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A super-refractory inclusion containing nonstoichiometric spinel from the CO3.0 chondrite Yamato 81020
| Title: | A super-refractory inclusion containing nonstoichiometric spinel from the CO3.0 chondrite Yamato 81020 |
| Authors: | Yurimoto, Hisayoshi Browse this author →KAKEN DB | | Rubin, Alan E. Browse this author | | Itoh, Shoichi Browse this author →KAKEN DB | | Wasson, John T. Browse this author |
| Issue Date: | Feb-2022 |
| Publisher: | John Wiley & Sons |
| Journal Title: | Meteoritics & Planetary Science |
| Volume: | 57 |
| Issue: | 2 |
| Start Page: | 472 |
| End Page: | 483 |
| Publisher DOI: | 10.1111/maps.13652 |
| Abstract: | We studied a unique super-refractory inclusion with a core-mantle structure from CO3.0 Yamato 81020 by secondary ion mass spectrometry, electron microprobe, and scanning electron microscope techniques. The core consists largely of hibonite and nonstoichiometric Al-rich spinel indicating formation as a liquid at an exceptionally high temperature (>1900 degrees C). The mantle consists almost entirely of melilite with gehlenitic compositions (ranging from angstrom k(2) to angstrom k(25)). The oxygen- and magnesium-isotopic compositions of the core and mantle are very different; typically, Delta O-17 (equivalent to delta O-17 - 0.52 delta O-18) similar to-26 parts per thousand and integral(Mg) (mass fractionation of Mg isotopes) similar to 10 parts per thousand/amu in the core and Delta O-17 similar to-7 parts per thousand and integral(Mg) similar to 1 parts per thousand/amu in most of the mantle. The chemical and O, Mg-isotopic data indicate that the core and mantle formed in separate events, and that the melilite now in the core was formed during the mantle-melting event, probably filling preexisting voids and surficial cavities. Analyses of core and mantle phases plot along a single Al-26-Mg-26 isochron with initial (Al-26/Al-27)(0) corresponding to 4.8 +/- 1.0 (+/- 2 sigma) x 10(-5), suggesting a similar formation age to normal CAIs in chondrites. |
| Rights: | This is the peer reviewed version of the following article: Yurimoto, H., Rubin, A.E., Itoh, S. and Wasson, J.T. (2022), A super-refractory inclusion containing nonstoichiometric spinel from the CO3.0 chondrite Yamato 81020. Meteorit Planet Sci, 57: 472-483., which has been published in final form at https://doi.org/10.1111/maps.13652. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/88186 |
| Appears in Collections: | 理学院・理学研究院 (Graduate School of Science / Faculty of Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 圦本 尚義
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