1994 Fiscal Year Final Research Report Summary
Tectonics of the Outer Zone of Southwest Japan as inferred from microtextur of its constituen rock
| Project/Area Number |
04640705
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
地質学一般
|
|---|
| Research Institution | HIROSHIMA UNIVERSITY |
|---|
Principal Investigator |
HARA Ikuo Hiroshima Univ., Faculty of Science, Professor., 理学部, 教授 (50033824)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
HAYASAKA Yasutaka Hiroshima Univ.Faculty of Science, Research Associate, 理学部, 助手 (10198830)
MIYAMOTO Takami Hiroshima Univ.Faculty of Science, Associate Professor, 理学部, 助教授 (00090548)
TAKESHITA Toru Hiroshima Univ., Faculty of Science, Associate Professor, 理学部, 助教授 (30216882)
|
|---|
| Project Period (FY) |
1992 – 1994
|
| Keywords | Sambagawa megaunit / Chichibu megaunit / metamorphic rocks of high-pressure type / Subduction zone / tectonic erosion / underplating / P-T-t-D path / folding mechanism |
|---|
| Research Abstract |
The Outer Zone of Southwest Japan consists of the four megaunits.Chichibu megaunit II,Sambagawa megaunit.Chicibu megaunit I and Shimant megaunit in descending order of structural level.On the basis of microtextures of the Sambagawa megaunit rocks, especially Saruta nappe (I+II) schists and Fuyunose nappe schists, it has been clarified that in subduction channel sediment subduction occurs a accompanying tectonic crosion and mixing of the hanging wall rocks.From analysis of microtextures and P-T-t-D path of the Sogauchi nappe schists, it has been pointed out that they consist of three subnappes, ST subnappe, KAT subnappe and NOM subnappe in descending oreder of structural level, which are succesively underplated with downward decrease of pressure and temperature, and that the underplating processes is ascribed to upflow of subducted sehiments from control point of subduction channel.From relationship in microtextures and P-T-t-D path between the Sogauchi nappe schists and the Sakamoto-Niyodo nappe schists (Chichibu megaunit I), it has benn concluded that the Sambagawa megaunit schists as metamorphic rocks of high-pressure type were exhumed along the mechanial boundary of the Cretaceous convergence zone.The folding of the Sambagawa megaunit schists during the last phase of deformation shows a transition from flexural-flow type to flexural-slip type.
|
-
[Publications] Hara I.,Shiota T.,Hide.K.,Kanai K.,Goto M.,Seki S.,Kaikiri.K.,Takeda K.,Hayasaka Y.,Miyamoto T.,Sakurai Y and Ohtomo Y.: "Tectoric evolution of the Sambagawa Schists and its implicatiens in convergent margin processes." Jour.sci.Hiroshima Univ.Ser,C.9. 495-595 (1992)
Description
「研究成果報告書概要(和文)」より
-
-
-
-
-
-
-
-
[Publications] Hara, I., Shiota, T., Hide, K., Kanai, K., Goto, M., Seki, S., Kaikiri, K., Takeda, K., Hayasaka, Y., Miyamoto, T., Sakurai, Y and Ohtomo, Y :"Tectonic evolution of the Sambagawa schists and its implicatiens in convergent margin processes." Jour.Sci.Hiroshima Univ.Ser.C. 9. 495-595 (1992)
Description
「研究成果報告書概要(欧文)」より
-
[Publications] Sakakibara, N., Hara.I., Kanai K., Kaikiri, K., Siota, T., Hide, K., and Paulitsch, P :"Quartz microtextures of the Sambagawa schists and their implicant ions in convergent margin processes." The Island Arc. 1. 186-197 (1992)
Description
「研究成果報告書概要(欧文)」より
-
[Publications] Shiota, T., Hara, I., Seki, S., Ikeda, Y., Okudaira, T and Hide, K :"Sinistral en echelon Folding of the Sambagawa schists and its tectonic implication." Jour.Sci.Hiroshima Univ.Ser.C. 9. 671-683 (1993)
Description
「研究成果報告書概要(欧文)」より
-
-
-
