摘要
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 Jineheng gold deposit lies in the north of Tongbai-Dabie orogenic belt in the Lu oshan County of the Henan Province. Ore bodies of veins and lens are controlled by ductile shear zone,and are hosted by metamorphic rocks of upper Proterozoic Huwangang Formation. In ac- cordance with paragenetic association of minerals and intercalation relationship of different veins, hydrothermal ore-forming period can be divided into 3 stages, quartz gold-pyrite stage, quartz-polymetallic sulfides stage and quartz-carbonate stage respectively. Based on the geological setting ore formation and the geologic feature of deposit, we further investigate the fluid inclusions in the quartz and the fluorite of each ore-forming stage as well as the oxygen and hydrogen isotope com-position of the quartz are studied. It shows that the ore-forming of the gold deposit is character-ized by medium to low temperature,medium to low salinity and low density system. The 3180 and 3D values in the ore forming fluid range from -5.98‰-＋4.1‰ and -72‰--86‰ respec-tively. The O-H isotope composition suggests that the ore-forming fluids originated from the mix-ing of magmatic and meteoric water. It s recognized that the evolution and migration of ore-form-ing fluids occur along the ductile shear zone from high temperature to low temperature,from high pressure to low pressure, from deep to .;hallow enrichment evolution. Finally, the metallogenic material enriched to ore deposit gradually in favorable structures.
出处
《矿物岩石》
CAS
CSCD
北大核心
2012年第3期51-61,共11页
Mineralogy and Petrology
基金
中国有色工业协会鑫达金银开发中心项目“河南罗山鑫恒金矿找矿综合研究与成矿预测”
