| Project/Area Number |
15500692
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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 |
Geography
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| Research Institution | Kinjo University |
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Principal Investigator |
MORIYA Ichio Kinjo University, Faculty of Social Work, Professor, 社会福祉学部, 教授 (50052494)
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| Project Period (FY) |
2003 – 2004
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| Project Status |
Completed (Fiscal Year 2004)
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| Budget Amount *help |
¥2,400,000 (Direct Cost: ¥2,400,000)
Fiscal Year 2004: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 2003: ¥1,300,000 (Direct Cost: ¥1,300,000)
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| Keywords | Afar Triangle / Ethiopian Rift / Evolution / Lava field / Shield volcano / Stratovolcano / Caldera volcano / Monogenetic volcanoes / 第四紀火山 / Afar三角帯 |
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| Research Abstract |
Geomorphological characteristics and the developments of the volcanic edifices in Ethiopia have been studied with interpretation of topographic maps and aerial photographs. About 20 lava fields with shield volcanoes 500-1000m high exist in the northern end of Afar Triangle Rift Valley. Some of the lava fields have fresh pit craters in the summits. A pit crater in Erta Ale lava field is active now. From the southern rim of Afar Triangle to the southern part of the Ethiopian Rift Valley, stratovolcanoes such as Densi and Zuquala, caldera volcanoes such as Shalla and Awasa and monogenetic volcanoes such as Budemeda co-exist and have buried Wonji Graben with the thick eruptive materials. Cantale and Galiboldi volcanoes standing at the boundary between Afar Triangle and Ethiopian Rift Valley have both characteristics of the volcanoes in the both regions that Cantale and Galiboldi volcanoes spout felsic pyroclastic products to form calderas while the two volcanoes flowed out mafic and fluidal lavas to form lava lakes and lava fields. Badda large shield volcano (4215m in altitude) in the eastern rim of Ethiopian Rift Valley has ca.10 glacial cirques in the summit where several long dykes are exposed by glacier and frost action. Along Wonji fault system cut large felsic pyroclastic deposits, mafic magmas extruded overall to form scoria and spatter cone rows and fluidal lava flows. These facts suggest that any continental crust is not under Afar Triangle while a thick continental crust exists under Ethiopian Rift Valley and felsic magma reservoirs have been formed in the continental crust.
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