西藏嘎拉勒铜金矿床金和银的赋存状态研究

班公湖-怒江成矿带是西藏重要的铜多金属成矿带。嘎拉勒铜金矿床是该成矿带中发现较晚、研究程度较低且具代表性的矽卡岩型铜金矿床,矿石有用组分中金、银的赋存状态研究相对开展的较少,限制了矿床进一步的综合开发利用。作者通过野外地质调查与采样,采用光学显微镜鉴定、扫描电镜观察和X射线能谱仪测试分析等手段和方法,对矿石成分组分做了详细的研究,重点研究了矿床中金、银的赋存状态及主要载金矿物的特征。嘎拉勒铜金矿床金矿物以自然金、银金矿为主,其次为金银矿,可见粒间金、裂隙金及相对较少的包裹金形式,主要的载金矿物为石英、白云石、方解石、金属氧化物、硫化物及自然铋等。银矿物主要以金银系列矿物形式存在,少量自然银与放射性元素共生,此外,还有少量辉银矿。研究成果填补了该矿区金、银赋存状态研究的空白,对矿床的开发、利用有着重要的指示意义。

The modes of occurrence of gold and silver in the Galale copper gold deposit, Tibet

The Bangong Co-Nujiang River metallogenic belt is an important Cu polymetallic ore belt in Tibet. The Galale copper gold deposit was found relatively late in this metallogenic belt. It is a representative skarn type copper gold deposit, but the study of this deposit is at a low level. The study of the modes of occurrence of gold and silver in the useful components of the ore remains very insufficient, which restricts the further development and utilization of the ore deposit. The authors made a detailed study of the ore components by such means as sampling and field geological integrated investigation, optical microscope identification, scanning electron microscopy, energy dispersive X-ray spectrometer, and chemical formula calculation of mineral crystals. The gold minerals occur mainly as native gold and electrum and subordinately as küstelite. There are also intergranular gold, fissure gold and a relatively small amount of inclusion gold. The gold-bearing minerals are mainly quartz, dolomite, calcite, metal oxides, sulfides and native bismuth. Silver minerals mainly exists in the form of gold and silver minerals, with a small amount of silver minerals coexistent with radioactive elements. In addition, there exists a small amount of argentite. The results achieved by the authors have filled the gap of understanding the modes of occurrence of gold and silver in this area, and also provide important implications for the develop- ment and utilization of mineral deposits.