Dating of amphibolite occurring within the 2.5 ga granite in kawadgaon area, Bastar Craton, Central India

Results of geochronological studies (Rb-Sr, Pb-Pb and Sm-Nd Systematics) on amphibolite (metamorphosed dyke) occurring within the 2.5 Ga granite in Kawadgaon area, Bastar Craton, Central India, are presented in this study. The amphibolite has yielded Rb-Sr isochron age of 2245 ± 250 Ma. The reported age of amphibolite is distinctly younger, and indicates that the studied metamorphosed basic rock is intrusive not only into the Archaean Bengpal Group, but also in the 2.5 Ga granite. Further, the age of amphibolite is close to the age of pegmatitic muscovite (∼2330 Ma) from the Kawadgaon area, and falls in the range of granitic activity that spanned over the period 2300 to 2100 Ma in Bastar Craton. Sm-Nd depleted mantle model ages (T_DM) from c. 2599 to 2140 Ma indicate that the investigated amphibolite was derived from a comparatively younger protolith.