2015 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, 総合文化研究科, 助教 (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, 利用研究推進部門, 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 / mantle composition |
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| Outline of Annual Research Achievements |
The aim of this study is to examine the bulk composition of primary mantle and core of photo-planets by means of melting experiments at high pressures relevant to those expected in an Earth-size magma ocean. Following our experiment on carbonaceous (CI2) chondrite (origin: Tagish Lake), we carried out melting experiments on enstatite (EH3) chondrite (origin: Sahara) up to 40 GPa using multi-anvil press (MAP) apparatus equipped with sintered diamond anvils. Because temperatures as high as ~3000 K are hardly obtainable in the multi-anvil apparatus, we conducted additional experiments using the laser-heated diamond anvil cell (DAC). Despite different heating techniques, the results obtained in the DAC and multi-anvil apparatus are compatible with each other, revealing that at 30 GPa that Bridgmanite and stishovite are the liquidus phases. We noted however that there is a possibility that stishovite could be the liquids phase at lower pressure while bridgmanite would crystallise first at lower mantle pressures. The melting temperatures of EH3 are similar to that reported for a synthetic enstatite chondrite (Andrault et al., 2011) suggesting a limited effect of impurities in this system.
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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
The experiments are progressing rather smoothly although more runs need to be completed to constrain closely the phase relations of CI2 and EH3 chondrites. More efforts need to be put in analysing the C-content of CI2 run products.
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| Strategy for Future Research Activity |
In FY28, we will carry out melting experiments on EH3 and CI2 chondrites in order to wrap up the study of the melting relations of those two compositions. Additional data are needed in the range of 30 to 50 GPa and T higher than 2500 K. It is indeed still challenging to reach T ~3000 K in those experiments in the multi-anvil apparatus and therefore we will continue to conduct supporting experiments on these compositions using the laser-heated diamond anvil cell, in collaboration with Dr Tateno (Okayama University). The carbon-content of CI2 chondrite run products will be investigated more accurately through a collaboration with Dr Stagno (Roma University).
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| Causes of Carryover |
Following the initial plan, we are buying sintered diamond (SD) and tungsten carbide (WC) anvils to carry out high-pressure experiments in the cult-anvil press. A set (x8) of sintered diamond anvils should have been bought using the FY2015 funding. However due to the long waiting list at the company producing these items, the products would not be delivered before of the end of the FY. Therefore, we chose to buy additional WC anvils using FY2015 funding while the budget of the multi-year funding would be transported to FY2016 to support the purchase of SD anvils.
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| Expenditure Plan for Carryover Budget |
We plan to use the incurring amount for supporting the purchase of a set (x8) of sintered diamond anvils.
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[Presentation] Making planets from melting of chondrites at ultra high-P and T.2015
Author(s)
Greaux, S., Nishi, M., Tange, Y., Kawai, K., Ichikawa, H., Irifune, T. and Maruyama, S.
Organizer
Workshop: "The origin of the solar system, early evolution, and the birth of life"
Place of Presentation
Misasa, Okayama University (Japan)
Year and Date
2015-11-12 – 2015-11-13
Int'l Joint Research / Invited
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[Presentation] Direct sound velocity measurements of pyrolite across the mantle transition region2015
Author(s)
Greaux, S., Irifune, T., Nishi, M., Higo, Y., Inoue, T., Arimoto, T. and Liu, Z.
Organizer
ELSI/Shingakujustu joint Workshop: "The Earth's Mantle and Core: Structure, Composition, Evolution”
Place of Presentation
Matsuyama, Ehime University (Japan)
Year and Date
2015-11-04 – 2015-11-07
Int'l Joint Research
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[Presentation] The composition of the Earth's mantle: constraints from experiments at ultra-high pressure.2015
Author(s)
Greaux, S., Nishi, M., Tange, Y., Stagno, V., Du, W., Irifune, T., Higo, Y., Kawai, K. and Maruyama, S.
Organizer
WPI site visit
Place of Presentation
Tokyo, Tokyo Institute of Technology (Japan)
Year and Date
2015-08-28 – 2015-09-02
Int'l Joint Research
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