大兴安岭中南段布敦化铜矿床金鸡岭矿段流体包裹体研究  

Fluid inclusion study of Jinjiling ore block in Budunhua Cu deposit along middle-south section of Da Hinggan Mountains

作　　者：武新丽 毛景文[2] 周振华[2] 

机构地区：[1]华北冶金地质勘查局第四地质队,河北秦皇岛066013 [2]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

出　　处：《矿床地质》2014年第1期210-222,共13页Mineral Deposits

基　　金：中国地质调查局地质调查项目(1212011085260);内蒙古重要矿产资源潜力评价及区域成矿规律研究项目(2006-02-YS01);北方古生代斑岩-矽卡岩型铜矿成矿背景、成矿过程与找矿方向项目(N1312-3)联合资助

摘　　要：内蒙古布敦化铜矿床位于人兴安岭中南段，包括金鸡岭和孔雀山2个矿段，前者属于斑岩型，后者属于热液脉型，文章对金鸡岭矿段开展了详细的流体包裹体研究。金鸡岭矿段成矿过程可分为早、中、晚3个阶段，即毒为主成矿阶段。流体包裹体研究表明，早阶段主要发育富气相包裹体、气液两相包裹体和含子矿物多相包裹体，中阶段以气液两相包裹体为主，并发育少量含子矿物多相包裹体，晚阶段仅发育气液两相包裹体。早、中、晚阶段流体包裹体的均—温度和w（NaClcq）变化范围分别为320～550℃、240～550℃、140～300℃和12．2%～43．2％、6．3‰～17．2％、0．5％～9．7％。激光拉曼探针分析显示，早、中阶段包裹体气相成分为CH4和H20，而晚阶段的包裹体气相成分只含H2O。早阶段多种类型包裹体共生，且均一温度相近，指示早阶段流体发牛过沸腾作用。笔者认为早阶段成矿作用主要与高温、高盐度、含CH4流体的沸腾作用有关，中阶段的成矿作用则土要是流体混合向导致黄铜矿等金属硫化物的析出，晚阶段基本不成矿，只形成少量的黄铁矿。Situated in the middle-south section of the l）a Hinggan Mountains, the budunhua Cu deposit of Inner Mon golia consists of two ore blocks, i.e. , Jinjiling and Kongqueshan; the former belongs to the porphyry type and the latter belongs to the hydrothermal vein type. In this paper, the authors carried out a detailed study of fluid inclusions in the Jinjiling ore block. The ore-forming processes of the Jinjiling ore block can be divided into ear- ly, middle and late stages, which are characterized respectively by the arsenopyrite-pyrite （chalcopyrite）-quartz assemblage, the chalcopyrite-pyrrhotite-quartz assemblage and the carbonate-pyrite-quartz vein assemblage, withthe middle stage being the main ore-forming stage. Studies of fluid inclusions have shown that the early stage is dominated by liquid-rich inclusions, vapor-liquid two phase inclusions and polyphase inclusions with daughter- minerals, whereas the middle stage is dominated by vapor-liquid two phase inclusions and a small number of polyphase inclusions with daughter minerals. The late stage is characterized by the development of vapor-liquid two phase inclusions. The homogenization temperature is 320--550℃ for the early stage, 240--550℃ for the main stage and 140--300℃ for the late stage, while the salinity w（NaClcq） is 12.2% --43.2% for the early stage, 6.3 %-17.2 % for the main stage and 0.5 %-9.7 % for the late stage. Laser Raman spectroscopy indi- cates that the principal gas components of the fluid inclusions trapped in early and middle stages are CH4 and H20, whereas late stage inclusions only trap H20. At the early stage, the polytype inclusions coexist with each other and the homogenization temperature is similar, suggesting the existence of fluid boiling. This paper argues that the mineralization at the early stage was related to high temperature, high salinity and boiling fluid inclu- sions with Ct-I4, while the mineralization of the middle stage was mainly related to fluid mixing which led to the precipitation of the metal sulfi

关 键 词：地球化学 流体包裹体 斑岩型铜矿床 金鸡岭矿段 布敦化铜矿床 大兴安岭中南段 

分 类 号：P618.41[天文地球—矿床学]