微细浸染型金矿床成矿机制新探

通过对微细浸染型金矿床矿物流体包裹体的化学组成、金矿物的化学成分、主要共、伴生矿物组合的研讨,结合该类型矿床的成矿环境及金氢化物、金合金氢化物、金羰基化合物的物理化学性质,认为金氢化物、金合金氢化物、金羰基化合物是微细浸染型金矿床金的主要迁移形式。它们从地球深部富氢、富CO强还原环境,随岩浆、热液、热气迁移至地壳浅部,由于压力、温度、pH值下降、Eh值上升,氢、CO逃逸,氧化、分解形成微粒金矿物,沉淀富集形成金矿床。此后,如再发生地质构造、地壳演化运动,微粒金矿物可重新活化,进行接力式迁移、叠加富集。

DISCUSSION ON THE METALLOGENIC MECHANISM OF THE SUPERFINE IMPREGNATION AU DEPOSIT

The chemical composition of the fluid inclusion and the Au mineral,main paragenetic mineral and associate mineral have been discussed in the paper. And the metallogenic environment of such deposit and the physicoche mical properties of the gold hydride,gold alloy hydride,and gold carbonyl compound have been studied. It is can be concluded that the main migration species of the Au in the superfine impregnation deposit are the gold hydride,alloy hydride,gold carbonyl compound,which migrate into the earth surface from the deep along with the magma,thermal fluid and hot gas and were decomposed into superfine Au mineral. Then it sediment and concentrate to Au deposit. The geological structure and crustal evolution developed after the deposit will activate the superfine Au mineral,and make it migrate and concentrate once again.