泥質変成岩の部分融解におけるアルカリ長石と斜長石の花崗岩質メルトへの溶解過程 Dissolution processes of alkali feldspar and plagioclase in granitic melts during partial melting of a metapelitic rock

この論文にアクセスする

この論文をさがす

著者

    • 森田 秀彦 MORITA Hidehiko
    • 千葉大学大学院自然科学研究科人間・地球環境科学専攻 Graduate School of Science and Technology, Chiba University
    • 廣井 美邦 HIROI Yoshikuni
    • 千葉大学大学院理学研究科地球科学コース Department of Earth Sciences, Graduate School of Science, Chiba University
    • 古川 登 FURUKAWA Noboru
    • 千葉大学大学院理学研究科地球科学コース Department of Earth Sciences, Graduate School of Science, Chiba University

抄録

Partial melting experiments of migmatitic pelitic gneiss were performed at 850 °C and 200 MPa with varied run duration up to 1008 hrs. Granitic melts form at almost all grain boundaries between various minerals including alkali-free pairs such as sillimanite-quartz. The melts exhibit compositional heterogeneity, particularly in SiO<sub>2</sub> and Al<sub>2</sub>O<sub>3</sub>. Relatively voluminous melts form at feldspar-quartz boundaries, where the melt thickness increases with the run duration. In low-SiO<sub>2</sub> domains located relatively far from quartz grains, Al<sub>2</sub>O<sub>3</sub> mineral grains form around and in feldspar grains. The melts surrounding feldspars are enriched in Al<sub>2</sub>O<sub>3</sub>. In addition to the Al<sub>2</sub>O<sub>3</sub> mineral, euhedral An-rich plagioclase newly forms around alkali feldspar, typically at the alkali feldspar-plagioclase boundaries. On the other hand, pre-existing plagioclase is partially modified to form 'reaction zones' composed of fine-grained An-rich plagioclase and interstitial melt along twin surfaces and cracks. The An-rich plagioclase at the outermost part of these reaction zones subsequently dissolves in the melts. These results indicate that the dissolution processes of alkali feldspar and plagioclase in peraluminous granitic melts are controlled not only by diffusive supply of SiO<sub>2</sub> from quartz but also by the growth of Al-rich minerals and the interface reactions.

収録刊行物

  • 岩石鉱物科学  

    岩石鉱物科学 37(4), 96-109, 2008-07-30 

    日本鉱物科学会

参考文献:  22件

参考文献を見るにはログインが必要です。ユーザIDをお持ちでない方は新規登録してください。

各種コード

  • NII論文ID(NAID)
    10021369733
  • NII書誌ID(NCID)
    AA1146088X
  • 本文言語コード
    JPN
  • 資料種別
    ART
  • ISSN
    1345630X
  • NDL 記事登録ID
    9646297
  • NDL 雑誌分類
    ZM46(科学技術--地球科学--岩石・鉱物・鉱床)
  • NDL 請求記号
    Z15-117
  • データ提供元
    CJP書誌  NDL  J-STAGE 
ページトップへ