In December, 1987, Project 233 of the International Geological Correlation Pro gram hosted an international conference in Nouakchott, Mauritania. Discussions were focused on the "Tectonothermal Evolution Of The West Mrican Orogens And Circum-Atlantic Terrane Linkages." A wealth of new information was pre sented during the conference, and it was apparent that the time was appropriate to prepare a systematic volume dealing with the geology of northwest Mrica. The present volume is an outgrowth of this conference, but is not merely a compilation of the papers presented in Nouakchott. Instead, it...