Characteristics of soure region and tectonic implications of Early Indosinian Weiya gabbroic rock,eastern Tianshan mountains  

作　　者：张遵忠 顾连兴 邵毅 许建荣 翟建平 吴昌志 郑远川 唐俊华 汪传胜 三金柱 

机构地区：[1]East China Mineral Exploration and Development Bureau for Non-ferrous Metals [2]School of Environment,Nanjing University [3]State Key Laboratory of Mineral Deposit Research,Department of Earth Sciences [4]No.704 Brigade of Xinjiang Geoexploration Bureau for Non-ferrous Metals

出　　处：《Journal of Central South University of Technology》2008年第2期237-243,共7页中南工业大学学报（英文版）

基　　金：Projects(40672040,40472042 and 40603008) supported by the National Natural Science Foundation of China;Project(2001CB409802) supported by the Major State Basic Research Development Program of China; Project(2005038237) supported by the Postdoctoral Science Foundation of China; Project supported by the Opening Foundation of State Key Laboratory of Continental Dynamics,Northwest University

摘　　要：Based on the detailed petrographic study,the characteristics of source region of the Weiya gabbro and tectonic implications were studied.The results show that the gabbroic rock consists mainly of gabbro,with less amount of ultra-mafic rocks.The ultra-mafic rocks show cumulate texture and are gradually transitional contact with gabbro,indicating that they are cumulate products of parental magma.The ultra-mafic rocks consist mainly of spinel periodite and spinel clinopyroxenite.The former is mainly composed of olivine(65%-70%),spinel(10%-15%),hornblende(5%-10%) and phlogopite(5%-10%);the latter consists mainly of clinopyroxene(70%-80%),spinel(15%-20%) and phlogopite(0-10%),with minor amounts of carbonate(0-2%).No olivine or orthopyroxene is found.The gabbro is composed mainly of clinopyroxene(35%-40%),plagioclase(An 55-65,40%-45%),hornblende(5%-15%),with variable amounts of carbonate(0-5%).Petrographic observations show that the source region of the Weiya gabbroic rock is water-rich due to intensive intra-continental A-type subduction occurring in this region during late Permian to early Triassic.Based on the detailed petrographic study, the characteristics of source region of the Weiya gabbro and tectonic implications were studied. The results show that the gabbroic rock consists mainly of gabbro, with less amount of ultra-mafic rocks. The ultra-mafic rocks show cumulate texture and are gradually transitional contact with gabbro, indicating that they are cumulate products of parental magma. The ultra-mafic rocks consist mainly of spinel periodite and spinel clinopyroxenite. The former is mainly composed of olivine （65%-70%）, spinel （10%-15%）, hornblende （5%-10%） and phlogopite （5%-10%）; the latter consists mainly of clinopyroxene （70%-80%）, spinel （15% 20%） and phlogopite （0-10%）, with minor amounts of carbonate （0-2%）. No olivine or orthopyroxene is found. The gabbro is composed mainly of clinopyroxene （35%-40%）, plagioclase （An 55-65, 40%-45%）, hornblende （5%-15%）, with variable amounts of carbonate （0-5%）. Petrographic observations show that the source region of the Weiya gabbroic rock is water-rich due to intensive intra-continental A-type subduction occurring in this region during late Permian to early Triassic.

关 键 词：PETROGRAPHY GABBRO INDOSINIAN Weiya eastern Tianshan 

分 类 号：P588.1[天文地球—岩石学]