Superplasticity of minerals 2

• Project/Area Number: 26247087
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Economic geology
• 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): 2014-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥32,370,000 (Direct Cost: ¥24,900,000、Indirect Cost: ¥7,470,000); Fiscal Year 2017: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2016: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2015: ¥5,460,000 (Direct Cost: ¥4,200,000、Indirect Cost: ¥1,260,000); Fiscal Year 2014: ¥15,990,000 (Direct Cost: ¥12,300,000、Indirect Cost: ¥3,690,000)
• Keywords: 超塑性 / マントル / 地震波速度異方性 / 低指数面粒界 / 岩石・鉱物・鉱床学 / 結晶軸選択配向 / 粒子回転 / 鉱物 / オリビン / 粒界すべり / 斜長石

Outline of Final Research Achievements

Grain boundary migration, grain boundary sliding, rigid-body grain rotation and grain-neighbor switching occur during diffusion creep. We show that grain boundary sliding during diffusion creep induces grains to rotate. Preferential grain boundary sliding on low-viscosity boundaries results in the development of crystallographic preferred orientation. Finally, diffusion creep (superplastic) Earth hypothesis is proposed.

Research Products

• [Journal Article] Rocks and advanced ceramics (2017)
  • Author(s): 平賀岳彦
  • Journal Title: The Journal of the Geological Society of Japan Volume: 123 Issue: 6 Pages: 379-390
  • DOI: 10.5575/geosoc.2017.0009
  • NAID: 130005858615
  • ISSN: 0016-7630, 1349-9963
  • Year and Date: 2017-06-15
  • Peer Reviewed
• [Journal Article] Grain- to multiple-grain-scale deformation processes during diffusion creep of forsterite + diopside aggregate: 1. Direct observations (2017)
  • Author(s): G. Maruyama, T. Hiraga
  • Journal Title: Journal of Geophysical Research Volume: 122 Issue: 8 Pages: 5890-5915
  • DOI: 10.1002/2017jb014254
  • Peer Reviewed
• [Journal Article] Grain- to multiple-grain-scale deformation processes during diffusion creep of forsterite + diopside aggregate: 2. Grain boundary sliding-induced grain rotation and its role in crystallographic preferred orientation in rocks. (2017)
  • Author(s): G. Maruyama, T. Hiraga
  • Journal Title: Journal of Geophysical Research Volume: 122 Issue: 8 Pages: 5916-5934
  • DOI: 10.1002/2017jb014255
  • Peer Reviewed
• [Presentation] Grain- to multiple-grain-scale deformation processes during diffusion creep (2017)
  • Author(s): Hiraga, T., Maruyama, G. & Nakakoji, T.
  • Organizer: American Geophysical Union
  • Int'l Joint Research / Invited
• [Presentation] Diffusional creep of fine-grained olivine aggregates: Chemical and melt effects (2017)
  • Author(s): Yabe, K. & Hiraga, T.
  • Organizer: American Geophysical Union
  • Int'l Joint Research
• [Presentation] Precise measurements of grain boundary transport properties of polycrystalline forsterite + enstatite by grain growth and creep experiments (2016)
  • Author(s): Hiraga, T., Nakakoji, T., Nagao, H., Ito, S., Kano, M.
  • Organizer: American Geophysical Union
  • Place of Presentation: San Francisco, U.S.A
  • Int'l Joint Research
• [Presentation] Grain rotation during diffusion creep of forsterite + diopside (2015)
  • Author(s): Takehiko Hiraga, Genta Maruyama
  • Organizer: American Geophysical Union
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2015-12-18
  • Int'l Joint Research / Invited
• [Presentation] Superplastic flow of the earth’s upper mantle (2015)
  • Author(s): Takehiko Hiraga
  • Organizer: International Conference on Superplasticity in Advanced Materials
  • Place of Presentation: 東京大学（東京都文京区）
  • Year and Date: 2015-09-10
  • Int'l Joint Research
• [Presentation] High-temperature creep of fine-grained anorthite aggregate (2014)
  • Author(s): Kosuke Yabe, Sanae Koizumi, Takehiko Hiraga
  • Organizer: American Geophysical Union
  • Place of Presentation: San Francisco, USA
  • Year and Date: 2014-12-17
  • Int'l Joint Research