1. Wadia Institute of Himalayan Geology, Dehradun 248 001, India
2. Institut für Geologie, Baltzerstrasse 3, 3012 Bern, Switzerland, and Centro Universitario Datazioni e Archeometria, Università di Milano Bicocca, 20126 Milano, Italy
3. Department of Geology, Center of Advanced Study, Kumaun University, Nainital 263 002, India