Challenge to the visualization of the formation process of the epithermal gold deposit and its application to the developments of rare metal resources

对浅成热液型金矿床的形成过程进行观测是不可能的。因此，为了阐明浅成热液型金矿新的精确形成机制，对天然浅成热液型金银脉样、地热发电厂形成的硅质矿床、人工硅质含金物质进行了稀土元素模式和金银化学状态的研究。通过对浅成热液金矿脉样品和硅质矿床的分析，合理推断Ce和Eu异常在形成时保持了氧化还原条件，局部微量元素分析也支持了整体分析结果。另一方面，人工材料中金的化学状态与天然金样品中金的化学状态不同，表明其他热液可能与热升热液混合。

It is impossible for us to observe the formation process of epithermal gold deposit. Therefore, in order to elucidate the new and precise formation mechanism of epithermal gold deposits, natural epithermal gold-silver vein sample, siliceous deposit formed at geothermal power plant and artificial siliceous gold-bearing material were examined in terms of REE patterns as well as the chemical state of gold and silver. Based on the analysis of epithermal gold vein sample and siliceous deposit, it is reasonably concluded that Ce and Eu anomaly kept the redox condition when those were formed, and bulk analysis result were supported by local analysis for trace elements. On the other hand, the chemical state of gold in artificial materials were different from that in natural gold sample, suggesting that the other hydrothermal fluid should be mixed with hot ascending hydrothermal fluid.