论文部分内容阅读
河南省罗山县金城金矿位于桐柏-大别造山带北侧,矿体受北西西向韧性剪切带控制,呈脉状、透镜状产于中元古界浒湾组变质岩中。根据矿物共生组合和脉体穿插关系,将热液成矿作用分为3个阶段:石英-金-黄铁矿阶段、石英-金-多金属硫化物阶段、石英-萤石-碳酸盐矿物阶段。本文在详细分析金城金矿床成矿地质背景、矿床地质特征的基础上,研究该矿床各阶段石英和萤石中流体包裹体,以及石英的氢、氧同位素特征。包裹体研究表明该金矿床的成矿流体分3个阶段,为中低温、中低盐度、低密度体系。成矿流体的δD为-72.0‰～-86.6‰(均值-79.0‰),δ18 O值为-5.98‰～+4.1‰(均值-0.32%),氢氧同位素分析表明初始成矿流体来源自岩浆热液,后期有大气降水成分加入。各阶段的流体具有沿韧性剪切带从深部到浅部,从高温到低温,从高压到低压运移和演化的趋势,最终在浅部构造有利的导矿-容矿构造逐渐富集成矿。
The Jincheng Gold Mine in Luoshan County, Henan Province, is located on the north side of the Tongbai-Dabie orogenic belt. The ore body is controlled by the NW-West ductile shear zone and is vein-shaped and lenticular in the metamorphic rocks of the Arvalian Paneo Formation. According to the symbiosis of mineral assemblages and vein interpenetration, the hydrothermal mineralization is divided into three stages: quartz-gold-pyrite stage, quartz-gold-polymetallic sulphide stage, quartz- fluorite- carbonate mineral stage. Based on the detailed analysis of the metallogenetic geological background and geological characteristics of the Jincheng gold deposit, the paper studies the fluid inclusions in quartz and fluorite and the hydrogen and oxygen isotopic characteristics of quartz in each stage of the deposit. The study of inclusions shows that the ore-forming fluid of this gold deposit is divided into three stages, which are middle-low temperature, middle-low salinity and low density systems. The δD values of ore-forming fluids ranged from -72.0 ‰ to -86.6 ‰ (mean -79.0 ‰) and δ18 O values ranged from -5.98 ‰ to + 4.1 ‰ (mean, -0.32%). Oxygen and oxygen isotope analysis indicated that the ore-forming fluids originated from magma Hydrothermal, later added to the composition of atmospheric precipitation. The fluid in each stage has the tendency to migrate and evolve from high pressure to low pressure along the ductile shear zone from deep to shallow, from high temperature to low temperature, finally enrich the ore-forming structure enriched in the shallow ore-bearing structure.