Elsevier

Tectonophysics

Volume 160, Issues 1–4, 20 March 1989, Pages 135-150
Tectonophysics

Structure and development of the Sagami trough and the Boso triple junction

https://doi.org/10.1016/0040-1951(89)90388-0Get rights and content

Abstract

The Sagami trough is located at the particular plate margin where the Izu forearc is subducted underneath the Honshu forearc. At its southeastern end, the world's only known TTT-type triple junction (Boso triple junction) has developed. Several different kinds of basins occur in different segments along the Sagami trough and at the triple junction. The bathymetric, geologic, and geophysical data obtained during the Kaiko Project and from additional studies are summarized together with our onland studies. We suggest that the right-lateral oblique plate motion formed an eduction margin in the Sagami basin, while a normal subduction margin and an oblique subduction margin have been formed in the Middle Sagami trough basin. These tectonic phenomena resulted from the long-lasting compressional covergence between the Philippine Sea plate and Eurasian plate since the early or middle Miocene. The North basin on the northeasternmost margin of the Philippine Sea plate near the Boso triple junction has developed as a stretched basin due to the westward motion of the Philippine Sea plate with respect to the Eurasian plate.

References (53)

  • H. Akiyoshi

    Reflection seismic study around the trench triple junction

  • M. Ando

    Seismo-tectonics of the 1923 Kanto Earth-quake

    J. Phys. Earth

    (1974)
  • T.H. Chase et al.

    Bathymetry of the North Pacific

    (1970)
  • T. Eto

    Stratigraphic study of the Hayama Group, Miura Peninsula, Japan

    J. Fac. Sci., Tokohama Natl. Univ., Ser. 2

    (1986)
  • K. Fujioka et al.

    Geology of the Boso submarine escarpment, southeast of Tokyo — preliminary report of the Tansei Maru cruise KT83-20

    Bull. Earthquake Res. Inst.

    (1984)
  • E. Honza

    Subduction along the Sagami and Suruga troughs, central Japan

    Quat. Res.

    (1984)
  • H. Kagami

    Internal structures of the accretionary wedge in the Nankai trough off Shikoku, Southwestern Japan

  • Topography and structure of trenches around Japan — data atlas of Franco-Japanese Kaiko project, phase I

  • S. Kaneko

    Right-lateral faulting in Miura Peninsula, south of Tokyo, Japan

    J. Geol. Soc. Jpn.

    (1969)
  • D. Karig et al.
  • S. Kato et al.

    Multichannel seismic survey in the Nankai, Suruga and Sagami troughs

    Rep. Hydrogr. Res.

    (1983)
  • S. Kato et al.

    Submarine topography of the eastern Sagami trough to the triple junction

    Rep. Hydrogr. Res.

    (1985)
  • M. Kimura

    Marine geology in the Sagami-Nada Sea and its vicinity

    Mar. Geol. Map. Ser., Geol. Surv. Jpn.

    (1976)
  • G.DeV. Klein et al.

    Geological summary of the North Philippine Sea, based on Deep Sea Drilling Project Leg 58 results

  • Y.S. Kong et al.

    Subbottom geological structure of Sagami Bay

    Bull. Ocean Res. Inst. Univ. Tokyo

    (1984)
  • M. Koyama et al.

    Paleomagnetism of the Chikura Group in the Southern Boso Peninsula

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