| Project/Area Number |
13640429
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
固体地球物理学
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| Research Institution | National Institute of Polar Research |
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Principal Investigator |
NOGI Yoshifumi National Institute of Polar Research, Division of Research, Associate Professor, 研究系, 助教授 (90280536)
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| Co-Investigator(Kenkyū-buntansha) |
ISHIKAWA Naoto Kyoto University, Graduate school of Human and Environmental Studies, Associate Professor, 大学院・人間環境学研究科, 助教授 (30202964)
FUNAKI Minoru National Institute of Polar Research, Division of Research, Associate Professor, 研究系, 助教授 (10132713)
FUKUDA Yoichi Kyoto University, Graduate school of Science, Associate Professor, 大学院・理学研究科, 助教授 (30133854)
MOTOYOSHI Yoichi National Institute of Polar Research, Division of Research, Professor, 研究系, 教授 (90211606)
SHIRAISHI Kazuyuki National Institute of Polar Research, Division of Research, Professor, 研究系, 教授 (90132711)
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| Project Period (FY) |
2001 – 2003
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| Keywords | Gondwana / Continental breakup / Tectonics / Seafloor spreading / Hot spot / Magnetic anomaly / Gravity anomaly / Geological structure |
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| Research Abstract |
The seafloor spreading evolution in the Southern Indian Ocean is key to understanding the initial breakup of Gondwana. The new constraints on Gondwana breakup process in the Southern Indian Ocean are obtained.
Structural orientations in the East Enderby Basin are deduced from vector magnetic anomalies and satellite derived gravity anomalies. V-shaped structural trends pointing to the southwest, west of the Southern Kerguelen Plateau, are interpreted as trace of spreading propagators away from Kerguelen hot spot. These oceanic spreading fabrics may be analogous to the Reykjanes Ridge south of Iceland. The NNW-SSE trending structure off Pritz Bay may indicate the initial breakup direction of the East Enderby Basin, and a change in seafloor spreading direction, from an initial NNW-SSE breakup direction to a NW-SE direction, are also suggested.
The structural lineaments and the magnetic anomaly lineations were reasonably explained by introducing the extinct ridges between the Conrad Rise and the Gunnerus Ridge, although the complicated seafloor spreading history in the West Enderby Basin were suggested. The structural trends just to the south of Conrad rise can be interpreted as the fracture zones and most likely formed during initial break up. We also suggest that the part of the Conrad Rise formed during initial breakup of Gondwana. The part of the Conrad Rise may be related to plume activity and formed during initial breakup of Gondwana.
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