山东金翅岭金矿成矿流体特征

摘 要]通过流体包裹体岩相学、显微测温学和包裹体稀土元素等的分析,研究山东金翅岭金矿床成矿流体性质和演化,研究结果表明:流体包裹体主要为气液两相包裹体,另有少量液相包裹体。包裹体气相成分主要以H₂O、CO₂为主。液相成分属Na⁺-K⁺-Ca²⁺-Mg²⁺-Cl^--SO²_-4体系,成矿流体为岩浆热液夹有变质水和大气降水的混合流体。流体包裹体的均一温度介于140～350℃,金的主成矿期为第域和第芋阶段,成矿温度范围为290℃～185℃,流体盐度介于7.3%～8.9%,为中-低温、低盐度的成矿流体。石英、黄铁矿包裹体稀土元素特征研究表明:轻稀土富集,重稀土亏损,具有中等负铕异常,标准化曲线为略右倾曲线。

Characteristics of Ore-forming Fluid from the Jinchiling Gold Deposit in Shandong Province

This work analyzed the fluid inclusions,micro-thermometry and rare earth elements of the Jinchiling gold deposit in Shandong Province.The objective was to study the property and evolution of the ore-forming fluid of this gold deposit.The result shows that these inclusions are dominated by gas and liquid two-phase ones,with few of liquid phase.The compositions of gas in the inclusions are primarily H2O and CO2.The liquid composition is Na+-K+-Ca2+-Mg2+-Cl--SO2-4,and ore-forming fluid is the mixed fluid of magmatic hydrothermal and meteoric water.The homogenization temperature is 140℃～350℃.The main mineralization of gold occurred in the second and third stages of the evolution when the temperature was 185℃～290℃.And the salinity of fluid inclusions is 7.3% to 8.9%,implying an ore-formation fluid of intermediate-low temperature and low salinity.The REE(rare earth element) analysis shows that the inclusions are characterized by LREE(light rare earth element) enrichment,HREE(heavy rare earth element) deplerion,middle negative Eu anomalies,and slightly right-deviation standardization curves.