摘要
湘西雪峰山地区分布着众多的金、钨、锑矿床(点)是湘西-鄂西多金属成矿带的重要组成部分,铲子坪大型金矿床是其中颇具代表性矿床之一。文章对铲子坪金矿床主成矿阶段石英中的流体包裹体进行了系统的研究。结果表明,该矿床内流体包裹体主要为气液两相,存在少量纯气相和纯液相包裹体。成矿流体均一温度主要集中在160~220℃和280~360℃两个区间,盐度集中8%~11%NaCleqv,密度集中在0.62~1.00 g/cm3,成矿流体主要为一种中高温、低盐度的Na Cl-H2O体系,成矿环境为低压(39.4~98.9 MPa)中成(3.9~8.2 km)环境。流体包裹体气相成分以H2O为主,次为CO2;液相组分中,阳离子以Na+和Ca2+为主,阴离子以SO2-4和Cl-为主,属Cl--SO2-4-Ca2+-Na+型水化学类型。流体包裹体H和O同位素研究表明,岩浆水和变质水是成矿流体的主要来源,在成硫后期有大气降水的掺入,成矿流体具混合流体特征。成矿作用阶段,矿区内构造破碎带为含矿热液集中和金的沉淀提供了良好的容矿构造场所,印支期的岩浆热液活动占主导作用。铲子坪金矿的成因类型为中高温岩浆热液型。
The Xuefeng Shan area is an important part of the metallogenic belt of mercury,antimony,gold,lead,zinc,iron and manganese in western Hunan and western Hubei Province,of which the Chanziping large gold deposit is a representative. Systematic studies including petrography,microthermometry,and laser Raman microprobe were carried out on the main metallogenic stage of fluid inclusions in quartz of this deposit. Fluid inclusions from the gold deposit dominated by the gas-liquid two phase,containing a small amount of pure gas phase and liquid phase inclusions. Ore-forming fluid uniformity temperatures concentrate in 160 ~ 220℃ and 280 ~ 360℃. The salinity of ore-forming fluid is between 8% ~ 11% Na Cleqv. The mineralization density ranges from 0. 62 to 1. 00 g / cm3. The ore-forming fluids belong to Na Cl- H2 O type characterized by medium temperature,low salinity and low density. They formed at a medium pressure( 39. 4 ~ 98. 9 MPa) and in a medium( 3. 9 ~ 8. 2 km depth) environment. The gaseous content of the fluid inclusion is primarily H2 O,and secondly CO2. In the liquid phase components,cation mainly includes Na+and K+and anion mainly contains Cl-and F-,implying the Cl-- SO2-4- Ca2 +- Na+hydrochemical type. The analysis results of hydrogen and oxygen isotopic elements show that ore-forming fluids are mainly derived from magmatic water and metamorphic water mixed with meteoric water later. Ore-forming fluid has the feature of mixed fluids. In the mineralization stage,the structural fracture zone in the mine provided a good ore-holding place for the ore-bearing hydrothermal concentration and precipitation of gold,and magmatic hydrothermal activity of Indo-Chinese epoch played a leading role. The genetic type of the Chanziping gold deposit can be classified into the high temperature magmatic hydrothermal type.
出处
《地质与勘探》
CAS
CSCD
北大核心
2015年第2期212-224,共13页
Geology and Exploration
基金
中国地质调查局大调查项目(No.1212010632005)
地质矿产调查评价专项(No.1212011120790)资助
关键词
流体包裹体
成矿流体
金矿床
铲子坪
湘西
fluid inclusion,mineralization fluid,gold deposit,Chanziping,western Hunan
