The elusive nature of the Rheic Ocean suture in SW Iberia

摘要: The Rheic Ocean suture resulted from pre-Carboniferous oceanic subduction followed by Late Devonian-Carboniferous Variscan collision. In SW Iberia, this has been classically located along the boundary between Ossa-Morena and South Portuguese Zones based on presence of three units: (i) a conspicuous metamafic unit (Beja-Acebuches) that crops out interpreted as ophiolite; (ii) low-grade metasedimentary with minor mid-ocean ridge basalt-like lithologies (Pulo do Lobo unit), thought to represent subduction-related accretionary prism; (iii) allochthonous Cubito-Moura contains high-pressure ophiolitic-like rocks. We report new structural geochronological data allow us reinterpret origin internal structure Beja-Acebuches Pulo units. Thus, both protoliths metabasalts would have formed in context an intracollisional extensional stage interrupted collision at early Carboniferous time, after consumption, first continental Later on, was resumed oblique left-lateral regime gave way coeval frontal (folds thrusts) lateral (shear zones strike-slip faults) structures, variable pressure-temperature conditions space distribution time. As consequence superposition transtension complex transpression, Iberia obscure nearly cryptic appearance.