2019 Fiscal Year Final Research Report
Examination of PGE destribution in the sub-continental mantle: an approach from tiny sulfide mineral
| Project/Area Number |
17K14416
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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 | The University of Tokyo |
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Principal Investigator |
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Keywords | マントル / 硫化鉱物 / 白金族元素 / 交代作用 / かんらん岩 |
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| Outline of Final Research Achievements |
I aimed at estimating precise abundances of platinum-group elements (PGE) in the mantle with this project. To attain the estimation, secondary effects derived from the infiltration of magma and/or fluid should be properly removed form the samples. Therefore, I focused on revealing the mechanism of secondary PGE mobilization and redistribution of PGE through such melt/fluid infiltration. With nanometer-scale to micrometer-scale investigations, I could elucidate that PGE can be mobilized via carbonaceous magma infiltration, and that trails of sub-micrometer-sized sulfide minerals host PGE separated form the carbonaceous magma. With the results from this project, I propose that the samples suffered from the infiltration of carbonaceous magma should be removed from the series of samples used for the estimation of mantle PGE composition.
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| Free Research Field |
マントル岩石学
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| Academic Significance and Societal Importance of the Research Achievements |
マントルの白金族元素（PGE）含有量推定は，地球の形成過程を論じる上で重要である．特に，地球形成以降二次的な改変を受けていない”汚れない”初期マントルのPGE組成推定は地球形成初期の現象理解に特に重要である．本研究では，その推定を行うため最も重要である二次的な改変の実態を解明した．本研究結果を考慮すると，炭素質マグマによる影響が確認されるサンプルを推定から外すべきだということを明確に示すことができた．
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