1. Department of Geology, University of Calcutta, 35 Ballygunge Circular Road, Kolkata 700019, India
2. Department of Geology, Durgapur Government College, Durgapur 713214, India
3. Department of Earth and Planetary Systems Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, Japan 739-8526