18 Palaeomagnetic analysis of the Lakhna Dykes (Bastar Craton, India) yields a palaeopole at 36.6°N, 19 132.8°E, dp=12.4°, dm=15.9°, and the U-Pb zircon age obtained from one of the rhyolitic dykes is 20 1466.4 ± 2.6 Ma (MSWD=0.21, concordia age based on two analyses with identical Pb/U ages), 21 similar to previously published U-Pb ages. Major and trace element analyses of the Lakhna Dykes 22 30 2 model. Our preferred reconstruction implies a long Palaeo-to Mesoproterozoic accretionary orogen 31 stretching from south-eastern Laurentia through south-western Baltica to south-eastern India. Breakup 32 of India and Baltica probably occurred in the Late Mesoproterozoic, but additional constraints are 33 needed. 34

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The E-W running Salem-Attur shear zone demarcates the tectonic boundary between Archaean Dharwar Craton in the north and Proterozoic Southern granulite terrane in the south. This study reveals that the shear zone is a low angle thrust. The thrust zone is around 10 m thick and it merges with the main shear zone along the strike. The thrust is developed on charnockite near Odyarpatti, which is retrograded into schists. Further, it is marked by gently dipping mylonitic foliation and subhorizontal lineation. The S-C fabric, mantled porphyroclasts and intragranular faults indicate northeasterly slip along the thrust. Recumbent shear folds SF 1 are developed within the thrust zone. The thrust has been folded by late stage F 2 fold which has brought variation in the orientation of the mylonitic foliation from subhorizontal to vertical attitude; the mylonitic lineations have been rotated to subvertical orientation also. Additionally, the F 2 crenulations and shear cleavages and intersection lineations are superimposed on the mylonitic fabric. Thrusting along the Salem-Attur shear zone is probably the cause for upliftment of the charnockites to the upper crust. Post-upliftment stage has witnessed brittle deformation in the form of development of shear fractures in NNE-SSW and E-W directions. Pseudotachylites are emplaced along these fractures.

a b s t r a c tThe paper is a reply on the comments by Basu and Bickford on the article Ratre et al., 2010, JAES 39, 565-577, that reports an age range of 1450-517 Ma for the Khariar basin (Purana) in India. Basu and Bickford agree with the lower age of the basin but they argue for ca 1000 Ma as the upper age. Though our inference about the upper age at 517 Ma is based on structural studies, we still maintain that.