Passive continental margins offer the unique opportunity to study the processes involved in continental extension and break up and the role of hot-spot related magmatism. A combined on- and offshore seismic experiments was designed to characterize the Southern African passive margin at the location of the Walvis Ridge, to assess the interaction of the presumed plume with continental lithosphere and to determine the deep structure of the transition from the coastal fold belt to the stable craton, where the Walvis Ridge hits the African continent. The project integrates three experiments, (A) an onshore, coast-parallel refraction seismic profile, (B) two onshore-offshore wide-angle seismic transects, and (C) a combined on- and offshore seismic imaging of the sub-Moho velocity (Pn tomography) at the ocean-continent transition. The derived lithospheric structure of the margin together with results from other geoscientific studies (e.g., conducted within the SPP-SAMPLE) will help to address questions such as, how continental crust and plume head interact, what the extent and volumes of magmatic underplating is, and how and which inherited (continental) structures might have been involved and utilized in the break up process.
Experiment time frame
Methods & Equipment