吉林荒沟山金矿床成矿流体特征
Geochemical Characteristics of Ore-Forming Fluid in Huanggoushan Gold Deposit,Jilin Province

荒沟山金矿床为吉南老岭金-多金属成矿带内较具代表性矿床之一，产于元古宇老岭群珍珠门组地层之中，受韧性剪切带构造控制.按地质特征、矿物组合及矿脉之间的穿切关系，将荒沟山金矿床热液成矿作用划分为Ⅰ黄铁矿-毒砂-石英阶段和Ⅱ晚期辉锑矿-乳白色石英两个阶段.系统的流体包裹体岩相学及显微测温研究表明：Ⅰ阶段石英中发育含CO2三相、碳质及气液两相3种类型的原生流体包裹体，成矿流体属不混溶的中低温、低盐度NaCl-H2O-CO2体系热液，在成矿过程中发生过不混溶作用而导致金等有用元素沉淀富集；Ⅱ阶段石英颗粒中主要发育气液两相包裹体，成矿流体属均匀的NaCl-H2O体系热液.碳、氢、氧同位素研究表明，Ⅰ阶段成矿流体主要来源于岩浆热液，Ⅱ阶段流体除继承早阶段的热液外，还有大气降水的混入；δD和δ13CV-PDB 值分析结果证明两个成矿阶段流体均与地层发生过较强的水岩反应.矿床成因属于中温岩浆热液矿床.
Occurred in Zhenzhumen Formation of Laoling Group of Proterozoic Era and controlled by ductile shear belt,the Huanggoushan gold deposit is one of the most representative deposits in Laoling gold-polymetallic metallogenic belt in southern Jilin Province.Based on the geological characteristics,mineral assemblage and the crosscutting relationship between different kinds of veins,the hydrothermal mineralization processes can be divided into two main stages, namely, stageⅠpyrite arsenopyrite quartz and stage Ⅱ later stibnite-milky quartz.Systematic study on petrography and microthermometry of fluid inclusions shows that quartz of Stage Ⅰcontains three types of primary fluid inclusions,which are CO2 bearing three phases,carbonic and aqueous two phases inclusions respectively,and the ore forming fluid is of medium to low temperature and low salinity NaCl-H2O-CO2 kind of solutions and immiscibility happened in the ore forming process,which led to the enrichment of gold etc.;in quartz of Stage Ⅱ,there are aqueous two phases fluids only and ore forming fluid is of homogeneous NaCl-H2O kind of solutions. Isotopic studies of carbon,hydrogen and oxygen show that the ore forming fluids of mineralization StageⅠmainly derived from magmatic solutions, whereas fluids of mineralization stage Ⅱ mainly came from meteoric water in addition to the relicts of stageⅠore forming solutions. The values of δD and δ13CV-PDB reveal that the ore forming fluids of both mineralization StageⅠand Ⅱall experienced strong rock water reaction.The genesis of the gold deposit is medium temperature magmatic hydrothermal deposit