New insights into the provenance and tectonic evolution of the Paleoproterozoic Aravalli Basin, NW India

Abstract

The tectonic setting of the Paleoproterozoic Aravalli Basin remains a subject of debate, primarily due to limited geochemical data, which complicates the establishment of a definitive stratigraphic framework and geodynamic evolution model for the Aravalli orogen. New petrological and geochemical data of the clastic (meta)sedimentary rocks, including quartzite, wacke and metapelites, have been used to reconstruct the sedimentary provenance and tectonic evolution of the Aravalli Basin. The Aravalli quartzites show quartz dilution, most likely representing a recycled sedimentary source without any significant heavy mineral addition. In contrast, the geochemical compositions of the wackes and metapelites do not suggest any significant sedimentary sorting and reflect the chemical characteristics of the source rocks. Weathering trends in the A-CN-K diagram indicate predominantly low to moderate weathering in the source area. Some samples deviate from the predicted weathering trend, reflecting plagioclase alteration to illite (now muscovite) or K-feldspar due to post-depositional K-metasomatism. The elemental ratios (Th/Sc, Zr/Sc and TiO₂/Zr) indicate that the detritus for the Aravalli sediments was largely sourced from the felsic igneous rocks. The results of REE modelling suggest that late Neoarchean (2.57–2.50 Ga) and late Paleoproterozoic (1.88–1.70 Ga) granitoids exposed in the Aravalli orogen and the adjacent Bundelkhand Craton constituted the dominant potential source rocks for the Aravalli sediments. The integration of new results, with the previously obtained igneous and detrital zircon U-Pb ages, constrain the deposition of Aravalli (meta)sedimentary sequence in a passive margin setting at <1.74–1.60 Ga.