Geological Characteristics, Metallogenic Regularity, Sources of Ore-Forming Material of the Bauxite District, Yushan, Xin'an, Henan Province

Yushan bauxite district in Henan Province consists of Yushan deposit, Licun deposit, Xingshuwa deposit and Meiyaowa deposit. Distribution, depth and rock features of aluminum-containing rocks of Benxi Formation directly control the bauxite occurrence and spatial characteristics. The distribution, occurrence, depth and integrity of ore-bearing rock are controlled by tectonics in this district. There is a positive correlation between the thickness of the aluminum-containing rocks and thickness plus grade of bauxite, namely, the bauxite is thicker and richer while the thickness of the aluminum-containing rocks is bigger. Bauxite minerals were deposited in the ancient terrain, large sunken sedimentary basin dominated the distribution range and trend of bauxite belt, whereas, the shape, the occurrence and the scale of the bauxite ore bodies were restrained by small depressions, caverns, doline funnel and the like. The Yushan bauxite deposits are typically karst-type deposit. All ore-forming material comes from the weathering of the upper crust such as non-granitoid and basalt. Bauxite materials being transited for a distance suggests that bauxite material sources are not highly correlated to basement carbonate rocks and exterior instead of in situ. Qinling ancient land may be an important source for the ore-forming matter.