新疆祁漫塔格巴什尔希钨锡矿床流体包裹体地球化学研究  

Fluid inclusion geochemistry of Bashierxi tungsten-tin deposit in Qimantag area,Xinjiang

作　　者：丰成友[1] 于淼[2] 李大新[1] 李国臣[3] 周安顺[4] 李鑫[4] 

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]中国地质大学地球科学与资源学院,北京100083 [3]核工业北京地质研究所,北京100029 [4]吉林省地质调查院,吉林长春130061

出　　处：《矿床地质》2013年第1期20-36,共17页Mineral Deposits

基　　金：国家自然科学基金项目(批准号:41172076);中国博士后科学基金项目(编号:20090460132);中国地质调查局地质调查项目(1212011085528);中国地质调查局青年地质英才计划(201112)的联合资助

摘　　要：白干湖矿田是由柯可卡尔德、白干湖、巴什尔希和阿瓦尔等钨锡矿床构成的一个超大型钨锡矿田,其中的巴什尔希矿床正处于勘查阶段。文章对其开展了详细的流体包裹体岩相学、显微测温和氢、氧同位素地球化学研究,结果表明热液石英脉中流体包裹体以含CO2包裹体最多,其次为液体包裹体,含子矿物包裹体很少见,属于H2O-CO2-NaCl体系。均一温度范围广,介于260～440℃,集中在300～380℃;成矿流体w(NaCleq)较低,大多介于4%～12%;CO2摩尔分数〔x(CO2)〕为0·043%～0·595%,集中于0～0.2%。CO2相密度约0·74～0·84g/cm3,H2O相密度1·02～1·10g/cm3;成矿时流体压力为80～160MPa。流体演化经历成矿前期、成矿期和成矿后期3个期次,各期次流体演化趋势不同,整体上流体从成矿前期到成矿后期均一温度和盐度逐渐降低。流体包裹体氢、氧同位素组成表明钨锡主成矿期流体以岩浆水为主到后期硫化物矿化阶段又混合有大气降水。The Baiganhu W-Sn orefield consists of Kekekaerde,Baiganhu,Bashierxi and Aware deposits.Of these deposits,the Bashierxi W-Sn deposit is under exploration.Fluid inclusion microthermometry indicates that the ore-forming fluid of the Bashierxi W-Sn deposit is of the H2O-CO2-NaCl system.The fluid inclusions in hydrothermal quartz veins have 3 types：rich CO2-bearing inclusions,aqueous inclusions and rare hypersaline inclusions.The ore-forming fluid is characterized by a wide homogenization temperature range,varying from 260℃ to 440℃ and concentrated between 300℃ and 380℃,low salinity （generally varying in the range of 4%～12%）,x（CO2）of 0.043%～0.595%,relative density of CO2 about 0.74～0.84 g/cm3,relative density of H2O 1.02～1.10 g/cm3 and fluid pressure 80～160 MPa.All these properties of fluid inclusions are similar to features of some tungsten deposits abroad.The evolution of fluid inclusion underwent three stages：pre-mineralization stage,mineralization stage and post-mineralization stage,with each stage reflecting different trends of evolution.In general,the homogenization temperature and salinity of fluid inclusion decreased from the pre-mineralization stage to the post-mineralization stage.An analysis of H-O isotope reveals that the hydrothermal fluid was mainly of magmatic hydrothermal fluid at the W-Sn mineralization stage,mixed with meteoric water at the sulfide mineralization stage.According to the relationship between the properties of inclusions,the pressure of inclusions is positively correlated with the homogenization temperature,and the vapor ratio has a significant impact on the x（CO2）.

关 键 词：地球化学 流体包裹体 钨锡矿床 巴什尔希 白干湖矿田 祁漫塔格 东昆仑 

分 类 号：P618.44[天文地球—矿床学] P618.67[天文地球—地质学]