*Du Khac Nguyen¹、Tomoaki Morishita¹、Yusuke Soda¹、Biswajit Ghosh²、 Yumiko Harigane³、Christopher J. MacLeod⁴、Peter Blum⁵、Henry J.B Dick⁶ (1.School of Natural System, College of Science and Technology, Kanazawa University, Japan、2.Department of Geology, University of Calcutta, India、3.Institute of Geology and Geoinformation, Geological Survey of Japan、4.School of Earth and Ocean Sciences, Cardiff University, Wales、5.International Ocean Discovery Program, Texas A&M University, USA、6.Department of Geology and Geophysics, Woods Hole Oceanographic Institution, USA)