广东玉水铜多金属矿床流体包裹体特征及地质意义

Characteristics and geological significance of fluid inclusions in the Yushui copper polymetallic deposit, Guangdong Province

广东玉水铜多金属矿床位于华南MVT（密西西比河谷型）铅锌矿床成矿带东段，铜铅锌矿体主要呈不规则囊状产于下石炭统忠信组滨海相石英砂（砾）岩和上石炭统壶天群白云岩之间，少量呈不规则脉状分布于白云岩中。其主矿体中铜的品位极高，2013年入选品位为15.5%；矿石主要呈块状，少量浸染状。矿石矿物主要包括黄铜矿、斑铜矿、辉铜矿、方铅矿、浅色闪锌矿、黄铁矿、赤铁矿、磁铁矿等，主要脉石矿物为白云石、方解石，局部偶见石英。发育赤铁矿-磁铁矿和硫化物两个成矿阶段。选取主成矿阶段——硫化物阶段硫化物矿石中的闪锌矿和石英进行流体包裹体研究，结果表明：玉水流体包裹体主要以气液两相包裹体为主，气液比5%~20%，均一温度范围为90~289℃，其中闪锌矿中流体包裹体均一温度90~289℃，石英中流体包裹体均一温度110~287℃，方解石中流体包裹体均一温度125~210℃，包裹体盐度范围集中在8%~15%。激光拉曼探针测试表明流体包裹体气体成分主要是H2O，个别气相成分CO2。流体包裹体研究，结合矿床地质地球化学研究成果表明玉水铜多金属矿床是一个层控的低温热液型矿床。

The Yushui copper polymetallic deposit is located in the east zone of the South China MVT (Mississippi valley type zincleaddeposits) metallogenic belt. The orebody mainly occurs between the littoral quartz sandstone of lower Carboniferous ZhongxinGroup and littoral dolomite of upper Carboniferous Hutian Group, with a small number of mineral veins hosted in dolomite. The oregrade is so high that the processing grade was 15.5% in 2013. The ore is mainly in massive form while a small amount of ore beingdisseminated. The ore minerals include chalcopyrite, bornite, chalcocite, galena, sphalerite, pyrite, hematite and magnetite, and the main gangue minerals consist of dolomite, calcite and a small amount of quartz. The mineralization can be divided into hematitemagnetitestage characterized by existence of gel texture gangue and sulfide stage. By analyzing the temperature and salinity of fluidinclusions in sphalerite and quartz from the main metallogenic stage (sulfide stage) the authors found that the fluid inclusions fromthe Yushui copper polymetallic deposit mainly consist of gas-liquid two phase inclusions, with the gas-liquid ratio ranging from5% to 20%, and the homogenization temperature ranging from 90℃ to 289℃. In addition, the homogenization temperature of fluidinclusions in sphalerite ranges from 90℃ to 289℃; the homogenization temperature of fluid inclusions in quartz ranges from 110℃to 287℃ ; the homogenization temperature of fluid inclusions in calcite ranges from 125℃ to 210℃, the inclusion salinity range isconcentrated on 8wt%-15wt%. The laser Raman microprobe test shows that the gas composition of the fluid inclusion is H2O withminor CO2. Fluid inclusion study combined with geological and geochemical studies of the deposit suggests that the Yushui copperpolymetallic deposit is a stratabound and epithermal deposit.