Résumé
Discovery of Saccogonum cf. saccatum (Upper?)Cambrian brachiopod, in the Paleozoic Western High Atlas between the Ait Lahsen Talmakent fault and the Tichka granite shows that the age of these epimetamorphic rocks ranges from Lower Cambrian to Lower Ordovician. Correlations in the western Atlas suggest that the Ait Lahsen-Talmakent fault was yet active during Middle Cambrian. In Morocco, Upper Cambrian is characterized by epeirogenic movements with strong erosion, so that sedimentary rocks of this age are seldom preserved.