Mesoarchaean crustal history of the eastern Indian Craton: SmNd and UPb isotopic evidence

A variety of xenoliths representing high-Al trondhjemites and supracrustal lithologies occur within Mesoarchaean granitoid rocks of the eastern Indian Craton. A trondhjemitic xenolith from the Bonai pluton yields a UPb age of 3380+6−4 Ma for magmatic zircon and a minimum age of 3448 Ma for xenocrystic zircon grains. This sample also shows an ϵNd value of −4.2 and TDM of 3.9 Ga whereas four other xenoliths yield ϵNd values ranging from +0.3 to +1.8 and TDM of 3.54 to 3.37, which are consistent with published data from the region and suggest a derivation from protoliths with relatively short-lived crustal residence times.