The Mozambique Ridge (MOZR) and the Agulhas Plateau (AP) are
prominent bathymetrically elevated rises off south-eastern
Africa connected by a rise of less bathymetric expression.
Intuitively, this observation would imply that the plateaus and
rises underwent a related crustal formation. Deep crustal ocean-
bottom seismometer data and a multichannel seismic reflection
profile from the southern MOZR show evidence for its
predominantly oceanic crustal origin with excessive volcanic
eruption and magmatic accretion phases. The lower two-thirds of
the crustal column exhibit P-wave velocities of more than 7.0
km/s, increasing to 7.5-7.6 km/s at the crustal base. These
velocities suggest that the lower crust was accreted by large
volumes of mantle-derived material to form an over-thickened
equivalent of an oceanic layer 3. When comparing the velocity-
depth model and the observations of the seismic reflection data
with those of the AP, a resemblance can be established which
concludes that a greater Southeast African La