2013 Fiscal Year Final Research Report
Verification of ultra-low strain rate effect on olivine rheology
| Project/Area Number |
23340162
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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 |
Petrology/Mineralogy/Science of ore deposit
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| Research Institution | Hiroshima University |
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Principal Investigator |
ANDO Jun-ichi 広島大学, 理学(系)研究科(研究院), 准教授 (50291480)
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| Co-Investigator(Kenkyū-buntansha) |
HIRAGA Takehiko 東京大学, 地震研究所, 准教授 (10444077)
MORISHITA Tomoaki 金沢大学, 自然システム学系, 教授 (80334746)
OHFUJI Hiroaki 愛媛大学, 地球深部ダイナミクス研究センター, 准教授 (80403864)
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| Project Period (FY) |
2011-04-01 – 2014-03-31
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| Keywords | マントルのレオロジー / オリビン / 塑性変形 / 歪速度効果 / コットレル雰囲気 |
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| Research Abstract |
In this research, we observed the microstructures of both alpine-type peridotites and peridotite xenoliths in basalt, and analyzed the microchemistry around the dislocations developed in the olivine grains of the studied samples, using optical microscopy, EPMA, EBSD, TEM and ATEM techniques to clarify if the ultra-low strain rate has any effect on the olivine plasticity. We detected Fe-concentration along dislocation line in all observed samples, which was probably caused by Cottrell atmosphere. This result strongly suggests that the effect of ultra-low strain rate on olivine plasticity is very important to understand the dynamics of the upper mantle, which has not been studied so far. In addition, we tried to do the deformation experiments of olivine to support the above conclusion, which has yet to produce any confirming results.
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