胶东地区留家沟金矿床成矿流体特征研究

Study on Ore-forming Fluids Characteristics of Liujiagou Gold Deposit in Eastern Shandong

留家沟金矿床位于胶东栖(霞)-蓬(莱)金成矿带内。本文对该矿床石英矿物中的流体包裹体进行了首次研究,研究表明,该矿床石英矿物中流体包裹体以纯液包裹体为主,其次为H_2O-CO_2气液两相包裹体。流体包裹体盐度范围集中于3wt%NaCl～12wt%NaCl,密度集中在0.80g/cm^3～1.02g/cm^3,表明矿床成矿流体属低盐度、低密度的富含CO_2的流体;流体包裹体均一温度在201℃～425℃,主要集中于220℃～300℃,代表了矿床主成矿阶段的成矿温度,属中低温热液矿床;成矿流体捕获压力为207Mpa～298Mpa,主要集中于253Mpa～290Mpa,估算成矿深度约8.43km～9.67km,属中深成矿床。

Liujiagou gold deposit is located in Qixia-Penglai metallogenic belt. The paper studied the characteristics of fluid inclusions in quartz minerals in this deposit. It is showed that the fluid inclusions in quartz minerals of the deposit are mainly liquid single-phase inclusions,and secondly are H2O-CO2 two-phase inclusions. The salinity is 3wt%NaCl ~ 12wt.%NaCl, the density is 0.80g/cm3 ~ 1.02g/cm3,the ore-forming fluids have characteristics of low salinity、low density and rich with CO2.Homogenization temperature is 201 ℃~ 425 ℃, and mainly 220 ℃~ 300 ℃,this represents the temperature of major metallogenic stage,the deposit is middle-low-temperature hydrothermal deposit. The metallogenic pressure is 207Mpa ~ 298Mpa,and mainly 253Mpa ~ 290Mpa, the mineralization depth is 8.43km ~ 9.67km,the deposit is was formed in the middle depth .