*Akira Usui¹, Hikair Hino¹, Suzushima Suzushima¹, Naotaka Tomioka², Teruhiko Kashiwabara², Kyoko Yamaoka³, Michinari Sunamura⁴ (1.Marine Core Research Center, Kochi University, 2.Japan Agency of Earth and Marine Science a Technology, 3.Geological Survey of Japan, AIST, 4.Earth and Planetary Sciences, University of Tokyo)