| Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
| 公開日 |
2003-03-01 |
| タイトル |
|
|
タイトル |
Yamato nakhlites: Petrography and mineralogy |
| 言語 |
|
|
言語 |
eng |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
nakhlites |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
Martian meteorites |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
Y000593 |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
Y000749 |
| キーワード |
|
|
主題Scheme |
Other |
|
主題 |
Y000802 |
| 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 |
10.15094/00006024 |
|
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) |
Imae, Naoya
Ikeda, Yukio
Shinoda, Keiji
Kojima, Hideyasu
Iwata, Naoyoshi
|
| 著者所属(英) |
|
|
言語 |
en |
|
値 |
Antarctic Meteorites Research Center, National Institute of Polar Research |
| 著者所属(英) |
|
|
言語 |
en |
|
値 |
Department of Material and Biological Sciences, Ibaraki University |
| 著者所属(英) |
|
|
言語 |
en |
|
値 |
Department of Geosciences, Faculty of Science, Osaka City University |
| 著者所属(英) |
|
|
言語 |
en |
|
値 |
Antarctic Meteorites Research Center, National Institute of Polar Research |
| 著者所属(英) |
|
|
言語 |
en |
|
値 |
Faculty of Sciences, Yamagata University |
| 抄録(英) |
|
|
内容記述タイプ |
Other |
|
内容記述 |
We carried out the petrographical and mineralogical study of new Yamato nakhlites, Yamato 000593 (Y000593), Y000749 and Y000802, with electron probe microanalyser and Fourier transform infrared microspectrometer. Euhedral pyroxenes (En_<20-40>Fs_<22-40>Wo_<38-40>) are the predominant phase with a modal proportion of 75-80 vol% and occur as elongated grains (～1mm x 0.5mm) with thin Fe-rich rims. The chemical composition of the augite cores comprising most of the volume of these pyroxene crystals is homogeneous and nearly identical with those in other nakhlites. Fe-rich rims are present in contact with the mesostasis. Anhedral ferroan olivines (Fa_<62-78>; 8-18 vol%, ～0.5 mm) and subhedral titanomagnetites (< 1 vol%, smaller than ～0.1mm) are minor phenocrysts. The remainder of the meteoritic material is mesostasis (8-15 vol%), which predominantly consists of plagioclase (An_<26-32>Ab_<63-65>Or_<4-8>). Minor phases in the mesostasis are pyrrhotite (Fe_<0.86-0.88>S; smaller than 20μm), apatite (smaller than 20μm), titanomagnetite, Ca-poor pyroxene, fayalitic olivine (Fa_<～85>), tridymite and iddingsite. We distinguish these Yamato nakhlites from other nakhlites based on the chemical compositional ranges of the cores and rims of olivine and pyroxene phenocrysts. We suggest that the chemical variations of these minerals for the Yamato nakhlites are intermediate between those of NWA817 and others (Nakhla, Governador Valadares, and Lafayette). The study by Fourier transform infrared microspectrometer of altered phases both on rims and fractures in olivine phenocrysts and in mesostasis revealed the existence of OH-bearing minerals, which might be mixtures of montmorillonite (70%) and goethite (30%). The existence of bubbles in an OH-bearing phase in olivine grains in contact with the fusion crust suggests that the alteration occurred before atmospheric entry (i.e. Martian origin). |
| 雑誌書誌ID |
|
|
収録物識別子タイプ |
NCID |
|
収録物識別子 |
AA11182426 |
| 書誌情報 |
Antarctic meteorite research
巻 16,
p. 13-33,
発行日 2003-03
|
| 出版者 |
|
|
出版者 |
National Institute of Polar Research |
KJ00000040860 (7.6 MB)
.png)
