1990 Fiscal Year Final Research Report Summary
CONSIDERATION ON THE RELATION BETWEEN DUCTILE FLOW AND MOTAMORPHIC REACTIONS IN THE HIGH PRESSURE MOTAMORPHIC BELTS.
| Project/Area Number |
01470054
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
鉱物学(含岩石・鉱床学)
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| Research Institution | Hokkaido University |
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Principal Investigator |
WATANABE Teruo Faculty of Science, Department of Geology, Associate Professor, 理学部, 助教授 (40135900)
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| Co-Investigator(Kenkyū-buntansha) |
NIIDA Kiyoaki Faculty of Science, Department of Geology, Senior Lecturer, 理学部, 講師 (30111149)
MAEDA Jinichiro Faculty of Science, Department of Geology, Lecturer, 理学部, 助手 (50165643)
ARITA Kazunori Faculty of Science, Department of Geology, Senior Lecturer, 理学部, 講師 (30091408)
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| Project Period (FY) |
1989 – 1990
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| Keywords | Kamuikotan Belt / Sheath fold / New England Fold Belt / Fluid inclusions / Ductile-brittle boundary / Fe-pumpellyite / Micro-reactor |
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| Research Abstract |
Summarized is deformation style of pelitic schists in the high pressure metamorphic belts such as the Kamuikotan Belt, Sangun Belt, and New England Fold Belt, and New England Fold Belt (Australia). Especially, sheath fold found in the New England Fo13EA\ : ld Belt was studied in detail. The sheath fod is precisely tongue-like fold, i.e., deformed of modified sheath fold and the fold is considered to have been produced not only by simple shear but also by pure shear with shear directional change. Thus, 13EA\ : sheath fold in incompetent layrs were destroied their original form and the fold transformed to isoclinal rootless fold. Such fold showing ductile flow is often observed in pelitic schists in the high pressure metamorphic belts.
Quartz fabrics produced by such ductile flow were examined in the Kumuikotan Belt. Fluid inclusions in the pelitic schists of the Kamuikotan Belt. The fluid inclusions indicate a deformation phase crossing a ductile-brittle boundary. Ductile flow of13EA\ : pelitic rocks is important in formation of tectonic melange similar as serpentinite matrix of serpentinite melange.
Preliminary experimental study for synthesis of Fe-pumpellyite was attempted at 3kb and 5kb(at 250ﾟC) for about 2 weeks. However, run products were ferroan smectites and smectite + garnet. To complete experimental study, over one month is required f13EA\ : or the experimental duration.
But, the micro-reactor is not strong enough for such a long period experimental work at 5kb. Therefore, the experimental study of metamorphic reaction with ductile flow at high pressure is a subject of further study.
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