Stratigraphic implications of late Carboniferous and early Permian megafloras in Lérida, south-central Pyrenees; Comparison with the Cantabrian Mountains

Abstract

Comparison is made between the stratigraphic development of Carboniferous and Permian strata in the Cantabrian Mountains and the central Pyrenees, the latter being markedly less complete. Both belong te the same general palaeogeographical area. Elements of the upper Carboniferous and lower Permian succession in the Pyrenees are dated by means of plant megafossil assemblages which are listed and discussed with regard to stratigraphic age. Records in the literature are complemented by hitherto unpublished assemblages brought together by the first author. It is concluded that the central Pyrenees of Lérida contain a small remnant of unconformable upper Westphalian D) (or basal Cantabrian?) strata (at Aguiró), which are followed, also unconformably, by an upper Stephanian C-lower Autunian succession (Malpás Formation). Further Autun ian strata occur in an either conformable or slightly unconformable succession. The very substantial stratigraphic gaps in the Carboniferous of the central Pyrenees are apparent in Fig. 2. [RESUMEN] La representacion muy completa del Carbonífero y Pérmico de la Cordillera Cantábrica ha servido para atribuir los fragmentos de serie existentes en el Pirineo central, al tratarse del mismo área paleogeográfica general. Mediante los registros de megaflora, tanto los publicados como les correspondientes a recogidas propias. se han podido datar tres intervalos continentales posteriores al Namuriense (¿y Westfaliense inferior?). El primero corresponde a las capas de Aguiró, de edad westfaliense D superior o cantabriense inferior; el segundo al Estefaniense C superior y/o Autuniense inferior; el tercero a un Autuniense más alto. Hay discordancias aparentes por debajo del Westfaliense D superior (Aguiró) y del Estefaniense C superior (Malpás). La práctica totalidad del Westfaliense parece fallar en el Pirineo cenital; lo mismo ocurre con el Estefaniense del que únicamente las partes basal?) y más alta parecen estar representadas (Fig. 2).