論文

査読有り
2015年

Rare-earth, major, and trace element geochemistry of deep-sea sediments in the Indian Ocean: Implications for the potential distribution of REY-rich mud in the Indian Ocean

GEOCHEMICAL JOURNAL
  • Kazutaka Yasukawa
  • ,
  • Kentaro Nakamura
  • ,
  • Koichiro Fujinaga
  • ,
  • Shiki Machida
  • ,
  • Junichiro Ohta
  • ,
  • Yutaro Takaya
  • ,
  • Yasuhiro Kato

49
6
開始ページ
621
終了ページ
635
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.2343/geochemj.2.0361
出版者・発行元
GEOCHEMICAL SOC JAPAN

We analyzed 1338 deep-sea sediment samples from 19 Deep Sea Drilling Project/Ocean Drilling Program sites covering a large portion of the Indian Ocean, and constructed a new and comprehensive data set of their bulk chemical compositions, including rare-earth, major, and trace elements. The bulk-sediment rare-earth and yttrium (REY) composition of the REY-enriched samples, characterized by relatively small negative Ce anomalies, almost no Y anomalies, and enrichment in heavy rare-earth elements, can be interpreted as the superposition of the REY compositions of apatite and hydrogenous Fe-Mn oxides. Although the hydrothermal component is a key factor in the formation of REY-rich mud in the Pacific Ocean, it is less important in the Indian Ocean, probably because there is less hydrothermal input of Fe-oxyhydroxides from seafloor hydrothermal vents there. The relationships among Fe2O3, MnO, P2O5, Co, and total REY contents suggest that a primary factor controlling REY enrichment in deep-sea sediments is the sedimentation rate. A low sedimentation rate allows both fish debris apatite and hydrogenous Fe-Mn (oxyhydr)oxides to accumulate in the surface sediments. On the basis of these results, we identified two potential areas in the Indian Ocean where REY-rich mud may be present in surface sediments: the south-southeastern Wharton Basin and the southern Central Indian Ocean Basin. The resource potential of the latter area might be particularly high if the distributions of REY-rich mud and Fe-Mn nodule fields broadly overlap.

Web of Science ® 被引用回数 : 19

リンク情報
DOI
https://doi.org/10.2343/geochemj.2.0361
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000366786700006&DestApp=WOS_CPL

エクスポート
BibTeX RIS