Deformation and in situ stress in the Nankai Accretionary Prism from resistivity‐at‐bit images, ODP Leg 196

DOI Web Site Web Site 被引用文献7件
  • L. C. McNeill
    Southampton Oceanography Centre University of Southampton Southampton UK
  • M. Ienaga
    Ocean Research Institute The University of Tokyo Tokyo Japan
  • H. Tobin
    Department of Earth and Environmental Science New Mexico Institute of Mining and Technology Socorro New Mexico USA
  • S. Saito
    Deep Sea Research Center, JAMSTEC Yokosouka Japan
  • D. Goldberg
    Borehole Research Group, Lamont‐Doherty Earth Observatory Columbia University Palisades New York USA
  • J. C. Moore
    Department of Earth Sciences University of California Santa Cruz California USA
  • H. Mikada
    Deep Sea Research Center, JAMSTEC Yokosouka Japan

抄録

<jats:p>Borehole resistivity images from ODP Leg 196 allow rapid and complete qualitative assessment of deformation within the toe of the Nankai prism, Japan. Borehole breakouts were common within the prism but prominent in the trench‐wedge unit around the frontal thrust, suggesting reduced sediment strength. Breakouts indicate consistent σ<jats:sub>2</jats:sub> orientations (∼050°), compatible with northwesterly convergence. Deformation is dominated by discrete zones, including the frontal thrust and décollement zone. Prism fractures trend ∼NE–SW, consistent with convergence. The décollement shows minimal deformation and the dominant structural trend is ∼N–S. Prism deformation zones are characterized by high resistivity (compaction), whereas the décollement is apparently dilated, both with conductive fractures. Distribution of fracture orientations varies between log units confirming lithologic and rheologic influence. Pore pressure is elevated within the décollement and the misalignment of conductive fractures may reduce permeability.</jats:p>

収録刊行物

被引用文献 (7)*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