Geochemical insights of Permian Barakar Formation, West Bokaro Basin—Implications on provenance, paleoclimate, and paleoenvironment in eastern Gondwanaland

Early Permian paleogeography within the Gondwana Basins remains debated, particularly with respect to paleoclimatic and paleodepositional aspects The Barakar Formation (lower Permian) of the West Bokaro Basin, India, represents a key Lower Gondwana succession, preserving an important record of sedimentation during post-glacial warm paleoclimatic evolution. Marine influences during deposition of the Barakar Formation, as evident from the sedimentary facies (tide-wave influences) and marine fossils, various geochemical proxies are used in this paper to confirm the potential marine influence. The present study involves geochemical analysis of the siliciclastic rocks (sandstone, shale and sandstone-mudstone heterolith; total 33 samples) of the Barakar Formationto assess provenance, paleoclimate, paleoredox conditions, and the paleodepositional environment within the prevalent tectono-sedimentary framework. Based on geochemical signatures (ratios of different trace elements), the rocks point to a predominantly felsic provenance; most likely derived from granite–granodiorite sources of the Proterozoic Chhotanagpur Gneissic Complex within the adjacent Singhbhum cratonic block. High values for Chemical Index of Alteration (CIA) and the ratios of various majorelement oxides and trace lements point to intense chemical weathering under a predominant warm and humid climatic condition, which is further supported by proxies such as WIP, A-CN-K and MWRF plots. Redox-sensitive trace element systematics (e.g., V/Ni, V/(V + Ni), Cu/Zn, Ce/Ce*, etc.) indicate oxic–dysoxic conditions for sandstones and dysoxic–anoxic conditions for shales, suggesting fluctuating bottom-water oxygenation during deposition. The values of V/(V + Ni) and the ratios of the major element oxides indicate a continental–marine transitional setting, affirming the events of episodic marine incursions. Tectonic discrimination diagrams further suggests sedimentation in a passive riftogenic setting, characterisitic of the Gondwana basins. Collectively, these findings provide revised constraints on sediment source, paleoweathering intensity, and basin evolution, with supportive evidence for marine influence, which contribute to a better understanding of the Early Permian post-glacial paleogeographic transition within the Gondwana supercontinent.