Geology of West Africa and Canary and Cape Verde Islands

Abstract

West Africa consists essentially of a Precambrian granitized craton (radiometric ages of 2700 to 1600 m.y.) covered by a thin sedimentary blanket, the oldest sedimentary rocks being as much as 1000 m.y. old. The Precambrian basement has been warped into three major uplifts trending approximately east-northeast (Fig. 1): the Léo uplift (Dorsale de Léo, also known as the Liberia-Upper Volta uplift, and Bouclier éburnéen); the Reguibat uplift; and the Anti-Atlas uplift. Deposition during most of Paleozoic time apparently occurred in epicontinental seas. The principal preserved depositional areas are the Taoudeni basin in Mauritania and Mali (Fig. 2); the Tindouf basin in Morocco, Algeria, Mauritania, and Spanish Sahara; the Volta basin in Ghana and Upper Volta; and the Bové basin in Guinea and Portuguese Guinea.