内蒙古敖汉旗大黑山金矿床地质特征与构造控矿作用

大黑山金矿产于华北地台北缘努鲁儿虎隆起带太古代深变质杂岩中,与燕山期侵入的大黑山花岗质杂岩体具密切的成因联系。金矿床属于破碎蚀变岩和蚀变岩-石英脉型,其W18O为2.89-14.74‰,W34S为-1.30-4.27‰,成矿温度在235-300℃之间,故为中温岩浆热液矿床。矿区内广泛发育近EW向、NE向和NW向三组断裂构造,主要工业矿体受近EW向破碎带控制,而NE向和NW向破碎带矿化较弱,但二者与近EW向破碎带的复合部位往往形成富矿体。地质调查表明,金矿床主要受控于中浅层次的脆性断裂,而与深层次的韧性剪切带无直接联系。 

CHARACTERISTICS OF THE DAHEISHAN GOLD DEPOSIT IN-AOHAN QI,INNER MONGOLIA,AND THE STRUCTURAL-CONTROL OF MINERALIZATION

The Daheishan gold deposit located in the Nuluerhu uplift belt in the northern margin of the North China Platform developed in the Archean high-grade metamorphic complex.The origin of the gold deposit is closely related to the Yanshanian Daheishan granitic intrusion.The gold deposit belonging to fragmentation-alteration type and or alteration-quartz vein type is regarded as a mesothermal ore deposit since its mineralization temperature ranges from 235℃ to 300℃,W18O from 2.89‰ to 14.74‰,and W34S from-1.30‰ to 4.27‰.The nearly W-E-trending faults,which are the major fractures that control industrial ore bodies,and NE-and NW-trending ones with weak mineralization developed widely in the mining area.The pay shoot,however,was usually formed where the W-E-trending faults join the NW-and NE-trending ones.Detailed study in the field suggests that the gold mineralization is mainly controlled by the brittle faults formed at shallow and medium depth,rather than by a ductile-shear zone formed at a deep level.