桂西北明山金矿载金矿物的电子探针研究

Electron microprobe analysis on gold-bearing minerals from Mingshan gold deposit in northwest Guangxi

对明山金矿主要载金矿物(毒砂和黄铁矿)进行了电子探针面扫描、线扫描图像及元素定量分析。研究表明,Au的平均含量:毒砂中为0.186%,粗晶黄铁矿中为0.120%,细晶黄铁矿中为0.128%,草莓状黄铁矿中为0.143%;显示Au在毒砂中含量最高,而在不同世代和类型的黄铁矿中,以草莓状黄铁矿中Au含量较高。金在不同的载金矿物中分布不均匀,存在明显的金富集点,并主要以"不可见"显微-超显微包体金的形式存在于载金矿物中,不排除有少量晶格金的存在。

Mingshan Carlin-type gold deposit is located in the northwest Guangxi.Based on microscopic obser-vations and electron proble analysis,the gold content is determined in different generational pyrite and arseno-pyrite from the major gold-bearing minerals.It is shown that the highest content is Au in arsenopyrite,with an average content of 0.186%.The strawberry-type pyrite has higher content of Au in different generations of py-rite,with an average of 0.143%.The coarse-grained pyrite has an average of 0.120%,fine-grained pyrite with an average of 0.128%.Eletron proble analysis shows that the distribution of the invisible gold in different gold-bearing minerals (especially arsenopyrite)is rather inhomogeneous.Therefore,the major modes of occur-rence for gold are the “invisible”microscopic-ultra microscopic inclusions gold grain,with minor ones being“invisible”lattice gold.