• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to previous page

Origin and formation environment of deep mantle diamonds and the role of fluid

Research Project

Project/Area Number 20H02009
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Review Section Basic Section 17040:Solid earth sciences-related
Research InstitutionTohoku University

Principal Investigator

Ohfuji Hiroaki  東北大学, 理学研究科, 教授 (80403864)

Co-Investigator(Kenkyū-buntansha) M Satish‐Kumar  新潟大学, 自然科学系, 教授 (50313929)
鍵 裕之  東京大学, 大学院理学系研究科(理学部), 教授 (70233666)
Project Period (FY) 2020-04-01 – 2023-03-31
Project Status Completed (Fiscal Year 2022)
Budget Amount *help
¥18,070,000 (Direct Cost: ¥13,900,000、Indirect Cost: ¥4,170,000)
Fiscal Year 2022: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
Fiscal Year 2021: ¥5,200,000 (Direct Cost: ¥4,000,000、Indirect Cost: ¥1,200,000)
Fiscal Year 2020: ¥9,620,000 (Direct Cost: ¥7,400,000、Indirect Cost: ¥2,220,000)
Keywordsダイヤモンド / C-H-O流体 / マグネサイト / 炭素同位体 / 高圧実験 / NanoSIMS / マントル / 深部流体 / 炭酸塩 / 包有物 / 電子顕微鏡
Outline of Research at the Start

本研究は,マントル深部由来のダイヤモンド中に含まれる流体包有物に特に注目し,内部を充填する析出物の鉱物・化学組成と量比を調べ,ダイヤ生成流体の化学的特徴を明らかにする.また,ダイヤモンドの炭素同位体組成や微量元素パターンも考慮に入れ,多角的見地より深部由来ダイヤの起源と生成環境を探る.さらに,還元的なC-H-O流体と地殻・マントル物質の共存系で高圧実験を通して固液間相互作用とダイヤ生成における流体の役割を明らかにする.

Outline of Final Research Achievements

Analysis of nano-scale inclusions in natural samples indicates that the formation of “deep diamonds” is most likely to occur in a fluid-saturated environment. High-pressure experiments in the presence of carbonate and a CH4-rich C-H-O fluid revealed that the diamonds produced by the reaction between them have a very wide range of carbon isotopic compositions, suggesting that similar carbon isotopic compositions (-25 to -15‰) found in some E-type diamonds and deep diamonds are likely the result of carbon isotope assimilation through the reaction of subducted carbonate and reduced C-H-O fluids derived from biogenic materials. Mixing of the CO2 fluid produced by carbonate decomposition with the surrounding CH4-rich reducing C-H-O fluid may be the key to the formation of “deep diamonds”.

Academic Significance and Societal Importance of the Research Achievements

本研究の結果,起源・成因のよく分かっていないマントル深部起源のダイヤモンドの形成にCH4やH2Oなどの混合からなるC-H-O流体が密接に関与し,そのような流体と沈み込み帯から地球深部へ供給される炭酸塩との反応が深部起源ダイヤの起源となり得ることが初めて明確に示された.ダイヤモンドは,地球の深部に渡る炭素の大循環の主役であり,その成因を理解することは,地球における物質循環とその時間的変動・進化を捉える上でも意義は大きい.

Report

(4 results)
  • 2022 Annual Research Report   Final Research Report ( PDF )
  • 2021 Annual Research Report
  • 2020 Annual Research Report
  • Research Products

    (14 results)

All 2023 2022 2021 2020 Other

All Int'l Joint Research (2 results) Journal Article (8 results) (of which Int'l Joint Research: 3 results,  Peer Reviewed: 8 results,  Open Access: 5 results) Presentation (4 results) (of which Int'l Joint Research: 4 results)

  • [Int'l Joint Research] Russian Academy of Sciences(ロシア連邦)

    • Related Report
      2020 Annual Research Report
  • [Int'l Joint Research] Gemological Institute of America(米国)

    • Related Report
      2020 Annual Research Report
  • [Journal Article] Diamond formation from methane hydrate under the internal conditions of giant icy planets2021

    • Author(s)
      Kadobayashi Hirokazu、Ohnishi Satoka、Ohfuji Hiroaki、Yamamoto Yoshitaka、Muraoka Michihiro、Yoshida Suguru、Hirao Naohisa、Kawaguchi-Imada Saori、Hirai Hisako
    • Journal Title

      Scientific Reports

      Volume: 11 Issue: 1 Pages: 8165-8165

    • DOI

      10.1038/s41598-021-87638-5

    • Related Report
      2021 Annual Research Report 2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Formation of polycrystalline graphite aggregates in high-pressure metamorphic rocks from the Kokchetav Massif, Northern Kazkhstan2021

