摘要
本文对纳米比亚罗什皮纳地区罗雷铜矿区中部侵位于奥兰治河群石英云母片岩中的花岗闪长岩进行了锆石U-Pb年代学和全岩地球化学分析。结果表明,岩浆锆石的207Pb/206Pb加权平均年龄为1875.1±3.8Ma(n=21,MSWD=0.59),指示了该岩体为古元古代亚马逊造山运动晚期的岩浆作用产物;该花岗闪长岩富硅、富铝,为弱过铝质岩石,稀土配分曲线为右倾型,具有明显Eu负异常,显示I型花岗岩类的特点。地质与地球化学分析显示罗雷铜矿区中部花岗闪长岩岩浆源自壳-幔混合源区,在上升演化过程中经历了显著的分离结晶作用;该花岗闪长岩体具有富铜岩浆岩的特点,是该铜矿床的成矿岩体;罗雷铜矿区中部花岗闪长岩及其成矿作用形成于亚马逊造山运动后碰撞的构造背景。
The middle granodiorite in the Luolei Copper district,Roshipina area,Namibia,intruded in the Orange group(quartz-mica schist).The 206Pb/238U weighted age of magmatic zircons from the granodiorite intrusion is 1875.1±3.8 Ma(n=21,MSWD=0.59),which suggests that the magma was formed in the Paleoproterozoic,and was part of the magmatism during in the Amazon orogeny process.The 10 tested samples from the middle granodiorite intrusion in the Luolei Copper district are from peraluminous rocks,which exhibit the geochemical characteristics of enriched LREE,depleted HREE,and display distinctly negative Eu anomaly.The geochemical characteristics of the middle granodiorite intrusion in the Luolei district suggest it is an I-type granitoid,and the magma was derived from the mixing of the lower crust and upper mantle sources,and experienced distinct fractional crystallization during its emplacement.Moreover,the whole-rock geochemical features indicate the middle granodiorite intrusion is Cu-rich granitoid,which is the ore-forming intrusion of the Luolei Copper deposit.Combining the geology,geochronology and geochemistry characteristics,we conclude that the middle granodiorite intrusion related the Cu mineralization in the Luolei district was formed within a post-collisional background.
作者
黄映聪
陈敦理
王文军
万江
孟高原
肖娥
王艳芬
刘静
HUANG Yingcong;CHEN Dunli;WANG Wenjun;WAN Jiang;MENG Gaoyuan;XIAO E;WANG Yanfen;LIU Jing(College of Earth Science,East China University of Technology,Nanchcing,330013;Fundamental Science on Radioactive Geology and Exploration Technology Laboratory,East China University,Nanchcing,330013;China Merchants Chongqing Communications Research&Design Co.Ltd,Chongqing,400000;Jiangxi coal geology bureau comprehensive team,Nanchang,310000;East China Geological Exploration Bureau of Jiangsu Nonferrous Metals,Nanjing,210000;Cangzhou Institute of Hydrology Survey and Design,Changzhou,061000)
出处
《地质学报》
EI
CAS
CSCD
北大核心
2020年第10期2994-3007,共14页
Acta Geologica Sinica
基金
国家自然科学基金项目(编号41202160)
东华理工大学博士科研启动基金项目(编号DHBH2018021)资助。
