内蒙古温都尔庙地区白音诺尔一带变质基性火山岩年代学和地球化学研究  

Chronology and geochemistry of meta-basic volcanics of Baiyinnuoer region in Wenduermiao area,Inner Mongolia

作　　者：李尚启 陈跃军[2] 韩仁道[3] 李森林[1] 石强[1] 吴国学[1] LI Shang-qi CHEN Yue-jun HAN Ren-dao LI Sen-lin SHI Qiang WU Guo-xue(College of Earth Sciences, Jilin University, Changchun 130061, China Research Center of Paleontology ＆ Stratigraphy, Jilin University, Changchun 130026, China No.3 Bureau of China Metallurgical Geology Bureau, Taiyuan 030000, China)

机构地区：[1]吉林大学地球科学学院,长春130061 [2]吉林大学古生物学与地层学研究中心,长春130026 [3]中国冶金地质总局三局,太原030000

出　　处：《世界地质》2017年第2期428-440,共13页World Geology

基　　金：基金项目:中国地质调查局天津地质调查中心(12120115030401)

摘　　要：对内蒙古中部温都尔庙地区白音诺尔变质基性火山岩进行了锆石LA-ICPMS U-Pb年代学和地球化学研究。结果表明,变质基性火山岩原岩形成于(254.8±6.2)Ma,时代为晚二叠世。地球化学特征研究显示研究区变质基性火山岩属于亚碱性拉斑系列,大离子亲石元素(LILE)Ba、Rb、Sr强烈亏损,高场强元素(HFSE)Nb、Zr富集,元素Eu为正异常,具有E-MORB地球化学特征,岩浆来源于富集的岩石圈地幔,结合地质特征应属于蛇绿岩组成部分,反映该地区在晚二叠世古亚洲洋尚未闭合,其闭合时间可能在早三叠世之后。LA-ICPMS zircon U-Pb dating and geochemical data of meta-basic volcanics of Baiyinnuoer region from Wenduermiao area in central Inner Mongolia were studied. The results indicate that the meta-basic volcanics formed in （254.8±6.2）Ma, belonging to Late Permian. Meanwhile, geochemical studies show that the meta-basic volcanics belongs to sub-alkaline tholeiitic series. The rocks were obviously depleted in （LILE） Ba, Rb, Sr and rich in （HFSE） Nb and Zr, with positive anomalies of Eu. Geochemistry analysis shows that meta-basic volcanics are very similar to E-MORB, and the magma was derived from enriched lithospheric mantle. Combining with the geology features the rocks should belong to the ophiolite component, which indicates that Paleo-Asian Ocean has not been closed in the Late Permian and the closing time of Paleo-Asian Ocean should be later than the Early Triassic.

关 键 词：白音诺尔 变质基性火山岩 锆石U-PB年龄 地球化学 蛇绿岩 

分 类 号：P597[天文地球—地球化学] P595[天文地球—地质学]