秋田県五城目地域の鮮新‐更新統笹岡層に対する古地磁気学的研究

DOI Web Site 被引用文献3件 参考文献56件

書誌事項

タイトル別名
  • Paleomagnetic study of the Plio-Pleistocene Sasaoka Formation in the Gojome area, Akita Prefecture, northeast Japan.
  • アキタケン ゴジョウメ チイキ ノ センシン コウシントウ ササ オカソウ ニ タイスル コ チジキガクテキ ケンキュウ

この論文をさがす

抄録

We describe results of a paleomagnetic study for sedimentary rocks of the Plio-Pleistocene Sasaoka Formation in the Gojome area in Akita Prefecture, northeast Japan. Samples were collected from 26 sites over the Gojome Syncline, an open syncline with a nearly horizontal fold axis. Progressive thermal demagnetization revealed high-temperature characteristic remanences from 11 sites ; 5 sites on the lower part of the measured section had normal polarity, and 6 sites on the upper part were reversely magnetized. The incremental fold test showed that the best grouping of the remanence directions occurred when the syncline was 80% unfolded. Unfolding it at the same percentage climaxed the anti-parallelism of a set of normal remanences and that of reversed ones. The possibility that the rocks acquired the remanences during folding (synfolding remanence) seems to be unlikely from the stratigraphically ordered polarity sequence. Alternatively, it is suggested that strain has altered the initial angular relationship between the bedding plane and the remanence. For this reason the discussion on vertical-axis crustal rotation becomes only qualitative, but little rotation may be deduced from the northerly mean directions at all stages of unfolding. The normal-to-reversed polarity-reversal horizon at the middle part of the measured section is correlated, with the aid of available biostratigraphic information, to the Gauss-Matuyama chron boundary at about 2.6 Ma.

収録刊行物

  • 地質学雑誌

    地質学雑誌 107 (2), 129-141, 2001

    一般社団法人 日本地質学会

被引用文献 (3)*注記

もっと見る

参考文献 (56)*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