Study on fractionation behaviours for HFS elements in environmental samples

• Project/Area Number: 26800278
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Geochemistry/Cosmochemistry
• Research Institution: University of Tsukuba
• Principal Investigator: SAKAGUCHI Aya 筑波大学, 数理物質系, 准教授 (00526254)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Project Status: Completed (Fiscal Year 2016)
• Budget Amount: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2016: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000); Fiscal Year 2015: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2014: ¥910,000 (Direct Cost: ¥700,000、Indirect Cost: ¥210,000)
• Keywords: HFS元素 / 鉄マンガンクラスト / Zr / Hf / 放射性トレーサー / ジルコニウム / ハフニウム / DFO / XAFS

Outline of Final Research Achievements

In this study, we have attempted to clarify the accumulation/fractionation mechanisms of “geochemical twin” Zr and Hf in ferromanganese crusts (FMCs) by performing sequential extraction and DFO complexed radio-Zr and radio Hf adsorption experiments, wchich includes XAFS analysis for synthesised and natural samples.The their KDs between natural FMCs and seawater were around 10^8, and their ratios were fractionated compared to that of seawater. The observed Zr chemical states in FMCs resembled that for coprecipitation with ferrihydrite, coprecipitation with d-MnO2 and a basalt-like composition, although the results of sequential extraction showed that Zr and Hf existed predominantly in the Fe fraction. In the case of the adsorption experiments for DFO-Zr and DFO-Hf to ferrihydrite and d-MnO, it was found that the Hf-DFO underwent more adsorption on both minerals than Zr-DFO. The observed bond length of Hf-O was slightly shorter than that of Zr-O in the synthesised minerals.

Research Products

• [Int'l Joint Research] ウィーン大学(オーストリア)
• [Presentation] Fractionation of Zirconium-Hafnium in Ferromanganese Crusts (2016)
  • Author(s): Inagaki J, Sakaguchi A, Inoue M, Usui A, Haba H, Kashiwabara T, Yamasaki S, Sueki K & Takahashi Y
  • Organizer: Goldschmidt 2016
  • Place of Presentation: Pacifico Yokohama, Yokohama, Kanagawa, Japan
  • Year and Date: 2016-06-26
  • Int'l Joint Research
• [Presentation] Fractionation of Zirconium-Hafnium in Ferromanganese Crusts (2016)
  • Author(s): J. INAGAKI, A. SAKAGUCHI, M. INOUE, A. USUI, M. HABA, T. KASHIWABARA, S. YAMASAKI, K. SUEKI, Y. TAKAHASHI
  • Organizer: Goldschmidt Conference
  • Place of Presentation: PACIFICO Yokohama, Yokohama, Kanagawa
  • Year and Date: 2016-06-26
  • Int'l Joint Research
• [Presentation] 鉄マンガンクラスト中におけるZrとHfの分別 (2016)
  • Author(s): 坂口綾、稲垣純平、井上美南、臼井朗、羽場光宏、柏原輝彦、高橋嘉夫
  • Organizer: 日本地球惑星連合
  • Place of Presentation: 千葉県千葉市幕張メッセ国際会議場
  • Year and Date: 2016-05-22
• [Presentation] 鉄マンガンクラスト中のジルコニウム-ハフニウム分別挙動 (2016)
  • Author(s): 坂口 綾、稲垣 純平、井上 美南、臼井 朗、羽場 宏光、柏原 輝彦、山﨑 信哉、末木 啓介、高橋 嘉夫
  • Organizer: JpGU meeting 2016
  • Place of Presentation: 幕張メッセ(千葉県千葉市)
  • Year and Date: 2016-05-22
  • Int'l Joint Research
• [Presentation] Fractionation of Zirconium-Hafnium in Ferromanganese Crusts (2016)
  • Author(s): A. Sakaguchi, J. Inagaki, M. Inoue, A. Usui, T. Kashiwabara, Y. Takahashi
  • Organizer: International Workshop on Marine Manganese Minerals -Geology, Geochemistry, Microbiology, Exploration, and Economics-
  • Place of Presentation: 高知大学、高知コアセンター（高知県高知市、南国市）
  • Year and Date: 2016-03-17
  • Int'l Joint Research
• [Presentation] 深海底化学堆積物･鉄マンガンクラスト中のZr-Hf分別 (2014)
  • Author(s): 井上美南、○坂口綾、柏原輝彦、臼井朗、髙橋嘉夫
  • Organizer: 日本地球化学会年会
  • Place of Presentation: 富山大学（富山市）
  • Year and Date: 2014-09-16 – 2014-09-18
• [Presentation] Fractionation of Hafnium-Zirconium in ferromanganese crusts (2014)
  • Author(s): M. Inoue, ○A. Sakaguchi, T. Kashiwabara, A. Usui, Y. Takahashi
  • Organizer: 日本地球惑星連合2014年大会
  • Place of Presentation: 幕張メッセ（千葉市）
  • Year and Date: 2014-04-28 – 2014-05-02
• [Remarks] 筑波大学研究者総覧
  • URL: http://www.trios.tsukuba.ac.jp/researcher/0000003614