2005 Fiscal Year Final Research Report Summary
Ultra-high Pressure Earth Science of the Core and Core-Mantle Boundary
| Project/Area Number |
14102009
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| Research Category |
Grant-in-Aid for Scientific Research (S)
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| Allocation Type | Single-year Grants |
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| Research Field |
Petrology/Mineralogy/Science of ore deposit
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| Research Institution | Tohoku University |
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Principal Investigator |
OHTANI Eiji Tohoku University, Graduate School of Science, Professor, 大学院理学研究科, 教授 (60136306)
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| Co-Investigator(Kenkyū-buntansha) |
KONDO Tadashi Tohoku University, Graduate School of Science, Associate Professor, 大学院理学研究科, 助教授 (20252223)
SUZUKI Akio Tohoku University, Graduate School of Science, Assistant Professor, 大学院理学研究科, 助手 (20281975)
KUDO Tomoaki Kyusyu University, Faculty of Science, Associate Professor, 大学院理学研究院, 助教授 (40312540)
TERASAKI Hidenori Tohoku University, Graduate School of Science, Assistant Professor, 大学院理学研究科, 助手 (50374898)
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| Project Period (FY) |
2002 – 2005
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| Keywords | Diamond anvil cell / Multianvil press / Metallic iron / Core / Core-mantle boundary / Light element / Potassium / Iron-water reaction |
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| Research Abstract |
In this study we clarified the reactions occurring at the Core-Mantle boundary and structure and properties of the Earth's Core using two types of apparatuses such as a diamond anvil cell and multianvil apparatus.
The results can be summarized as follows :
1.We clarified the reactions between metallic iron and water up to 84 GPa and high temperatures. At pressures above 10 GPa and temperatures above 1000K, Iron and water react to form iron hydrite and iron oxide. This reaction is important during the core formation stage and at the present core-mantle boundary. This result implies that hydrogen can be incorporated into the Earth core.
2.We have studied experimentally the reactions between metallic iron and perovskite and post-perovskite in the pressure range from 30 to 135 GPa at 3000 K which is the real Core-mantle boundary condition. We observed formation of magnesiowusite and dissolution of Si and 0 into the molten iron under the present pressure and temperature conditions. The solubility of these elements increases with increasing pressure and temperature significantly.
3.We studied the dissolution of potassium into the molten iron under the Core conditions of 135 GPa and 3500 K. Molten iron dissolves potassium about 0.8 wt. %, and the present results showed at first that the core can contain radiogenic potassium and can produce some radiogenic heat.
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