About This Item

Share This Item

The AAPG/Datapages Combined Publications Database

AAPG Bulletin


Volume: 56 (1972)

Issue: 4. (April)

First Page: 682

Last Page: 693

Title: Geophysical Reconnaissance on African Shelf: 2. Margin Sediments from Gulf of Guinea to Walvis Ridge

Author(s): R. Leyden (2), G. Bryan (2), M. Ewing (2)


On the West Africa continental rise, between 5 and 13°S lat., diapiric structures have been recorded which terminate in a scarp at the base of the rise. This distribution is comparable with the Sigsbee rise and scarp in the Gulf of Mexico. The northern limit of the diapirs, which are assumed to be salt, is not known, but the southern limit appears to be the bulge of Angola at approximately 13°S. Fourteen short reflection traverses of the margin and 26 sonobuoy refraction profiles were recorded in the region. Seismic refraction velocities averaging 4.3 km/sec at depths of 4.5 km on the rise are assigned to salt of Early Cretaceous Aptian age. Other velocity-age correlations are attempted near the Cuanza basin. Combined geophysical evidence indicates that a slight excess of non-magnetic material, consisting in part of evaporitic sediments, is present on the West African margin.

Pay-Per-View Purchase Options

The article is available through a document delivery service. Explain these Purchase Options.

Watermarked PDF Document: $14
Open PDF Document: $24

AAPG Member?

Please login with your Member username and password.

Members of AAPG receive access to the full AAPG Bulletin Archives as part of their membership. For more information, contact the AAPG Membership Department at [email protected].