Coal-Bauxite-Iron Structure and Geochemical Features of Bauxites Ore-Bearing Rock Series in Southeast Guizhou

The bauxite in southeast Guizhou is hosted within the Lower Permian series Liangshan Group. The ore-bearing rock series shows a typical coal-bauxite-iron structure of the sedimentary type bauxite deposit, i.e. the aluminum shale intercalated within siderite tuberculosis developed at the bottom, aluminiferous rock association intercalated within multiple-layer pisolitic or earthy bauxite in the middle, and carbonaceous shale and sandstone intercalated with coal seams from the lower to the upper in the profile of bauxite. Presumably, the sedimentary environment is of stable structural setting, belonging to marine-terrigenous facies to coastal-swamp facies. Coal-bauxite-iron structure is very common in bauxite deposits, and sedimentary bauxite is the product of deep desilication and deiorning caused by the changes of the physical and chemical environment during mineralizing process. In addition, external environment provides sufficient organic material source. Therefore, multiple geological anomalies triggered by chemical and physical changes during the formation of layered structure of ore-bearing rock series can be used as prospecting criteria for bauxites.