投稿时间:2013-01-04
修订日期:2013-09-12
网络发布日期:2013-12-29
中文摘要:河南省杨砦峪金矿床位于华北克拉通南缘,是小秦岭地区大型的石英脉型金矿床。据野外观察,成矿过程经历了4个阶段:Ⅰ黄铁矿-石英脉阶段;Ⅱ石英-黄铁矿阶段;Ⅲ石英-多金属硫化物阶段;Ⅳ石英-碳酸盐阶段。包裹体岩相学、显微测温以及激光拉曼显微探针研究显示,该矿床为CO2-H2O-NaCl±CH4流体体系,并且发生不混溶。从第Ⅰ成矿阶段到Ⅳ成矿阶段,流体包裹体的均一温度范围分别是307~407℃,270~320℃,225~272℃和166~226℃,呈现逐步降低的趋势;盐度w(NaCleq)平均值分别为7.3%,7.1%,9.0% 和6.4%。各阶段成矿压力为120~178 MPa,85~140 MPa,75~130 MPa和60~122 MPa,呈现逐渐降低的趋势。流体不混溶作用是导致杨砦峪矿质沉淀的重要原因,其诱因可能与控矿断裂由压扭转为张扭所导致的构造减压有关。
Abstract:Located in the southern margin of the North China Craton, the Yangzhaiyu gold deposit in Henan Province is one of numerous lode gold deposits in Xiaoqinling region. The ore-forming process can be divided into four stages, i.e., Ⅰpyrite-quartz vein stage, Ⅱ quartz-pyrite stage, Ⅲ quartz-polymetallic sulfides stage, and Ⅳ quartz-carbonate stage. Researches based on petrography, fluid inclusion tests and Laser Raman spectroscopic analysis suggest that ore-forming fluids are mainly composed of CO2-H2O-NaCl±CH4. There is an immiscible process in the fluid system. The homogenization temperatures of ore-forming fluids from stageⅠto stage Ⅳ are 307.0~406.8℃,270.3~319.6℃,225.4~272.1℃ and 166.3~226.3℃ respectively, with the corresponding average salinities being 7.25% NaCleqv,7.14% NaCleqv,8.97% NaCleqv and 6.39% NaCleqv. The trapping pressures of fluid inclusions are estimated to be 120~178 MPa, 85~140 MPa, 75~130 MPa and 60~122 MPa for each stage. Fluid immiscibility must have played an important role in ore genesis. The cause of fluid immiscibility might have been related to tectonic decompressing.
keywords:geochemistry fluid inclusions fluid immiscibility Yangzhaiyu gold deposit Xiaoqinling gold district
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中图分类号:P681.51
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基金项目:本文得到全国危机矿山接替资源找矿综合研究项目“小秦岭地区金矿床成矿规律总结研究(编号:20089939)”和中国地质大学(武汉)教学实验室开放基金(编号:SKJ2011112)共同资助
引用文本:
熊索菲,丁振举,姚书振,熊杰,胡新露,何谋春,谭满堂.2013.河南小秦岭杨砦峪金矿床成矿流体特征[J].矿床地质,32(6):1249~1261XIONG SuoFei,DING ZhenJu,YAO ShuZhen,XIONG Jie,HU XinLu,HE MouChun,TAN ManTang.2013.Characteristics of ore-forming fluid of Yangzhaiyu gold deposit in Xiaoqinling gold district, Henan Province[J].Mineral Deposits32(6):1249~1261
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