On the relationship between troilite and/or magnetite rimmed FeNi metals and subtype in CO3 chondrites
スポンサーリンク
概要
- 論文の詳細を見る
A lot of troilite and/or magnetite rimmed FeNi metal grains have been found in 22 CO3 chondrites. The morphology of these grains is the most characteristic in opaque mineral assemblages in CO3s. These could be formed by reactions of FeNi metals with S-rich and/or O-rich gas. The number density of rimmed FeNi metals are correlated with subtype of CO3s. The grain size and the rim thickness of these grains are not significantly correlated with subtype. Magnetite is dominantly found in lower subtype (<3.2) and troilite is abundant but magnetite does not occur except Isna (3.6) and Ornans (3.3) in higher subtype (<3.2). In the subtype less than 3.2,troilite as inner rim and magnetite as outer rim could coexist for some rimmed FeNi metals (ALH-77307 and Y-81020). These textural variations were not formed by one series of thermal metamorphism but formed by (1) the differences of O/S conditions at the time of thermal metamorphism on the parent body, (2) oxidation from intermediate subtype to lower type and sulfidation from intermediate subtype to higher subtype, or (3) thermal metamorphism of rimmed FeNi metals especially in chondrules enclosed in mafic silicates at lower subtype formed in the solar nebula.
著者
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Imae Naoya
Antarctic Meteorites Research Center National Institute Of Polar Research
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Imae Naoya
Antarctic Meteorite Research Center National Institute Of Polar Research
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Kojima Hideyasu
Antarctic Meteorite Research Center National Institute Of Polar Research
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Kojima Hideyasu
Antarctic Meteorite Center National Institute Of Polar Research 10-3 Midori-cho Tachikawa Tokyo 190-
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Kojima Hideyasu
Antarctic Meteorite Research Center, National Institute of Polar Research
関連論文
- On the relationship between troilite and/or magnetite rimmed FeNi metals and subtype in CO3 chondrites
- Sulfide textures of a unique CO3-chondrite (Y-82094) and its petrogenesis
- Comparative study on the major element chemical compositions of Antarctic chondrites to those of non-Antarctic falls with reference to terrestrial weathering
- Yamato nakhlites: Petrography and mineralogy
- Yamato-791093, a metal-sulfide-enriched H-group chondritic meteorite transitional to primitive IIE irons with silicate inclusions
- Foreword
- Noble gas signatures of Antarctic nakhlites, Yamato (Y) 000593, Y000749, and Y000802
- An experimental study of hydrous mineral formation by reaction between forsterite and water vapor
- Antarctic micrometeorite collection at a bare ice region near Syowa Station by JARE-41 in 2000
- Search for Antarctic meteorites in the bare ice field around the Yamato Mountains by JARE-41
- Visible and near-infrared spectral survey of Martian meteorites stored at the National Institute of Polar Research
- The Yamato nakhlite consortium
- Minor element chemistry of low-Ca pyroxene in Allan Hills-77252, an L3-6 regolith breccia