Elsevier

Tectonophysics

Volume 82, Issues 1–2, 1 February 1982, Pages 1-24
Tectonophysics

Complexities in the tectonic evolution of the West Philippine Basin

https://doi.org/10.1016/0040-1951(82)90085-3Get rights and content

Abstract

The oceanic West Philippine Basin can be subdivided into a main basin, a northwest sub-basin and a southern sub-basin. These basins have undergone different tectonic histories. Magnetic anomalies 21(?)-17 are present in the main basin and indicate that it formed by two-limbed seafloor spreading. The now extinct spreading center is located within a zone of rough topography associated with the northwest-trending Central Basin Fault (CBF). The morphology of the CBF is primarily the result of post-spreading tectonism. The magnetic anomaly pattern of the main basin does not extend into the southern sub-basin or the northwest sub-basin. Geometrical constraints indicate that the southern sub-basin did not form as part of the southern limb of the main basin. The southern sub-basin may have formed immediately before a ridge jump to the main basin spreading axis. Alternatively, possible shallower crustal depth in the southern sub-basin may indicate that the sub-basin is younger than the main basin and formed separately from it. In the northwest sub-basin, which originated as part of the main basin, the dominant topographic trends are perpendicular to those in the main basin. This difference as well as higher heat flow and shallower depth in the northwest sub-basin indicate that it has undergone a deformational event which did not affect the main basin. This deformation may be related to subduction along the east Luzon margin in mid-Tertiary time. The Gagua Ridge, an uplifted sliver of oceanic crust along the western edge of the northwest sub-basin, may have originated during this event.

References (36)

  • D.E. Hayes et al.

    Tectonics

  • D.E. Hayes et al.

    Crustal Structure

  • M. Henry et al.

    Two seismic refraction profiles in the West Philippine Sea

  • H.H. Hess

    Major structural features of the western North Pacific, an interpretation of H.O. 5485, Bathymetric Chart, Korea to New Guinea

    Geol. Soc. Am. Bull.

    (1948)
  • D.E. Karig

    Structural History of the Mariana Island Arc System

    Geol. Soc. Am. Bull.

    (1971)
  • D.E. Karig

    Basin genesis in the Philippine Sea

  • D.E. Karig et al.

    Structure and sediment distribution in the northwest corner of the West Philippine Basin

  • D.E. Karig et al.

    Origin of the West Philippine Basin

    Nature

    (1973)
  • Cited by (0)

    Lamont-Doherty Geological Observatory Contribution No. 3229.

    1

    Present address: Chevron Overseas Petroleum Inc., 575 Market St., San Francisco, Ca. 94105, U.S.A.

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