Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
2001-10-01 |
タイトル |
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タイトル |
Carbonic fluid inclusions in ultrahigh-temperature metamorphic rocks from Tonagh Island in the Archean Napier Complex, East Antarctica: A preliminary report |
言語 |
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言語 |
eng |
キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
carbonic fluid inclusion |
キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
ultrahigh-temperature granulite |
キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
Tonagh Island |
キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
Archean Napier Complex |
キーワード |
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言語 |
en |
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主題Scheme |
Other |
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主題 |
East Antarctica |
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 |
10.15094/00003083 |
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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) |
Tsunogae, Toshiaki
Santosh, M.
Osanai, Yasuhito
Owada, Masaaki
Toyoshima, Tsuyoshi
Hokada, Tomokazu
Crowe, Warwick A.
Miyano, Takashi
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著者所属(英) |
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en |
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Institute of Geoscience, the University of Tsukuba/Department of Natural Environmental Science, Kochi University/Department of Earth Sciences, Okayama University/Department of Earth Sciences, Yamaguchi University/Graduate School of Science and Technology, Niigata University/National Institute of Polar Research/Department of Geology and Geophysics, University of Western Australia/Institute of Geoscience, the University of Tsukuba |
抄録(英) |
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内容記述タイプ |
Other |
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内容記述 |
We report here the occurrence of high density CO_2-rich fluid inclusions in ultrahigh-temperature metamorphic rocks from Tonagh Island of the Archean Napier Complex, East Antarctica. A study on the different lithological units from Tonagh Island (garnet gneiss, sapphirine granulite, garnet-orthopyroxene gneiss, and magnetite-quartz gneiss) shows the common presence of carbonic fluid inclusions entrapped within various minerals. The melting temperatures of fluids in the first three rock types lie in the range of -56.3 to -57.2℃, close to the triple point for pure CO_2 (-56.6℃). Fluid inclusions in magnetite-quartz gneiss show slight depression in their melting temperatures (-56.7~-57.8℃) suggesting traces of additional fluid species such as CH_4 and/or N_2 in the dominantly CO_2-rich fluid. Homogenization of pure CO_2 inclusions in the garnet gneiss, sapphirine granulite, and garnet-orthopyroxene gneiss occurs into the liquid phase at temperatures in the range of -34.9~+4.2℃. This translates into high CO2 densities in the range of 0.9-1.1 g・cm^<-3>. The estimated CO_2 isochore intersects the counterclockwise P-T trajectory of Tonagh Island at around 6-9 kbar at 1100℃, which corresponds to the peak metamorphic conditions of Tonagh Island derived from mineral phase equilibria. We therefore infer that CO_2 was the dominant fluid species present during the ultrahigh-temperature metamorphism in Tonagh Island. The stability of anhydrous minerals such as orthopyroxene in the study area might have been effected by the lowering of H_2O-activity due to the presence of CO_2 at peak metamorphic conditions (>1100℃). |
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 |
AA1130866X |
書誌情報 |
Polar geoscience
巻 14,
p. 25-38,
発行日 2001-10
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出版者 |
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出版者 |
National Institute of Polar Research |