Seabed Morphology, Structural Geology and Tectonics of the NE Bicol Saddle: Linking the Benham Rise with Luzon

M Aurelio¹, D Bringas², H Catapang² & K Queaño³

¹National Institute of Geological Sciences, University of the Philippines, Quezon City
²National Mapping and Resource Information Authority, Taguig City
³Mines and Geosciences Bureau, Quezon City

Abstract

Multi-beam bathymetric data in the Benham Rise area and vicinity are interpreted and integrated with Luzon-inland geology, earthquake data and re-interpreted offshore seismic profiles to establish the structural geological and tectonic setting of the region. These are further integrated with paleomagnetic results from eastern Luzon to constrain the geodynamic evolution of the Benham Rise – Luzon area. The southern and southwestern segments of the Benham Rise show characteristics of an accreted terrane, manifested in the form of numerous compressive features such as thrust faults and strike-slip faults. This terrane accretion is responsible for the formation of the northeast Bicol Saddle where the morphological continuity of the Benham Rise with Luzon is best manifested.

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