小西南岔铜金矿床脉型钼矿化特征及其与铜金矿化关系研究

吉林延边小西南岔铜金矿床北山矿段新发现的钼矿体呈规模较小的石英脉,空间上与相邻铜金矿体平行,它们受相同的构造体系控制。钼矿石中金属矿物以辉钼矿为主,并明显被黄铜矿和黄铁矿沿裂隙、晶隙充填交代,表明其形成于该矿床大规模铜金矿化的早期阶段。该石英脉中发育富气相、气液二相以及含子矿物多相包裹体,成矿流体为中高温(300～380℃)、高盐度(12.99%～47.36%NaCleqv)的NaCl-H2O体系,成矿流体曾发生过沸腾现象,表现出大规模铜金矿化早阶段的成矿流体特征。结合前人相关资料认为,北山矿段的辉钼矿石英脉应是该矿床大规模铜金矿化早期阶段的产物。该认识为小西南岔铜金矿床同位素测年及成矿机制深入研究奠定了理论基础。

Characteristics of fluid inclusion in lode molybdenum mineralization and its geological significance in Xiaoxinancha copper gold deposit

The quartz-molybdenite vein, discovered newly in the Beishan ore block of Xiaoxinancha copper-gold mine, is parallel to adjacent copper-gold ore bodies, indicating that they are commonly controlled by the same structure system. The metal minerals in molybdenum ore is dominated by molybdenite obviously cutting by later pyrite and chalcopyrite. The lode molybdenum mineralization shows the similar minerals assemble as early metallogenic stage of the major copper-gold mineralization. Primary inclusions in quartz minerals from the vein include gas, aqueous twophase and daughter-mineral inclusions. The ore-forming fluid is of high temperature （300 to 380 ℃ ） , high salinity （12.99 % to 47.36 % NaCleqv） and belongs to the NaCl- H2O fluid system. The fact that different types of inclusions are coexistent, together with their approximate homogeneous temperature, confirms that the fluid underwent the process of boiling as early-stage fluid of the major copper-gold mineralization in the deposit. Comparing with data on the Xiaoxinancha deposit, it can be concluded that the quartz-molybdenite vein is formed in the early metallogentic stage of copper-gold mineralization. The conclusion in this paper can supply basic data for isotopic dating and metallogenetic mechanism.