内蒙古红岭铅锌矿床成矿流体地球化学特征及矿床成因  

Ore-Forming Fluid Geochemical Characteristics and Genesis of Pb-Zn Deposit in Hongling,Inner Mongolia

作　　者：李剑锋[1] 王可勇[1] 陆继胜 张雪冰[1] 权鸿雁[1] 王承洋[1] 魏良民 

机构地区：[1]吉林大学地球科学学院,吉林长春130061 [2]内蒙古赤峰红岭有色矿业有限责任公司,内蒙古赤峰025420

出　　处：《地球科学（中国地质大学学报）》2015年第6期995-1005,共11页Earth Science-Journal of China University of Geosciences

基　　金：中国地质大学地质过程与矿产资源国家重点实验室开放课题基金项目(No.GPMR201307)

摘　　要：红岭铅锌矿是内蒙古东南部的大型代表性矿床之一.目前,对该矿床成矿流体地球化学特征、性质及演化问题尚缺乏系统研究.对其展开了系统的流体包裹体研究.结果表明,矿区矽卡岩期Ⅰ阶段石榴石中发育含NaCl子矿物三相(SL)、气相-富气相(LV)及气液两相(VL)3种类型的原生流体包裹体,Ⅱ阶段中石英颗粒主要发育LV和VL两种类型原生流体包裹体,测温结果表明矽卡岩期成矿流体属中-高温、高盐度的不均匀NaCl-H2O体系热液,在成矿过程中发生过沸腾作用而导致铅、锌、铜等有用元素沉淀富集.石英-硫化物期Ⅲ→Ⅵ阶段中矿物均主要发育较单一的VL型包裹体,其中Ⅲ阶段热液均一温度较矽卡岩期明显降低,而盐度没有明显变化;Ⅳ阶段成矿流体均一温度明显增高、盐度明显降低,反映了有新的高温、低盐度体系热液的加入;而Ⅴ→Ⅵ阶段成矿流体均一温度及盐度逐渐降低,体现了一种不断与外来天水混合的演变趋势;整体上看,石英-硫化物期流体为简单的中-低温、低盐度NaCl-H2O体系热液.流体包裹体C、H、O同位素研究表明,红岭矿床矽卡岩期Ⅱ阶段成矿流体以岩浆水为主;石英-硫化物期成矿流体源自大气降水与岩浆水的混合流体,晚阶段逐渐演化为以大气降水为主.矿床S、Pb同位素研究表明,区内成矿物质具深源特点.Hongling lead-zinc deposit is one of the representative large deposits in southeastern Inner Mongolia.Presently,there’s very little research on geochemical characteristics and evolution of ore-form fluids,and ore genesis.The fluid inclusions are systemly re-searched in this paper,The results show that there are three types of primary fluid inclusions in garnet of garnet-skarn stage （Ⅰ）inclu-ding halite-bearing three-phase,aqueous two-phase as well as vapor-rich two-phase;there are two types of primary fluid inclusions in quartz of stage （Ⅱ）including aqueous two-phase as well as vapor-rich two-phase.It is found in our microthermometric study that the ore-forming fluid is of high temperature,high salinity and immiscible NaCl-H2 O type solutions and the boiling process plays important role in the precipitation of Pb,Zn,and Cu.Quartz of mineralization stage Ⅲ to Ⅳ of quartz-sulfide epochs contains only aqueous two-phase of fluid inclusions.The homogenization temperature of this type of fluid inclusions is obviously lower than that of skarn epoch, while the salinity does not obviously change.The homogenization temperatures of fluid inclusions show a rising trend with salinities dis-playing a dropping trend of stage Ⅳ,and it may be caused by adding of high temperature,low salinity type fluid.The dropping of homogenization temperatures and salinities of ore-forming fluids from mineralization stages Ⅴ to Ⅵ suggests that meteoric water contin-uously joining into the ore-forming fluid.Overall,the ore-forming fluids of quartz-sulfide epoch is of medium-low temperature and low salinity NaCl-H2 O type solutions.C,H,O isotope study of fluid inclusions shows that the ore-forming fluids of skarn epoch mainly came from magmatic water and that of quartz-sulfide epoch came from mixed magmatic water and meteoric water,whereas at the latest stage of mineralization,the ore-forming fluids mainly came from meteoric water.The study of S,Pb isotopes implies that the ore-forming materials posed a deep source feature

关 键 词：红岭铅锌矿床 成矿流体 地球化学 矿床 内蒙古东南部. 

分 类 号：P611.1[天文地球—矿床学]