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 its coastal basins are well exposed and accessible for detailed stratigraphic studies and onshore-offshore correlations, whereas the Mesozoic-Ceno- zoic marginal basins off eastern North America underlie only the present continental shelf and slope. During the past decade, the Northwest African margin was stu- died in great detail, particularly by the Woods Hole Oceano- graphic Institution, Lamont-Doherty Geological Observatory, Imperial College London, Shell Internationale Petroleum Maat- schappij (Den Haag), Kiel University, and the Bundesanstalt fiir Geowissenschaften und Rohstoffe (BGR) at Hannover. A num- ber of important synthesis papers summarized these results; e. g., Summerhayes et al., 1971; Dillon and Sougy, 1974; Seibold and Hinz, 1974; Uchupi et al., 1976; Lehner and de Ruiter, 1977 (all quoted in the references of Seibold, this Vol. ).