北海道日高町の濃鮮緑色角閃石斑状変晶を含む角閃岩転石の岩石学

• 森下 知晃

  金沢大学大学院自然科学研究科 現所属: 金沢大学フロンティアサイエンス機構

• 荒井 章司

  金沢大学大学院自然科学研究科 海洋開発機構地球内部変動研究センター

• 田村 明弘

  金沢大学大学院自然科学研究科

• 石田 義人

  金沢大学大学院自然科学研究科

書誌事項

タイトル別名

• Petrology of a peculiar amphibolite boulder rich in deep vivid green-colored amphibole porphyroblast from Hidaka Town, Hokkaido, Japan
• ホッカイドウ ヒダカマチ ノ ノウセン リョクショク カクセンセキ ハンジョウ ヘンショウ オ フクム カクセンガン テンセキ ノ ガンセキガク

抄録

A peculiar amphibolite rich in deep vivid green-colored amphibole porphyroblast was found as a boulder in the Chiroro River of Hidaka Town, Hokkaido, Japan. The amphibolite mainly consists of deep vivid green-colored amphibole (porphyroblast), colorless amphibole (matrix) and plagioclase with a small amount of chlorite, epidote and chromian spinel. Deep vivid green-colored amphibole porphyroblast is more than 20 modal % in the rock. Chromian spinel rarely occurs as inclusions in deep vivid green-colored amphibole porphyroblast. The Cr₂O₃ content of the deep vivid green-colored domain is usually ∼1 wt% (up to 2.5 wt% nearby chromian spinel) whereas that of colorless amphibole in the matrix is low, < 0.1 wt%. Deep vivid green-colored amphibole porphyroblast is heterogeneous in chemical compositions within each grain and is divided into three domains as follows: (1) high-Cr₂O₃ (∼1 wt%, up to 2.5 wt%) and Al₂O₃ (> 10 wt%) green-colored domain, (2) relatively high-Cr₂O₃ (∼1 wt%) and low- Al₂O₃ (< 10 w%) green-colored domain and (3) low-Cr₂O₃ (< 0.1wt%) and Al₂O₃ (< 10 wt%) colorless domain. Chondrite-normalized rare earth element (REE) patterns of both deep vivid green-colored amphibole porphyroblast and colorless amphibole in the matrix are characterized by low light REE with positive Eu anomaly. The Cr#[= Cr/(Cr + Al) atomic ratio] and TiO₂ content of chromian spinel in the amphibolite are similar to those in a serpentinite complex of the Kamuikotan Zone. The amphibolite was formed by either amphibolitization of a rock containing chromian spinel derived from the surrounding serpentinite complex or extensively metasomatized serpentinite due to interaction with surrounding metamorphic rocks.

収録刊行物

• 岩石鉱物科学

  岩石鉱物科学 37 (1), 1-14, 2008

  一般社団法人　日本鉱物科学会

キーワード

• Amphibolite
• Amphibole
• Chromium
• Serpentinite
• Hidaka

詳細情報

• CRID: 1390001206525023488
• NII論文ID: 10020737412
• NII書誌ID: AA1146088X
• DOI: 10.2465/gkk.37.1
• ISSN: 13497979
• ISSN: 1345630X
• NDL書誌ID: 9501500
• Web Site: http://hdl.handle.net/2297/12437
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I9501500
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • IRDB
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可