辽宁凌海市金家金矿床流体包裹体研究

Fluid Inclusions of Jinjia Gold Deposit in Linghai City of Liaoning Province

金家金矿床位于辽宁省凌海市,包括刘屯和金屯两个矿体,矿石类型主要为硫化物石英脉型。对采取地表、坑道及钻孔中的含金石英脉样品进行包裹体测温和成分分析,以研究矿床形成的物理化学条件。结果表明,成矿只有一期,成矿流体是含CO_(2)及Ca^(2+)、Na^(+)、Cl^(-)的NaCl-H_(2)O-CO_(2)体系。均一温度直方图呈单峰式,成矿温度平均为210℃,盐度为8.5%(NaCl),矿化度为38.35 g/L,密度为0.91 g/cm^(3),压力为79×10^(5)~262×10^(5) Pa,氧分压逸度为-70.36,pH值为6.12,氧化还原电位(Eh)为-0.37 V。包裹体成分中的阴离子主要为Cl^(-),金主要以氯的络合物形式被搬运迁移。综合认为金家金矿是在弱酸、还原环境形成的浅成中低温矿床。

Jinjia gold deposit is located in Linghai city of Liaoning province.Ore type of this deposit is mainly sulfide quartzvein type,including Liutun orebody and Jintun orebody.Inclusions in samples of gold bearing quartz vein from the surface,tunnel and drill hole are analyzed to study the metallogenic physicochemical conditions.The results show that there is only one metallogenic period.Ore-forming fluid is a NaCl-H_(2)O-CO_(2) system and riches in CO_(2),Ca^(2+),Na^(+)and Cl^(-).Histogram of homogenization temperature of inclusions is unimodal type.The ore-forming temperature is 210℃,salinity is 8.5%(NaCl),degree of mineralization is 38.35 g/L,density is 0.91 g/cm^(3),pressure is 79×10^(5)~262×10^(5) Pa,the fO2 is-70.36,pH value is 6.12,and Eh is-0.37 V.The anions in ore-forming fluid is chiefly Cl^(-)and the gold is transfered and migrated in the form of chlorine complex.Comprehensive analysis reveals that Jinjia gold deposit is a hypergene medium-low temperature deposit formed in weak acid and reduced environment.