2017 Fiscal Year Final Research Report
Geometry, chemistry and hydraulic properties of shear cracks: Rock fracturing processes by geofluid infiltration
| Project/Area Number |
15K17783
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Petrology/Mineralogy/Economic geology
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| Research Institution | Tohoku University |
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Principal Investigator |
Uno Masaoki 東北大学, 環境科学研究科, 助教 (50748150)
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| Research Collaborator |
Mindaleva Diana
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| Project Period (FY) |
2015-04-01 – 2018-03-31
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| Keywords | 剪断クラック / 地殻流体 / 流体移動 / 変成岩 / 流体流入時間スケール / 流体圧勾配 / 透水係数 |
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| Outline of Final Research Achievements |
In this study, new methods were developed for constraining the time-scale, fluid-pressure gradients, and permeability of crustal fluid-rock fracture samples. As analogies for island arc and continental arc crusts, fluid-rock reaction zones were investigated for Sanbagawa metamorphic belt and Sor Rondane Mountains of east Antarctica. The results revealed very short fluid infiltration time-scales of several hours to days, high fluid-pressure gradients of ~kbar/cm from the cracks to the host rocks, and very high and low permeabilities for the cracks and the host rocks (~-15 and -20 to -23 in log10 [m2] unit, respectively). These time-scales and hydraulic parameters enables quantitative comparisons between geophysically-observed fluid transport phenomena and geologically-observed shear cracks.
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| Free Research Field |
岩石―流体反応と沈み込み帯のダイナミクス
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