| Project/Area Number |
10680104
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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 |
自然地理学
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| Research Institution | Toyo University |
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Principal Investigator |
WATANABE Mitsuhisa Toyo Univ., Dep. Literature, Associate Prof., 文学部, 助教授 (30222409)
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| Project Period (FY) |
1998 – 1999
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| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1999: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1998: ¥1,600,000 (Direct Cost: ¥1,600,000)
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| Keywords | active fault / archaeological site / paleoseismicity / geomorphologic development |
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| Research Abstract |
Geomorphologic development and the deformation of archaeological site close to active fault are investigated in the western marginal area of Takada Plain, Nozawa Village, Nagano Prefecture and Hokusei Town, Mie Prefecture. Archaeological site is very useful to examine the paleoseismicity as follows:
Monoclinal deformations have been accumulated at least since ca.100 ka in the western marginal area of Takada Plain. The Otsuka site is located in the flexural scarp. Although the ruins of Kofun age are not deformed, the surface of Jomon age is possibly affected by faulting. The Shinano (Chikuma) River has formed several fluvial terraces since the Middle Pleistocene around the Nozawa Village where no active fault trace is known. The Higashihara site located on the lower terrace surface shows the tilting about 10 degrees toward east. The latest faulting event occurred ca.3ka and the age of penultimate one is older than ca.5.5 ka. The history of past faulting events can be investigated on the basis of the geomorphologic development and the deformation of the archaeological site. Hokusei-Tado Flexure is located in the western fringe of the Yoro Mts, Mie Prefecture. The fault vertically offsets the young terrace surface by 1.5-1.8 m. The surface is not dated and three is no historic record of seismic disaster. However, the surface of Kamisosaku site on the fluvial surface is dipping toward SW displaying the evidence for recent reactivation of the Hokusei-Tado Flexure since 6th century.
The timing of past faulting event is clearly shown by reference to the deformation of archaeological site. We need to prmote the co-operative works of archaeologist and tectonic geomorphologist taking the geomorphologic development into account.
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