*Krishnan Sajeev¹、P Rajkumar²、Ippei Kitano³、Durgalakshmi Durgalakshmi⁴、Madhusoodhan Satish-Kumar⁵、Sayantani Chatterjee⁶、Ian S Williams⁴、Eiichi TAKAZAWA⁵ (1.Centre for Earth Sciences, Indian Institute of Science、2.Advanced Facility for Microscopy and Microanalysis, Indian Institute of Science, Bengaluru 560 012, India.、3.The Hokkaido University Museum, Hokkaido University, Sapporo, Hokkaido 060-0810, Japan、4.Research School of Earth Sciences, Australian National University, Canberra 2601, Australia、5.Department of Geology, Faculty of Science, Niigata University, Niigata 950-2181, Japan、6.Earthquake Research Institute, The University of Tokyo, Tokyo113-0032, Japan )