*Yongsheng HUANG^1,2, Satoshi Okumura³, Kazuhisa Matsumoto³, Naoko Takahashi³, Hong Tang⁴, Tatsumi Tsujimori^3,5, Michihiko Nakamura³, Yuan Li^1,2 (1.Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, 2.CAS Center for Excellence in Deep Earth Science, Guangzhou 510640, China, 3.Department of Earth Science, Graduate School of Science, Tohoku University, Sendai, 980-8578, Japan, 4.South China Sea Environmental Monitoring Center, SOA, Guangzhou 510300, China., 5.Center for North Asian Studies, Tohoku University, Sendai, 980-8576, Japan)

*Masanari Arao¹, Michihiko Nakamura¹, Mayumi Mujin¹, Naoki Araya¹, Takayuki Nakatani², Mari Sumita³, Hans-Ulrich Schmincke³ (1.Tohoku University, 2.AIST, 3.GEOMAR)

*Natsuko Sekiya¹, Michihiko Nakamura², Naoki Araya², Shingo Takeuchi³, Yukiko Suwa⁴ (1.Division of Earth and Planetary Materials, Department of Earth Science, Faculty of Science, Tohoku University, 2.Department of Earth Science, Graduate School of Science, Tohoku University, 3.Central Institute of Electric Power Industry, 4.CERES, Inc.)