Hydrothermal remobilization and redox trapping of uranium in metabasalts of the Bodal mine, Central India

Uranium is a strategically important metal with applications in nuclear energy, medicine, radiometric dating, food processing, industrial radiography, material sciences, and catalysis. This study presents a detailed microtextural and geochemical investigation of uranium mineralization from the Bodal uranium mine, Mohla-Manpur-Chowki, Central India. Uranium occurs as both crystalline and colloidal precipitates, with coffinite [U(SiO₄)_1-x(OH)_4x] and gummite representing the dominant uranium-bearing phases. The mineralization is spatially and genetically associated with altered metabasalts. Petrographic and geochemical evidence indicates that late-stage hydrothermal alteration played a crucial role in uranium remobilization and ore enrichment. Sulphide minerals, including cobaltite (CoAsS), galena (PbS), arsenopyrite (FeAsS), and chalcopyrite (CuFeS₂), are intimately associated with uranium phases and likely acted as effective reductants and sorption substrates, facilitating uranium precipitation under reducing conditions. The ore assemblage is accompanied by abundant accessory minerals such as zircon, allanite, and apatite. Substitution of U⁴⁺ for Zr⁴⁺ in zircon locally records uranium-rich hydrothermal fluids and contributes to zirconium enrichment. Collectively, these observations suggest that hydrothermal fluid–rock interaction and redox-controlled precipitation were the dominant processes responsible for uranium enrichment at the Bodal mine.

Keywords: Uranium mineralization; Hydrothermal alteration; Redox-controlled precipitation; Bodal mine; Central India