赤峰-朝阳金矿化集中区主要金矿类型及地质特征研究

赤峰—朝阳金矿化集中区是我国重要的金矿产地之一。区内已经发现200多处金矿床(点),其中主要金矿床的产出都与太古代深变质岩和中生代的火山岩有关。EW、NNW和NE向断裂是主要的容矿构造,多组断裂的交汇处是矿化的有利部位。根据区域成矿特点及矿床特征可划分出3种矿床类型,即石英脉型、石英脉-蚀变岩混合型和隐爆角砾岩型。地球化学研究表明,成矿物质以深源为主;成矿流体是原始岩浆热液和古大气降水的混合流体;属中浅成、中低温热液型金矿床。

Major Types and Geological Features of Gold Mineralization Occurred in the Chifeng-Chaoyang Gold Concentration Region

The Chifeng-Chaoyang gold concentration region,with more than 200 gold deposits or occurrences,is one of major gold production areas in China.It is recognized that the major gold deposius occurred in the region are hosted by or closely related to the Archean metamorphic rocks or Mesozoic magmas.Regional or local EW-,NE-and NNW directed faults control the distribution of gold mineralization,and their cross-cuttings are the most favorable sites that localize major gold deposits.Based on regional metallogenitic characteristics and geological peculiarities of those gold deposits,three major types of gold mineralization can be recognized in the Chifeng-Chaoyang region as following: auriferous quartz vein,quartz vein mixed with altered rocks,and breccia-pipe.Geochemical study indicates that the mineralizing material was sourced mainly from mantle and the mineralizing fluids were magmatic fluids mixed with contemporaneous meteoritic water;It is suggested that the gold deposits occurred in the Chifeng-Chaoyang region can be largely classified into the epithermal to mesothermal mineralization.