内蒙古毕力赫金矿Ⅱ号矿带原生晕特征及找矿意义

毕力赫金矿位于华北克拉通北缘,是一座大型低温热液—斑岩型金矿,产于花岗闪长斑岩和围岩火山碎屑岩内外接触带中.随着矿山开采工作的持续进行,该矿山资源量面临危机,加强探边摸底工作势在必行.为了寻找有效的地球化学找矿指标,采用无火焰原子吸收光谱法(AAN)、等离子质谱法(ICP-MS)和原子荧光光谱法(AFS)等多种分析方法...

Primary Halo Characteristics of No. 2 Ore Belt in Bilihe Gold Deposit,Inner Mongolia and Its Prospecting Significance

Bilihe gold deposit is a large low-temperature hydrothermal and porphyry gold metallogenic system in the northern margin of North China Craton，which is hosted in internal and external contact zone of granodiorite and surrounding pyroclastic rock.The mining area has appeared a sharp drop of resource reserves due to continuous mining work.In order to ensure the sustainable development of the mine and improve the utilization rate of gold ore resources，there has arisen a critical necessity to strengthen geochemical exploration of deepand peripheral resources in the mining area.The primary halo prospecting method directly takes rocks or ores as the research target，which is considered to be the most direct and effective deep prospecting method at present and has achieved good results in the exploration of gold deposits.This paper take the mining No.2 ore belt as the research taget and analyze various elements such as Au，Ag，Cu，Pb，W，Mo，Bi，As，Sb，Hg of the primary halo of boreholes.The characteristics of element content，element association and spatial distribution of primary halo in three boreholes of No.2 ore belt in Bilihe mining area have been studied to find effective geochemical prospecting indicators.The results show that the main indicator elements of gold mineralization in Bilihe mining area are Au，W，Mo，As，Sb and Hg.There are two groups of gold metallogenic indicator element associations in Bilihe mining area，namely，Au-W-Mo high-temperature element association and Au-As-Sb-Hg low-temperature element association.Au-W-Mo element association indicates high-grade gold mineralization，strong gold mineralization activity and large metallogenic scale，which can be used as the main prospecting indicator for high-temperature porphyry gold deposits in the mining area.Au-As-Sb-Hg element association indicate low-grade gold mineralization，relatively weak gold mineralization activity and limited metallogenic scale，which can be used as the main prospecting indicator for vein-type low-temperature hydrothermal gold deposits in the mining area.Weak gold mineralization information can be obtained by applying 10×10^-9 gold content as the lower limit of primary halo anomaly of gold deposits.The distribution range of gold mineralization can be accurately determined by applying 100×10^-9 gold content as the inner zone of primary halo anomaly of gold deposits.The inner anomaly range of primary halo delineated by this method is much larger than the distribution range of gold orebodies.Therefore，Using primary halo prospecting method for deep prediction and evaluation can effectively enlarge weak information of gold mineralization.