【摘要】 西秦岭寒武系中的层控金矿床,产于由碳质硅岩和碳质板岩组成的硅岩建造中。极其特征的硅岩建造为评价喷流作用及其对金矿床形成的控制,提供了重要的依据。研究表明,无论是围岩还是金矿石中,均普遍含有较高的硒,达到工业综合利用的要求。在局部地段甚至可圈出独立的硒矿体。在金矿石中,硒主要呈独立矿物和以类质同象形式存在于硫化物中,且硒与金存在密切的正相关关系。根据硒的富集特征和产出环境,笔者指出了我国硒的找矿前景。更多还原

【Abstract】 The gold deposits, occurring in the south subzone of western Qinling Mountains, include Laerma and Qiongmo ore deposits and Yaxiang ore occurrence. They are the only typical and important stratabound gold deposits that closely associated with submarine cxhalative-sedimenta-tion. The deposits exist in the Cambrian siliceous formation composed of black siliceous rocks and slate. The presence of the typical siliceous rocks offers an important evidence to evaluate the possible submarine exhalative system and its control over the formation of the gold deposits. Bedded-quasibedded and lencular orebodies occur in the siliceous formation. More than 80 percent of the orebodies are present in the siliceous rocks. Element paragenesis and mineral assemblage of the ores are very complicated . More than 80 kinds of minerals were identified in the ores. In addition to ordinary minerals such as pyrite, marcasite, stibnite, native gold etc. , there are a number of copper,uranium and selenium minerals. In some parts, independent Cu,Sb,U, Mo and Se orebodies could be delimited. The concentration of selenium is abnormally high. In the Se-en-riched gold ores, Se is generally within the range of n× 10-5-n× 10-4(even up to n × 10-3) . And selenium occurs mostly as independent selenium minerals, only part of it is distributed in the sulfides in dispersed or isomorphous forms. Sometimes, selenium is dispersed in transparent minerals ( e. g. quartz ,barite and so on). With such a complex element paragenesis (Au-Cu-U-Mo-Se-PGE),this type of gold deposits has been reported for the first time in China and is worthy of being further studied.更多还原