東北日本弧，青麻火山の形成史と主成分化学組成

• 戸谷 成寿

  山形大学大学院理学研究科地球共生圏科学専攻

• 伴 雅雄

  山形大学理学部地球環境学科

書誌事項

タイトル別名

• Volcanic history and major element bulk chemistry of the Aoso volcano, Northeast Japan arc.
• トウホク ニホン コ アオソ カザン ノ ケイセイシ ト シュセイブン カガク ソセイ

抄録

The Aoso volcano is one of the representative stratovolcanoes of the Aoso-Osore volcanic zone in the northeast Japan arc. The volcanic activity of the Aoso volcano can be classified into two stages; the stages are separated by a caldera collapse event. The volumes of the products are 3.6 km³ (earlier stage) and 0.8 km³ (later stage). During the initial part of the earlier stage, thin lava flows (olivine orthopyroxene clinopyroxene basaltic andesite, SiO₂=54.7-55.3%), block and ash flows (olivine bearing orthopyroxene clinopyroxene andesite, SiO₂=57.9-58.5%), and thick lava (orthopyroxene clinopyroxene andesite, SiO₂=59.0-59.9%) were extruded. The products construct either a conical shaped stratovolcano or series of stratovolcano. After that, scoria flows (orthopyroxene clinopyroxene andesite, SiO₂=60.2%) and pumice flows (quartz orthopyroxene clinopyroxene hornblende andesite, SiO₂=62.1-62.3%) spewed out, which might have caused the caldera at the top of this volcano. All the rocks during this stage can be plotted as linear lines on the co-variant diagrams. During the initial part of the later stage, pyroclastic rocks (olivine bearing hornblende orthopyroxene quartz dacite, SiO₂=68.2-69.8%) were erupted, and lava domes grew. The lava domes can be separated into two types. One consists of clinopyroxene bearing orthopyroxene quartz dacite (SiO₂=66.6-67.0%), whilst the other is clinopyroxene orthopyroxene dacite (SiO₂=64.4-66.8%). All the eruptive rocks of this stage characteristically include mafic inclusions (quartz olivine bearing basaltic andesite and andesite, SiO₂=53.8-57.5%). Each type of lava dome displays a distinct chemical trend in the covariant diagrams. All of the later stage products have higher SiO₂ contents than the earlier stage products. Some of the later stage products, especially the pyroclastic rocks, were not plotted on the extrapolated lines of the trend drawn by the earlier stage products.

収録刊行物

• 岩石鉱物科学

  岩石鉱物科学 30 (3), 105-116, 2001

  一般社団法人　日本鉱物科学会

キーワード

• Aoso volcano
• Aoso-Osore volcanic zone
• Mafic inclusion
• Calc-alkaline andesite
• Northeast Japan arc
• Quaternary volcano
• Volcanic stratigraphy
• Volcanic history
• Bulk chemistry

詳細情報

• CRID: 1390282681502995712
• NII論文ID: 10006211501
• NII論文ID: 30039841347
• NII書誌ID: AA1146088X
• DOI: 10.2465/gkk.30.105
• COI: 1:CAS:528:DC%2BD3MXmtVWnu78%3D
• ISSN: 13497979
• ISSN: 1345630X
• NDL書誌ID: 5842689
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I5842689
• 本文言語コード: ja
• データソース種別:
  • JaLC
  • NDL
  • Crossref
  • CiNii Articles
• 抄録ライセンスフラグ: 使用不可