中文摘要:前河金矿区位于华北地台南缘,赋存在中元古界熊耳群安山岩和英安岩中,矿体受断裂破碎带控制。含矿热液在迁移过程中与围岩发生了广泛的流体_岩石反应而引起热液蚀变。本区石英中有4种类型的流体包裹体,均一温度范围为145~331℃,其中含CO2包裹体的完全均一温度主要分布在中_高温区。成矿流体的密度和压力变化范围分别是0.68~0.94 g/cm3和(367.01~896.55)×105Pa。金大量沉淀成矿时的流体特征为:温度213~260℃、密度0.80~0.89 g/cm3和压力(502.86~710.57)×105Pa。流体相为SO2-4>Na+>Cl->K+型,CO2/H2O比值及N2、H2S、Ar、C2H6等挥发分的含量明显增高,f(CO2)、f(H2S)、f(CH4)和Eh值增大;f(O2)、f(H2O)和pH值减小。在青磐岩化安山岩的基础上发生的流体-岩石反应是造成本矿床金沉淀成矿的最主要原因。
Abstract:The Qianhe gold deposit controlled by the fracture zone is hosted in the ductile shear zone of weakly metamorphosed rocks of the Middle Proterozoic Xiong'er Group. The ores occur as veinlike or lenticular bodies within altered andesitic_dacitic host rocks. Hydrothermal alteration resulted from the fluid_rock interaction in the migration process of ore_bearing hydrothermal fluids. There are four types of fluid inclusions in the gold deposit. Fluid inclusion data indicate that the temperature, density and pressure of the fluids are 145~331℃, 0.68~0.94 g/cm3 and (367.01~896.55)×105Pa in the whole fluid_rock interaction stage and 213~260℃, 0.80~0.89 g/cm3, (502.86~710.57)×105Pa in the gold deposition stage. Besides, the fluids of the main ore_forming stage are characterized by the increasing of the CO2/H2O ratio, the content of N2, H2S, Ar, C2H6 in vapor phase components, and the values of f(CO2), f (H2S), f (CH4) and Eh, and the deceasing of f (O2), f (H2O) and pH. The fluid ion components are characterized by SO2-4>Na+>Cl->K+. The fluid_rock interaction based on propylitic andesite seems to be the main cause for gold deposition.
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基金项目:高等学校创新引智计划(B07011)
引用文本:
曹 烨,李胜荣,申俊峰,要梅娟,李庆康,毛付龙.2008.豫西前河构造蚀变岩型金矿成矿过程中的流体-岩石反应[J].矿床地质,27(6):714~726曹 烨,李胜荣,申俊峰,要梅娟,李庆康,毛付龙.2008.Fluid-rock interaction in ore_forming process of Qianhe structurecontrolled alteration-type gold deposit in western Henan Province[J].Mineral Deposits27(6):714~726
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