EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Permian post-collisional basic magmatism from Corsica

Andrea Boscaini1, Andrea Marzoli1, Joshua H.F.L. Davies2,3, Massimo Chiaradia3, and Hervé Bertrand4
Andrea Boscaini et al.
  • 1Department of Geosciences, University of Padova, Padova, Italy (
  • 2Département des sciences de la Terre et de l’atmosphère, Université du Québec à Montréal, Montréal, Québec, Canada
  • 3Section des Sciences de la Terre, Université de Genève, Genève, Switzerland
  • 4Laboratoire de Géologie de Lyon, ENS de Lyon, Université Lyon 1, CNRS, UMR 5276, Lyon, France

Post-Variscan early Permian magmatism is widespread in Corsica with mafic dykes emplaced during the extensional tectonic phase which followed the Variscan orogeny. This study focuses on a mafic dyke swarm intruded in the region of Ajaccio (Corsica, France). New U-Pb zircon geochronological data show that these intrusions were emplaced at ca. 282 Ma. Most Ajaccio dykes have a calc-alkaline affinity, while a few dykes show tholeiitic affinity resembling N-MORB basalts. Calc-alkaline to tholeiitic dykes are characterized by enriched to depleted Sr-Nd-Pb isotopic compositions, respectively. We interpret these data as evidence that an enriched mantle source, which was likely formed during Variscan subduction, sourced the calc-alkaline suite, while a depleted mantle component dominates the source of the tholeiitic suite. Notably, coeval Permian mafic intrusive bodies from throughout Corsica and from the Southern, Central and Western Alps display similar ages and geochemical features to the Ajaccio dyke swarm. This indicates that a widespread Permian magmatic province developed in a post-orogenic extensional tectonic setting at the margin of the former Variscan belt

How to cite: Boscaini, A., Marzoli, A., Davies, J. H. F. L., Chiaradia, M., and Bertrand, H.: Permian post-collisional basic magmatism from Corsica, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-9633,, 2020

This abstract will not be presented.