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514599 
Journal Article 
Geodynamic evolution of the SW Europe Variscides 
Ribeiro, A; Munha, J; Dias, R; Mateus, A; Pereira, E; Ribeiro, L; Fonseca, P; Araujo, A; Oliveira, T; Romao, J; Chamine, H; Coke, C; Pedro, J 
2007 
1 
Tectonics
ISSN: 0278-7407 
26 
6 
English 
The early evolution of SW Europe Variscides started by opening of the Rheic ocean at similar to 500 Ma, splitting Avalonia from Armorica/Iberia. Subduction on the SE side of Rheic generated the Paleotethys back-arc basin (430-390 Ma, splitting Armorica from Iberia), with development of Porto-Tomar-Ferreira do Alentejo (PTFA) dextral transform defining the boundary between continental Armorica and Finisterra microplate to the W. Obduction of Paleotethys was followed by Armorica/Iberia collision and emplacement of NW Iberian Allochthonous Units at 390-370 Ma, whereas toward the west of PTFA, there was antithetic ophiolite obduction (Beja-Acebuches and Rheic ophiolites plus Finisterra continental slices) on top of Ossa-Morena Zone, with simultaneous development of eclogites and orogenic magmatism under a flake double wedge tectonic regime. Continued convergence (<370 Ma) proceeded by intracontinental deformation, with progressive tightening of the Ibero-Armorican Arc through dextral transpression on the Cantabrian Indentor, from Iberia to Armorica. The proposed model is discussed at the light of the driving mechanism of "soft plate tectonics.''. 
ibero-armorican arc; beja-acebuches ophiolite; lagoa-augen-gneiss; ossa-morena zone; pb zircon age; plate-tectonics; ne portugal; crustal; structures; northern africa; southern iberia