赞比亚中部泛非期Hook岩基地质特征及成矿潜力分析  

Geological characteristics and mineralization potential analysis for the Pan-African Hook Batholith in Central Zambia

作　　者：古阿雷 王杰[1] 任军平 左立波 孙宏伟 邢仕 刘子江 Ezekiah Chikambwe GU A-lei;WANG Jie;REN Jun-ping;ZUO Li-bo;SUN Hong-wei;XING Shi;LIU Zi-jiang;Ezekiah Chikambwe(Tianjin Center,China Geological Survey,Tianjin 300170,China;No.5 Geological Team,Bureau of Geologic Exploration and Mineral Development of HeBei Province,Hebei Tangshan 063000,China;Geological Survey Department of Zambia,P.O.Box.50135 Lusaka,Zambia)

机构地区：[1]中国地质调查局天津地质调查中心,天津300170 [2]河北省地矿局第五地质大队,河北唐山063000 [3]赞比亚地质调查局,赞比亚卢萨卡P.O.Box.50135

出　　处：《地质调查与研究》2020年第1期63-71,80,共10页Geological Survey and Research

基　　金：商务部技术援外项目“援赞比亚北部省卡萨马地区区域地质与地球化学调查([2012]558)”;“援赞比亚东北地区航空物探和地质地球化学综合填图([2015]352)”;中国地质调查局项目“莫桑比克-坦桑尼亚钽锆钛资源调查(DD20201150)”。

摘　　要：泛非期Hook岩基位于赞比亚中部地区,是研究冈瓦纳超大陆拼合期间刚果克拉通与卡拉哈里克拉通碰撞相关构造岩浆作用特征的天然实验室。通过对岩基岩浆岩的岩石学、年代学、地球化学和地质矿产等资料的归纳整理,获得以下认识:岩基花岗岩类是一套偏铝质、钙碱性-碱性系列岩石,具有富Na、K,贫Ca、Mg、Al等元素特征,属于A型花岗岩。岩浆作用发生在(566~519)Ma之间,可进一步划分为早期(566~544)Ma和晚期(544~519)Ma两个阶段,分别对应A2型花岗岩和A1型花岗岩特征,显示造山后向后造山伸展转换的构造环境。岩基原始岩浆为壳幔混合源区,为同源岩浆经过结晶分异作用演化的结果,岩浆在上升过程中可能经历了微弱的地壳物质的混染作用。岩基东部蒙布瓦地区发育铁氧化物-铜-金(IOCG)成矿系统,特别是晚期正长质岩体出露地区可能是寻找类似找矿靶区的重要找矿标志。The Pan-African Hook Batholith is located in central Zambia, which is a natural laboratory to study the characteristics of tectonic magmatism as a result of collisional stage interaction between the Congo Craton and the Kalahari Craton during the assembly of the Gondwana supercontinent. By summarizing the petrology,chronology, geochemistry and mineral geology of magmatic rocks. We conclude that Hook granitoids are characterized as aluminous, calc-alkaline to alkaline series rocks, which show rich in Na, K, depleted in Ca, Mg,Al and other elements, with typical A-type granitoid geochemical signature. Magmatism occurred between 566 Ma and 519 Ma, which can be further divided into two stages: early stage(566~544 Ma)for A2-type and late stage(544~519 Ma)for A1-type, respectively, indicating the tectonic environment of the extension and transformation of post-orogenic orogeny. The primitive magma is the mixed source region of crust and mantle,which was generated by the fractional crystallization and show evidence of only minimal crustal contamination during ascent. There has an iron oxide copper gold(IOCG)metallogenic system in the eastern Hook area,especially the exposed area of the late syenitic bodies,which may be an important prospecting indicator for finding similar prospecting target areas.

关 键 词：泛非期 地质特征 成矿潜力 Hook岩基 IOCG成矿系统 赞比亚中部 

分 类 号：P595[天文地球—地球化学] P581[天文地球—地质学]