Provenance and tectonic settings of sandstones of Jhuran Formation (Kimmeridgian to Tithonian); Mundhan dome, Kachchh, Western India

The study focuses on the sandstones of the Jhuran Formation (JF) (Kimmeridgian to Tithonian age) exposed in the Mundhan dome (MD), Kachchh, analyzing their provenance and tectonic setting through petrography, heavy mineral analysis, and geochemistry. Petrographical work, including modal analysis, reveals that these sandstones are predominantly composed of quartz, feldspars, and rock fragments in a modal ratio of Q₈₇F₈L₅. Geochemical analysis shows high SiO₂ levels, a higher concentration of Na₂O compared to K₂O, and relatively low Fe₂O₃, which aligns with the petrographical findings. The heavy mineral data points to the origin of these sediments from plutonic and metamorphic sources. Combined petrographical and geochemical evidence suggests that the sandstones were deposited in a passive continental margin with minimal recycling, which is further corroborated by paleo-weathering indices. Tectonic discrimination diagrams suggest a quartzose sedimentary provenance, indicating that the sediments were primarily derived from a cratonic interior area. These findings imply that the sediments from the JF in the MD were sourced from plutonic and/or metamorphic terrains, probably from the Aravalli craton, and were deposited in a passive continental setting within a non-marine to transitional settings of deltaic environment. The findings of the present study will aid in understanding the sedimentation history of the correlatable Mesozoic outcrops in the Kachchh basin.