Gabor C. Tari1, Jim S. Molnar1, Richard Hedley2, David P. Meaux3, Robert Pawlowski3
(1) Vanco Energy Company, Houston, TX
(2) Lasmo Pakistan, Karachi, Pakistan
(3) AOA Geophysics, Houston, TX
ABSTRACT: Correlation of Syn-rift Structures between Offshore Morocco and Nova Scotia, Canada
The reconstruction of the relative positions of the North American and African continents before the opening of the central Atlantic Ocean have either been based on morphological fits using coastlines and different isobaths, seafloor magnetic and fracture data or on matching pre-breakup paleomagnetic poles of the stable cratons. None of the existing reconstructions utilize syn-rift structures which are expected to be preserved on these conjugate passive margins.
Based on newly acquired reflection seismic and potential field data offshore Morocco, an anomalous basement high is defined beneath the Tafelney Plateau. This high not only has a bathymetric expression, but it has a pronounced signature on various satellite-based and shiptrack potential field maps. Its NW trend is oblique both to the coastline/shelf-edge and the expected orientation of Atlantic transform faults. We interpret the basement high of the Tafelney Plateau as a high-relief accommodation zone analogous to many well-studied examples in the present-day East African rift system. It developed between two normal fault systems with opposing polarities. The actual Early to Middle Jurassic breakup occurred obliquely across the accommodation zone leaving most of it on the Moroccan margin.
The correlation of syn-rift structural elements across the central Atlantic basin based on seismic reflection and potential field data has important implications for hydrocarbon exploration in these frontier deepwater provinces.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado