一个典型的复成因矿床—江西武山铜矿

武山铜矿存在两种不同类型矿床,含铜黄铁矿型为海底喷气沉积成因,矽卡岩型铜矿系接触交代成因。在特定的地质条件下,它们迭生在一起,是一个典型的复成因矿床。

A TYPICAL POLYGENETIC DEPOSIT-WUSHAN COPPER DEPOSIT, JIANGXI PROVINCE

Wushan copper deposit in Jiangxi Prov. is composed of two deposits types: stratiform Cu-bearing pyrite type (mass sulphide) and skarn type. Studied on the geological characters, Physic-chemical condition of mineralization and stable isotopes show that they belong to two types. Cu-bearing pyrite deposit occurs in the transition zone from beach to neritic basin, which controlled the NWW striking outside-beach growth faults occurence. Ore bodies are stratiform and lenticular, and occur in the transitional zone from clastic to carbonate facies of the Huanglong formation. Based on the study, the present authers consided that this stratiformed Cu-bearing pyrite deposits were formed in a submarine nviroment, by exha-ltive sedimentation and interaction of sea-water with hydrothermal liquids. It was formed at a depth less than 200 meters, temprature from 100 to 200@, with relative salinity (7%) and weakacid to alkli environment. After the Cu-bearing pyrite deposit was formed, Yanshanian granodio-rite intruded. The latter not only intruded into the Cu-bearing pyrite beds, but also reformed it, and formed contact-metasomatic copper deposit (skarn type) in its contact zone with carbonate country rocks. So Wushan copper deposit is typically polygene orign.