BHUMIKA DAS
Articles written in Journal of Earth System Science
Volume 129 All articles Published: 1 May 2020 Article ID 0117 Research Article
BHUMIKA DAS M W Y KHAN HARISH DHRUW
The Darai–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. $SiO_{2}–Al_{2}O_{3}–Fe_{2}O_{3}$ 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 A–L–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.
Volume 129, 2020
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