Geochronology and detrital zircons sources from the Sierra Albarrana Domain (SW Iberian Massif)

Abstract

This study compiles the U-Pb and 40Ar/39Ar geochronology of the metasedimentary, migmatitic and granitic rocks of the Sierra Alba-rrana Domain, based on data recently published by the authors to-gether with other bibliographic sources. Maximum depositional ages (MDA) and magmatic and metamorphic events ages are discussed.MDAs suggest that this domain was deposited during the midd-le Cambrian (ca. 511) and U-Pb ages of zoned magmatic and me-tamorphic zircon grains indicate that the main tectono-magmatic event is late Cambrian (granite emplacement; 481 ± 2 Ma) to early Ordovician (migmatization; 478 ± 2 Ma). The 40Ar-39Ar ages eviden-ce a Cambro-Ordovician metamorphic event (ca. 482 Ma) and ano-ther related to the Variscan Orogeny (ca. 337-392 Ma). The most important detrital source corresponds to a Cambrian magmatic event (535-515 Ma), probably developed during the initial episodes of the early Paleozoic rifting affecting the N margin of Gond-wana. The remaining Mesoproterozoic, Paleoproterozoic and Archean zircon grains would have been contributed by Paleoproterozoic base-ment and/or older continental crust recycled in the western sections of the Gondwana margin. We suggest that this domain is probably part of the autochthonous section of the Central Iberian Zone (CIZ) and derived from the Saharan Metacraton and/or Tuareg Shield.