Variscan ophiolites in NW Iberia: Tracking lost Paleozoic oceans and the assembly of Pangea

In the Galicia Region of the NW Iberian Massif several allochthonous complexes (Cabo Ortegal, Ordenes and Malpica-Tui) contain a rootless Variscan suture that can be traced along the belt, from Iberia to the Bohemian Massif in Central Europe. Within these allochthonous complexes are several ophiolite zones bounded by two different continental terranes. There exist in NW Iberia two different ophiolite groups with different chemical compositions, isotopic signatures and structural positions. The Bazar and Vila de Cruces ophiolites, characterized by c. 500 Ma protolith ages, represent the Lower Group, whereas the Careon, Purrido and Moeche ophiolites containing 395 Ma maficultramafic sequences represent the Upper Group. This younger group constitutes the most widespread ophiolites in the Variscan Belt. A thick serpentinite melange (Somozas Melange) occurring at the base of the Cabo Ortegal Complex also belongs to the ophiolite zones of the Variscan suture. In this paper we describe the Galician ophiolites of the Variscan suture and discuss their tectonic setting of formation. We interpret the generation of the Galician ophiolites within the geodynamic and paleogeographic evolution of the Rheic Ocean and the Pangea supercontinent.