Surveys in Geophysics

, Volume 37, Issue 3, pp 557–578

Magnetic Signatures and Curie Surface Trend Across an Arc–Continent Collision Zone: An Example from Central Philippines

  • Pearlyn C. Manalo
  • Carla B. Dimalanta
  • Noelynna T. Ramos
  • Decibel V. Faustino-Eslava
  • Karlo L. Queaño
  • Graciano P. YumulJr.
Article

DOI: 10.1007/s10712-016-9357-3

Cite this article as:
Manalo, P.C., Dimalanta, C.B., Ramos, N.T. et al. Surv Geophys (2016) 37: 557. doi:10.1007/s10712-016-9357-3

Abstract

Ground and aeromagnetic data are combined to characterize the onshore and offshore magnetic properties of the central Philippines, whose tectonic setting is complicated by opposing subduction zones, large-scale strike-slip faulting and arc–continent collision. The striking difference between the magnetic signatures of the islands with established continental affinity and those of the islands belonging to the island arc terrane is observed. Negative magnetic anomalies are registered over the continental terrane, while positive magnetic anomalies are observed over the Philippine Mobile Belt. Several linear features in the magnetic anomaly map coincide with the trace of the Philippine Fault and its splays. Power spectral analysis of the magnetic data reveals that the Curie depth across the central Philippines varies. The deepest point of the magnetic crust is beneath Mindoro Island at 32 km. The Curie surface shallows toward the east: the Curie surface is 21 km deep between the islands of Sibuyan and Masbate, and 18 km deep at the junction of Buruanga Peninsula and Panay Island. The shallowest Curie surface (18 km) coincides with the boundary of the arc–continent collision, signifying the obduction of mantle rocks over the continental basement. Comparison of the calculated Curie depth with recent crustal thickness models reveals the same eastwards thinning trend and range of depths. The coincidence of the magnetic boundary and the density boundary may support the existence of a compositional boundary that reflects the crust–mantle interface.

Keywords

Magnetism Curie point depth Arc–continent collision Central Philippines 

Funding information

Funder NameGrant NumberFunding Note
Department of Science and Technology (PH)

    Copyright information

    © Springer Science+Business Media Dordrecht 2016

    Authors and Affiliations

    • Pearlyn C. Manalo
      • 1
    • Carla B. Dimalanta
      • 1
    • Noelynna T. Ramos
      • 1
    • Decibel V. Faustino-Eslava
      • 2
    • Karlo L. Queaño
      • 3
      • 4
    • Graciano P. YumulJr.
      • 4
    1. 1.Rushurgent Working Group, National Institute of Geological SciencesUniversity of the Philippines, DilimanQuezon CityPhilippines
    2. 2.School of Environmental Science and ManagementUniversity of the Philippines, Los BañosLagunaPhilippines
    3. 3.Mapua Institute of TechnologyIntramuros, ManilaPhilippines
    4. 4.Apex Mining Company Inc.Ortigas CityPhilippines

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