Trace and REE geochemistry of bauxite deposit of Daraia??Daldali plateau, Kabirdham district, Chhattisgarh, India

摘要

The Daraia??Daldali plateau preserves well developed laterite type bauxite deposits as a result of in-situ weathering of basaltic rocks (Deccan Traps). The bauxite ore is essentially composed of gibbsite and boehmite in subordinate amount, along with anatase and brookite as accessory minerals. Kaolinite, goethite, hematite, ilmenite, gibbsite and brookite are found in lateritic bauxite and laterite samples invariable amounts. $SiO_{2}a??Al_{2}O_{3}a??Fe_{2}O_{3}$ diagram illustrates strong bauxitization resulting from desilication in the early stage. The disilication was followed by bauxitization and deferruginization at late stages as a result of reducing and oxidizing conditions, respectively, due to fluctuating water table, which is evidently supported by Aa??La??F plot. Progressive loss/gain in FMTE, LILE, HFSE and REE during bauxitization process of basalt through lateritic bauxite facies is observed. La/Y varying from 1.17 to 4.11 suggests prevalence of alkaline conditions. Positive Eu/Eu* anomaly in these samples is suggestive of colloidal precipitation of gibbsite from pore water of lateritic residuum. Mass increase of Ce in laterite samples further supports to its sorption on goethite and hematite mineral phases.