SURFICIAL SLIDES AND SLUMPS ON THE CONTINENTAL SLOPE AND RISE OF SOUTH-WEST-AFRICA - RECONNAISSANCE STUDY

Off South West Africa, a large slide and a large slump have displaced about 250 km3 of surficial sediment from the lower continental slope onto the upper continental rise. The slide and slump scars together cover an area of about 6000 km2; they affect only the upper few tens of meters of the sediment column. A debris flow extends about 250 km downslope from the slide scar, and deformed sediments extend a similar distance downslope from the slump scar. Apparently the slide and the slump were triggered during the late Pleistocene; neither of them gave rise to turbidity currents. Slides and slumps like these appear to be common on both active and passive continental margins. Their presence in these environments merits careful study in view of deep water exploration and production drilling for oil and gas. © 1979.