组成指示其与大陆地壳物质具有明显的亲缘性;以上资料揭示,伊吾地区在晚石炭世已经处于后碰撞构造环境。The Late Carboniferous intrusions in Yiwu region of Xinjiang were produced in the eastern section of Tianshan-Xingmeng orogenic belt.LA-ICP-MS technological analysis shows that the quartz diorite zircon 206Pb/238U age of the study area is 312.4±1.5Ma(MSWD=0.18,n=30),suggesting Late Carboniferous epoch.The petrochemical data show that the late Carboniferous intrusive rocks in Yiwu region belong to aluminum alkaline rock series characterized by LREE enrichment and HREE flat type,with moderate Eu negative anomaly.Trace elements in rocks are characterized by enrichment of light rare earth elements and large ion lithophile elements such as Ba and Th,and the relative loss of Nb,Ti and P;strong P element loss may be associated with apatite crystallization separation.These elements and the continental crust material have an obvious affinity.These data reveal that the Yiwu region was in a post-collision tectonic environment in the Late Carboniferous.

关 键 词：伊吾地区 晚石炭世 石英闪长岩 LA-ICP-MS 锆石U-PB年龄 岩石地球化学 

分 类 号：P534.45[天文地球—古生物学与地层学] P597.3[天文地球—地质学]