(1. 中南大学 有色金属成矿预测与地质环境监测教育部重点实验室，长沙 410083； 2. 中南大学 地球科学与信息物理学院，长沙 410083； 3. 湖南华中矿业有限公司，长沙 410003)
摘 要: 根据脉体穿插关系和矿物组合特征，将李坝金矿床的成矿作用划分为热液期和表生期，其中热液期又可划分为黄铁矿阶段、黄铁绢英岩阶段和多金属硫化物阶段3个成矿阶段。运用电子探针(EPMA)对3个成矿阶段的主要金属硫化物(黄铁矿、毒砂、闪锌矿)开展成分分析和Au赋存状态分析。结果表明：李坝金矿床黄铁矿w(Co)/w(Ni)比值(0.15~4.50)及闪锌矿内FeS分子数(18.81%~22.97%)指示该矿床形成于中高温的物理化学环境。主要金属硫化物含金量、黄铁矿As-Au图解及Au元素面扫描分析图指示黄铁矿和毒砂是李坝金矿床重要载金矿物，Au主要是以纳米级显微-超显微自然金(Au0)的形式存在。综合地质特征及金属硫化物的地球化学特征，推测李坝金矿床属于与中川岩浆活动有关的中高温中深成热液金矿床。
关键字: 金属硫化物；化学成分；电子探针；李坝金矿床
（1. Key Laboratory of Metallogenic Prediction of Nonferrous Metals and Geologicao Environment Monitor (Central South University), Ministry of Education, Changsha 410083, China; 2. School of Geoscience and Infophysics, Central South University, Changsha 410083, China; 3. Hunan Huazhong Mining Co., Ltd., Changsha 410083, China）
Abstract:Based on the ore veins intercalation and minerals association, the mineralization in Liba gold deposit can be divided into hydrothermal stage and exogenous stage. The hydrothermal stage consists of three phases, which are pyrite phase, beresite phase, and polymetallic phase. Component analysis and Au distribution states analysis of metal sulfides (pyrite, arsenopyrite, sphalerite) of three phases were carried out by means of electron probe microanalysis (EPMA). The results show that the w(Co)/w(Ni) ratio(0.15-4.50) of pyrite and FeS molecular number(18.81%-22.97%) in sphalerite indicate that the Liba gold deposit forms in the medium-high temperature environment. The Au content, As-Au relationship diagram and distribution analysis of Au element in metal sulfides indicate that pyrite and arsenopyrite are the main gold-bearing minerals in Liba gold deposit, besides micro and sub-micro native gold inclusion are the dominant occurrence in pyrite and arsenopyrite. Based on the geological characteristics and the component characteristic of metal sulfides, Liba gold deposit is regarded as a medium-high temperature and medium-deep hydrothermal gold deposit which is closely related to Zhongchuan instructive.
Key words: metal sulfides; component; EPMA; Liba gold deposit
