Abstract The recent discovery of Ediacaran ophiolites in the SW Iberian Massif has made it possible to pinpoint the evolution of the Cadomian basement of Europe. The Calzadilla and Mérida ophiolites (gabbroic protoliths dated at c. 600 and 594 Ma, respectively) have geochemical characteristics typical of supra-subduction zone ophiolites. They are interpreted as originating during the initial opening of a forearc basin with boninitic magmatism (Calzadilla), followed by the formation of a back-arc basin with arc-tholeiites (Mérida). Widening of the back-arc led to the rifting and drifting of a section of the active continental margin (Cadomia). Closure of these oceanic domains initiated rapid contraction, culminating in the collision of Cadomia with Gondwana (c. 590–540 Ma). The application of a PANALESIS model to this palaeogeographic setting confirms the plausibility of Cadomian rifting and the likely opening of broad oceanic domains. It also confirms the final collision of Cadomia with Gondwana, although the synthetic and regional data disagree in the precise chronology of the convergence and collision of Cadomia with the West Africa Craton. This work shows that the evolution of the Cadomian basement is much more complex than traditionally considered.

Abstract Field relationships and new U–Pb geochronology data indicate a temporal link between the diverse high-K mafic–intermediate magmas of the Ossa–Morena Zone (OMZ). Ages of c. 338–335 Ma for the Vale de Maceiras gabbro and the Campo Maior microdiorite and quartz-diorite indicate that plutonism took place during a Variscan extensional D 2 deformation event in the OMZ. The syntectonic nature of the Vale de Maceiras pluton is attested to by the orientation of intrusive contacts, magmatic foliation and the growth of contact metamorphic minerals in relation to the Variscan extensional D 2 foliation. The Campo Maior microdiorite, quartz-diorite and orthomigmatites are temporally linked to high-temperature mylonitic gneisses formed simultaneously with the Variscan extensional D 2 deformation event. The geochemical features of the Vale de Maceiras and Campo Maior mafic–intermediate rocks show an affinity with the sanukitoid series. This finding suggests that the observed geochemical variability, from tholeiitic to calc-alkaline and sanukitoid, in the Visean OMZ plutonic rocks ( c. 349–335 Ma) may have been inherited from partially melted mantle domains that were previously contaminated by crustal melts during subduction.