内蒙古巴林左旗双尖子山银多金属矿床微量稀土元素特征及其矿床成因制约  

Constraint on the Genesis of the Shuangjianzishan Silver-Polymetallic Deposit,Balinzuo Qi,Inner Mongolia:Evidence from Trace and Rare Earth Elements

作　　者：江彪[1] 武广[1] 陈毓川[1] 张通 刘文元[3] 张彤[4] 李雪娇[4] JIANG Biao;WU Guang;CHEN Yuchuan;ZHANG Tong;LIU Wenyuan;ZHANG Tong;LI Xuejiao(） MLR Key Laboratory of Metallogeny and Mineral Assessment, Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing, 100037, China;） State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences , Beijing , 100083, China;） The Provincial Key Laboratory of Mineral Resources, College of Zij in Mining, Fuzhou University, Fuzhou ,350108 , China;） Institute of Geological Survey of Inner Mongolia Autonomous Region, Huhhot, 010020, China)

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]中国地质大学,地质过程与矿产资源国家重点实验室,北京100083 [3]福建省矿产资源重点实验室福州大学紫金矿业学院,福州350108 [4]内蒙古自治区地质调查院,呼和浩特010020

出　　处：《地质学报》2018年第4期769-786,共18页Acta Geologica Sinica

基　　金：内蒙古地勘基金内蒙古锡林浩特市-巴林左旗铜多金属矿成矿规律及选区研究项目(2015-01-YS01); 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(编号：DD20160346)联合资助

摘　　要：新近发现、规模巨大的双尖子山银多金属矿床地球化学的研究还很薄弱,制约了对该矿床成矿物化条件、成矿物质来源及矿床成因的认识。通过对矿区微细浸染型、细脉硫化物型、块状硫化物型矿石中与银成矿关系密切的闪锌矿、黄铁矿、方铅矿和毒砂的微量元素及稀土元素特征的研究,结果显示,成矿流体显示出富Cl热液所具有的微量元素特征,且具有从早期到晚期成矿温度和f_(O_2)递降的有序演化过程。通过对比硫化物与矿区出露的主要岩浆岩(岩脉)稀土元素的LREE/HREE、δCe和δEu特征,以及不同矿体中As、Sn、Sb等元素在的含量差异,表明双尖子山银多金属矿床成矿物质具有多来源特征或存在多期成矿作用的叠加。Cu、Co、Cr等幔源元素的富集则暗示成矿过程中不排除有幔源物质的参与。将双尖子山矿床闪锌矿与我国典型的岩浆热液型、SEDEX型、MVT型及层控-岩浆热液叠加型矿床的闪锌矿中Mn、Cd、Sn、Ga、Tl含量,Cd/Mn、Zn/Cd比值及REE特征对比研究结果显示,其具有岩浆热液型矿床微量元素和稀土元素特征,从而进一步确定本矿床成因类型上属于岩浆热液型银多金属矿床。The geochemistry research of the super-large Shuangjianxishan silver polymetallic deposit is still poor and this restricts our understanding of metallogenic condition,source of the ore-forming material and genesis of the deposit.The study carried out detailed analysis of the trace and rare earth elements for sphalerite,pyrite,galena,and arsenopyrite from the disseminated sulfide ore,vein sulfide ore,and massive sulfide ore.The results show that the metallogenic fluid is characteristic of Cl-rich hydrothermal fluid with temperature and f（O2） gradually decreasing from early to late ore-forming stages.By comparing the LREE/HREE,δCe andδEu characteristics of sulfide and magmatic rocks exposed（dikes）in the mining area,and the difference of As,Sn,and Sb in the different orebodies,this study suggests that the ore-forming materials are multiple sources or the superposition of multistage mineralization.The enrichment of mantle derived elements,such as Cu,Co and Cr,suggests that the mantle derived material should not be excluded during the mineralization.Comparison study with magmatic hydrothermal type,SEDEX type,MVT type,and stratabound magmatic hydrothermal superimposed type,the Mn Cd,Sn,Ga,Tl content,Cd/Mn,Zn/Cd ratio and REE of the sphalerite from the Shuangjianzishan deposit shows that the deposit is characteristic of trace and rare earth elements of magmatic hydrothermal fluid and can be classified into the magmatic hydrothermal type.

关 键 词：双尖子山 银多金属矿床 微量元素 稀土元素 内蒙古 

分 类 号：P618.2[天文地球—矿床学]