Project/Area Number |
15K05338
|
Research Category |
Grant-in-Aid for Scientific Research (C)
|
Allocation Type | Multi-year Fund |
Section | 一般 |
Research Field |
Petrology/Mineralogy/Economic geology
|
Research Institution | The University of Tokyo |
Principal Investigator |
Murakami Takashi 東京大学, 大学院理学系研究科(理学部), 名誉教授 (00253295)
|
Co-Investigator(Kenkyū-buntansha) |
鈴木 庸平 東京大学, 大学院理学系研究科(理学部), 准教授 (00359168)
宇都宮 聡 九州大学, 理学研究院, 准教授 (40452792)
|
Research Collaborator |
KANZAKI YOSHIKI カリフォルニア大学, 博士研究員
|
Project Period (FY) |
2015-04-01 – 2018-03-31
|
Project Status |
Completed (Fiscal Year 2017)
|
Budget Amount *help |
¥4,680,000 (Direct Cost: ¥3,600,000、Indirect Cost: ¥1,080,000)
Fiscal Year 2017: ¥1,690,000 (Direct Cost: ¥1,300,000、Indirect Cost: ¥390,000)
Fiscal Year 2016: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2015: ¥1,430,000 (Direct Cost: ¥1,100,000、Indirect Cost: ¥330,000)
|
Keywords | 大気進化 / 酸素 / 二酸化炭素 / 風化 / 古土壌 / 先カンブリア時代 |
Outline of Final Research Achievements |
The late Archean and early Proterozoic witnessed tremendous changes on the Earth’s surface environments: climate change, ocean evolution and life evolution to which atmospheric oxygen and carbon dioxide concentrations can give more accurate limitations. We made quantitative calculations based on newly constructed weathering models: an increase from 10E-6 to 10E-3 atm between 2.5 and 1.8 Ga in atmospheric oxygen, and a decrease from 10E-0.5 to 10E-1.5 atm between 2.8 and 1.8 Ga in atmospheric carbon dioxide. The carbon dioxide concentrations were high enough not to maintain the Earth above the freezing point. Our results has given a deeper understanding of the changes on the Earth’s surface environments between 2.8 and 1.8 Ga.
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