Petrography of Badabagh Member (Bathonian) Sandstone of Jaisalmer Formation (Western Rajasthan, India): Implications for provenance and tectonic setting

AbstractPetrographic, and petrofacies investigations were performed on thirty-three samples of medium to fine grained (mostly fine), moderately to well-sorted sandstone from Bathonian Badabagh Member, Jaisalmer Formation, western Rajasthan. The grains are sub-angular to sub-rounded in shape, with some well-rounded quartz grains. The framework composition of sandstone consists mostly of monocrystalline and polycrystalline quartz, low- to high-grade metamorphic and sedimentary rock fragments, as well as subordinate feldspar with low plagioclase to total feldspar ratios and accessory minerals. Petrographic investigations reveal that sandstones from the Badabagh Member of the Jaisalmer Formation are dominantly quartz-arenite with subordinate amount of sub-litharenite to sub-arkose. The sandstones have abundance of metamorphic and sedimentary rock fragments having former supersede the latter, which derived from a continental block, recycled orogen provenance of quartzose lithic terrains under tropical humid climate as indicated by weathering index which signifies the moderate hills to low plains relief. The majority of the quartz in the sandstones is undulatory, indicating provenance with lower and middle-upper rank metamorphic affinity. Corroboration of palaeocurrent data along with petrographical and sedimentological studies suggests that the Badabagh Member sandstone was predominantly derived from the rocks of Aravalli Delhi Fold Belt (ADFB) and Malani Igneous Suites, which is located to the south and southeast of the basin.