投稿时间：2011-09-15
修订日期：2012-01-08
中文摘要:东桐峪金矿床位于小秦岭金矿田的中西部,其含金石英脉受韧性剪切构造带的控制。该矿床的构造-成矿过程可划分为4个阶段:Ⅰ黄铁矿-乳白色石英脉阶段;Ⅱ灰白色石英-黄铁矿阶段;Ⅲ石英-多金属硫化物阶段;Ⅳ石英-碳酸盐阶段。相对于小秦岭地区的其他金矿床,东桐峪金矿床的流体包裹体研究资料相对缺乏。文章表明,该矿床内的流体包裹体类型主要为CO2-H2O包裹体和水溶液包裹体,见少量纯液相CO2包裹体。显微测温表明,Ⅰ阶段的构造-成矿流体以中温、富CO2等挥发分为特征,包裹体均一温度为221~392℃,盐度w(NaCleq)为5.5%~7.9%,密度为0.84~0.93 g/cm3;Ⅱ阶段和Ⅲ阶段以CO2-H2O±CH4流体为主,包裹体均一温度为205~350℃(Ⅱ阶段)和224~271℃(Ⅲ阶段),盐度w(NaCleq)集中于5.1%~7.1%,密度为0.83~0.96 g/cm3;Ⅳ阶段的流体演化为中-低温、低盐度的盐水溶液体系,包裹体均一温度为175~185℃。文章对该矿床各成矿阶段的压力进行了估算,Ⅰ、Ⅱ、Ⅲ阶段的流体最小捕获压力分别为123~160 MPa、160~170 MPa、170 MPa左右。
Abstract:The Dongtongyu gold deposit is located in the middle-west part of the Xiaoqinling gold orefield.Gold-bea-ring quartz veins are controlled by the ductile shear zone.According to the vein types and their crosscutting relationships, mineralization of the Dongtongyu gold deposit can be divided into four stages: Ⅰ pyrite-white quartz vein stage; Ⅱ gray quartz-pyrite stage; Ⅲ quartz-polymetallic sulfides stage; Ⅳ quartz-carbonate stage. The main types of fluid inclusions in vein quartz are CO2-H2O fluid inclusions and aqueous fluid inclusions, with small amounts of pure CO2 fluid inclusions. The fluid inclusions of stage Ⅰ are characterized by mesothermal CO2-rich fluids,with homogenization temperatures of fluid inclusions being 221~392℃,salinities w(NaCleq) 5.5%~7.9%,and densities 0.84~0.93 g/cm3.The fluid inclusions at stage Ⅱ and stage Ⅲ are characterized by CO2-H2O±CH4 fluids,with homogenization temperatures being 205~350℃ (stage Ⅱ) and 224~271℃ (stage Ⅲ),salinities w(NaCleq) 5.1%~7.1%,and densities 0.83~0.96 g/cm3.The fluids at the quartz-pyrite-carbonate stage are epithermal-mesothermal low salinity aqueous solutions,with homogenization temperatures being 175~185℃.In this paper,the minimum trapping pressure of fluid inclusions are estimated to be 123~160 MPa, 160~170 MPa and 170 MPa for stage Ⅰ, Ⅱand Ⅲ.The main gold mineralization was related to the post-orogenic extension environment,with the evolution characteristics corresponding to the evolution of shear zones.
keywords:geochemistry fluid inclusions structure-mineralizing stages trapping pressures Dongtongyu gold deposit
文章编号：
中图分类号：P618.51
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基金项目:本文得到全国危机矿山接替资源找矿专项典型矿床及成矿规律总结研究项目(20109903)和国家自然科学基金项目(40972066)资助
引用文本：
吴晓贵,徐九华,魏浩,林龙华,张国瑞,惠德锋,董华芳.2012.小秦岭东桐峪金矿床的流体包裹体研究[J].矿床地质,31(2):195~206WU XiaoGui,XU JiuHua,WEI Hao,LIN LongHua,ZHANG GuoRui,HUI DeFeng,DONG HuaFang.2012.A study of fluid inclusions of Dongtongyu gold deposit in Xiaoqinling area[J].Mineral Deposits31(2):195~206
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