New palaeobotanical data from Carboniferous Culm deposits constrain the age of the Variscan deformation in the eastern Pyrenees

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, maxim...

وصف كامل

التفاصيل البيبلوغرافية
الحاوية / القاعدة:Geologica Acta
المؤلفون الرئيسيون: C. MARTÍN-CLOSAS, S. TRIAS, J.M. CASAS
التنسيق: مقال
اللغة:الإنجليزية
منشور في: Universitat de Barcelona (UB), Geociències Barcelona (Geo3BCN), Institut de Diagnosi Ambiental i Estudis de l'Aigua (IDAEA), Universitat Autònoma de Barcelona (UAB) 2018-06-01
الموضوعات:
الوصول للمادة أونلاين:https://revistes.ub.edu/index.php/GEOACTA/article/view/19570
الوصف
الملخص: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 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.
تدمد:1696-5728