2016 Fiscal Year Annual Research Report
| Project/Area Number |
26287105
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| Research Institution | Ehime University |
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Principal Investigator |
GREAUX Steeve 愛媛大学, 地球深部ダイナミクス研究センター, WPI研究員 (90543166)
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| Co-Investigator(Kenkyū-buntansha) |
西 真之 愛媛大学, 地球深部ダイナミクス研究センター, 助教 (10584120)
河合 研志 東京大学, 理学(系)研究科(研究院), 准教授 (20432007)
市川 浩樹 愛媛大学, 地球深部ダイナミクス研究センター, WPI研究員 (50570503)
丹下 慶範 公益財団法人高輝度光科学研究センター, 利用研究促進部門, 研究員 (70543164)
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| Project Period (FY) |
2014-04-01 – 2018-03-31
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| Keywords | chondrite / melting temperature / high pressure / magma ocean / planetary accretion |
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| Outline of Annual Research Achievements |
Melting experiments have been carried out on natural carbonaceous (origin: Tagish Lake) and enstatite (origin: Sahara) chondrites at high pressure of 5, 12, 21, 25, 30 and 50 GPa and temperatures between 1400 and 2600 C using multi-anvil apparatus. In addition, 5 melting experiment were conducted using the laser heated diamond anvil cells. After HP experiments, samples were recovered to atmospheric conditions and polished for textural and chemical characterization of the mineral phases using FE-SEM and electron microprobe on accurately polished surfaces. Preliminary results show the effect of volatile on the melting temperature of Tagish Lake (CI2) with respect to Allende (CV3) meteorite, enstatite chondrite (EH3) and KLB1, respectively. Results on the phase equilibria are used to derive a model of accretion and possible core segregation that takes into consideration the possible stability of carbon and hydrous species along with a Fe-Ni sulfide melt.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Development of the TEL3 high pressure cell to reach higher temperatures have been successful in achieving T= 2650 C at 30 GPa, which prove to be sufficient to melt completely dry enstatite chondrite sample. The design of the TEL3 cell is now being adapted to the TEL1.5 cell that is used to reach pressures up to 50 GPa. Using this new TEL1.5 cell, we expect to carry out experiment at 50 GPa and nearly 3000 C (current cell only allows T up to 2200 C) in this FY. In these conditions, we should be able to melt completely any dry and volatile-rich chondrites, and thus wrap up this project within this FY.
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| Strategy for Future Research Activity |
From our experiments at 30 GPa using TEL3 cells, we identified that thermal insulation plays a crucial role into maintaining the cell stable under high-pressure and high-temperature. Also, after testing several options for the heater and capsule materials, we found that rhenium heater and graphite capsule provides the most stable environment for heating at T > 2500 C while keeping the melt sealed. Improvements given to the TEL3 cells will be carried to the TEL1.5 cell although the smaller size of the ceramic parts and the use of sintered diamond anvils instead of tungsten carbide brings some difficulty in the fabrication of the cell assembly. To overcome this problems, we started to prepare parts using a 3D micro-milling machine.
In this FY, we plan to carry out few additional experiments at 50 GPa and T higher than 2200 C. Recovered samples will be polished using an ion beam cross section polisher, which provides accurately polished surface while being non-destructive for the melt fraction of the sample.
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[Presentation] Study of magma ocean processes by high pressure melting experiments on natural chondrites2017
Author(s)
Greaux, S., Tateno S., Nishi, M., Tange, Y., Irifune, T. and Maruyama, S.
Organizer
4th ELSI symposium: Early Earth, Venus & Mars Three Experiments in Biological Origins
Place of Presentation
Kuramae Hall (Tokyo-ken, Tokyo)
Year and Date
2017-01-12 – 2017-01-15
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