金川铜镍硫化物矿床亲铜元素全岩地球化学特征及其相关性分析  

Geochemical characteristics and correlation analysis of whole rocks of chalcophile elements in Jinchuan Cu-Ni sulfide deposit

作　　者：李万里 李德贤 黎隆交 毛先成[1,2] Li Wanli;Li Dexian;Li Longjiao;Mao Xiancheng(Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geological Environment Monitoring(Central South University),Ministry of Education,Changsha 410083,Hunan,China;School of Geosciences and Info-physics,Central South University,Changsha 410083,China;Jinchuan Nickel Cobalt Research&Design Institute Co.,Ltd.,Jinchang 737104,Gansu,China)

机构地区：[1]有色金属成矿预测与地质环境监测教育部重点实验室(中南大学),湖南长沙410083 [2]中南大学地球科学与信息物理学院,湖南长沙410083 [3]金川集团股份有限公司镍钴研究设计院,甘肃金昌737104

出　　处：《地质学刊》2022年第3期266-277,共12页Journal of Geology

基　　金：国家自然科学基金项目“矿床时空结构定量表征与智能理解”(42030809);“面向隐伏矿体三维预测的地质体形态控矿特征深度学习”(41972309);“顾及可迁移性成矿特征的深部三维预测研究”(42072325)。

摘　　要：金川Cu-Ni硫化物矿床地处龙首山隆起带内,是中国最大、世界第三的Cu-Ni硫化物矿床。半金属元素(Te、As、Bi、Sb、Se,TABS)作为形成铂族元素矿物(PGM)的重要元素,其分布过程的控制以及对矿石成因的指示作用缺乏研究。采用全岩亲铜元素分析、背散射观测等实验方法,对各矿区不同类型的矿石进行研究。结果显示:可利用亲铜元素比值与R因子(硅酸盐岩浆/硫化物)模拟金川Cu-Ni硫化物矿床硫化物的熔离过程,定量模拟示踪金川矿石的成矿作用,Cu/Te-Te与Bi/Pd-Bi模拟结果与Cu/Pd-Pd模拟结果一致。半金属元素如Te、Bi等也可用于铜镍硫化物矿床硫化物熔离过程的模拟;半金属元素也可以指示矿石成因,R因子定量模拟分析发现浸染状矿石由硫化物熔体较快速冷凝形成,网状矿石的形成经历了硫化物深部部分熔离作用,富铜矿石由富Bi、Cu的残余硫化物熔体经冷凝结晶作用形成。Jinchuan Cu-Ni sulfide deposit,located in the Longshoushan uplift belt,is the largest Cu-Ni sulfide deposit in China and the third largest in the world.Semi-metallic elements(Te,As,Bi,Sb,Se,TABS)are important elements in the formation of platinum group element minerals(PGM).However,the control of their distribution process and the indication of ore genesis are not fully studied.Different types of ores in different mining areas were studied by various means including whole rock chalcophile element analysis and backscattering observation.The results show that the sulfide dissociation process in the Jinchuan Cu-Ni sulfide deposit can be simulated by using the chalcophile element ratio and R factor(silicate magma/sulfide),and the mineralization of Jinchuan ore can be quantitatively simulated.The simulation results of Cu/Te-Te and Bi/Pd-Bi are consistent with the simulation results of Cu/Pd-Pd.Semi-metallic elements such as Te and Bi can also be used to simulate the sulfide dissociation process in Cu-Ni sulfide deposits.Semi-metallic elements can also indicate the origin of ore.Quantitative simulation analysis of R factor shows that the disseminated ore is formed by rapid condensation of sulfide melt,the formation of network ore has undergone deep partial melting of sulfide,and the copper-rich ore is formed by condensation crystallization of residual sulfide melt rich in Bi and Cu.

关 键 词：铂族元素 半金属元素 R因子 铜镍硫化物矿床 甘肃金川 

分 类 号：P611.1[天文地球—矿床学]