2011 Fiscal Year Final Research Report
Estimate of atmospheric oxygen rise in the Paleoproterozoic : Fe behavior under very low oxygen conditions
| Project/Area Number |
21340157
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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 | The University of Tokyo |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
KOGURE Toshihiro 東京大学, 大学院・理学系研究科, 准教授 (50282728)
UTSUNOMIYA Satoshi 九州大学, 大学院・理学系研究院, 准教授 (40452792)
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| Project Period (FY) |
2009 – 2011
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| Keywords | 生体・環境鉱物 / 大気進化 / 古土壌 / Fe / 風化 / 酸化速度 |
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| Research Abstract |
Because weathering is a mineral-water-atmosphere interaction, a weathering profile retains records of atmospheric oxygen level at the time of weathering. Especially, the Fe concentration in a weathering profile reflects an atmospheric oxygen level. Mineral dissolution and Fe oxidation experiment under low O^2 conditions, analysis of paleosols(ancient weathering profiles) and weathering model reveal that the atmospheric oxygen level changed from<10^<-6> to> 10^<-3> atm between 2. 5 and 2. 0 billion years ago. This increase would have affected ocean chemistry and life evolution.
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