西南天山中—新生界层控砂砾岩型铜铅锌矿成矿规律

Metallogenic regularity of Meso-Cenozoic stratabound glutenite-type Cu-Pb-Zn deposits in the southwestern Tianshan Mountains

西南天山是新疆中—新生界层控砂砾岩型铜铅锌矿的重要产出地区,以萨热克铜矿、乌拉根铅锌矿、花园铜矿、伽师铜矿为代表,均产于隆起剥蚀区边缘的红层盆地中并严格受层位控制,赋矿盆地的下部为煤系生烃岩,中部为渗透性良好的砂砾岩铜铅锌矿储集层,上覆膏岩及泥岩等密闭盖层,具有铜铅锌-铀-煤-天然气同盆共存富集的成矿特征。文章总结了西南天山赋矿盆地沉积-构造演化及赋矿层位特征,研究了铜铅锌典型矿床的控矿条件和成矿作用特征。通过对比分析,总结了中—新生界砂砾岩型铜铅锌矿的区域成矿规律,认为有机质与铜铅锌成矿关系密切,推测在原始矿源层的基础上,在隆起部位经油田卤水叠加形成铜铅锌贫矿体,喜马拉雅期断裂构造沟通深源成矿流体再次叠加形成铜铅锌富矿体。总结构建了西南天山中—新生界层控砂砾岩型铜铅锌矿的成矿模式,以期为已知矿山深边部勘查及区域找矿工作部署提供依据。

The southwestern Tianshan Mountains is an important producing area of the Meso-Cenozoic stratabound glutenite-type Cu-Pb-Zn deposits in Xinjiang.Sareke copper mine,Wulagen lead-zinc mine,Huayuan copper mine and Jiashi copper mine are the representative deposits,which all occur in the red bed basin on the edge of the uplift denudation area and are strictly controlled by strata.The lower part of the ore-bearing basin is composed of coal-bearing hydrocarbon-generating rocks,the middle part is well-permeable glutenites as the Cu-Pb-Zn reservoir,and the overlying layer is a sealed cap formed by gypsum rocks and mudstones,showing the ore-forming characteristics of co-enrichment of Cu-Pb-Zn-Uranium-coal-natural gas in the same basin.In this paper,we summarized the sedimentary-tectonic evolution of these ore-bearing basins and the characteristics of ore-bearing layers,and analyzed the ore-controlling conditions and metallogenic characteristics of typical copper,lead and zinc deposits.Combining with comparative analysis,we summarized the regional metallogenic regularity of the Meso-Cenozoic glutenite-type Cu-Pb-Zn deposit,and hold the view that organic matter is closely related to Cu-Pb-Zn mineralization.Moreover,it is inferred that Cu-Pb-Zn-lean ore bodies were formed over the original source layer in the uplift caused by the superimposition of oilfield brine;Cu-Pb-Zn-rich ore bodies were formed by the superimposition of deep-source ore-forming fluids from the Himalayan fault structure.The metallogenic model of the middle Cenozoic stratabound glutenite-type Cu-Pb-Zn deposits in the southwestern Tianshan Mountains provides a basis for the exploration of the known mines in their deep and edge,and also provides guidance for the regional prospecting work.