Possible juvenile Palaeoarchaean TTG magmatism in eastern India and its constraints for the evolution of the Singhbhum craton

High-precision SHRIMP U-Pb zircon dating yields a late Palaeoarchaean age (3290 +/- 8.6 Ma) for a large, unmetamorphosed, weakly peraluminous TTG body (the Keonjhargarh-Bhaunra pluton) in the Singhbhum craton of eastern India. One inherited subhedral zircon grain gave a concordant age of 3495.9 +/- 5.3 Ma and Nd isotope characteristics show a juvenile trend with epsilon Nd-t similar to 0 and T-DM 3395-3453 Ma. The data support a model of typical Archaean crustal evolution until late Palaeoarchaean times for the Singhbhum craton, which is in contrast to the more southerly Bastar craton where Palaeoarchaean non-TTG granites have been identified. These data demonstrate the diachronous development of continental crustal blocks now forming the basement of the eastern and central peninsular of India.