滇中播卡金矿床流体包裹体研究  

Study on fluid inclusions of the Boka gold deposit in central Yunnan

作　　者：肖晓牛[1,2] 余新明[1,2] 张晓坤[1] 肖娥[1] 齐秋菊[1] 王武名[1] 游奔 刘荣芳[1] 

机构地区：[1]江苏省有色金属华东地质勘查局,江苏南京210007 [2]福建金东矿业股份有限公司,福建三明365101

出　　处：《地学前缘》2017年第3期309-318,共10页Earth Science Frontiers

基　　金：国家自然科学基金项目(41402077)

摘　　要：播卡金矿位于滇中元古宇铜多金属成矿带之东川矿集区,矿体呈脉状、网脉状、角砾状产于中元古界昆阳群地层中,受断裂构造控制。本文在详细的矿床地质观察和研究基础上,将本区成矿作用分为3个阶段:第1阶段为石英-黄铁矿阶段,第2阶段为石英-多金属硫化物阶段,第3阶段为石英-碳酸盐阶段。成矿主要集中在第1和第2阶段。本文通过金矿成矿各阶段的流体包裹体的岩相学观察,结合流体包裹体的显微测温、气液相成分分析,讨论了成矿流体的性质、演化过程。研究表明:第1阶段的流体包裹体均一温度在105~368℃,盐度为7.59%~44.32%(NaCleq);第2阶段的流体包裹体均一温度范围在119~294℃,盐度为5.26%~17.87%(NaCleq);第3阶段的流体包裹体均一温度在115~195℃,盐度为4.18%~14.57%(NaCleq)。流体包裹体气相成分以H_2O为主,其次为少量CO_2;液相成分以Na+、Cl-为主,其次为Ca^(2+)、SO_4^(2-),成矿流体主要属于NaCl-H_2O体系。综合矿床地质特征和成矿流体研究,本文认为播卡金矿属于岩浆热液矿床。The Boka gold deposit is located in the Dongchuan ore concentration area of the central Yunnan Proterozoic copper-polymetallic belt. The Au-bearing veins, stockwork and breccias occured in the strata of the Middle Proterozoic Kunyang Group and are controlled by faults. Hydrothermal mineralization of the deposit can be divided into stages 1, 2 ＆ 3, respectively named the quartz-pyrite, the quartz-polymetallic sulfide and the quartz-calcite stage. Our studies of deposit characteristics show that stage 1 and 2 were the main Au mineralization stages. Based on the study of fluid inclusion, which included petrography, homogenization temperature and liquid/gas composition analyses, the characteristics and evolution of the ore- forming fluid were further investigated. The results show that the homogenization temperatures of the ore- forming fluid are in the ranges of 105 - 368 ℃, 119 - 294 ℃ and 115 - 195 ℃ and salinities in the ranges of 7.59 - 44. 32 wt. % （NaCleq）, 5.26 - 17. 87 wt. % （NaCleq） and 4. 18 - 14. 57 wt. 0% （NaCleq） for stages 1, 2 and 3, respectively. Content studies of fluid inclusions indicate the gas composition of the ore-forming fluid are mainly H20 with little CO2, whereas the liquid composition are mainly Na^＋ and Cl^- with small amount of Ca^2＋ and SO4^2-. Clearly the main types of the ore-forming fluid belong to the NaCl-H2O system. We conclude that the Boka deposit is a typical magrnatic hydrothermal deposit based on its geological and fluid inclusion features.

关 键 词：流体包裹体 岩浆热液矿床 热液成矿作用 播卡金矿 滇中 

分 类 号：P618.51[天文地球—矿床学] P611[天文地球—地质学]