紫金山铜金矿床Cu-S矿物变化规律及地质意义

Variation law of Cu-S minerals and geological significance in Zijinshan Cu-Au deposit

在系统采样和岩矿鉴定的基础上,对紫金山铜金矿床Cu-S矿物变化规律进行了详细的研究,发现从矿床浅部到矿床深部,铜蓝的形态从较为细小的针柱状、棉絮状逐渐变化为较大的板柱状;而Cu-S矿物组合表现为浅部以蓝辉铜矿为主,深部以铜蓝为主。它们分别有力地说明铜矿体并不是次生富集成因,而是原生热液成因;矿床深部的氧逸度和硫逸度均高于矿床浅部。因此可以推测在现在已见矿床底部不远处还有斑岩型矿床的找矿潜力。

Based on systematically sampling and rock-mineral identification,the variation law of Cu-S minerals is studied in detail.It is found that covellite morphology changed from fine needle and cotton fiber shape to plate column shape from shallow to deep depth of this deposit.At the same time,the Cu-S mineral assemblages changed from dominant in digenite to dominant in covellite.The former indicates that the copper ore body is the genesis of primary hydrothermal metallization,and the latter indicates that the oxygen fugacity and sulfur fugacity are both higher in the deep depth of this deposit than in the shallow depth.Therefore,it can be inferred that there is prospecting potential of porphyry deposit below this deposit.