Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
1996-03-01 |
タイトル |
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タイトル |
Yamato-86789: A heated CM-like carbonaceous chondrite |
言語 |
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言語 |
eng |
資源タイプ |
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資源タイプ識別子 |
http://purl.org/coar/resource_type/c_6501 |
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資源タイプ |
departmental bulletin paper |
ID登録 |
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ID登録 |
10.15094/00004698 |
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ID登録タイプ |
JaLC |
ページ属性 |
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内容記述タイプ |
Other |
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内容記述 |
P(論文) |
著者名(英) |
Matsuoka,Kenji
Nakamura,Tomoki
Nakamuta ,Yoshihiro
Takaoka, Nobuo
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著者所属(英) |
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en |
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Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University/Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University/Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University/Department of Earth and Planetary Sciences, Faculty of Science, Kyushu University |
抄録(英) |
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内容記述タイプ |
Other |
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内容記述 |
We have studied the mineralogy and petrology of the Yamato (Y)-86789 meteorite and concluded that this meteorite is a new member of heated carbonaceous chondrites with CI-CM affinities. Y-86789 contains 14vol% of translucent chondrules which mainly consist of fibrous phyllosilicate-like materials. The high abundance of the phyllosilicate-like minerals in chondrules suggests severe aqueous alteration. Major parts of the matrix are also composed of the phyllosilicate-like materials. The phyllosilicate-like materials have compositions of a mixture of serpentine and saponite. However, the phyllosilicate-like materials show consistently high analytical totals; thus, they are dehydrated. X-ray diffraction measurements of the phyllosilicate-like materials reveal that they are mainly composed of olivine. Diffractions from serpentine and saponite are absent from the X-ray powder patterns. These results suggest that Y-86789 has experienced heating and the phyllosilicate minerals which were once present in Y-86789 were dehydrated to from anhydrous materials such as olivine. Y-86789 has textural, mineralogical, and compositional characteristics similar to those of Y-86720,which is one of the three unusual Antarctic carbonaceous chondrites with CI-CM affinities that show evidence of dehydration. Chondrules are completely replaced by the phyllosilicate-like materials and are surrounded by fine-grained rims. Some chondrules contain Ca-carbonates. There is an abundance of troilite in the matrix, but magnetite and PCP, which are common in CM chondrites, are absent. Some large troilite grains have a euhedral lath-like morphology. The bulk chemical composition of Y-86789 is also similar to that of Y-86720. On the basis of these similarities, we propose that Y-86789 and Y-86720 are paired meteorites. |
雑誌書誌ID |
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収録物識別子タイプ |
NCID |
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収録物識別子 |
AA10784627 |
書誌情報 |
Proceedings of the NIPR Symposium on Antarctic Meteorites
巻 9,
p. 20-36,
発行日 1996-03
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出版者 |
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出版者 |
National Institute of Polar Research |