    • Author(s)
      Mikailenko, D.S., Korsakov, A.V., Ohfuji, H., Rezvukhina, O.V., Pekov, I.V.
    • Journal Title

      Doklady Earth Sciences

      Volume: 497 Issue: 1 Pages: 227-231

    • DOI

      10.1134/s1028334x21030089

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Sn-V centers in diamond activated by ultra high pressure and high temperature treatment2021

    • Author(s)
      Fukuta Rei、Murakami Yohei、Ohfuji Hiroaki、Shinmei Toru、Irifune Tetsuo、Ishikawa Fumitaro
    • Journal Title

      Japanese Journal of Applied Physics

      Volume: 60 Issue: 3 Pages: 035501-035501

    • DOI

      10.35848/1347-4065/abdc31

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Int'l Joint Research
  • [Journal Article] Plastic deformation and strengthening mechanisms of nanopolycrystalline diamond2021

    • Author(s)
      Wang, Y., Shi, F., Gasc, J., Ohfuji, H., Wen B., Yu, T., Officer T., Nishiyama, N., Shinmei, T., Irifune, T., Dung, M.
    • Journal Title

      ACS Nano

      Volume: 15 Issue: 5 Pages: 8283-8294

    • DOI

      10.1021/acsnano.0c08737

    • Related Report
      2021 Annual Research Report
    • Peer Reviewed / Open Access / Int'l Joint Research
  • [Journal Article] Microdiamond in a low-grade metapelite from a Cretaceous subduction complex, western Kyushu, Japan2020

    • Author(s)
      Nishiyama Tadao、Ohfuji Hiroaki、Fukuba Kousuke、Terauchi Masami、Nishi Ukyo、Harada Kazuki、Unoki Kouhei、Moribe Yousuke、Yoshiasa Akira、Ishimaru Satoko、Mori Yasushi、Shigeno Miki、Arai Shoji
    • Journal Title

      Scientific Reports

      Volume: 10 Issue: 1 Pages: 11645-11645

    • DOI

      10.1038/s41598-020-68599-7

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Stability of methane hydrate at high-pressure and high-temperature of up to 40 GPa and 573 K2020

    • Author(s)
      Kadobayashi Hirokazu、Ohfuji Hiroaki、Hirai Hisako、Ohtake Michika、Yamamoto Yoshitaka
    • Journal Title

      Journal of Physics: Conference Series

      Volume: 1609 Issue: 1 Pages: 012007-012007

    • DOI

      10.1088/1742-6596/1609/1/012007

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] High-pressure phase transition of methane hydrate in water-methane-ammonia system2020

    • Author(s)
      Kadobayashi Hirokazu、Hirai Hisako、Machita Kenji、Ohfuji Hiroaki、Muraoka Michihiro、Yoshida Suguru、Yamamoto Yoshitaka
    • Journal Title

      Journal of Physics: Conference Series

      Volume: 1609 Issue: 1 Pages: 012006-012006

    • DOI

      10.1088/1742-6596/1609/1/012006

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed / Open Access
  • [Journal Article] Nano-polycrystalline diamond synthesized through the decomposition of stearic acid2020

    • Author(s)
      H. Kawamura, H. Ohfuji
    • Journal Title

      High Pressure Research

      Volume: 40 Issue: 1 Pages: 162-174

    • DOI

      10.1080/08957959.2019.1708910

    • Related Report
      2020 Annual Research Report
    • Peer Reviewed
  • [Presentation] Carbon isotopic analysis of microcrystalline diamond samples recovered from MA experiments by NanoSIMS2023

    • Author(s)
      Kawamura, H., Takahata, N., Ishida, A., Sasaki, K., Shirai, K., Ohfuji, H., Suzuki, A.
    • Organizer
      5th International Seminar on High-Pressure Mineralogy
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Nano-polycrystalline diamond from carbonate-rich pseudotachylyte2022

    • Author(s)
      Ohfuji, H., Nishiyama, T.
    • Organizer
      IMA2022
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Decomposition mechanism of magnesite in the presence of C-H-O fluids at high-pressure2022

    • Author(s)
      Kawamura, H., Ohfuji, H., Suzuki, A.
    • Organizer
      IMA2022
    • Related Report
      2022 Annual Research Report
    • Int'l Joint Research
  • [Presentation] Carbon isotope fractionation during the formation of Diamond from Stearic acid under HP-HT condition2022

    • Author(s)
      Kawamura, H., Ohfuji, H., Satish-Kumar, M., Suzuki, A
    • Organizer
      4th International Seminar “High-Pressure Mineralogy: Theory and Experiment”
    • Related Report
      2021 Annual Research Report
    • Int'l Joint Research

URL: 

Published: 2020-04-28   Modified: 2024-01-30  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi