WEKO3
アイテム
Trace element and isotopic characteristics of inclusions in the Yamato ordinary chondrites Y-75097, Y-793241 and Y-794046
https://doi.org/10.15094/00004641
https://doi.org/10.15094/00004641ff9dfc0f-97c2-426b-be65-61c9632ac58d
名前 / ファイル | ライセンス | アクション |
---|---|---|
KJ00000036447 (2.0 MB)
|
Item type | 紀要論文(ELS) / Departmental Bulletin Paper(1) | |||||
---|---|---|---|---|---|---|
公開日 | 1994-03-01 | |||||
タイトル | ||||||
タイトル | Trace element and isotopic characteristics of inclusions in the Yamato ordinary chondrites Y-75097, Y-793241 and Y-794046 | |||||
言語 | ||||||
言語 | eng | |||||
資源タイプ | ||||||
資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||
資源タイプ | departmental bulletin paper | |||||
ID登録 | ||||||
ID登録 | 10.15094/00004641 | |||||
ID登録タイプ | JaLC | |||||
ページ属性 | ||||||
内容記述タイプ | Other | |||||
内容記述 | P(論文) | |||||
著者名(英) |
Nakamura, Noboru
× Nakamura, Noboru× Morikawa, Noritoshi× Hutchison, Robert× Clayton, Robert N.× Mayeda, Toshiko K.× Nagao, Keisuke× Misawa, Keiji× Okano, Osamu× Yanai, Keizo× Matsumoto, Yukio |
|||||
著者所属(英) | ||||||
言語 | en | |||||
値 | Department of Earth and Planetary Sciences, Faculty of Science, Kobe University/Department of Earth and Planetary Sciences, Faculty of Science, Kobe University/Department of Mineralogy, The Natural History Museum/Enrico Fermi Institute, University of Chicago/Enrico Fermi Institute, University of Chicago/Institute for Study of the Earth's Interior, Okayama University/Department of Earth and Planetary Sciences, Faculty of Science, Kobe University/Department of Geosciences, Faculty of Science, Okayama University/Department of Earth and Planetary Sciences, Faculty of Science, Kobe University/National Institute of Polar Research | |||||
抄録(英) | ||||||
内容記述タイプ | Other | |||||
内容記述 | Igneous inclusions and hosts of the Yamato ordinary chondrites Y-75097 (L6), Y-793241 (L6) and Y-794046 (H5) were analyzed for lithophile trace elements, and Rb-Sr, rare gas and oxygen isotopes, together with preliminary petrographic examinations. On a three oxygen-isotope plot, all the inclusions lie near the H-chondrite field. The Y-75097 host and inclusion were severely shocked and the Rb-Sr systematics were disturbed by a 500Ma event which was defined by the K-Ar age. The Y-793241 host and inclusion are unshocked and have an old K-Ar age of 4270±170Ma and undisturbed Rb-Sr systematics for the bulk meteorite. Both Y-75097 and Y-793241 inclusions have similar chemical compositions and mineral assemblages consisting mainly of olivine (Fa_<25>), and minor plagioclase (An_<12-19>), chlor-apatite, merrillite and chromite. Olivines in both inclusions equilibrated with those of their L6 hosts. The two inclusion mantles consisting of mainly olivine and plagioclase show a highly fractionated REE pattern with middle REE depletion and a large positive Eu anomaly (50-100 times chondritic) (V-shaped). A model calculation suggests that this remarkable REE fractionation was produced by thermal equilibration with the phosphate-rich cores of inclusions during the igneous formation and the metamorphic event. The Y-794046 inclusion comprises abundant anhedral olivines (Fa_<20.5>), fractured pyroxenes (Fs_<14-16.5>) and microcrystalline plagioclase (An_<3-5>Ab_<81-96>Or_<0-16>). The inclusion did not equilibrate with its host which has less Fe-rich olivines (Fa_<19>) and more Fe in pyroxenes (Fs_<17.5>). The inclusion shows an unfractionated REE pattern. We suggest that the three inclusions formed by melting of differentiated precursor materials carrying unfractionated REE. They were then incorporated into the L-or H-chondrite parent bodies and subjected to the early thermal metamorphism, which eventually overprinted the fractionated REE in the Y-75097 and Y-793241 inclusions by solid/solid equilibrium partitioning. The Y-794046 inclusion was subjected to less extensive equilibration, so that REE abundances remained unfractionated. | |||||
雑誌書誌ID | ||||||
収録物識別子タイプ | NCID | |||||
収録物識別子 | AA10784627 | |||||
書誌情報 |
Proceedings of the NIPR Symposium on Antarctic Meteorites 巻 7, p. 125-143, 発行日 1994-03 |
|||||
出版者 | ||||||
出版者 | National Institute of Polar Research |