%0 Journal Article
%A Navidad Fernández De La Cruz, Marina
%A Castiñeiras García, Pedro
%A Casas Tuset, Josep María
%A Liesa Torre Marín, Montserrat
%A Fernández Suárez, Javier
%A Barnolas Cortina, A.
%A Carreras, Jordi
%A Gil Peña, Inmaculada
%T Geochemical characterization and isotopic age of Caradocian magmatism in thenortheastern Iberian Peninsula: Insights into the Late Ordovician evolution of thenorthern Gondwana margin
%D 2010
%@ 1342-937X
%U https://hdl.handle.net/20.500.14352/42024
%X This paper presents new geochronological, geochemical and isotopic data for Late Ordovician magmatism(455±2 Ma) from the Variscan massifs in the northeastern Iberian Peninsula. This magmatism is mainlycomposed of aluminous and metaluminous plutonic rocks and a sequence of calc-alkaline ignimbrites andepiclastic volcanic rocks, which were deformed and metamorphosed during the Variscan orogeny. Themetaplutonic rocks are located in the lower part of a Neoproterozoic/Early Cambrian metasedimentarysequence in the Canigó massif (Eastern Pyrenees). Aluminous orthogneisses have isotopic signatures thatindicate a crustal origin, whereas metaluminous orthogneisses originate from a mixture of juvenile andcrustal melts. The metavolcanic rocks define a calc-alkaline ignimbritic sequence of crustal origin located inthe lower part of the Late Ordovician sequence in the Les Gavarres massif (Catalan Coastal Ranges). TDM agesfor all the studied Late Ordovician rocks range from Mesoproterozoic to Paleoproterozoic (1.3 Ga, 1.5 Ga,1.7 Ga and 2.2 Ga), suggesting a Neoproterozoic crust with Paleoproterozoic components and an arcsignature, as the most probable source for the crustal melts. The isotopic similarities between the studiedsamples and other Early Ordovician magmatic rocks of the Central and Western Iberian Massif suggestrepeated melt extractions from a common basement as the source for the Early and Late Ordovicianmagmatism in the Iberian realm. However, the studied massifs are more closely linked to other massifs fromthe Mediterranean realm. The most probable tectonic setting for the emplacement of the Late Ordovicianvolcanic and plutonic bodies is that of an extensional regime, which postdates a previous Ordoviciancontractional event and the opening of the Rheic Ocean.
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