%0 Journal Article
%A Arenas Martín, Ricardo
%A Martínez Catalán, José Ramón
%A Sánchez Martínez, Sonia
%A Fernández Suárez, Javier
%A Andonaegui Moreno, María Del Pilar
%A Pearce, Julian A.
%A Corfu, Fernando
%T The Vila de Cruces Ophiolite: A Remnant of the Early Rheic Oceanin the Variscan Suture of Galicia (Northwest Iberian Massif)
%D 2007
%@ 0022-1376
%U https://hdl.handle.net/20.500.14352/50229
%X The Vila de Cruces ophiolite is one of the ophiolitic units involved in the Variscan suture of the northwest IberianMassif. This ophiolite consists of a tectonically repeated succession of greenschist facies volcanic rocks, commonalternations of metasediments of pelitic or siliceous character, and scarce orthogneisses, metagabbros, and serpentinites.The protolith age of a granitic orthogneiss that intruded the mafic rocks is dated at 497±4 Ma (U-Pb inzircons). This age can be considered a reference for the generation of the ophiolite. According to their contents ofsome of the most immobile trace elements, the greenschist and the metagabbros are derived from basaltic magmaswith compositions similar to those of island-arc tholeiites. The influence of a subduction zone in the generation ofthe original basaltic magmas can be deduced from the marked negative Nb anomaly observed in all the metabasicrocks of this ophiolite. The granitic orthogneisses can also be genetically related to the basic rocks because they aresimilar to granitic rocks generated in volcanic arcs. The Vila de Cruces ophiolite is interpreted as a suprasubductionzone ophiolite generated in Late Cambrian times, during the early stages of the opening of the Rheic Ocean. Theophiolite was probably generated in a back-arc basin developed during the first stages of the pulling apart and laterdrift of one or more peri-Gondwanan terranes, one of them represented by the upper allochthon of the northwestIberian Massif.
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