Metallogenic mechanism of gibbsite from accumulated bauxite in western Guangxi province

The mineral assemblage, spatial features of minerals distribution, characters of occurrence, generations of minerals forming, chemical compositions, rare earth elements and water contents inside or surrounding ore -body have been securely researched. The results indicate that the gibbsite from accumulated bauxite (Salento-type) in western Guangxi province was formed through hydratation of diaspore. The formation of gibbsite was strictly controlled by the concentrations of Al~(3+)?~(4-)and pH in of underground water. It experienced several periods as precipitation, solidification, devitrification and crystallization of Al(OH)3. In early period kaolinite was formed by means of leaching and secondary quartz was formed in lightly leached position. This kind of bauxite is considered to be not only a new deposit type, and its particular genesis to be shown as a degeneration bauxite deposit as well.