柴达木盆地北缘三角顶金矿床成矿特征及其找矿意义

三角顶金矿是在柴达木盆地北缘唯一发现的产出于中酸性岩体中“似玲珑式”金矿,矿床具有重要的区域找矿意义。对该矿床的地质特征、矿石类型、岩矿石原生晕特征、含金石英脉的流体包裹体特征以及区域成矿事件进行了综合分析,探讨了矿床成矿特征及其找矿意义。含金石英脉、含金硅化糜棱岩反映了三角顶矿区多期次、多流体参与的叠加复合成矿作用,其中含金石英脉呈现浅成中低温中低盐度流体的特征,与岩浆作用关系密切;含金硅化糜棱岩型矿石与动力变质作用关系更为密切;三角顶金矿成矿深度由西向东增大,西矿区石英脉型矿体代表了该期成矿的顶部,形成了石英脉型的穹顶式金矿化层。在矿区西侧的石英脉型穹顶式金矿化层和矿区东侧的含金糜棱岩化带中,找矿潜力巨大。

Metallogenic Characteristics and Its Prospecting Significance of the Sanjiaoding Gold Deposit in the Northern Margin of Qaidam Basin

The Sanjiaoding gold deposit is the only “Linglong-like” gold deposit in intermediate-acid intrusions found in the northern margin of Qaidam Basin, which is very important in regional prospecting. This paper compiled the geological characteristics of the deposit, type of ores, primary features of halos of the ores and rocks, the characteristics of fluid inclusions in the gold-bearing quartz veins, and related regional metallization events, and further investigated the metallogenic characteristics and prospecting significance of the deposit. The gold-bearing quartz veins and gold-bearing silicified mylonites resulted from the combined effects of multi-stage fluid activities with various compositions in the Sanjiaoding area. Fluid inclusions hosted in the gold-bearing quartz veins show features of shallow medium-low temperature and medium-low salinity, and are genetically related to magmatism. The gold-bearing silicified mylonite-type ores are caused by regional dynamic metamorphism. The mineralization depth of the Sanjiaoding gold deposit increases from west to east, and the quartz-vein type in the western ore deposit fields represents the top of the system of this period, forming a dome-like gold mineralization layer. Such dome-like gold mineralization layer of the quartz-vein type in the west segment and the gold-bearing mylonitization zone in the east segment, have great potential targets for further prospecting.