石油技術協会誌
Online ISSN : 1881-4131
Print ISSN : 0370-9868
ISSN-L : 0370-9868
75 巻, 5 号
選択された号の論文の4件中1~4を表示しています
講演
論説
  • 久保田 資浩, 本山 功, 川村 好毅, 上栗 伸一, 小笠原 憲四郎
    2010 年 75 巻 5 号 p. 371-381
    発行日: 2010年
    公開日: 2012/03/01
    ジャーナル フリー
    The Ishikari-Hidaka sedimentary basin which ranges from Iwamizawa to the coastal area of Hidaka District, Hokkaido, is occupied by thick Neogene sedimentary rocks. These include Miocene rocks that consist mainly of sandstone, mudstone, interbedded sandstone and conglomerate (gravity flow deposits), siliceous hard mudstone, and diatomaceous mudstone, showing various vertical and lateral changes in lithofacies. We have surveyed the Miocene Takinoue, Kawabata, Iwamizawa and Oiwake Formations exposed in the southern part of Iwamizawa City and have examined radiolarian assemblages of these formations to discuss the temporal sedimentary history of the basin. Radiolarian fossils from the examined geologic section are indicative of the Dendrospyris? sakaii Zone to Lychnocanoma magnacornuta Zone, suggesting that the Kawabata, Iwamizawa, and Oiwake Formations were deposited during the Middle Miocene (∼15 to ∼12.2 Ma), the late Middle Miocene (∼12.2 to 11.7 Ma), and the Late Miocene (after 11.7 Ma), respectively. Correlation between the study area, Yubari area and Hobetsu area revealed diachronous nature in change from domination of coarse gravity flow deposition of the Kawabata Formation to biosiliceous fine-grained facies of the Iwamizawa Formation.
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