CONTINENTAL ORIGIN OF THE MOZAMBIQUE PLATEAU - A GRAVITY-DATA ANALYSIS

The origin of the Mozambique Plateau (Southwest Indian Ocean), remains unclear from present geological and geophysical studies. Gravity and seafloor topography data are used in an attempt to ascertain the nature of this structure, characterized by extensional deformation and intrusion of volcanic material. The interpretation of gravity anomalies, using the transfer functions method and direct 2-D modelling, indicates that the plateau is locally compensated at depth of 27-31 km. From these results, which are consistent with the structure having a continental upper crust, it is proposed that oceanic crust and lithosphere was created underneath the initial plateau. The continental origin thus inferred for the Mozambique Plateau allows tighter geometrical fits of Southern Gondwana fragments.