东天山白鑫滩铜镍硫化物矿床矿石铂族元素特征及其矿床成因  

Ore PGE characteristics of Baixintan magmatic sulfifide Ni—Cu deposit in East Tianshan Mountains and its genensis discussion

作　　者：李鑫[1,2,3] 姜岩 薛炯 胡可美 卞霄 郑涛 苏玉平 马强[3] 骆毕继[3] LI Xin;JIANG Yan;XUE Jiong;HU Kemei;BIAN Xiao;ZHENG Tao;SU Yuping;MA Qiang;LUO Biji(No.1 Regional Geological Survey Party of Xinjiang Geology and Mineral Development Center,Urumqi830011;No.10 Geological Survey Party of Xinjiang Geology and Mineral Development Center,Hotan,Xinjiang848000;The Faculty of Earth Sciences,China University of Geosciences,Wuhan430074)

机构地区：[1]新疆维吾尔自治区地质矿产勘查开发局第一区域地质调查大队,乌鲁木齐830011 [2]新疆维吾尔自治区地质矿产勘查开发局第十地质大队,新疆和田848000 [3]中国地质大学(武汉)地球科学学院,武汉430074

出　　处：《地质论评》2024年第2期654-668,共15页Geological Review

基　　金：新疆哈密市白鑫滩铜镍矿床详查、新疆哈密市白鑫滩一带铜多金属矿普查项目(编号:T17-3-XJ014)的成果。

摘　　要：笔者等针对矿床不同的矿石类型中PGE的含量进行了综合分析和理论计算和研究。该理论对于通过铂族元素可以精细刻画出岩浆结晶分异过程中元素的迁移、富集规律,示踪成矿母岩浆的物质来源。通过本次研究对于寻找与镁铁—超镁铁岩有关的铜镍矿床中综合评价铂族元素提供了一定的方向和借鉴,能够进一步指导和推动铜镍矿中伴生铂族元素的评价和利用。新疆白鑫滩铜镍硫化物矿床是近年来东天山新发现的镍矿床,矿床规模镍已达到中型,铜为小型矿床。矿床矿石以海绵陨铁状结构为主,且矿床中铜矿石资源量大于镍矿石资源量。本次工作针对矿区东西部两个最大的矿体系统地采集了样品,并分析了矿体中铂族元素含量,根据大量铂族数据的统计与模拟计算,获得了白鑫滩矿床母岩浆的PGE组成:Os=0.335×10^(-9),Ir=0.267×10^(-9),Ru=0.277×10^(-9),Rh=0.144×10^(-9),Pt=4.94×10^(-9),Pd=2.32×10^(-9),Ni=338×10^(-6),Cu=174×10^(-6)。通过R因子与硫化物分异结晶过程模拟,白鑫滩铜镍硫化物矿床的R因子为115。综合分析对比不同矿床矿石铂族元素特征,表明白鑫滩成矿岩体为地幔物质来源,成矿作用主要受母岩浆的结晶分异作用控制。Platinum group elements can be used to accurately depict the migration,enrichment,and trace elements in the mother material source.By examining the platinum group elements in magnesia—ultramafite copper nickel deposits,we can provide a comprehensive evaluation that offers direction and reference points for the evaluation and utilization of associated platinum group elements in copper and nickel ore.Methods:In this study,we systematically collected samples from the two largest ore bodies in the eastern and western parts of the mining area.We then analyzed the platinum group element content of the ore bodies.Through statistical analysis and simulation of a large amount of platinum group data,we were able to determine the PGE composition of the parent magma of the Baixintan deposit.Results:By simulating the differential crystallization process of R factor and sulfide,the R factor of the Baixintan copper—nickel sulfide deposit was found to be 115.Through a comprehensive analysis and comparison of the characteristics of platinum group elements in different ore deposits,it was determined that the rock mass was sourced from the mantle material,and that the metallogenic process was mainly controlled by the crystallization differentiation of the parent magma.Conclusions:(1)The Baixintan copper—nickel ore is mainly composed of massive,dense and sparse immersed ore,block ore and low-grade immersed ore bodies.The platinum elements in the block ore exhibit a significant abnormality in iridium,with iridium enrichment in sulfide melt.The content of sulfide melt is closely related to the enrichment,indicating that changes in ore type enhance the enrichment of PGE.Therefore,a comprehensive evaluation of platinum elements in bulk ore should be taken into consideration in the future.(2)Based on statistical and simulation calculations of a large amount of platinum group data,the PGE composition of the parent magma of Baixintan deposit was determined to be:Os=0.335×10^(-9),Ir=0.267×10^(-9),Ru=0.277×10^(-9),Rh=0.144×10^(-9),

关 键 词：白鑫滩矿床 东天山 铜镍矿 铂族元素 定量模型 

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