Geochemistry and U–Pb Zircon Ages of the Bandal Granitoids Complex of the Himachal Region, Northwestern Himalaya (India): Constraints on Crustal Evolution and Columbia Supercontinent Assemblage

ABSTRACT To investigate the Paleoproterozoic magmatism and tectonic setting along the northern margin of the Indian block, and their potential link with the Archean–Paleoproterozoic Aravalli‐Delhi‐Bundelkhand (ADB) Craton of northwestern India, we integrate field observations, whole‐rock geochemical analyses, and U–Pb zircon geochronological data of the Bandal Granitoids Complex (BGC) in the Lesser Himalayan region of the Himachal Pradesh. The whole‐rock geochemistry of granitic gneiss samples suggests that the peraluminous S‐type granite, characterised by Nb, Sr, P, and Ti depletion, reflects subduction‐related accretion along the northern margin of the Indian block. The U–Pb zircon age of the BGC granitoids ranges from ~1.92 to 1.88 Ga and ~1.86 to 1.85 Ga with a few inherited older ages of ~2.45–2.33 Ga. Based on the geochemical and U–Pb zircon age results, it is inferred that Paleoproterozoic magmatism along the north margin of the Indian block is associated with the subduction–accretion process at ~1.97–1.92 Ga, followed by slab rollback and break‐off that subsequently triggered back‐arc basin development at ~1.86–1.85 Ga. Moreover, comparison of available U–Pb zircon ages from the LHS zone and the ADB Craton suggests continuous subduction accretion and back‐arc magmatism between ~2.10 and 1.85 Ga, associated with the assembly of the Columbia supercontinent.