[S-CG61] 海洋底地球科学

[SCG61-04] 南鳥島南東方海域におけるレアアース泥の地球化学

*藤永 公一郎^1,2、安川 和孝^3,1、町田 嗣樹^1,2、佐藤 峰南¹、下村 遼³、田中 えりか³、見邨 和英³、臼井 洋一⁴、飯島 耕一⁴、高橋 亜夕⁴、山本 浩文⁴、鈴木 勝彦⁴、中村 謙太郎³、加藤 泰浩^2,3,1,4、MR16-07 乗船者一同 (1.千葉工業大学次世代海洋資源研究センター、2.東京大学大学院工学系研究科エネルギー・資源フロンティアセンター、3.東京大学大学院工学系研究科システム創成学専攻、4.海洋研究開発機構海底資源研究開発センター)

キーワード：レアアース、レアアース泥、南鳥島、海底鉱物資源、深海堆積物

Since the discovery of the new and high-grade resource for rare-earth elements and yttrium (REY), or “REY-rich mud” with 400 – 8000 ppm of total REY content, in the Japanese exclusive economic zone (EEZ) surrounding Minamitorishima Island (Iijima et al., 2016; Fujinaga et al., 2016), we conducted eight research cruises over five years. During the MR16-07 cruise by R/V MIRAI from November 1 to 25, 2016, we investigated the distribution of the REY-rich mud in several basins located southeastern off Minamitorishima Island, mainly the area outside the Minamitorishima EEZ. We collected 12 sediment cores by piston coring, and implemented bulk chemical analyses by using ICP-MS for trace and rare-earth elements, and XRF for major elements. In the presentation, we report the sedimentological and geochemical features of the deep-sea sediments, and the distribution of REY-rich mud in the southeastern basins nearby the Minamitorishima EEZ.