Metallogenic conditions and model of the superlarge Shuiyindong stratabound gold deposit in Zhenfeng County, Guizhou Province

Abstract：The Shuiyindong gold deposit was found in the middle 1990s and has now become a superlarge stratabound gold deposit through nearly ten years of exploration. The orebodies occur in the stratified or stratoid shape in high-porosity bioclastic limestone of the Upper Permian Longtan Formation within 300 m near the axis of the Huijiabao Anticline. The shape of the orebodies is similar with that of the anticline. They are strictly controlled by carbonate rocks, and both their hanging wall and footwall consist of claystone or silty claystone, with clear-cut boundaries. The gold mineralization is represented by the association of silicification, dolomitization and pyritization. Silicification and dolomitization are metallogenic preconditions. The possibility of carbonate mineralization and gold grade of ores depend on the hydrothermal alteration of pyrite and its alteration intensity. The deposit is characterized by the large number of orebodies, small thickness and high grade, and a single orebody may reach a medium-sized deposit scale. This deposit has the features of medium- and low-temperature, ultrahigh-pressure hydrothermal mineralization. Gold is hosted by arsenic-bearing pyrite zones growing along the cores of idiomorphic pyrite.