Neodymium Isotope Constraints on the Origin of TTGs and High-K Granitoids in the Bundelkhand Craton, Central India: Implications for Archaean Crustal Evolution

Abstract The Bundelkhand craton in central India consists mainly of abundant high-K granitoids formed at the Archaean-Proterozoic boundary and several enclosed rafts TTGs (tonalite-trondhjemite-granodiorites) up to 3.5 Ga. Therefore, is a key locality for studies on Archaean crustal growth emergence multisource granitoid batholiths that stabilised supercontinent 2.5 Based their geochemical characteristics, are divided into low silica–high Mg (sanukitoids hybrids) high silica–low (anatectic) groups. We aim provide new insights role juvenile versus sources evolution TTG, sanukitoid, hybrid, anatectic by comparing signatures with Nd isotope evidence contributions residence times. ages as well εNd(t) values model point towards partial melting or short-lived mafic crust different depths. Paleoarchaean show short times from newly crust, whereas Neoarchaean have long crust. This may reflect transition primitive oceanic plateau (3.4-3.2 Ga) plume settings, resulting protocontinent, 2.7 Ga subduction island arc accretion along protocontinent. convergent settings mantle wedge preexisting Sanukitoids hybrid originated mantle, latter showing stronger contributions, were products pure melting. Our data support change early strong crust-mantle interactions A-P boundary, probably reflecting onset cycles.