GEOLOGIC CHARACTERS AND EXPLORATION DIRECTION OF BEIGANGOU GOLD DEPOSIT IN HUAIROU, BEIJING

The Beigangou gold deposit, located in the middle section of Yanshan metallogenic belt, belongs to quartz vein type in ductile shear zone. The Neoarchean metamorphic rock, which contains abundant gold, is the source bed for gold metallogenesis. Ductile shear zone controls the gold metallization, which can be divided into two stages. The gold metallization is related to the brittle deformation of the ductile shear zone. Natural gold occurs mainly in the microfissures, intergranular porosities or cavities of pyrite, chalcopyrite and their oxides. The wallrock alteration is in tense, with mainly pyritization, silicification, sericitization, carbonation, albitization, chloritization, baritization etc. The exploration in the future should focus on quartz vein type and altered rock type of gold mineralization in No. 1 fault belt and shear zone quartz vein type of gold mineralization in the tensional extended range of No. 2 ductile shear zone in the east.