The late Neoproterozoic-early Palaeozoic extension along the West African craton and the Peri-Gondwanan terranes
Résumé
In the westernmost part of the High Atlas, two Palaeozoic formations, rich in mafic volcanic rocks, are distinguished. They belong to different structural blocks created during the Variscan orogeny. New U–Pb dating yields an Early Cambrian age. The basaltic lavas have the composition of continental tholeiites and the magmatic signature of an initial rifting tectonic setting. They are related to the western Moroccan Cambrian rift. Their geodynamical context could be a passive margin initiated from an active rift that aborted in the Middle Cambrian.