西藏乃东地区雅鲁藏布江缝合带中蛇绿混杂岩的变质作用及岩石学特征  

METAMORPHISM AND PETROLOGICAL CHARACTERISTICS OF OPHIOLITE MELANGE IN YARLUNG ZANGBO SUTURE ZONE,NEDONG REGION,TIBET

作　　者：包国志 王玉玺 张志平 汪宏涛 晏齐胜 鲁有朋 BAO Guo-zhi;WANG Yu-xi;ZHANG Zhi-ping;WANG Hong-tao;YAN Qi-sheng;LU You-peng(The Third Institute of Geology and Mineral Exploration,Gansu Provincial Bureau of Geology and Mineral Exploration and Development,Lanzhou 730050,China;Gansu Xinyuan Dituo Mining Co.,LTD.,Lanzhou 730050,China)

机构地区：[1]甘肃省地矿局第三地勘院,甘肃兰州730050 [2]甘肃鑫源地拓矿业有限责任公司,甘肃兰州730050

出　　处：《甘肃地质》2021年第4期30-37,共8页Gansu Geology

基　　金：西藏乃东县地区1∶5万区域地质调查(H46E016007,H46E016008,H46E017007,H46E017008)项目。

摘　　要：雅鲁藏布江缝合带位于青藏高原南部,是印度板块向欧亚板块俯冲的产物,代表着新特提斯洋岩石圈的残片。文章对西藏乃东地区雅鲁藏布江缝合带中蛇绿混杂岩的变质作用及岩石学特征进行了研究。该带总体呈近东西向延伸,受变地质体主要为晚侏罗—早白垩世泽当蛇绿岩。通过野外地质调查、岩相学及岩石地球化学分析,结合岩石成因研究及构造环境判别,认为泽当蛇绿岩由地幔橄榄岩、辉长质杂岩、镁铁质杂岩、海相沉积物及伴生铬铁矿和斜长花岗岩等组成,属低绿片岩相—高绿片岩相区域变质岩。The Yarlung Zangbo Suture Zone,located in the southern part of the Tibetan Plateau,is the product of the subduction of the Indian plate to the Eurasian plate,and represents the remnants of the New Tethyan ocean lithosphere.The metamorphism and petrological characteristics of ophiolite in yarlung Zangbo suture zone of Tibet and eastern China are studied in this paper.The belt extends nearly east-west in general,and the altered geological bodies are mainly late Jurassic-early Cretaceous Zedang ophiolites.Through field geological survey,lithology and rock geochemical analysis,combined with the study of the formation of rocks and tectonic environment discrimination,think jersey when ophiolite is composed of mantle peridotite,gabbro complex,mafic complex,Marine sediment and associated chromite and plagioclase granite and so on,belong to low greenschist facies-high greenschist facies regional metamorphism rock.

关 键 词：蛇绿混杂岩 变质作用 岩相学 地球化学 西藏乃东地区 雅鲁藏布江缝合带 

分 类 号：P511.5[天文地球—地质学] P548