Study of ultrabasic (peridotitic) pseudotachylytes

• Project/Area Number: 20540466
• 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: Kyoto University
• Principal Investigator: OBATA Masaaki Kyoto University, 大学院・理学研究科, 教授 (20126486)
• Co-Investigator(Renkei-kenkyūsha): KANAGAWA Kyuichi 千葉大学, 大学院・理学研究科, 教授 (40185898) ; OZAWA Kazuhito 東京大学, 大学院・理学系研究科, 教授 (90160853)
• Project Period (FY): 2008 – 2010
• Project Status: Completed (Fiscal Year 2010)
• Budget Amount: ¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000); Fiscal Year 2010: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000); Fiscal Year 2009: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000); Fiscal Year 2008: ¥1,820,000 (Direct Cost: ¥1,400,000、Indirect Cost: ¥420,000)
• Keywords: 断層 / かんらん岩 / 摩擦溶融 / マントル / 地震 / マイロナイト / Balmuccia / 変形 / 摩擦融解 / 断層岩 / シュードタキライト / 変形岩 / メルト

Research Abstract

Ultramafic pseudotachylyte from the Balmuccia peridotite (N. Italy) was classified into two major categories : (1) igneous textured type and (2) mylonitic type. It was revealed from their field relationships and mineralogical characteristics that the latter type was generated earlier and thus at greater depths than the former type. In particular, the recognition and characterization of the latter type is a major achievement of our project. This discovery has opened up a way to understand the seismogenic processes in the upper mantle in more detailed and realistic ways.

