湖南沃溪金-锑-钨矿床成矿物质来源及成矿元素的共生机制

湖南沃溪金-锑-钨矿床的赋矿围岩为元古界板溪群浅变质岩系,是一套富含金、锑、钨等有用组分的矿源层。该矿床的成矿溶液属弱酸性—弱碱性,矿化剂中含有丰富的硫离子。矿床系通过变质水和地下水的混合热液使矿源层中的矿质发生活化、迁移和再沉淀而形成。由于元素化学性质等的差异,造成矿源层中金、锑、钨的先后活化,表现为溶液中早期富含钨,而晚期富含金和锑等。

SOURCE OF ORE MATERIAL AND PARAGENESIS OF OREBUILDING ELEMENTS IN WOXI An-Sb-W DEPOSIT, HUNAN

According to research on isotopes, fluid-inclusions and distribution of ore-building elements in Woxi Au-Sb-W deposit as well as its sourrouding strata, ft is suggested in this paper, that the ore hosted atrata-weakly metamorphosed sediments of Proterozoic, Banxi Group, are enriched in Au, Sb, W, and played the role of source bed during the period the forming fluid, remobilizing and transporting the ore material from the source bed into the deposit, was a mixture of metamotphic water and circulat ing meteoric water. The ore-formig fluid was weakly acidic to alkalescent and rich in HS-. This made the gold to be separated from base metalls and associate with woifrum and shbium. Due to difference of chemical properties of Au, Sb and W, they were separtely remobilized from the source bed. The ore-forming fluid was therefore rich in w at the early dsge, and rich in Au and sb in the later stage.