| Project/Area Number |
10440142
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Geology
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| Research Institution | Shimane University |
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Principal Investigator |
NAKAYAMA Katsuhiro Department of Geoscience, Interdisciplinary Faculty of Science and Engineering, Shimane University, Associate Professor, 総合理工学部, 助教授 (20243420)
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| Project Period (FY) |
1998 – 1999
|
| Project Status |
Completed (Fiscal Year 1999)
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| Budget Amount *help |
¥11,500,000 (Direct Cost: ¥11,500,000)
Fiscal Year 1999: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1998: ¥9,500,000 (Direct Cost: ¥9,500,000)
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| Keywords | volcanic sediments / depositional mechanism / grain-size distribution / grain density / sediment gravity flow |
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| Research Abstract |
Grain support mechanisms of reworked volcaniclastic sediments are quantitatively identified by analysis of grain-size distribution, grain density, and settling velocity, combined with outcrop observation. Focused sediments are Miocene and Pliocene tephra beds in fluvial and marine sediments, and consist predominantly of volcanic glass particles and pumice grains. Hydraulic settling equivalence can be tested by comparing the settling velocities of these two-type grains calculating with grain diameters and grain densities. Dispersive pressure equivalence is also tested with the Sallenger's formula. Fluidized or liquefied grain support mechanism can be exists when fluid escape velocities greater than minimum fluidized flow velocity. These two velocities can be estimated using grain settling velocities. The analytical methods used here can be applied to any unconsolidated sediments which are composed of different grain populations in diameter and density.
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