Geochemical data from clastic rocks of the Ossa-Morena Zone (Iberian Massif) show that the main source for the Ediacaran
and the Early Cambrian sediments was a recycled Cadomian magmatic arc along the northern Gondwana margin. The geodynamic
scenario for this segment of the Avalonian-Cadomian active margin is considered in terms of three main stages: (1) The 570–540 Ma
evolution of an active continental margin evolving oblique collision with accretion of oceanic crust, a continental magmatic arc
and the development of related marginal basins; (2) the Ediacaran–Early Cambrian transition (540–520 Ma) coeval with important
orogenic magmatism and the formation of transtensional basins with detritus derived from remnants of the magmatic arc; and (3)
Gondwana fragmentation with the formation of Early Cambrian (520–510 Ma) shallow-water platforms in transtensional grabens
accompanied by rift-related magmatism. These processes are comparable to similar Cadomian successions in other regions of
Gondwanan Europe and Northwest Africa. Ediacaran and Early Cambrian basins preserved in the Ossa-Morena Zone (Portugal
and Spain), the North Armorican Cadomian Belt (France), the Saxo-Thuringian Zone (Germany), the Western Meseta and the
Western High-Atlas (Morocco) share a similar geotectonic evolution, probably situated in the same paleogeographic West African
peri-Gondwanan region of the Avalonian-Cadomian active margin