Item type |
紀要論文(ELS) / Departmental Bulletin Paper(1) |
公開日 |
2002-10-01 |
タイトル |
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タイトル |
SHRIMP geochronology of a mylonite zone on Tonagh Island: characterisation of the last high-grade tectonothermal event in the Napier Complex, East Antarctica |
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 |
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 |
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 |
SHRIMP geochronology |
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 |
mylonite |
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 |
10.15094/00003106 |
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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) |
Crowe,WarwickA.
Osanai,Yasuhito
Toyoshima,Tsuyoshi
Owada,Masaaki
Tsunogae,Toshiaki
Hokada ,Tomokazu
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著者所属(英) |
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en |
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Tectonics Special Research Centre, Department of Geology and Geophysics, University of Western Australia/Department of Earth Sciences, Okayama University/Graduate School of Science and Technology, Niigata University/Department of Earth Sciences, Yamaguchi University/Institute of Geoscience, the University of Tsukuba/Department of Geology, National Science Museum |
抄録(英) |
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内容記述タイプ |
Other |
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内容記述 |
Tonagh Island within the highest-grade zone of the Napier Complex, East Antarctica, consists of a strongly layered sequence of quartzofeldspathic gneiss, mafic granulite and ultramafic gneiss subdivided into five lithostratigraphic units by major NE-SW to E-W trending steeply-dipping D_6 shear zones. D_6 shear zones cut the principal foliation defined by D_1 and D_2 structures associated with the ultrahigh-temperature metamorphism. Zircons from two mylonite samples with moderate NE pitching mineral lineations within a D_6 shear zone and a D_6 mylonite and ultramylonite sample from within high strain zones that have an overprinting sub-horizontal mineral lineation were analyzed. All samples have anhydrous mineral assemblages with a late textural association of biotite, which formed pre- to syn- a secondary overprinting high temperature mylonitic fabric. Zircons in all samples contain a structureless zone that constitutes most of the grain area and commonly have a relict discordant, oscillatory-zoned core. The core may be obscured to the extent where only a structureless or an indistinct remnant remains These internal patterns are consistent with recrystallisation and annealing processes resulting in resetting of the U-Pb system during mylonitsation involving possibly three events between ca. 2550 Ma and ca. 2470 Ma. The timing of D_6 mylonitisation between ca. 2470-2550 Ma on Tonagh Island requires an earlier timing for UHT metamorphism. This is consistent with regional models that attribute UHT metamorphism to pre- ca. 2550 Ma tectonothermal events in the Napier Complex. |
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 15,
p. 17-36,
発行日 2002-10
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出版者 |
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出版者 |
National Institute of Polar Research |