Please use this identifier to cite or link to this item:
Title: New U-Pb SHRIMP zircon ages for pre-variscan orthogneisses from Portugal and their bearing on the evolution of the Ossa-morena tectonic zone
Author: Cordani, U. G.
Nutman, A. P.
Andrade, A. S.
Santos, J. F.
Azevedo, M. do Rosário
Mendes, M. H.
Pinto, M. S.
Keywords: Cadomian orogeny
Iberian Massif
Ossa-Morena Zone
U-Pb geochronology
Issue Date: 2006
Publisher: Academia Brasileira de Ciências
Abstract: New SHRIMP U-Pb zircon ages for the Portalegre and Alcáçovas orthogneisses document a complex pre-Variscan history for the Iberian basement in Portugal. The available geochemical and geochronological data for the Alcáçovas orthogneiss (ca. 540 Ma) tend to favor its involvement in a Cadomian orogenic event. This is consistent with the development of an active continental margin setting at the end of the Proterozoic and supports a Gondwanan provenance for the Iberian crust. On the other hand, the Ordovician emplacement age obtained for the magmatic precursors of the Portalegre orthogneisses (497 ± 10 Ma) provides additional evidence for the occurrence of rift-related magmatic activity during the Lower Paleozoic.
Peer review: yes
DOI: 10.1590/S0001-37652006000100013
ISSN: 0001-3765
Appears in Collections:DGeo - Artigos

Files in This Item:
File Description SizeFormat 
a13v78n1.pdfdocumento principal435.11 kBAdobe PDFView/Open

Formato BibTex MendeleyEndnote Degois 

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.