Carboniferous normal faults in the Eastern Pyrenees: evidences and age constrains of syn-orogenic Variscan extension

Josep Maria Casas, Oscar Fernández, Francesc Domingo
2007 Geodinamica Acta  
The pre-Variscan rocks of the Pyrenees exhibit a polyphase deformation linked to the Variscan crustal shortening and a low-pressure-high-temperature metamorphism. However, there is scarce chronostratigraphic evidence of this Variscan deformation. In the Pyrenean low-grade metamorphic domains, maximum ages have been provided by the synorogenic Carboniferous Culm deposits. In medium-to high-grade metamorphic areas, the Variscan regional metamorphism or intrusive magmatic bodies constrain the age
more » ... constrain the age of the main Variscan deformation structures. However, these data usually provide a minimum age. Here, we present new palaeobotanical records that assign a Namurian age to the base of the Culm deposits of la Cerdanya in the eastern Pyrenees. This dating is based on the co-occurrence of the sphenopsids Archaeocalamites radiatus, Mesocalamites cistiiformis and the seed of Cardiocarpus sp. The plant remains were found in sandstone facies produced by high-density turbidity flows of a deep-sea fan system. The new biostratigraphic information constrains the age of the Carboniferous Culm succession in the eastern Pyrenees. Biostratigraphy. sphenophyta. turbidites. lower Carboniferous. Variscan orogeny. KEYWORDS A B S T R A C T C . M a r t í n -C l o s a s e t a l .
doi:10.3166/ga.20.385-392 fatcat:32ocmtpiz5a33mr55wbim4kzhe