投稿时间：2020-01-07
修订日期：2020-09-21
网络发布日期：2021-01-08
中文摘要:班康姆铜金矿床位于墨江-黎俯火山弧带的中段，成矿条件优越，区内中性侵入杂岩具有岛弧钙碱性火山岩的地球化学特征，属火山岛弧环境。氢、氧同位素特征及黄铁矿流体包裹体的He、Ar同位素特征均指示流体为岩浆流体与大气雨水型地下水的混合流体，晚期经历了开放系统的持续瑞利去气过程。硫同位素组成表明成矿系统的硫源主要为深源地幔硫，推断Au、Cu应来自地幔源区，在俯冲消减的构造背景下，携带大量Cu、Au等成矿金属构成富矿初始岩浆流体。热液成矿作用经历了高温矽卡岩蚀变阶段、中温青磐岩热液蚀变矿化阶段、低中温金矿化阶段和超低温热液碳酸盐化阶段4个阶段，中低温阶段为主要的矿化阶段，而北东-北北东向次级断裂带成为浅部重要的容矿空间。流体包裹体及稀土元素特征指示了矿床深部存在隐伏的岩体，很可能为含矿的斑岩体，这对班康姆矿床乃至成矿带的研究及勘查具有重大的意义。
Abstract:The Pangkuam copper-gold deposit is located in the middle region of the Luang Prabang-Loei volcanic arc zone with favorable minerogenetic conditions. The andesite intrusive complex in this region with the geochemical characteristics of island arc calc-alkaline volcanic rocks belongs to the environment of the volcanic island arc. Hydrogen-oxygen isotopes and He and Ar isotopes of pyrite fluid inclusions all indicate that the magma source of the fluid was a mixed fluid of magma fluid and atmospheric rainwater groundwater. The late stage experienced a continuous Rayleigh degassing process of open system. Sulfur isotope composition indicates that the sulfur source of the metallogenic system was mainly deep mantle sulfur. It is inferred that Au and Cu should have come from the mantle source region. Under the tectonic background of subduction and subduction, they carried a large amount of Cu, Au and other metallogenetic metals to form rich ore initial magma fluid. Hydrothermal mineralization experienced four stages:High temperature skarnization alteration stage, medium temperature propylite hydrothermal alteration mineralization stage, low temperature gold mineralization stage, and ultra-low temperature liquid carbonation stage. The medium and low temperature stage was the main mineralization stage, while the NE-NNE-trending secondary fault zone became an important ore-hosting space in the shallow part. The characteristics of fluid inclusions and rare earth elements indicate the existence of concealed rock bodies in the deep part of the deposit, which are probably porphyry bodies containing ore. The results obtained by the authors are of great significance to the study and exploration of the Pangkuam deposit and even the study of the metallogenic belt.
keywords:geology mineralization genesis of deposit indicating significance copper-gold deposit Pangkuam Laos
文章编号：
中图分类号：
文献标志码：
基金项目:本文得到广西科技基地和人才专项项目（编号：桂科AD17195022）资助
引用文本：
卢见昆,赵延朋,陈晓锋,康铁锁,莫江平.2020.老挝班康姆铜金矿床成矿作用研究及其指示意义[J].矿床地质,39(6):1122~1140LU JianKun,ZHAO YanPeng,CHEN XiaoFeng,KANG TieSuo,MO JiangPing.2020.A study of mineralization in Pangkuam copper-gold deposit of Laos and its indicating significance[J].Mineral Deposits39(6):1122~1140
图/表
