津巴布韦Turk金矿黄铁矿矿物特征及成矿意义  

Mineralogical Characters of Pyrite and its Gold Mineralization in Turk Mine,Zimbabwe

作　　者：王国峰[1] 张明云[1] 刘文斌[1] 

机构地区：[1]河南省地质调查院,郑州450007

出　　处：《地质调查与研究》2008年第4期309-314,共6页Geological Survey and Research

基　　金：国家国外矿产资源风险勘查项目:津巴布韦Chimanimani地区金矿勘查研究

摘　　要：采用光学和化学分析方法对津巴布韦Bubi绿岩带内Turk金矿伴生的黄铁矿进行形态、同位素和微量元素分布特征研究,认为碳酸盐岩中黄铁矿的硫同位素δ34S值,随黄铁矿形态变化而变化,表明硫来源是多元的。大多数样品硫同位素δ34S值近于0‰,反映了岩浆作用提供了硫的主要物质来源。少量样品的硫同位素δ34S值介于+4‰～+16‰之间,反映一部分硫来自海水。砷及其他元素的分布特征表明在碳酸盐岩层内存在几个不同世代的黄铁矿。早期富含砷的黄铁矿内金有一定程度的富集,但在碳酸盐岩内黄铁矿中金的浓度太低,不能产生金的显著富集。而在变玄武岩中,金明显富集,它是晚期含矿流体沿微细剪切带渗透,形成石英-方解石-黄铁矿组合,并把原来自形的黄铁矿破碎呈角砾状,伴随裂隙金生成。Morphological features of pyrite distributed in the carbonate and metabasalt, which develop to the east or at the central of Turk Mine, Bubi greenstone belt, Zimbabwe, are identified by optical microscope, respectively. In the carbonate sequence pyrite δ^34S values vary as its textural variety present in the samples and are interpreted as a mixed source of sulfur. Most samples have δ^34S values almost being equal to 0‰, and reflecting a magmatic sulfur source, however a small part of samples have 5 34S values that range from ＋ 4‰ to ＋16‰, which reflects a seawater sulfur source. All element content of pyrites in the both rock types are measured via PIXE analysis. The distribution of As and other elements show several different pyrite generations in the carbonate sequence. Although an obvious trend shows gold bearing in early-developed As-rich zones with pyrite, gold concentration in the pyrites from the carbonate were too low for gold introduction in this rock, instead in the altered basalts gold introduction can be shown that late fluid influx along micro-shears and produce the quartz-carbonate-pyrite alteration assemblage, further the originally euhedral pyrite crystals are brecciated.

关 键 词：Turk金矿 黄铁矿 矿化 碳酸盐岩 津巴布韦 Bulawayo—Bubi 

分 类 号：P618.51[天文地球—矿床学] P578.2[天文地球—地质学]