小秦岭金矿流体包裹体挥发组分与金的矿化

小秦岭石英脉型金矿矿物包裹体中挥发组分以Ｈ２Ｏ和ＣＯ２为主，还有少量的ＣＨ４、ＣＯ、Ｈ２、Ｈ２Ｓ等。富金矿石中包裹体的ＣＯ２＞３０ｍｏｌ％．ＣＯ２／Ｈ２Ｏ＞０．４，而贫金矿石中包裹体的ＣＯ２＜２０ｍｏｌ％，ＣＯ２／Ｈ２Ｏ＜０．２。前者包裹体的气体成分中含有较多的ＣＨ４、ＣＯ和Ｈ２等还原性气体．表明这种金矿的成矿流体以富含ＣＯ２为特征，ＣＯ２含量的变化对金的富集起着重要作用．因此金矿石中矿物包裹体的ＣＯ２含量或ＣＯ２／Ｈ２Ｏ比值可以作为深部预测的主要判据之一，并应用于小秦岭金矿山已取得良好的效果。

FLUID INCLUSION IN XIAOQINLING GOLD FIELD AND ITS SIGNIFICANCE TO GOLD MINERALIZATION

Gas chromatographic analysis of the fluid inclusion volatile in vein quartz from several gold deposits in Xiaoqinling gold field reveals that H,O and CO, are main components of volatile in the ore-forming fluid, and CH4, CO2, H2 and H2 S are minor ones. The gold-bearing fluid is significantly enriched in CO2. Variation of CO2 content bears close relationshipwith distribution of high grade ores.CO2 content of fluid inclusions in gold-rich ores(commonly more than 30 mole percent and CO2/H2O>0. 4)is higher than that in gold-poor ores. CO,content is typically less than 20 mole percent and CO2 /H2 is less than 0.2 in gold-poor ores. In addition,fluid inclusion volatile in gold-rich ores have a much higher concentration of redox gases (i. e.,CH4,CO and H2, etc.) CO2 content and CO2/H2O ration of fluid inclusion volatile may be a good exploration guide in deeper prediction of gold mineralization, and this method has achieved great successes in Xiaoqinling gold field.