Sm–Nd and Rb–Sr dating of amphibolite from the Nellore–Khammam schist belt, SE India: constraints on the collision of the Eastern Ghats terrane and Dharwar–Bastar craton

Abstract

The Nellore–Khammam schist belt, SE India, is sandwiched in between the Proterozoic Eastern Ghats terrane and the Archaean Dharwar–Bastar craton. We report Sm–Nd and Rb–Sr mineral isochron ages of amphibolite from the schist belt. The Sm–Nd and Rb–Sr ages are 824±43 Ma and 481±16 Ma, respectively. The Sm–Nd age indicates the timing of peak metamorphism, whereas the Rb–Sr age indicates the Pan-African thermal overprint. The peak metamorphism was related to collision of the Eastern Ghats terrane with the Dharwar-Bastar craton, which occurred during early Neoproterozoic time.