坦桑尼亚卢帕金矿田地质特征及成矿机制探讨  

Geological characteristics and metallogenic mechanism of Lupa gold field in Tanzania

作　　者：赵志强[1] 彭俊[1] 梁永安[1] 王滑冰 袁杨森[1] 司建涛[1] 都鹏飞[1] ZHAO Zhiqiang;PENG Jun;LIANG Yongan;WANG Huabing;YUAN Yangsen;SI Jiantao;DU Pengfei(No.2 Institute of Geological&Mineral Resources Survey of Henan,Zhengzhou 450001,Henan,China)

机构地区：[1]河南省地质矿产勘查开发局第二地质矿产调查院,河南郑州450001

出　　处：《矿产勘查》2020年第8期1728-1737,共10页Mineral Exploration

基　　金：国外矿产资源风险勘查专项(编号:201210B01600234)资助。

摘　　要：坦桑尼亚卢帕金矿田位于坦桑尼亚克拉通西南缘的早元古代乌宾迪造山带中,是坦桑尼亚重要的金矿聚集区之一。屯嘎金矿床位于卢帕金矿田中东部,区内发现3条金矿脉,提交(333)+(334)?类金资源量3t,金平均品位3.77×10-6。萨扎金矿床位于卢帕金矿田西北部,由肯戈(Kenge)金矿体和姆本戈(Mbenge)金矿体组成,金资源量约11.5 t,金平均品位为1.33×10-6。研究区金矿床类型主要为受剪切构造带控制的石英脉型金矿床。通过对屯嘎、萨扎等典型金矿床对比研究,总结分析了卢帕金矿田金矿床成矿地质条件、矿化蚀变特征、矿石结构特征等主要成矿要素,北西—南东向、北北东—南南西向等次级剪切构造带是本区主要的容矿构造,控制着金矿体的空间分布;镁铁质岩墙(岩脉)与金矿脉在空间上有密切的伴生关系,是重要的找矿标志。卢帕金矿田含矿断裂经历了韧性剪切和脆—韧性扩张2个阶段,含金矿脉主要为剪切构造带内糜棱岩相内雁列石英脉和断层充填脉。The Lupa goldfield,in the Paleoproterozoic Ubendian Belt which is located in the southwest of Tanzania craton,is one of the important gold ore concentration areas.Twiga gold deposit is located in the east-central Lupa goldfield,three gold veins are found in the area,3 tons for(333)+(334)?type gold resource are submitted and the average gold grade is 3.77×10-6.Saza gold deposit is located in the northwest of the Lupa goldfield,which are composed of Kenge and Mbenge gold ore-body,the gold resource is about 11.5 tons and he average gold grade is 1.33×10-6.The main deposit types are quartz vein type which is controlled by shear zone.Based on a comparative study of two typical gold deposits such as the Twiga and Saza gold mines,this paper summarize metalloenic essential factors,including metallogenic geological conditions,alteration and ore characteristics and so on.Based on a comparative study of three typical gold deposits such as the Nyasirori,Rwamkoma and Nyabarundu gold mines,this paper analysis metallogenic geological conditions,alteration and ore characteristics,and summarize gold metallogenic regularity of gold deposits in the Mara-Musoma greenstone belt.NW-SE,NNE-SSW trending secondary shear zones are main auriferous fractures which control the existence of the ore bodies.The distribution of the auriferous viens are related to mafic dykes which are the important prospecting marks.The auriferous fractures of the Lupa goldfield underwent ductile shear state and brittle-ductile shear state.The gold-bearing veins are echelon quart veins and fault-fill veins for mylonitization face in the shear zones.

关 键 词：金矿 地质特征 剪切构造 成矿机制 卢帕金矿田 坦桑尼亚 

分 类 号：P618.51[天文地球—矿床学]