内蒙古白音查干锡多金属矿床成矿作用研究Ⅰ:金属矿物组合及其成因机制  

Mineralization process of the Baiyinchagan tin polymetallic deposit in Inner Mongolia Ⅰ:Metallic mineral assemblage and metallogenic mechanism

作　　者：刘新[1,2] 王京彬 祝新友[1] 孙雅琳[1,3] 蒋昊原[1,3] 蒋斌斌 王海[1,4] 程细音[1] 

机构地区：[1]北京矿产地质研究院,北京100012 [2]中国科学院地球化学研究所矿床地球化学国家重点实验室,贵阳550002 [3]中国地质大学(北京),北京100083 [4]昆明理工大学国土资源工程学院,昆明650093

出　　处：《矿产勘查》2017年第6期967-980,共14页Mineral Exploration

基　　金：中国地质调查局国家二级项目内蒙古赤峰有色金属基地综合地质调查(编号:DD20160072);博士后科学基金项目(编号:2016M600930)联合资助

摘　　要：白音查干具有岩浆岩自蚀变阶段(Ⅰ)、隐爆角砾岩阶段(Ⅱ)、锡石硫化物阶段(Ⅲ)、锑矿化阶段(Ⅳ)4个成矿阶段,其中Ⅲ为主成矿阶段。闪锌矿为贯通型矿物,成分随成矿温度、压力改变发生系统性变化。Ag主要以银黝铜矿存在,少量Ag进入黄铜矿、方铅矿晶格形成类质同象银,晚阶段可能存在含银Pb-Sb(Bi)硫盐类矿物。成矿早阶段体系温度和氧逸度较高,Sn^(4+)和Zn^(2+)、Cu^(2+)、Pb^(2+)、Ag^+等分别以SnO_3^(2-)和氟络合物形式迁移。隐爆作用发生后,体系压力降低、pH值升高,金属元素以HS^-络合物形式迁移。成矿流体与大气降水混合后,还原性增强,HS-络合物分解,黄铁矿、毒砂、黄铜矿、闪锌矿、方铅矿、辉锑矿、白铁矿依次沉淀。此后体系中阴离子以SbS_3^(2-)为主,形成黝铜矿族矿物、车轮矿、脆硫锑铅矿等。The mineralization of Baiyinchagan tin polymetallic deposit has been divided into four mineralization stages, i.e., magmatic stage, cryptoexplosion breccias stage, cassiterite-sulfide stage, which is the major mineralization stage, and antimony mineralization stage. Sphalerite occurs in all of these stages, and its Fe content systemically changes with P and T. Sliver-bearing minerals mainly consist of freibergite and lattice silver, which were formed by isomorphic replacement of Ag with Cu and Pb. At the early high temperature oxidizing environment, Sn is transported as SnO2-3, while Zn2＋,Cu2＋,Pb2＋ and Ag＋ are transported as fluorine complexes. When the crypto explosion took place, the formation of HS- complex and another precipitation of metal minerals were resulted from the release of pressure and leak of CO2 accompanied with increasing pH. At the later mineralization stage, due to mixture of magmatic water with ore-forming fluid, the mineral of pyrite, arsenopyrite, chalcopyrite, sphalerite, galena, stibnite and marcasite was sequentially formed after the decrease of temperature , increase of reducibility and breaking down of HS-1 complex. At last, SbS2-3 is the main anion in the meteoric water, and the tetrahedrite group minerals, such as bournonite and jamesonite were formed in quick succession.

关 键 词：白音查干 锡多金属矿床 大兴安岭南段 金属矿物组合 成因机制 

分 类 号：P618.44[天文地球—矿床学]