黔西北筲箕湾铅锌矿床闪锌矿中的成矿流体特征  

Characteristics of Ore Forming Fluid in Sphalerite of Saojiwan Lead-Zinc Deposit in the Northwest of Guizhou Province,China

作　　者：胡晓燕[1] 蔡国盛 苏文超[1] 曾道国 王蝶[1,3] 

机构地区：[1]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 [2]贵州省有色金属和核工业地质勘查局,贵州贵阳550002 [3]中国科学院研究生院,北京100049

出　　处：《矿物学报》2013年第3期302-307,共6页Acta Mineralogica Sinica

基　　金：贵州省科学技术基金(编号:黔科合J字[2010]2232号);国家自然科学基金(批准号:41103030;41130423)

摘　　要：选取黔西北筲箕湾铅锌矿床作为研究对像,勘测其地质构造和矿体产出等特征,在显微镜下观察其矿石组构特征。利用红外显微镜对闪锌矿中的包裹体的类型、形态、盐度、均一温度进行了测量。分析结果表明,闪锌矿中的原生流体包裹体主要是富液相包裹体,气液比小,测得的均一温度范围为115.4～169.9℃,平均温度为140℃;冰点-0.5～-13.7℃,盐度0.88%～17.52%(eq.NaCl wt%),密度为0.92～1.06 g/cm3,流体的压力为1×105～5×105Pa。筲箕湾铅锌矿床成矿流体为浅成低温流体,盐度主要有低盐度流体和中等盐度两个端元,成矿机制可能是低盐度大气降水与携带矿质的中高盐度流体混和使铅锌产生沉淀形成。We studied the geology structure and orebody output characters of Saojiwan lead-zinc deposit in the northwest of Guizhou Province,China.Petrography and ore structures under microscope were studied.The fluid inclusion types,shapes,salinities and homogenized temperatures in sphalerite were studied and tested under infrared microscope.Liquid-rich inclusions are dominant types of fluid inclusion in sphalerite,with low ratio of gas phase to fluid phase.Homogenized temperature of fluid inclusions in sphalerite ranges from 115.4 ℃ to 169.9 ℃,with the mean temperature of 140 ℃.Freezing point of fluid inclusions in saphalerite ranges from-0.5 ℃ to-13.7 ℃,with salinity ranging from 0.88% to 17.52% NaCl eqv.Density of the fluid is in the range from 0.92 g/cm3 to 1.06 g/cm3 and the pressure is from 1×105 Pa to 5×105 Pa.These features show that the ore-forming fluid of saphalerite is characrateristic of low temperature and low pressure,with mainly two type salinity of low and medium salinity.They imply that the ore forming fluid of Saojiwan lead-zinc deposit may come from medium salinity metal-bearing fluid,and the mechanism of metal deposit may be induced by the mixing of low salinity atmospheric water and metal-bearing medium salinity fluid.

关 键 词：黔西北 铅锌矿 闪锌矿 成矿流体 

分 类 号：P611[天文地球—矿床学] P618[天文地球—地质学]