Investigation of grain boundary segregation and diffusion to understand chemical evolution of the earth's interior

• Project/Area Number: 20684024
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: The University of Tokyo
• Principal Investigator: HIRAGA Takehiko 東京大学, 地震研究所, 准教授 (10444077)
• Project Period (FY): 2008 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥18,460,000 (Direct Cost: ¥14,200,000、Indirect Cost: ¥4,260,000); Fiscal Year 2010: ¥2,340,000 (Direct Cost: ¥1,800,000、Indirect Cost: ¥540,000); Fiscal Year 2009: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000); Fiscal Year 2008: ¥14,040,000 (Direct Cost: ¥10,800,000、Indirect Cost: ¥3,240,000)
• Keywords: 極細粒高緻密鉱物多結晶体 / 不適合元素 / 粒界拡散 / 希ガス / 貴金属元素 / 超塑性 / 粒界の構造変態 / 高温炉 / マントル / スラブ / 下部マントル / せん断歪み / 地震断層 / 多結晶体 / フォルステライト / マントル鉱物 / 真空焼結 / 電子顕微鏡法 / 微粒粉 / エンスタタイト / ペリクレース

Research Abstract

Based on experimental studies on grain boundary diffusion and segregation, we are able to show the negligible role of grain boundaries on chemical evolution of the earth interior. Further, using our accumulated knowledge of grain boundary properties, we are able to demonstrate superplasticity of the minerals and to propose grain growth law as a function of mineral fractions.

Research Products

• [Journal Article] Mantle superplasticity and its self-made demise (2010)
  • Author(s): Hiraga, T., Miyazaki, T., Tasaka, M., Yoshida, H.
  • Journal Title: Nature Volume: 468 Pages: 1091-1094
  • Peer Reviewed
• [Journal Article] Synthesis of highly dense and fine-grained aggregates of mantle composites by vacuum sintering of mineral nano-powders (2010)
  • Author(s): Koizumi, S., Hiraga, T., Tachibana, C., Tasaka, M., Miyazaki, T., Kobayashi, T., Takamasa, A., Ohashi, N., Sano, S.
  • Journal Title: Physics and Chemistry of Minerals Volume: 37 Pages: 505-518
  • Peer Reviewed
• [Journal Article] Grain growth systematics for forsterite ± enstatite aggregates: Effect of lithology on grain size in the upper mantle (2010)
  • Author(s): Hiraga, T., Tachibana, C., Ohashi, N., Sano, S.
  • Journal Title: Earth and Planetary Science Letters Volume: 291 Pages: 10-20
  • Peer Reviewed
• [Journal Article] Synthesis of highly dense and fine-grained aggregates of mantle composites by vacuum sintering of mineral nano-powders (2010)
  • Author(s): Koizumi S., Hiraga, T., 他
  • Journal Title: Physics and Chemistry of Minerals (印刷中)
  • Peer Reviewed
• [Journal Article] Grain growth systematics for forsterite±enstatite aggregates : Effect of lithology on grain size in the upper mantle (2010)
  • Author(s): Hiraga, T., Tachibana, C., Ohashi, N., Sano, S.
  • Journal Title: Earth and Planetary Science Letters 291 Pages: 10-20
  • Peer Reviewed
• [Journal Article] Systematic distribution of incompatible elements in mantle pperidotite : importance of intr-and inter-granular melt-like components (2009)
  • Author(s): Hiraga, T., Kohlstedt D.L.
  • Journal Title: Contributions to Mineralogy and Peterology 158 Pages: 149-167
  • Peer Reviewed