津巴布韦大岩墙铂族矿床分布特征及成因分析  

Analysis of the distribution characteristics and genesis of platinum-groupelement deposits in the Great Dyke of Zimbabwe

作　　者：李斯 李冬月[1] 鲁佳[1] 何旭 蔡厚安[1] 张普斌[1] LI Si;LI Dongyue;LU Jia;HE Xu;CAI Houan;ZHANG Pubin(China Non-ferrous Metals Resource Geological Survey,Beijing 100012,China)

机构地区：[1]有色金属矿产地质调查中心,北京100012

出　　处：《矿产勘查》2023年第9期1661-1668,共8页Mineral Exploration

基　　金：自然资源部国外矿产资源风险勘查专项项目(20102053B0011)资助。

摘　　要：津巴布韦大岩墙是一套铁镁质和超铁镁质的层状基性-超基性岩体,是铂族元素主要成矿地带。本文通过对大岩墙中铂族矿床的分布规律进行研究得出,本区铂族矿床主要产于岩体中硫化物带(MSZ)的底部,矿体呈层状、似层状赋存于辉石岩中,其埋深具有在大岩墙的两翼浅、核部深的特征。电子探针分析表明,铂族元素主要产于以磁黄铁矿、镍黄铁矿、黄铁矿为主的硫化矿物组合中,镍和钴的含量均较低。成因分析表明,矿床中铂族元素的富集与基性-超基性的岩浆分异作用关系密切,原始岩浆来源于地幔,成矿环境为低氧逸度和高硫逸度的还原环境,并具有多期成岩成矿特征。The Great Dyke of Zimbabwe is a stratiform mafic-ultramafic layered intrusion comprising gabbroic and ultramafic cumulates,serving as a major host for platinum-group element mineralization.Through summariza⁃tion of the distribution patterns of platinum-group element deposits in the Great Dyke,it is concluded that the platinum-group element deposits in this area are predominantly located at the base of the sulfide zones(MSZ)within the intrusion.The orebodies occur as stratiform to semi-stratiform layers hosted in pyroxenites,and display a burial depth pattern of being shallow at the limbs and deep in the central part of the Great Dyke.The electron microprobe analysis indicates that the platinum-group elements are predominantly hosted in sulfide mineral assemblages dominated by pyrrhotite,pentlandite and chalcopyrite,with low contents of nickel and cobalt.Genetic analysis indicates that the enrichment of platinum group elements in the ore deposit is closely related to the magmatic differentiation of basic-ultrabasic magmas.The parental magmas are inferred to be derived from the mantle,and mineralization took place under reduced conditions of low oxygen fugacity and high sulfur fugacity,

关 键 词：基性-超基性岩 铂族矿床 硫化物带 大岩墙 津巴布韦 

分 类 号：P612[天文地球—矿床学]