摘要
THE Yindongpo gold deposit, situated in northern Tongbei County, northern Qinling orogenic belt, is alarge-scale one controlled by the Heqianzhuang anticline that plunges northwestwards and dips northeastwards. The ore-bodies locates in the carbon layers belonging to the Neoproterozoic Waitoushan Formation.Two ore-forming periods can be distinguished: the pre-Mesozoic epithermal mineralization in primary sediment with metamorphic superposition and the Mesozoic epithermal-mesothermal mineralization related totectonomagmatic activities. The principal ore-forming period can be divided into four stages. The ore bodies consist of networked and brecciated quartz veins. Gold is mainly rich in the veinlet-type quartz veinsthat formed during the diagentic-metamorphism or syn-metamorphic hydrothermal period, but a little inthe coarse veins related to later tectonomagmatic activities. The phenomenon that the fracturing degree
