金川铜镍硫化物矿床2号矿体铂族及亲铜元素地球化学特征  

Geochemical characteristics of platinum_group and chalcophile elements in No.2 orebody of Jinchuan Cu_Ni sulfide deposit

作　　者：王亮[1] 陈列锰[2] 宋谢炎[2] 江金进 符志强[1] 王玉山[4] 潘小平[4] 

机构地区：[1]成都理工大学地球科学学院,四川成都610059 [2]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵州贵阳550002 [3]贵州省国土资源勘测规划研究院,贵州贵阳550004 [4]金川集团股份有限公司,甘肃金昌737104

出　　处：《矿床地质》2014年第4期727-741,共15页Mineral Deposits

基　　金：中国科学院地球化学研究所矿床地球化学国家重点实验室项目(编号:SKLODG_ZY125_06);中国科学院国家外国专家局创新团队国际合作伙伴计划“陆内成矿作用研究团队”(KZZD_EW_TZ_20);国家自然科学基金(编号:40973038、41003022和41172090)资助

摘　　要：系统分析了金川Ⅱ号岩体中2号矿体西端、中部和东端的硫化物矿石中的铂族元素(PGE)和亲铜元素地球化学特征,以期探讨这些元素的空间变化规律及其成因,以及对金川矿床成矿过程的指示意义。研究结果表明:100%硫化物中,PGE(Ir、Ru、Rh、Pt、Pd)总体从西端到东端逐渐降低,且浸染状矿石和海绵陨铁状矿石的100%硫化物中PGE和亲铜元素含量的变化特征相似。表明金川2号矿体硫化物矿石的PGE和亲铜元素的含量主要受硫化物熔离作用的约束,硫化物熔体分离结晶和后期热液蚀变影响不明显。2号矿体浸染状矿石的100%硫化物中,PGE和亲铜元素含量总体低于1号矿体浸染状矿石的含量,但是前者西端的样品与后者东端的样品,上述元素特征相似,暗示二者是同一岩浆通道系统中硫化物熔离的产物,并且硫化物熔离形成2号矿体时具有比1号矿体低的R值,这也暗示了含矿岩浆是自1号矿体向2号矿体流动的。Geochemical characteristics of the platinum-group and chalcophile elements of sulfide ores sampled from the western, middle and eastern part of the No. 2 ore body in the Ⅱ segments of Jinchuan intrusion were systematically analyzed with the purlpose of investigating their spatial variation regularity and genesis as well as their in- dicative significance for the ore-forming process of the Jinchuan deposit. The results imply that the values of PGE（ Ir, Ru, Rh, Pt, Pd）on a 100% sulfide basis decrease gradually from the west to the east in general, and there is a similar variation of the concentrations of PGE and chalcophile elements on a 100 % sulfide basis in both disseminated and net-textured sulfide ores. The characteristics indicate that the concentrations of PGE and chal- cophile elements were restrained by the segregation of sulfides but little affected by fractional crystallization of sulfide melts and late-stage alteration. The concentrations of PGE and chalcophile elements of disseminated ores on a 100 % sulfide basis in No. 2 orebody are lower than those in No. 1 orebody, but the values of these elements in the western part of No. 2 orebody are similar to those in the eastern part of the No. 1 orebody, which implies that both of the orebodies resulted from the segregation of sulfides in the same magma conduit, and during the rock-forming process the ore-bearing magma flowed from No. 1 to No. 2 orebody because of the lower R value of No. 2 than that of No. 1 in the process of segregation of sulfide melts.

关 键 词：地球化学 铜镍硫化物 铂族元素 亲铜元素 金川矿床 

分 类 号：P618.41[天文地球—矿床学] P618.63[天文地球—地质学]