9521336 Steckler In the Cenozoic many margins underwent major changes in morphology and evolved from carbonate ramp to prograding clastic shelves, while the world climate changed permanently from a hothouse to icehouse conditions. On NJ margin the switch from carbonate ramp to siliciclastic shelf occurred in the early Oligocene. On the Angola margin the Eocene-Oligocene boundary time evidenced a major erosional event. My Miocene both margins were dominated by siliciclastic progradation and margins evolved to the modern continental margins with flat shelves and shelf- slope breaks. This pattern is also observed at other margins and require an increase in sediment supply from Oligocene to Miocene. By mid-Oligocene the carbonate factory had shut down over the previously dominant carbonate ramps. The siliciclastic shift occurs at the same time as the development of the icehouse conditions, a long-term lowering of sea level and increase in terrigenous sediment supply due to enhanced continental seasonality and erosion. The study will reconstruct the African margin to understand the shift in continental margin morphology and stratigraphy from seismic data. Backstripping or forward modeling of the margin will be performed to determine the approximate tectonic subsidence. ***
