Geochemical Perspectives on the Permian Barakar Formation, Gondwana Supergroup, WestBokaro Basin, India

Abstract: Early Permian sedimentation within the Gondwana intracratonic basins providesimportant insights into the sedimentation history. Integrated petrographic and geochemicalproxies offer an effective means to reconstruct these processes. This study examinessiliciclastic rocks—sandstone, shale, and sandstone–mudstone heteroliths from the PermianBarakar Formation of the West Bokaro Basin, eastern India. The rocks were analysed fortheir mineralogical and geochemical properties to interpret provenance, paleoclimate, paleo-tectonic setting, paleoredox conditions, and paleo-depositional environment. XRD, SEM, andpetrographic analyses, accompanied by major and trace element chemistry, supported by REEpatterns normalized to PAAS and UCC, indicate a predominant felsic provenance, which ispotentially considered to be the granite-granodiorite rocks of the Proterozoic ChhotanagpurGneissic Complex, Singhbhum cratonic block. Higher CIA values with A–CN–K plots, alongwith MFRW weathering trends, suggest intense chemical weathering under a warm, humidclimate. Relative abundance of redox-sensitive trace elements (e.g., V, Ni, Cu, Zn, Ce, etc.)points to oxic-dysoxic (for sandstone) and dysoxic-anoxic (for shale) conditions, oftensupported by presence of localized pyrite framboids and abundant organic matter in shalesand heteroliths. Tectonic discrimination diagrams indicate deposition in a passive marginriftogenic basin. Binary and ternary plots of common major element oxides suggest acontinental-marine transitional depositional setting, indicating marine incursions within thecontinental Gondwanaland. The results and the interpretations provide important cluesregarding the Early Permian post-glacial warm paleoclimatic transition within the broaderGondwana paleogeographic-paleoclimatic framework.