THE Walvis Ridge is a non-continuous aseismic feature in the south-eastern Atlantic Ocean with a general trend north-east/ south-west. Close to the principal interruptions of the ridge is a north-south topographiç lineation shown on Simpson's map (Fig. 1). The ridge appears to be attached at its northeast end to the shelf of Angola and South-west Africa and at its south-west end to the east flank of the Mid-Atlantic Ridge through two volcanic islands, Tristan da Cunha and Gough (Fig. 1). These two islands are made up of recent alkalibasalt-trachyte suite². . The geology of the Walvis Ridge has remained relatively unknown. [NOT CONTROLLED OCR]