紫金山东南矿段成矿期次、阶段浅析

Analysis of mineralization periods and stages of Zijinshan southeast ore block

通过对紫金山东南矿段铜钼(金)矿床地质矿化特征分析,指出铜钼矿化带主要赋存于花岗闪长斑岩的内外接触带,处于似斑状花岗闪长斑岩的上部,金矿化带赋存在表生氧化带的英安玢岩、隐爆角砾岩中。经过对矿石的组构特征、矿物生成顺序等特征分析,将矿床的成矿演化过程分为斑岩热液期、高硫化浅成低温热液期、表生氧化期三个主要矿化期次,进一步将斑岩热液期分为黑云母-钾长石化阶段、石英-绢云母化阶段、碳酸盐化阶段三个阶段;高硫化浅成低温热液期分为地开石化阶段、明矾石化阶段、硅化阶段三个阶段。研究结果为进一步研究矿床成因提供了依据。

By analyzing geological characteristics of mineralization of the Zijinshan southeast ore block Cu-Mo deposit,the paper demonstrates that the copper-molybdenum mineralization is mainly hosted by granodiorite porphyry inside and outside the contact zone and in the upper zone of porphyritic granodiorite porphyry.Gold mineralization is hosted in dacite porphyry,breccia of supergene oxidation zone.By analyzing of fabric characteristics of the ore and the mineral building order,the paper divides the mineralization evolution of deposit into three metallogenic periods,which are the porphyry hydrothermal period,the high sulfidation epithermal period and the supergene oxidation period.The porphyry hydrothermal period is further divided into three stages:the biotite-K-feldspar stage,the quartz-sericite stage,and the carbonate stage.The high sulfidation shallow epithermal period is also divided into three stages:the dickite petrochemical stage,the alum petrochemical stage,and the silicification stage.The finding of this paper can be serviced as a basis for further study of genesis.