| アイテムタイプ |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
| 公開日 |
1988-03-01 |
| タイトル |
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|
タイトル |
Qingzhen and Yamato-691: A tentative alphabet for the EH chondrites |
|
言語 |
en |
| 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 |
|
資源タイプ |
departmental bulletin paper |
| ID登録 |
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|
ID登録 |
10.15094/00004447 |
|
ID登録タイプ |
JaLC |
| ページ属性 |
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内容記述タイプ |
Other |
|
内容記述 |
P(論文) |
| 著者名(英) |
Goresy,A. El
Yabuki,Hideo
Ehlers,K.
Woolum,D.
Pernicka,E.
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| 著者所属(英) |
|
|
言語 |
en |
|
値 |
Max-Planck-Institute fur Kernphysik/The Institute of Physical and Chemical Research/Max-Planck-Institute fur Kernphysik/California State University/Max-Planck-Institute fur Kernphysik |
| 抄録(英) |
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|
内容記述タイプ |
Other |
|
内容記述 |
Petrological investigations of unequilibrated EH chondrites revealed the presence of three subgroups. They are identified based on the presence of different concentrations of MnS in niningerite. These differences were produced by partitioning of Mn between niningerite and enstatite as a result of different f_S2 and f_O2 during their formation. In order of increasing MnS-contents and hence increasing f_S2 and decreasing f_O2 these groups are : (A) Yamato (Y)-691 and Abee, (B) Indarch, and (C) Yamato-74370,South Oman, Qingzhen, Kota Kota, Kaidun III, and St. Marks. In the third subgroup the meteorites follow an equilibration and evolution sequence; Y-74370 the most primitive and St. Marks the most equilibrated. Y-691 is the most primitive in its subgroup. Differences in the chemical compositions of minerals in Y-691 and Qingzhen reveal a dichotomy in the compositions of niningerite, djerfisherite, kamacite, and perryite. Niningerites in Y-691 contain the least MnS (3.6-6.7 mole%) and counterparts in Qingzhen the most (12-14 mole%). K/Na ratios in djerfisherite are lower in Qingzhen than in Y-691. The Si concentration in kamacite in Qingzhen is higher than in Y-691. Ni in perryite in Qingzhen is higher than in Y-691. Na and K are highly fractionated between two sulfide lithologies. Na resides mainly in chondrules in caswellsilverite, in a Cl-bearing glass in the chondrules, and in Cr-rich sulfides in the matrix. In contrast, K is confined to djerfisherite, which occurs only in sulfide-rich objects in the matrix, and is highly depleted in chondrules. Two new layer structure minerals were discovered in Y-691 : (a) Na-Cu-Cr-sulfide with the general formula (NaCu) CrS_2,and (b) a Na-Cu-Zn-Cr-sulfide. An evolution scheme was constructed for the EH chondrites in the solar nebula and in their parent bodies. Niningerite and oldhamite condensed first and probably acted as nucleation sites for condensing sulfides, metals and silicates. Both minerals are abundant in chondrules, indicating that chondrule formation preceded all other sulfide- and metal-rich objects. For the first time, planetary metamorphic events were recognized. The Qingzhen Reaction, a breakdown of djerfisherite to troilite, covellite, idaite, bornite, and other unidentified phases, was discovered in Qingzhen and Y-691. Thermal episodes took place in the parent bodies at 1.4 Ba (Qingzhen), and 800 Ma (Y-691). Reverse zoning in niningerite indicates that Fe diffused from troilite to niningerite during the thermal event. In Y-691 sphalerite also formed during the metamorphic episode due to mobilization of Zn (and other volatiles). EH chondrites condensed in a chemically inhomogeneous region of the solar nebula where considerable variations in sulfur and oxygen fugacities existed. |
| 雑誌書誌ID |
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|
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 1,
p. 65-101,
発行日 1988-03
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| 出版者 |
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|
出版者 |
National Institute of Polar Research |
|
言語 |
en |
KJ00000036253 (5.1 MB)
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