湘西北张家界市李家铜矿流体包裹体地球化学特征

    Geochemical characteristics of fluid inclusions in Lijia copper mine, Zhangjiajie, Northwest Hunan

    • 摘要: 湘西北地区是著名的铅锌矿、锰矿产出地,为完善该地区成矿序列,对张家界市李家铜矿成矿期的石英、方解石、重晶石进行了流体包裹体均一温度、盐度、气相成分、群体液相成分和氢氧同位素测定。结果表明: 包裹体均一温度为146~282 ℃,流体盐度为0.71%~15.86%(NaCl),成矿流体气相成分含少量的CH4和H2,包裹体液相成分中离子以Ca2+、Mg2+、Na+、SO_4^2-及Cl-为主,氧同位素δ18O矿物值范围为11.6‰~17‰,氢同位素δD值范围为-54.7‰~-76.2‰。经计算,成矿压力为1.02~66.17 MPa,成矿深度为0.1~6.57 km。成矿热液为层控型热卤水,成矿时间自震旦纪陡山沱期一直持续到志留纪文洛克期。

       

      Abstract: Northwest Hunan is a famous area producing lead-zinc ore and manganese ore. In order to improve the research on the metallogenic sequence in this area, the authors made some analyses on the intramineral quartz, calcite and barite in Lijia copper mine in Zhangjiajie, which include homogenization temperature, salinity, gas compositions, liquid compositions and oxygen and hydrogen isotope. The results show that the homogenization temperature of the inclusion is from 146 ℃ to 282 ℃, and the salinity of the ore-forming fluid is from 0.71% to 15.86% (NaCl). The gas components of the ore-forming fluid have a little CH4 and H2, and the ions in the inclusion liquid compositions are mainly Ca2+, Mg2+, Na+, K+, SO_4^2- and Cl-. The oxygen isotope (δ18O矿物) value is from 11.6‰ to 17‰, and the hydrogen isotope (δD) value is from -54.7‰ to -76.2‰. By calculation, the metallogenic pressure is from 1.02 MPa to 66.17 MPa, and the metallogenic depth is from 0.1 km to 6.57 km. It can be concluded that the metallogenic hydrothermal solution is a stratabound hot brine, and the metallogenic time is from Sinian Doushantuo period to Silurian Wenloch period.

       

    /

    返回文章
    返回