The Northwest African and the conjugate Northeast American con- tinental margins provide excellent examples of mature passive continental margins which record in their thick sediment cover the birth and evolution of the Atlantic Ocean Basins during the past 200 million years. Due to a dense net of single- and multichannel seismic reflection lines, numerous Deep Sea Drill- ing Project (DSDP) sites and petroleum exploration wells, and the well-known onshore geology, the Northwest African margin is one of the bes"t-documen ted margins of the world. A particu- lar advantage of this margin is that...