内蒙古达茂旗哈力齐金矿床地质和流体包裹体特征及成因类型

Characteristics of ore geology and fluid inclusion of the Haliqi gold deposit,Damao County,Inner Mongolia,and its metallogenic type

通过近3年的多金属普查工作,在内蒙古达茂旗哈力齐地区发现了一个石英脉型金矿床。金矿床产于下泥盆统查干合布组浅变质岩中,受乌德岩浆构造混杂带北侧断层控制,矿化类型有石英脉型和糜棱状蚀变岩型两类。矿石的组成矿物主要有石英、绢云母、黄铁矿、褐铁矿、赤铁矿、毒砂、自然金等。矿石构造主要为脉状构造,偶见晶洞构造;矿石结构为交代反应边结构、交代港湾状结构、褐铁矿残留结构及环带结构等。围岩蚀变则以硅化、绢云母化及黏土化为主。流体成矿过程包括:石英-黄铁矿早阶段、石英-黄铁矿-毒砂-自然金主成矿阶段和碳酸盐-石英细脉晚阶段。流体包裹体研究表明,成矿主期发育水溶液包裹体和纯CO2包裹体,流体密度约0.85～0.9 g/cm3,估算其捕获温度为190～370℃,捕获压力约为61～183 MPa,成矿深度约6.1～6.9 km。研究表明,哈力齐金矿床为低密度低盐度的中—低温热液型矿床,具有造山型金矿床的特征。

With a 3-year investigation,the Haliqi gold deposit in Inner Mongolia,a quartz vein type gold deposit,was recently found in Damao Banner,Inner Mongolia.It is controlled by a fault north Wude magmatic tectonic melange belt and hosted in the Lower Devonian Chaganhebu group epimetamorphic rocks.Mineralization types include quartz vein type and mylonitic alteration type.The ore-forming minerals mainly consist of quartz,sericite,pyrite,limonite,hematite,arsenopyrite and native gold.Ores mainly take form of vein structure and are occasionally in the form of miarolitic structure.Textures of ores are metasomatic corona textures,metasomatic harbor-like textures,limonite relict textures and zonal textures.The wall-rock alterations are dominated by silicification,sericitization,and argillation.The hydrothermal ore-forming process includes three stages,namely the early stage characterized by pyrite-bearing quartz vein,the main stage characterized by quartz-pyrite-arsenopyrite-native gold process and the late stage characterized by carbonate-quartz veinlets.The study of fluid inclusions in quartz indicates that in the main stage fluid inclusions are dominated by aqueous solution inclusions and pure CO2 inclusions,with densities of 0.85-0.9 g/cm3,trapping temperatures of 190-370 ℃ and pressures of 61-183 MPa,and mineralization depth of 6.1-6.9 km.The study indicates that Haliqi deposit is a low density and low salinity epithermal gold deposit with features of orogenic type deposits.