*Nanako Koma¹, Hitoshi Hasegawa¹, Akira Usui², Hirokuni Oda⁵, Takashi Ito⁴, Yoshiro Nishio³, Go-Ichiro Uramoto², Takuya Matsuzaki², Tomoyo Okumura² (1.Faculty of science and Technology, Kochi University, 2.Center for Advanced Marine Core Research, Kochi University, 3.Research and Education Faculty, Kochi University, 4.Faculty of Education, Ibaraki Universit, 5.Institute of Geology and Geoinformation, Geological Survey of Japan, AIST)