Geological, geochemical and mineralogical characteristics of the Bamhantara bauxite over Deccan Basalt Province of Kabirdham district, Chhattisgarh, India

This study presents the probable environment from petrographical, mineralogical and geochemical analyses of representative samples from Bamhantara block, Kabirdham district, Chhattisgarh, India using EPMA and SEMEDS for petrological study, and XRF and ICP-MS for geochemical inference. Microscopic study revealed the dominance of boehmite minerals that specify the synenvironmental depositional condition, while circular/ well-rounded pisolitic texture indicated autochthonous deposits. The geochemical study determined the progressive changes in major, trace and REE concentrations from precursor rock to bauxite during weathering. Bamhantara bauxite has been formed under oxidizing (positive Ce anomalies; Ce/Ce^*, 0.92–2.15) and near alkaline to alkaline ((La/Yb)_N and La/Y ratio > 1) conditions. The analogous trend of REE for bauxite/laterite and precursor rock indicates that lateritic bauxite had an autochthonous origin and is a chemical disintegration product of Deccan Trap basalt under tropical to subtropical climates. The geochemical behaviour of REE revealed that bauxite/laterite was generated from type-2 basalt characterized by positive Ce, Eu and Dy anomaly. The low concentration of kaolinite indicates desilication under a hot tropical climate.