Petrology and phase equilibrium modeling of spinel-sapphirine-bearing mafic granulite from Akarui Point, L^|^uuml;tzow-Holm Complex, East Antarctica: Implications for the P-T path

• IWAMURA Shunki

  College of Geosciences, University of Tsukuba

• TSUNOGAE Toshiaki

  Faculty and Graduate School of Life and Environmental Sciences, University of Tsukuba Department of Geology, University of Johannesburg

• KATO Mutsumi

  Department of Earth Sciences, Chiba University

• KOIZUMI Tatsuya

  Faculty and Graduate School of Life and Environmental Sciences, University of Tsukuba

• DUNKLEY Daniel J.

  Department of Applied Geology, Curtin University

書誌事項

タイトル別名

• Petrology and phase equilibrium modeling of spinel-sapphirine-bearing mafic granulite from Akarui Point, Lützow-Holm Complex, East Antarctica: Implications for the <i>P-T</i> path
• Petrology and phase equilibrium modeling of spinel-sapphirine-bearing mafic granulite from Akarui Point, Lützow-Holm Complex, East Antarctica: Implications for the P–T path

抄録

We report new petrological and P-T data for spinel-sapphirine-bearing mafic granulite from Akarui Point in the upper amphibolite- to granulite-facies transitional zone of the Lützow-Holm Complex (LHC), East Antarctica, and provide unequivocal evidence for extreme crustal metamorphism possibly associated with the collisional orogeny during the Neoproterozoic. The reaction microstructures in the rock suggest the stability of the prograde pargasite + garnet + orthopyroxene + plagioclase + hematite assemblage followed by the formation of plagioclase + orthopyroxene + spinel + sapphirine symplectite after garnet. The application of mineral equilibrium modeling on the mafic granulite in the system NCFMASHTO yields a prograde condition of 11-12 kbar and ∼ 900 °C, followed by decompression to the peak stage (Pgs + Pl + Opx + Spl ± H₂O) of 5-6 kbar and 900-920 °C, and subsequent cooling to less than 890 °C, possibly along a clockwise P-T path. The high-temperature and possibly ultrahigh-temperature condition observed at Akarui Point might reflect an effect of a local thermal event or the presence of an exotic crustal block within the LHC, which are essentially associated with the complex collisional evolution of this region during the assembly of Gondwana.

収録刊行物

• Journal of Mineralogical and Petrological Sciences

  Journal of Mineralogical and Petrological Sciences 108 (6), 345-350, 2013

  一般社団法人　日本鉱物科学会

キーワード

• Granulite
• Pseudosection
• NCFMASHTO system
• Neoproterozoic-Cambrian
• East Antarctica

詳細情報

• CRID: 1390001206545228032
• NII論文ID: 130003383597
• DOI: 10.2465/jmps.130621a
• ISSN: 13493825
• ISSN: 13456296
• 本文言語コード: en
• データソース種別:
  • JaLC
  • Crossref
  • CiNii Articles
  • KAKEN
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