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尽管对微细浸染型金矿的研究已有丰富资料,但在成矿流体和矿质的主要来源问题上仍存在争议,深入研究和探讨这一问题,不仅是矿床成因理论研究的深入,更是关系到该类型金矿找矿方向。本文以该类型金矿硅化与金矿化密切相关为依据,采用硅同位素结合硅质阴极发光分析,对赋存于中三叠统、“大厂层”、上二叠统、下石炭统和印支期辉绿岩中的该类型金矿矿石和热液硅化石英与相应赋矿围岩进行对比研究,结果表明:在阴极发光下,原生硅化石英不发光,而围岩中的石英和次生硅化石英明显发光;与此对应,矿石和热液硅化石英与围岩的δSI值也可以明显分开,表现为:在中三叠统和“大厂层”赋矿地层中,前者在-0.1‰～0.4‰,后者(包括岩浆岩)在0.0‰～0.3‰;在上二叠统,下石炭统和印支期辉绿岩赋矿围岩中,前者在0.3‰～0.5‰,后者在-0.1‰～-0.2‰。上述结果均表明原生成矿硅质与围岩硅质的来源不同,由此揭示原生矿质并非围岩提供;此外,上述数据中,由矿石和热液硅化石英所代表的成矿硅质流体的δ~(30)Si值表现为由新地层(T_2和“大
Although there is abundant data on the study of finely disseminated gold deposits, there is still controversy over the main sources of ore-forming fluids and minerals. Studying and discussing this issue in depth is not only an in-depth study on the genetic theory of deposits, but also a relationship To this type of gold prospecting direction. Based on the close relationship between silicification and gold mineralization in this type of gold deposit, this paper uses silicon isotope combined with siliceous cathodoluminescence analysis to analyze the relationship between silicification and gold mineralization in the Middle Triassic, Dachang layer, Upper Permian, This type of gold deposits and hydrothermal silicified quartz in Indosinian diabase are compared with the corresponding ore-hosting rocks. The results show that under the condition of cathodoluminescence, the primary silicified quartz does not emit light, while the quartz in the surrounding rock and the secondary Corresponding to this, δSI value of ores and hydrothermal silicified quartz and the surrounding rock can also be clearly separated. The results show that in the middle Triassic and “Dachang” ore-hosting strata, the former is between -0.1 ‰ ~ 0.4 ‰, and the latter (including magmatic rocks) range from 0.0 ‰ to 0.3 ‰. In the Upper Permian, Lower Carboniferous and Indosinian diabase dikes, the former is between 0.3 ‰ and 0.5 ‰, At -0.1 ‰ ~ -0.2 ‰. The above results indicate that the source rocks of the primary ore and the surrounding rocks are different, which reveals that the primary mineral is not provided by the surrounding rock. In addition, in the above data, the ore-forming siliceous fluids represented by ores and hydrothermal silicified quartz The δ ~ (30) Si values are represented by the new strata (T_2 and "Da