%0 Journal Article
%A Díez Fernández, Rubén
%A Martínez Catalán, José Ramón
%A Gerdex, Axel
%A Abati Gómez, Jacobo
%A Arenas Martín, Ricardo
%A Fernández Suárez, Javier
%T U–Pb ages of detrital zircons from the Basal allochthonous units of NW Iberia:Provenance and paleoposition on the northern margin of Gondwana during theNeoproterozoic and Paleozoic
%D 2010
%@ 1342-937X
%U https://hdl.handle.net/20.500.14352/42426
%X LA-ICP-MS U–Pb ages of detrital zircons from eight siliciclastic samples from the Basal units of the Variscanallochthonous complexes of NW Iberia are used to establish the maximum depositional age and provenance oftwo tectonically-stacked metasedimentary sequences deposited on the outermost margin of Gondwana, andsubsequently involved in the Rheic Ocean suture. Themaximumdepositional ages for the two sequences is latestNeoproterozoic and latest Cambrian, respectively. The age spectra are also used to discuss the paleoposition of theNWIberian basement on the continentalmargin of Gondwana prior to the opening of the Rheic Ocean, which istentatively placed in northern Africa, between the West African and Saharan cratons. Based on similarities anddifferenceswith age data fromtheNWIberian autochthon and other allochthonous terranes involved inthe Rheicsuture, the relative proportions of Mesoproterozoic zircons in both assemblages are proposed as markers ofproximity to the eastern part of the West African craton during late Neoproterozoic and late Cambrian. Thegeodynamic processes that took place along this part of Gondwana during the late Neoproterozoic, late Cambrianand Early Ordovician are discussed in the light of the LA-ICP-MS results, as well as the sedimentological record,magmatic evolution and plate tectonic setting ofNWIberia. These processes are linked to late Neoproterozoic andCambro-Ordovician subduction events beneath the northern Gondwanan margin.
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