Paleozoic basins in West Africa and the Mauritanide thrust belt

Abstract

The evolution of the Paleozoic basins of West Africa is strongly depending on the structuration of the different belts which are surrounding the West African Craton. We distinguish the “Taoudeni Basin” located in the center of the craton from the basins located on the West African Craton margin (Tindouf, Tamale and several troughs limiting the western side of the Taoudeni Basin). Other basins are located on top of the Pan-African or Hercynian belts (Bové, Kandi, Ouallen in Semmen and Diourbel basins) or on top of the Proterozoic shields (The Ghana basins). Some are evidenced underneath the Mesozoic–Cenozoic coastal basins (Bové and Ghana basins). The sedimentation started with the Marinoan glacial event (620–580 Ma) and ended with the carbonates of the Early Carboniferous. The main tectonic or climatic events that occurred during this period are registered by the sediments. Among them are, the “Série pourprée glaciogenic deposits, the Pan-African II tectonic event (550–500 Ma) which affects the southwestern part of the Taoudeni Basin, the Late Ordovician glaciogenic event, the Early Silurian marine transgression, the Early Devonian marine regression and the Hercynian tectonic event (330–270 Ma) which affects the Paleozoic basins located on the western and northern parts of the West African Craton. The second part of this paper is devoted to a synthetic review of the Mauritanides Belt which is extending from Southern Senegal to the Moroccan High Atlas. This belt includes both old Pan-African belts and Paleozoic sediments (belonging to the western part of the Bové, Taoudeni and Tindouf basins) tectonised and metamorphosed during the Hercynian orogen. The third part points out the close relationships between the Paleozoic basins and the main tectonic event for the main periods of the West African Craton evolution.