ABSTRACT: The northern Montagne Noire possesses one of the most complete Cambrian-Lower Ordovician successions of West Gondwana. The strata are poorly fossiliferous, metamorphized and disturbed by Variscan tectonism, and their stratigraphic nomenclature dramatically multiplied by the designation of numerous informal units exclusively identifiable in their ownVariscan thrust slices and nappes. This paper presents an updated revision of lithostratigraphic units and volcanic complexes. Special attention is given to crosscutting relationships of the latter and the setting and age of fossiliferous phosphorites, such as the Watsonella crosbyi-bearing phosphatic limestones of the Marcou Formation. This mollusc is key to defining in the next future the Global Standard Cambrian (Terreneuvian) Stage1/Stage2 boundary. The absence of Cadomian tectono-thermal events is documented by meso- and microstructural and metamorphic analyses.