南秦岭七岔沟锑矿点流体包裹体和硫同位素特征及其成因浅析  

Fluid Inclusion and Sulfur Isotope Characteristics as well as Genesis of Qichagou Antimony Occurrence in South Qinling

作　　者：刘文文 刘圣鑫 周鼎 朱金 周豹 刘雷 袁航 汤旋 Liu Wenwen;Liu Shengxin;Zhou Ding;Zhu Jin;Zhou Bao;Liu Lei;Yuan Hang;Tang Xuan(Hubei Geological Survey,Wuhan,Hubei 430034;Hubei Geological Exploration Engineering Technology Research Center,Wuhan,Hubei 430034)

机构地区：[1]湖北省地质调查院,湖北武汉430034 [2]湖北省地质勘查工程技术研究中心,湖北武汉430034

出　　处：《资源环境与工程》2022年第4期420-426,462,共8页Resources Environment & Engineering

基　　金：湖北省地质局2020年度科技项目(KJ2020-59)。

摘　　要：南秦岭郧西地区发育一系列锑矿床(点)。以七岔沟锑矿点为例,在野外地质调查基础上,开展流体包裹体和原位硫同位素分析,浅析其成因。七岔沟锑矿点的矿体呈脉状、透镜状赋存于脆性断裂破碎带中,矿石矿物为辉锑矿,其成矿主要经历石英—黄铁矿—闪锌矿阶段、石英—闪锌矿—辉锑矿阶段(主成矿阶段)、石英—黄铁矿阶段3个成矿阶段。该矿点主成矿阶段的石英流体包裹体以富液两相包裹体为主,成矿流体均一温度集中于270~310℃,盐度集中于1.0%~5.6%NaCleq,推测成矿深度为5.5~7.5 km,表明其成矿流体为中低温、低盐度的浅成流体体系。该矿点主成矿阶段的硫化物原位δ^(34 )S为7.4‰~10.4‰,与耀岭河组地层δ^(34)S相似,暗示成矿物质可能来源于成矿流体对耀岭河组岩石的萃取。综合分析认为,七岔沟锑矿点具造山型矿床特征,成因类型属浅成中低温热液型。A series of antimony deposits(occurrences)are developed in Yunxi area of South Qinling.Taking Qichagou antimony occurrence as an example,field geological survey,fluid inclusion and in-situ sulfur isotope analysis are carried out to explore its genesis.The ore bodies are veined and lenticular in the secondary brittle fractured fault zone.The ore mineral is stibnite.Its mineralization mainly experiences three mineralization stages:quartz-pyrite-sphalerite stage,quartz-sphalerite-stibnite stage(main metallogenic stage)and quartz-pyrite stage.The quartz fluid inclusions in the main metallogenic stage are mainly liquid-rich two-phase inclusions.The homogenization temperature of the ore-forming fluid is concentrated in 270~310℃,and the salinity is concentrated in 1.0%~5.6%NaCleq.It is speculated that the metallogenic depth is 5.5~7.5 km,indicating that the ore-forming fluid is a shallow fluid system with medium-low temperature and low salinity.The in-situδ^(34)S of sulfides in the main metallogenic stage is 7.4‰~10.4‰,which is similar to theδ^(34)S of Yaolinghe Formation,suggesting that the metallogenic materials may come from the extraction of Yaolinghe Formation rocks by metallogenic fluids.The comprehensive analysis shows that the Qichagou antimony occurrence has the characteristics of orogenic deposit,and the genetic type belongs to medium-low temperature epithermal type.

关 键 词：锑矿 流体包裹体 原位硫同位素 浅成中低温热液型 南秦岭 

分 类 号：P618.66[天文地球—矿床学]