Cadomia origins: Paired Ediacaran ophiolites from the Iberian Massif, the opening and closure record of peri-Gondwanan basins Arenas, Ricardo Vérard, Christian Albert, Richard Rojo Pérez, Esther Sánchez Martínez, Sonia Novo Fernández, Irene Moreno Martín, Diana Gerdes, Axel García Casco, Antonio Díez Fernández, Rubén This work was supported by the Ministerio de Ciencia e Innovación (Spain), projects: PID2020-112489-GB-C21 and PID2020-112489-GB-C22. R.A. and A.G. acknowledge the financial support to FIERCE by the Wilhelm and Else Heraeus Foundation and the Deutsche Forschungsgemeinschaft. 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 Merida 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 fore-arc basin with boninitic magmatism (Calzadilla), followed by the formation of a back-arc basin with arc-tholeiites (Merida). Widening of the back-arc leads to the rifting and drifting of a section of the active continental margin (Cadomia). These oceanic domains initiated a rapid contraction, culminating in the collision of Cadomia with Gondwana (c. 590-540 Ma). The application of a PANALESIS model to this paleogeographic 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. 2025-04-10T08:56:18Z 2025-04-10T08:56:18Z 2023 journal article Published version: Arenas, Ricardo et al. Cadomia origins: Paired Ediacaran ophiolites from the Iberian Massif, the opening and closure record of peri-Gondwanan basins. Geological Society, London, Special Publications Vol. 542, 507-526. https://doi.org/10.1144/SP542-2022-328 https://hdl.handle.net/10481/103575 10.1144/SP542-2022-328 eng http://creativecommons.org/licenses/by-nc-nd/4.0/ open access Attribution-NonCommercial-NoDerivatives 4.0 Internacional Geological Society of London