ACKNOWLEDGEMENTS

We are thankful to G.S. Roy for extending logistic support in field. SS is thankful to the Director General, Geological Survey of India for permission to publish the paper. SB acknowledges the grant provided by DST, Govt. of India. Authors are thankful to Raymaond Enay, Universite Claude-Bernard – Lyon I for his comments on the earlier version of the manuscript. However, responsibility for the opinion expressed in this paper lies entirely with the authors. The manuscript benefited greatly from careful review by two anonymous reviewers.