1. Department of Earth Sciences, University of California, Riverside, California 92521, USA
2. c/o Dr. S. Chakravarti, Jorabari, Purva Palli, P.O. Santiniketan, Dst. Birbhum, Paschim Banga, 731235, India
3. Department of Mathematics and Physical Sciences, Moreno Valley College, 16130 Lasselle Street, Moreno Valley, California 92551, USA