This volume covers Leg 14 of the cruises of the Drilling Vessel Glomar Challenger. The main objectives of Leg 14, as outlined by the JOIDES Atlantic Advisory Panel of the DSDP, were to study the processes of sedimentation, sediment disposition and structural evolution of continental margins off West Africa and northern South America. The results off West Africa were then to be compared to those obtained off the eastern margin of the U.S.A. on Legs 1 and 11 of the DSDP in order to study the evolution of the North Atlantic and in particular to investigate the early history of continental drift. Specific targets and objectives included: 1) drilling several holes on or adjacent to the West African Continental Rise; 2) drilling a deep sea diapiric structure north of the Cape Verde Islands, presumed by many to be a salt dome; 3) drilling two large anomalous morphologic features-the Ceara Rise and Demerara Rise-off northeast South America. Leg 14 sailed from Lisbon, Portugal to San Juan, Puerto Rico from October to December of 1970.