Research Products

• [Journal Article] 超マフィックマイロナイトシュードタキライトの発見とその地震発生学的意義:マントル地震の震源過程の解明に向けて (2011)
  • Author(s): 小畑正明・上田匡将
  • Journal Title: 地学雑誌 101巻3号(印刷中)
  • NAID: 10030372677
• [Journal Article] 超マフィックマイロナイトシュードタキライトの発見とその地震発生学的意義-マントル地震の震源過程の解明に向けて (2011)
  • Author(s): 小畑正明, 上田匡将
  • Journal Title: 地学雑誌 Volume: 120(3)(印刷中 のため未定)
  • NAID: 10030372677
  • Peer Reviewed
• [Journal Article] Topotaxic relationships between spinel and pyroxene in kelyphite after garnet in mantle-derived peridotites and their implications to reaction mechanism and kinetics (2011)
  • Author(s): Obata, M., Ozawa, K.
  • Journal Title: Mineralogy and Petrology Volume: 101(印刷中 のため未定)
  • Peer Reviewed
• [Journal Article] Two contrasting fabric patterns of olivine observed in garnet peridotite from a mantle-derived ultramafic mass (2010)
  • Author(s): Kamei, A, Obata, M., Michibayashi, K., Hirajima, T.
  • Journal Title: Journal of Petroloy 51 Pages: 101-123
  • Peer Reviewed
• [Journal Article] Mantle earthquakes frozen in mylonitized ultramafic pseudotachylytes of spinel-lherzolite facies (2008)
  • Author(s): Ueda T., Obata M., Di Toro, G., Kanagawa, K., Ozawa, K.
  • Journal Title: Geology 36 Pages: 607-610
• [Journal Article] Mantle earthquakes frozen in mylonitized ultramafic pseudotachylytes of spinel-lherzolite facies. (2008)
  • Author(s): Ueda, T., Obata, M. Di Toro, G. Ozawa, K. Kanagawa, K.
  • Journal Title: Geology 36 Pages: 607-610
  • Peer Reviewed
• [Presentation] 北イタリアBalmuccia かんらん岩シュードタキライト断層脈中のかんらん石結晶上に定方位に発達する斜方輝石反応縁(「斜方輝石フリンジ」)とその意義:ストレスマーカー? (2010)
  • Author(s): 上田匡将、小畑正明、小澤一仁、Di Toro, G.
  • Organizer: 日本地質学会第117年学術大会
  • Place of Presentation: 富山
  • Year and Date: 2010-09-23
• [Presentation] 超塩基性シュードタキライトの観察から中～深部地震の震源過程とメカニズムを考える (2010)
  • Author(s): 小畑正明
  • Organizer: 日本地質学会第117年学術大会
  • Place of Presentation: 富山
  • Year and Date: 2010-09-19
• [Presentation] 超塩基性シュードタキライトの観察から中～深部地震の震源過程とメカニズムを考える (2010)
  • Author(s): 小畑正明
  • Organizer: 日本地質学会第117年学術大会
  • Place of Presentation: 富山大学
  • Year and Date: 2010-09-19
• [Presentation] Kelyphite and symplectite after garnet : microstmcmre, formation processes and reaction kinetics (2010)
  • Author(s): Obata, M.
  • Organizer: International Mineralogical Association, General Assembly
  • Place of Presentation: Budapest,ハンガリー(招待講演)
  • Year and Date: 2010-08-23
• [Presentation] ウルトラマイロナイトシュードタキライトとその地震発生学的意義 (2010)
  • Author(s): 小畑正明
  • Organizer: 地球惑星科学連合2010年大会
  • Place of Presentation: 千葉、幕張
  • Year and Date: 2010-05-26
• [Presentation] マントル岩上昇時に脆性-延性遷移帯で形成されたmylonitic pseudotachylyte、イタリアアルプス (2010)
  • Author(s): 上田匡将、小畑正明、小澤一仁、Di Toro, G.
  • Organizer: 日本地球惑星科学連合2010年度連合大会
  • Place of Presentation: 千葉、幕張
  • Year and Date: 2010-05-26
• [Presentation] ウルトラマイロナイト(sheared)シュードタキライトとその地震発生学的意義 (2010)
  • Author(s): 小畑正明
  • Organizer: 地球惑星科学連合2010年大会
  • Place of Presentation: 千葉,幕張メッセ
  • Year and Date: 2010-05-26
• [Presentation] Ductile and brittle deformation in peridotite recorded in ultramafic pseudotachylytes and associated fault (2009)
  • Author(s): Ueda, T.
  • Organizer: AGU(アメリカ地球物理連合)秋期大会
  • Place of Presentation: サンフランシスコ、米国
  • Year and Date: 2009-12-18
• [Presentation] Ductile and brittle deformation in peridotite recorded in ultramafic pseudotachylytes and associated fault rocks (Balmuccia, Italian Alps) (2009)
  • Author(s): Ueda T., Obata M., Ozawa K., Di Toro G.
  • Organizer: American Geophysical Union Fall Meeting
  • Place of Presentation: San Francisco、米国
• [Presentation] Frictional Melting and Deformation in the Upper Mantle (2008)
  • Author(s): Ozawa K., Ueda T., Obata M., Di Toro G., Kanagawa K., Nagahara H.
  • Organizer: Constraints from Cr-Al Spinel in Ultramafic Psuedotachylyte from Balmuccia. IGC(万国地質会議)
  • Place of Presentation: Oslo、ノルウェー
  • Year and Date: 2008-08-12
• [Presentation] 上部マントルにおける摩擦融解と変形過程:Balmuccia産の完晶質かんらん岩シュードタキライト中Cr-Alスピネルからの制約 (2008)
  • Author(s): 小澤一仁、上田匡雅、小畑正明、Di Toro Giulio、金川久一、永原裕子
  • Organizer: 2008年度連合大会
  • Place of Presentation: 千葉、幕張
  • Year and Date: 2008-05-26
• [Presentation] Shear localization, seismic rupture and frictional melting, observed in a mylonitized ultramafic pseudotachylyte from Balmuccia peridotite (2008)
  • Author(s): Obata M., Ueda T., Ozawa K., Di Toro, G., Kanazawa K.
  • Organizer: Ivrea Zone, N. Italy. AGU Chapman Conference on Shallow Mantle Composition and Dynamics 5th International Orogenic Lherzolite Conference
  • Place of Presentation: Mt.Shasta, California、米国
• [Presentation] Mylonitized ultramafic pseudotachylyte and associated deformation textures (2008)
  • Author(s): Ueda T., Obata M., Ozawa K., Di Toro G., Kanagawa K.
  • Organizer: Balmuccia peridotite massif
  • Place of Presentation: Ivrea Zone, Italy.
• [Presentation] Shear localization, seismic rupture and frictional melting, observed in a mylonitized ultramafic pseudotachylyte from Balmuccia peri-dotite, Ivrea Zone, N. Italy (2008)
  • Author(s): Obata, et al
  • Organizer: 第5回国際レルゾライト会議
  • Place of Presentation: Mt. Shasta, Calf., US
• [Remarks] ホームページ等