江西省兴源冲铜矿床同位素地球化学特征及成矿机制探讨  

Carbon,oxygen and sulfur isotopic geochemistry and metallogenic mechanism of Xingyuanchong copper deposit in Jiangxi Province

作　　者：刘婷[1,2] 刘成东[1] 严兆彬[1] 陈益平[1] 吴旭铃[3] 凡秀君[3] 

机构地区：[1]东华理工大学核资源与环境省部共建国家重点实验室培育基地,放射性地质与勘探技术国防重点学科实验室,江西南昌330013 [2]安徽工业经济职业技术学院,安徽合肥230051 [3]江西省地质调查研究院,江西南昌330030

出　　处：《矿床地质》2013年第3期614-624,共11页Mineral Deposits

摘　　要：兴源冲铜矿床地处九岭南缘铜多金属大型矿集区西段的黄茅地区。文章在成矿地质特征的基础上,通过对矿石进行稳定同位素地球化学研究,重点分析了成矿物质来源,探讨了矿床成矿机制。碳、氧同位素分析结果表明,矿区碳酸盐岩δ13CVPDB为-5·4‰～1·9‰,平均为0·6‰,δ18OSMOW变化范围为9·0‰～13·9‰,平均为10·9‰,主要为海相碳酸盐岩,碳、氧同位素图解表明碳可能主要来源于深部,且受高温变质作用和低温蚀变作用明显;矿石硫化物硫同位素δ34S变化范围主要在1·0‰～6·2‰之间,个别样品同位素比值偏大,对比相似矿床,表明该矿床具有海底喷流沉积和后期岩浆热液叠加作用的特征。上述同位素地球化学特征表明,兴源冲铜矿床是在中元古代海底火山沉积基础上,经新元古代晋宁造山期岩浆热液、动力变质叠加成矿作用所形成。The Xingyuanchong copper deposit of Huangmao area is located in the west segment of the South Jiuling large copper polymetallic ore concentration area. In combination with the metallogenic characteristics of the ore deposit, the authors mainly studied stable isotopes of the ores to probe into the sources of metallogenic materials and metallogenic mechanism o{ the deposit, a13 CVPDB values of carbonates in this area vary in the range of -5.4%0-1.9%0, 0.6%0 on average, whereas alSOsMow values range from 9.0%0 to 13.8%o, 10.9%0 on aver- age, indicating that carbonates were mainly marine carbonates. The δ180-δ13C diagram shows that carbon in the region probably came from the deep earth, and experienced metamorphism at high temperatures and alteration at low temperatures. Except two higher values of δ34S, most δ4S values in this deposit vary in the range of 1.0% -6.2%0; in comparison with other similar deposits, sulfur of this deposit is characterized by submarine exhala-tion sedimentation and hydrothermal superimposition. In combination with isotopic data and geological setting, it is proposed that the ore-forming processes of the Xingyuanchong copper deposit could be divided into two stages. At the first stage, submarine volcanic sediments or protore layers were formed in Mesoproterozoic. At the second stage, the pre-existing protores were altered by the hydrothermal fluids and dynamic metamorphism mainly derived from Jinnin~ orogenic period in Late Protemmie.

关 键 词：地球化学 稳定同位素 成矿物质来源 成矿机制 海底火山沉积 兴源冲 

分 类 号：P618.41[天文地球—矿床学]