内蒙古额尔古纳地区比利亚谷铅锌(银)矿床成矿流体特征与矿床成因  

ORE-FORMING FLUID AND ORE GENESIS OF THE BILIYA VALLEY LEAD-ZINC(SILVER)DEPOSIT IN ERGUNA REGION,INNER MONGOLIA

作　　者：段明新[1] 任云生[1] 侯召硕[1] 孙德有[1] 孙振明[1] 秦朝建[2] 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [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

出　　处：《矿物岩石》2014年第2期60-67,共8页Mineralogy and Petrology

基　　金：中国地质调查局项目(1212011121081);中国核工业地质局项目(201151)

摘　　要：比利亚谷矿床是内蒙古额尔古纳成矿带内新发现的一个铅锌（银）矿床，具有大型矿床的成矿潜力。主矿体呈脉状产于上侏罗统塔木兰沟组和满克头鄂博组火山岩地层中，受NW，NWW向张性断裂构造控制；主要金属矿物有方铅矿、闪锌矿、黄铁矿、黄铜矿、辉银矿等。为确定该矿床的成矿流体特征及成因类型，对矿石中的石英、重晶石和闪锌矿开展了流体包裹体的岩相学观察、显微测温和激光拉曼光谱分析。结果表明，上述矿物中主要发育富液相、CO2三相和少量含子矿物三相包裹体；富液相包裹体的均一温度与盐度分别为102℃～378℃和0．2％～10．5％NaCleqv，CO2三相包裹体的均一温度和盐度分别为124℃～256℃和1．8～11．2％NaCleqv，舍子矿物三相包裹体的均一温度与盐度分别为220℃和42．4％NaCleqv。单个流体包裹体气相成分的激光拉曼光谱分析显示，除石英中的部分富液相包裹体的气体成分含CO2外，不同矿物中的富液相包裹体的气体成分均为H2O。此外，该矿床成矿流体的盐度范围波动较大，重晶石中包裹体的均一温度分布范围较广，因此成矿流体属不均匀流体，流体混合作用是该矿床的重要成矿机制。综合认为，比利亚谷铅锌（银）矿床应属赋存于中生代火山岩中的与浅成一超浅成岩浆作用有关的中低温热液脉型矿床。The major orebodies of Biliya valley lead-zinc （silver） deposit,Inner Mongolia,characterized by ore-bearing quartz veins and controlled by the NW and NWW-trending faults,occur in the volcanic rocks of Late Jurassic Tamulangou Formation and Manketouebo Formation. Metal minerals in the ore include galena, sphalerite, pyrite, chalcopyrite and argentite. Petrography observation,microthermometry and Laser Raman spectroscopy of fluid inclusions from the quartz, sphalerite and baritite formed in the major mineralization stage have been carried out for the purpose of determination of ore-forming fluid and ore genesis. The results show that fluid inclusions in these minerals can be classified into three types of aqueous two-phase,CO2-bearing and daughter mineral-bearing multiphase. Homogenization temperatures and salinities of three types of fluid inclusions range from 102 ℃ to 378 ℃,0.2% NaCl eqv to 11.2% NaCl eqv,124 ℃ to 256 ℃, 1.8% NaCl eqv to 11.2% NaCl eqv,220 ℃,42.4% NaCl eqv,respectively. Laser Raman spectroscopy shows that the gas in aqueous two-phase inclusions is mainly composed of H20 with mi- nor CO2. According to the wide salinity range of the inclusion within quartz and the homogenization temperatures of fluid inclusions in barite, it is recognized that the mixing of the ore-forming fluid played an important role in the enrichment of the Biliya valley lead-zinc （silver） deposit,and the deposit is one of mesothermal-epithermal polymetallic deposits hosted by the Mesozoic volcanic rocks and associated with the hypabyssal or ultra hypabyssal magmatism.

关 键 词：地质特征 流体包裹体 比利亚谷铅锌(银)矿床 流体混合作用 额尔古纳地区 

分 类 号：P618.4[天文地球—矿床学]