粤西河台金矿床的流体包裹体及成矿流体

FLUID INCLUSIONS AND HYDROTHERMAL FLUIDS OF HETAI GOLD DEPOSIT, WESTERN GUANGDONG, CHINA

河台金矿床存在三种类型流体包裹体：低盐度（约1．5～6wt％NaCl）H2O-CO2包裹体、中等盐度（约6～14wt％NaCl）水溶液包裹体、富CO2包裹体。它们的均一化温度范围在130℃至310℃之间，捕获时的围压大约为50～170MPa。初始的成矿流体是一个低盐度的以H2O－NaCl-CO2为主的上学体系，主要源于大气水与变质建造水的混合。在演化过程中，成矿热液流体发生了CO2发泡和气液两相不混溶作用。根据均一化温度的统计分布推断，在245℃和170℃附近曾出现两次大规模的不混溶现象。

There are three compositional types of fluid inclusions in the Hetai gold field: low-salinity (about 1. 5 - 6 equiv. wt %Nacl ) H2O-CO2 type, moderate salinity (about 6 -14 equiv. wt % NaCl)aqueous type,and CO2-dominated type. Their homogenization temperatures range from 130℃ to 310℃, and the confined pressures from 50 MPa to 170MPa. The primary mineralizing fluid is a H2O-NaCl-CO2-dominated system with low salinity, principally derived from a mixed source of metamorphic and meteoric water. The CO2 effervescence and unmixing took place during the evolu-tion of this fluid. The statistic distribution of homogenization temperatures indicates that there were two times large-scale unmixing of the primary hydrothermal fluid into a moderately saline aqueous phaes and a non-saline CO2-dominated phase.