Mechanisms of subgrain boundary development and grain size decrease in mylonite

2011 Fiscal Year Final Research Report

• Project/Area Number: 21540501
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Petrology/Mineralogy/Science of ore deposit
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: RAIMBOURG Hugues 独立行政法人海洋研究開発機構, 地球内部ダイナミクス領域, 招聘研究員 (40509709)
• Co-Investigator(Kenkyū-buntansha): KOGURE Toshihiro 東京大学, 大学院・理学研究科, 准教授 (50282728)
• Project Period (FY): 2009 – 2011
• Keywords: 岩石変形 / マイロナイト / 細粒化 / 粒界 / 斜方輝石 / TEM / EBSD / FIB

Research Abstract

The deformation structures of orthopyroxene(Opx) in mylonite rock from Hidaka Metamorphic belt have been investigated mainly using transmission electron microscopy(TEM). Low-angle grain boundaries with the b-axis as the rotation axes and almost parallel to the(001) plane of Opx are common and their atomic structure are varied from coherent to semi-coherent and finally incoherent, depending on the misorientation angle of the boundaries. Asymmetric misfit dislocation densities along the two(100) interfaces between exsolved augite lamella and host Opx were also found, which is probably the origin of the folding of the Opx crystal.

Research Products

• [Journal Article] Electron backscatter diffraction(EBSD) analyses of phyllosilicates in petrographic thin sections (2012)
  • Author(s): Inoue, S. and Kogure, T.
  • Journal Title: American Mineralogist Volume: 97 Pages: 755-758
  • Peer Reviewed
• [Journal Article] Crystal bending, subgrain boundaries development and recrystallization in orthopyroxene during granulite-facies deformation (2011)
  • Author(s): Raimbourg, H., Kogure, T., and Toyoshima, T
  • Journal Title: Contribution to Mineralogy and Petrology Volume: 162 Pages: 1093-1111
  • DOI: DOI:10.1007/s00410-011-0642-3.
  • Peer Reviewed
• [Journal Article] Subduction interface processes recorded by eclogite-facies shear zone(Monviso, W. Alpls) (2011)
  • Author(s): Angliboust, S., Aard, P., Raimbourg, H., et al.
  • Journal Title: Lithos Volume: 127 Pages: 222-238
  • DOI: DOI:10.1016/j.lithos.2011.09.004
  • Peer Reviewed
• [Journal Article] Low-grade metamorphism around the down-dip limit of seismorgenic subduction zones : Example from an ancient accretionary complex in the Shimanto Belt, Japan (2011)
  • Author(s): Kameda, J., Raimbourg, H., Kogure, T., et al.
  • Journal Title: Tectonophysics Volume: 502 Pages: 383-392
  • DOI: DOI:10.1016/j.tecto.2011.02.010
  • Peer Reviewed
• [Journal Article] The role of compaction contrasts in sediments in decollement initiation in an accretionary prism (2011)
  • Author(s): Raimbourg, H., Ujiie, K., Kopf A., et al.
  • Journal Title: Marine Geology Volume: 282 Pages: 188-200
  • DOI: DOI:10.1016/j.margeo.2011.02.011
  • Peer Reviewed
• [Journal Article] Acoustic and mechanical properties of Nankai accretionary prism core samples (2011)
  • Author(s): Raimbourg, H., Hamano, Y., Saito, s., et al.
  • Journal Title: Geochemistry Geophysics Geosystem Volume: 12 Pages: Q0AD10
  • DOI: DOI:10.1029/2010GC003169
  • Peer Reviewed
• [Presentation] Crystal folding and recrystallization in naturally deformed orthopyroxene : insights from TEM imaging of subgrain/grain boundary developmen (2011)
  • Author(s): Raimbourg, H., Kogure, T., and Toyoshima, T.
  • Organizer: EGU General Assembly
  • Place of Presentation: EGU General Assembly
  • Year and Date: 2011-04-07
• [Presentation] Structure Nanoanalyses of Specified Regions in Minerals, Rocks and Soils through SEM-FIB-TEM Sequence (2010)
  • Author(s): Kogure, T., Kameda, J., Beaufort, D., and Raimbourg, H.
  • Organizer: 17th IFSM, International Microscopy Congress
  • Place of Presentation: Rio de Janeiro, Brazil
  • Year and Date: 2010-09-21