【摘要】 七家金矿床是华北克拉通北缘赤峰-朝阳金矿集区内一处新发现的石英脉型金矿床，赋存于中生代似斑状花岗岩中。金成矿阶段可划分为石英±黄铁矿、石英-多金属硫化物和石英-碳酸盐±黄铁矿3个阶段。金成矿与硅化和绢云母化热液蚀变关系密切。本文在野外地质调查基础上，利用光学显微镜和扫描电镜观察，结合金矿物电子探针成分分析，系统探讨了七家金矿床中金的赋存状态。结果表明，七家金矿床中金矿物主要以裂隙金、晶隙金和包体金3种形式存在，载金矿物以黄铁矿为主，石英次之，偶见黄铜矿和方铅矿等。根据金矿物粒度大小，可细分为粗粒金、中粒金、细粒金和微粒金，并以细粒-微粒金为主。金矿物形态多样，以粒状为主，另可见针线状、叶片状、钩状和枝杈状等。金矿物的成分以Au和Ag为主，金成色范围介于678～883之间，主要为自然金和银金矿，并含微量的Te、Fe和S等元素。综合地质和地球化学特征，认为七家金矿床属于中温岩浆热液型金矿床。更多还原

【Abstract】 The Qijia gold deposit is a recently discovered quartz-vein type gold deposit located in the ChifengChaoyang gold district along the northern margin of the North China Craton,hosted in the Mesozoic porphyroid granite. The gold mineralization can be divided into three mineralization stages: quartz±pyrite,quartz-polymetallic sulfide,and quartz-carbonate±pyrite. The gold mineralization is closely related to the silicification and sericitization.Based on field geological investigations,we systematically studied the occurrence state of gold from the Qijia gold deposit by using optical microscope and scanning electron microscope observations,combined with electron microprobe analysis for gold grains. The results indicate that gold in the Qijia gold deposit primarily occurs in three forms: fissure gold,interstitial gold,and inclusion gold. Gold grains are mainly observed in pyrite,followed by quartz,with occasional occurrences of chalcopyrite and galena. According to the grain size,gold can be subdivided into coarse-grained gold,medium-grained gold,fine-grained gold,and micro-grained gold,with fine-to micro-grained gold dominant. Gold exhibits diverse morphologies,predominantly granular-based,along with needle-like,leaflike,hook-like,and branch-like forms. The compositions of gold grains are primarily Au and Ag,with gold fineness range between 678 and 883. They are mainly native gold and electrum,containing trace amounts of Te,Fe,and S. Based on comprehensive geological and geochemical characteristics,we proposed that the Qijia gold deposit belongs to the mesothermal magmatic-hydrothermal type gold deposit.更多还原