In comparison to the South America’s southwest continental margin is the African margin an active or passive?

Question

Note the thickness of sediment on the southeastern and southwestern margin of the African continent? In comparison to the South America’s southwest continental margin is the African margin an active or passive margin?

Answer 1

The African is passive. The Atlantic is stretching while the Pacific is shrinking, and the shrinking is accomplished by the Nazca plate diving beneath the South American Plate, The coastal region of SW South America is one of the most volcanically and seismically active regions on earth. There is little coastal shelf and little sediment accumulation along the coast.

By contrast, the edge of the African plate is far to the west of SW Africa, there is a reasonably wide coastal shelf, sediment accumulation, and low levels of seismic activity and no currently active vulcanism.

For a plate map see

http://geology.com/plate-tectonics.shtml