胶东栖霞山城金矿流体包裹体特征及其成矿意义

Characteristics and Metallogenic Significance of Fluid Inclusion in Shancheng Gold Deposit in Qixia City in Jiaodong Area

摘要:

胶东栖霞山城金矿是产于太古宙基底变质岩系中的富含铜、铅、锌等有益组分的石英脉型金矿床，通过对成矿流体包裹体的研究表明：山城金矿包裹体多成群分布，形态规则，其类型以富液体包裹体为主，少部分为H2OCO2三相包裹体。流体包裹体的均一温度主要分布在150～240℃之间，与钾交代关系密切的早期成矿温度为290～310℃，多金属硫化物石英脉成矿温度在130～290℃区间，代表了成矿期的温度区间，成矿温度较钾交代的温度明显偏低。盐度为0.35%～13.5%，主要集中在3.5%～7%之间，属低中盐度，但多金属硫化物石英脉具有更宽泛的盐度区间。压力介于272～438MPa，平均为337.1MPa，不同矿化类型成矿流体压力值也存在明显差异，早期的钾交代型矿石的成矿流体压力相对较高，多金属硫化物石英脉型矿石流体压力相对较低。山城金矿成矿流体具有早期相对高温、高压、高盐度的流体，晚期成矿流体的温度、压力和盐度值都相对较低，说明成矿流体是连续演化的过程。

Abstract:

Shancheng gold deposit in Qixia city in Jiaodong area is a quartz vein type gold deposit. It is rich in copper, lead, zinc and other beneficial components. It occurs in Archean basement metamorphic rock series. Through study on oreforming fluid inclusions, it is showed that most of the inclusions in Shancheng gold deposit are distributed in groups with regular morphology. The types are mainly liquid rich inclusions, and a few are H 2O CO 2 threephase inclusions. The homogenization temperature of fluid inclusions is mainly 150 ~240 ℃. The early mineralization temperature closely related to potassium metasomatism is 290~310℃. The mineralization temperature of polymetallic sulfide quartz veins is 130~290℃, representing the temperature range of the mineralization period. The mineralization temperature is significantly lower than that of potassium metasomatism. The salinity is 0.5%~13.5%, and mainly between 3.5%~7%. It belongs to low and medium salinity, but the polymetallic sulfide quartz vein has a wider salinity range. The pressure is 272~438MPa, with an average value of 337.1MPa. There are also significant differences in the pressure values of oreforming fluids of different mineralization types. The pressure of oreforming fluids of early potassium metasomatic ores is relatively high, while that of polymetallic sulfide quartz vein ores is relatively low. The oreforming fluid of Shancheng gold deposit has relatively high temperature, high pressure and high salinity in the early stage, while the temperature, pressure and salinity of the late stage oreforming fluid are relatively low. It is indicated that the oreforming fluid is a continuous evolution process.