Research Article| May 01, 2014 Provenance variability along the Early Ordovician north Gondwana margin: Paleogeographic and tectonic implications of U-Pb detrital zircon ages from the Armorican Quartzite of the Iberian Variscan belt J. Shaw; J. Shaw † 1School of Earth and Ocean Sciences, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada †E-mail: jesshaw@uvic.ca. Search for other works by this author on: GSW Google Scholar G. Gutiérrez-Alonso; G. Gutiérrez-Alonso 2Departamento de Geología, Universidad de Salamanca, 33708 Salamanca, Spain Search for other works by this author on: GSW Google Scholar S.T. Johnston; S.T. Johnston 1School of Earth and Ocean Sciences, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada Search for other works by this author on: GSW Google Scholar D. Pastor Galán D. Pastor Galán 3Department of Earth Sciences, Universiteit Utrecht, P.O. Box 80.021, 3508 TA Utrecht, Netherlands Search for other works by this author on: GSW Google Scholar Author and Article Information J. Shaw † 1School of Earth and Ocean Sciences, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada G. Gutiérrez-Alonso 2Departamento de Geología, Universidad de Salamanca, 33708 Salamanca, Spain S.T. Johnston 1School of Earth and Ocean Sciences, University of Victoria, P.O. Box 1700 STN CSC, Victoria, BC V8W 2Y2, Canada D. Pastor Galán 3Department of Earth Sciences, Universiteit Utrecht, P.O. Box 80.021, 3508 TA Utrecht, Netherlands †E-mail: jesshaw@uvic.ca. Publisher: Geological Society of America Received: 29 May 2013 Revision Received: 29 Sep 2013 Accepted: 12 Dec 2013 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2014 Geological Society of America GSA Bulletin (2014) 126 (5-6): 702–719. https://doi.org/10.1130/B30935.1 Article history Received: 29 May 2013 Revision Received: 29 Sep 2013 Accepted: 12 Dec 2013 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation J. Shaw, G. Gutiérrez-Alonso, S.T. Johnston, D. Pastor Galán; Provenance variability along the Early Ordovician north Gondwana margin: Paleogeographic and tectonic implications of U-Pb detrital zircon ages from the Armorican Quartzite of the Iberian Variscan belt. GSA Bulletin 2014;; 126 (5-6): 702–719. doi: https://doi.org/10.1130/B30935.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Detrital zircon laser ablation–inductively coupled plasma–mass spectrometry U-Pb age data from the Lower Ordovician Armorican Quartzite (deformed passive margin strata of Gondwanan affinity) of the Iberian Massif are presented herein. The S-shaped coupled Iberian oroclines defined within these zones palinspastically restore to a 2300 km linear Variscan orogen with a paleomagnetically constrained Late Carboniferous north-south trend. Detrital zircons are used to assess paleogeography and interpreted geometry of the Iberian portion of the Gondwana passive margin. A common signature is identified by (1) Neoproterozoic (ca. 500–850 Ma), (2) Stenian–Tonian (ca. 0.9–1.1 Ga), and lesser (3) Paleoproterozoic and (4) Archean populations (ca. 1.8–2.15 and 2.5–2.7 Ga, respectively). Minor site-to-site variation in relative proportion of widely ranging age groups suggests near-uniform distribution of a highly varied detrital input. Provenance analysis reveals strong correlations with Cambro-Ordovician clastic rocks from northeast African realms. Similarity with underlying sequences suggests a common paleogeography from the Ediacaran through early Paleozoic and persistence of a provenance distinction within the autochthonous Iberian Massif. Consistent northward paleoflow within widespread northeast African lower Paleozoic sedimentary cover suggests long-distance sedimentary transport across a North African peneplain from outlying basement terranes. We propose that the 2300-km-long Cantabrian–Central Iberian portion of the early Paleozoic Gondwana margin stretched east-west along the northern limits of the then low-lying Saharan Metacraton and Arabian-Nubian Shield. Accepting paleomagnetic constraints, a 90° counterclockwise rotation is required to reorient the Iberian portion to a pre-oroclinal (Late Carboniferous) north-south trend. The mechanisms for accommodating such a rotation are unclear. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.
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