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Characterization of Ar-degassing from Antarctic meteorites
https://nipr.repo.nii.ac.jp/records/1731
https://nipr.repo.nii.ac.jp/records/1731d51e0fbe-3779-496e-9ff0-7857bfd97635
名前 / ファイル | ライセンス | アクション |
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Item type | 紀要論文(ELS) / Departmental Bulletin Paper(1) | |||||||
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公開日 | 1984-12-01 | |||||||
タイトル | ||||||||
言語 | en | |||||||
タイトル | Characterization of Ar-degassing from Antarctic meteorites | |||||||
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 | |||||||
ページ属性 | ||||||||
内容記述タイプ | Other | |||||||
内容記述 | P(論文) | |||||||
著者名(英) |
Kaneoka, Ichiro
× Kaneoka, Ichiro
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著者所属(英) | ||||||||
en | ||||||||
Geophysical Institute, Faculty of Science, University of Tokyo | ||||||||
抄録(英) | ||||||||
内容記述タイプ | Other | |||||||
内容記述 | Based on the Ar-degassing patterns from the Antarctic meteorites, it is intended to find some relationships between the types of Ar-degassing and the states of Antarctic meteorites. For this purpose, diffusion parameters (D/α^2,E) were obtained for each meteorite by using the ^<39>(Ar)-degassing pattern which had been obtained when those meteorites had been dated by the ^<40>(Ar)-^<39>(Ar) method. The diffusion constants (D/α^2) are estimated to be (0.2-3)×(10)^<-5> s^<-1> at 1000℃. The activation energies (E) range from about 10 to 50 kcal/mole, but mostly 20 to 40 kcal/mole. Nonequilibrated chondrites seem to have lower activation energies than equilibrated chondrites. On the basis of integrated fraction of Ar, a diagram is exploited to compare relative degassing patterns of Ar between neutron induced K-derived ^<39>(Ar) and the others (^<36>(Ar), ^<37>(Ar), ^<40>(Ar)). According to the Ar-degassing patterns in this diagram, the Antarctic meteorites are classified into three Types, A, B and C. It is found that achondrites are generally classified into Type A, where ^<40>(Ar) correlates well with ^<39>(Ar) and ^<36>(Ar) (and ^<37>(Ar)) degass at slightly higher temperatures than ^<39>(Ar). Chondrites are classified into Type B, where ^<40>(Ar) correlates with ^<39>(Ar), but ^<36>(Ar) (and ^<37>(Ar)) degass at definitely higher temperatures than ^<39>(Ar). Weathered achondrites and chondrites are generally grouped into Type C, where ^<40>(Ar) does not correlate with ^<39>(Ar) and degassing patterns of ^<36>(Ar) and ^<37>(Ar) are also non-systematic. Thus, such classification would give another measure to evaluate the reliability of an ^<40>(Ar)-^<39>(Ar) age obtained in addition to conventional criteria. | |||||||
雑誌書誌ID | ||||||||
収録物識別子タイプ | NCID | |||||||
収録物識別子 | AA00733561 | |||||||
書誌情報 |
Memoirs of National Institute of Polar Research. Special issue 巻 35, p. 272-284, 発行日 1984-12 |