论文部分内容阅读
为了阐明金矿化与蛇绿岩杂岩中地幔橄榄岩的共生关系,对三个地区(利古里亚、摩洛哥、沙特阿拉伯)产出的滑石菱镁片岩(碳酸盐化超镁铁岩)进行评述。滑石菱镁片岩的金含量一般是伴生超镁铁岩(5 ppb Au)的5—20倍,虽然也发育有含金量为1—10ppm的富金带。较高的金含量与硫化物或钴砷化物的矿化有关,或者与晚期含黄铁矿或毒砂的石英脉有关。与蛇纹岩的形成一样,形成滑石菱镁片岩的超镁铁岩碳酸盐化作用,似乎是在中温条件下(150—300℃)Na、Cl卤水的热液蚀变结果,这些卤水起源于地幔物质与海水的相互作用。金是从蛇纹石化超镁铁岩的不透明矿物中析出的。在热液系统演化过程中,金随富含CO_2、S、As、Cl、Na、K和B的流体沿构造接触带迁移,当该流体运移到还原和碱性环境时,金与石英,硫化物和砷化物一起沉淀。因此,滑石菱镁片岩应成为金矿勘探的新目标。
In order to elucidate the symbiotic relationship between gold mineralization and mantle peridotites in ophiolite complexes, the production of talc magnesite schist (carbonated ultramafite) in three areas (Liguria, Morocco, Saudi Arabia) Comment. The gold content of talc magnesite schists is typically 5-20 times that of associated ultramafic rocks (5 ppb Au), although gold rich bands ranging from 1 to 10 ppm are also developed. The higher gold content is associated with the mineralization of sulfides or cobalt arsenides or with the late quartz veins containing pyrite or arsenopyrite. As with the formation of serpentinite, the ultramafonic carbonation that forms the talc magnesite schist appears to be the result of the hydrothermal alteration of Na and Cl brine at moderate temperatures (150-300 ° C). These brine origins Interactions between mantle material and seawater. Gold is precipitated from the opaque minerals of serpentinized ultramafic rocks. During hydrothermal system evolution, gold migrates along the structural contact zone with fluids rich in CO 2, S, As, Cl, Na, K and B. When the fluid migrates to a reduction and alkaline environment, gold and quartz, Sulfide and arsenide precipitate together. Therefore, talc magnesite schist should be a new target for gold exploration.