Cambrian–early Ordovician volcanism across the South Armorican and Occitan domains of the Variscan Belt in France: Continental break-up and rifting of the northern Gondwana margin
| Autor: | Daniel Vizcaïno, Eric Monceret, J. Javier Álvaro, Andrés Gil Imaz, André Pouclet, Jacques-Marie Bardintzeff |
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| Přispěvatelé: | Ministerio de Economía y Competitividad (España), Instituto de Geociencias (CSIC-UCM), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Departamento de Ciencias de la Tierra, University of Zaragoza - Universidad de Zaragoza [Zaragoza], project CGL2013-48877-P from Spanish MINECO. |
| Rok vydání: | 2017 |
| Předmět: |
Palaeotethys Ocean
010504 meteorology & atmospheric sciences Earth science Earth and Planetary Sciences(all) [SDU.STU]Sciences of the Universe [physics]/Earth Sciences 010502 geochemistry & geophysics 01 natural sciences Cambro–Ordovician volcanic activity Middle-European Ocean Paleontology Asthenosphere Rhyolite 14. Life underwater Gondwana margin 0105 earth and related environmental sciences geography Underplating Rift geography.geographical_feature_category lcsh:QE1-996.5 Rheic Ocean Sedimentary basin Continental tholeiite Tremadocian lcsh:Geology Gondwana [SDU]Sciences of the Universe [physics] 13. Climate action Ordovician General Earth and Planetary Sciences Geology |
| Zdroj: | Geoscience Frontiers, Vol 8, Iss 1, Pp 25-64 (2017) Geoscience Frontiers Geoscience Frontiers, Elsevier, 2017, 8, pp.25-64. ⟨10.1016/j.gsf.2016.03.002⟩ Digital.CSIC. Repositorio Institucional del CSIC instname |
| ISSN: | 1674-9871 |
| Popis: | The Cambrian–lower Ordovician volcanic units of the South Armorican and Occitan domains are analysed in a tectonostratigraphic survey of the French Variscan Belt. The South Armorican lavas consist of continental tholeiites in middle Cambrian–Furongian sequences related to continental break-up. A significant volcanic activity occurred in the Tremadocian, dominated by crustal melted rhyolitic lavas and initial rifting tholeiites. The Occitan lavas are distributed into five volcanic phases: (1) basal Cambrian rhyolites, (2) upper lower Cambrian Mg-rich tholeiites close to N-MORBs but crustal contaminated, (3) upper lower–middle Cambrian continental tholeiites, (4) Tremadocian rhyolites, and (5) upper lower Ordovician initial rift tholeiites. A rifting event linked to asthenosphere upwelling took place in the late early Cambrian but did not evolve. It renewed in the Tremadocian with abundant crustal melting due to underplating of mixed asthenospheric and lithospheric magmas. This main tectono-magmatic continental rift is termed the “Tremadocian Tectonic Belt” underlined by a chain of rhyolitic volcanoes from Occitan and South Armorican domains to Central Iberia. It evolved with the setting of syn-rift coarse siliciclastic deposits overlain by post-rift deep water shales in a suite of sedimentary basins that forecasted the South Armorican–Medio-European Ocean as a part of the Palaeotethys Ocean. This research was funded by project CGL2013-48877-P from Spanish MINECO. |
| Databáze: | OpenAIRE |
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