广东大宝山北部层状矿体硫化物Re-Os测年及指示  

Re-Os dating of sulfides in the north stratiform ore body in Dabaoshan,Guangdong Province and its indication

作　　者：应立娟[1] 王登红[1] 李超[2] 王阔[3] 王开建[3] 王兰根[4] 王要武[4] 张熊[4] 蒋金昌 

机构地区：[1]中国地质科学院矿产资源研究所国土资源部成矿作用与资源评价重点实验室,北京100037 [2]中国地质科学院国家地质实验测试中心,北京100037 [3]中国地质大学(北京)地球科学与资源学院,北京100083 [4]广东省大宝山矿业有限公司,广东韶关512127

出　　处：《地学前缘》2017年第5期31-38,共8页Earth Science Frontiers

基　　金：中国科学技术部重大仪器专项(2011YQ050069);中国地质调查局中国矿产地质与成矿规律综合集成和服务(矿产地质志)项目(DD20160346);国家重点研发计划课题(2016YFC0600208)

摘　　要：广东省大宝山铜多金属矿,近年来在北部新发现层状铜硫矿体,新增铜资源量20.6万吨,与采区内层状铜硫主矿体特征基本一致。为解决层状铜硫矿体的成矿时代问题,采集北部层状矿体的块状硫化物矿石样品,首次直接对黄铜矿和磁黄铁矿开展Re-Os测年,探讨成矿时代,并分析矿床成因。黄铜矿样品的Re-Os等时线年龄为(243±41)Ma(MSWD=3.1),磁黄铁矿样品的Re-Os等时线年龄为(410±16)Ma(MSWD=15),指示黄铜矿的形成可能晚于磁黄铁矿,加里东期是否存在成矿事件仍需进一步研究。黄铜矿与磁黄铁矿的矿石学研究表明,黄铜矿交代磁黄铁矿,前者形成晚于后者,结合采区地质填图结果,认为大宝山矿区及外围属于一个大的岩浆成矿系统,存在多期次岩浆侵位,主体可能属于燕山期与岩浆热液有关的成岩成矿事件。The Dabaoshan copper polymetallic deposit, has increased its copper metal resources about 206000 tons owing to the north stratiform copper orebody found in recent years which is similar to the main stratiforrn copper-sulfur orebody in the pit. In order to solve the mineralization time issue of this stratiform copper orebody, massive sulfide ore samples were collected from this north copper orebody. Re-Os dating of chalcopyrite and pyrrhotite was carried out to determine the mineralization time and analyze the genesis of copper ore deposit. Re-Os isochron age of chalcopyrite is 243±41 Ma （MSWD=3. 1） and isochron age of pyrrbotite is 410± 16 Ma （MSWD= 15）, indicating the formation of chalcopyrite may be later than that of pyrrhotite. But whether there is a mineralization event in the Caledonian should be considered more carefully with more study. The ore mineralogic study of chaleopyrite and pyrrhotite shows that the chalcopyrite had replaced pyrrhotite, which suggests that the chalcopyrite was formed later than pyrrhotite. Combined with geological mapping in the pit, there may have been a large magmatic and mineralization system beneath Dabaoshan area and its periphery and multiple intrusions have occurred. This belongs to the Jurassic mineralization event related to the magmatie hydrothermal origin.

关 键 词：RE-OS测年 黄铜矿 磁黄铁矿 层状矿体 大宝山 

分 类 号：P597.3[天文地球—地球化学] P618.41[天文地球—地质学]