与碱性岩有关的浅成低温热液型金矿特征与控矿因素——以巴布亚新几内亚波尔盖拉金矿为例

    Ore-controlling factors and exploration indicators of alkaline magmatism related epithermal gold deposits: A case study of the Porgera gold deposit in Papua New Guinea

    • 摘要: 与碱性岩有关的浅成低温热液型金矿在全球特别是环太平成矿带中具有重要意义,波尔盖拉金矿位于新几内亚造山带内较为典型的该类型金矿床。矿床的矿化与碱性的波尔盖拉侵入杂岩体有关,矿化主要发育在岩体与白垩纪Chim组的接触部位,矿化作用分为2期,矿化形态主要为脉状和角砾岩矿化,成矿物质和成矿流体具有明显的岩浆来源的特征。与成矿有关的波尔盖拉杂岩体侵入时代为5.99Ma,与成矿时间一致,并来源于被交代富集型的上地幔,该类碱性岩浆对于金的富集具有重要的意义。通过总结该类矿床的控矿因素和找矿标志为中国企业在该地区寻找同类型金矿提供参考。

       

      Abstract: Epithermal gold deposits related to alkaline rocks possess a significant place in global metallogenic belts, especially in the Circum-Pacific metallogenic belt. Among them, the Porgera gold deposit located in the New Guinea orogenic belt is a typical deposit. The mineralization of the deposit is associated with alkaline Porgera intrusive complex and mostly occurs in the contact zone between the rock mass and the strata of Cretaceous Chim Formation. The ore-forming process can be divided into two stages, and the mineralization styles includes vein mineralization and breccia mineralization. The metallogenic materials and fluids of the deposit exhibit the characteristics of magma resources. The age of mineralization-related Porgera complex intrusion is 5.99Ma, which is consistent with the metallogenic epoch, and the magma of the intrusion originated from the metasomatic-enrichment type upper mantle. This kind of alkaline magma played an important role in gold concentration. The ore-controlling factors and indicators for the exploration of the deposits are summarized in this paper, which can provide guidance in search of similar deposits for China's mining enterprises.

       

    /

    返回文章
    返回