[B-PT05] Decoding the history of Earth: From Hadean to Modern

[BPT05-03] Distribution of extremely REY-rich mud in the southern part of the Minamitorishima EEZ

*Koichiro Fujinaga^1,2, Kazutaka Yasukawa^2,1, Shiki Machida^3,2, Tatsuo Nozaki^3,2, Yutaro Takaya^4,2, Junichiro Ohta², Kazutaka Oya², Daiki Niikuma⁴, Yoshiro Nishio⁵, Yuka Masaki³, Yoichi Usui³, Satoru Haraguchi³, Koichi Iijima³, Hiroshi Amakawa³, Katsuhiko Suzuki³, Kentaro Nakamura^2,3, Yasuhiro Kato^2,3,1, MR15-E02 Leg.2 cruise members (1.Chiba Institute of Technology, 2.Department of Systems Innovation, School of Engineering, University of Tokyo, 3.Japan Agency for Marine-Earth Science and Technology, 4.Department of Resources and Environmental Engineering School of Creative Science and Enginerring, Waseda University, 5.Research and Education Faculty, Kochi University)

Keywords:rare earth elements and yttrium (REY), REY-rich mud, Minamitorishima Island, deep-sea mineral resource

Since the discovery of the “extremely REY-rich mud” (ΣREY > 5000 ppm) in the Japanese exclusive economic zone (EEZ) surrounding Minamitorishima Island (Kato et al., 2013), we conducted seven research cruises over three years. In the MR15-E01 Leg 2 cruise, one of the latest research cruises by R/V Mirai from March 14 to 28, 2015, we focused to investigate the detailed distribution of the extremely REY-rich mud in the southern part from the Minamitorishima EEZ. During the cruise, we collected 13 sediment cores by piston coring. Here, we report the distribution, visual core descriptions, bulk-sediment chemical compositions of the deep-sea sediment in the southern part of the Minamitorishima EEZ in order to clarify geological and geochemical characteristics of the extremely REY-rich mud.