四国西部‘石鎚山第三系’のK‐Ar年代とその意味

書誌事項

タイトル別名
  • K-Ar ages of the 'Ishizuchiyama Tertiary System' in western Shikoku, Japan, and their implications.
  • シコク セイブ イシズチヤマ ダイ3ケイ ノ K Ar ネンダイ ト ソノ イミ

この論文をさがす

抄録

The 'Ishizuchiyama Tertiary System' consists of the Ishizuchi and Kuma Groups. The former Group lies on the latter one with clino-unconformity. We determined K-Ar biotite ages for two acidic tuff beds from the Kuma Group and the lower formation of the Ishizuchi Group, respectively. The tuffs from the Kuma Group give 16.9 and 15.5 Ma in age, and those from the Ishizuchi Group, 15.1 and 14.9 Ma. This small range of ages limits the timing of deformation associated with the formation of the E-W-trending Tobe thrust in the Kuma Group. The N-S-trending compression tectonics in western Shikoku at ca 15 Ma can be ascribed to an inversion tectonics from the N-S-trending extension tectonics associated with the opening of the Japan Sea, and prevailed in the whole southwest Japan.

収録刊行物

  • 地質学雑誌

    地質学雑誌 106 (4), 308-311, 2000

    一般社団法人 日本地質学会

被引用文献 (15)*注記

もっと見る

参考文献 (26)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