Palynological age constraint of Les Vilelles unit, Catalan Coastal Chain, Spain

F. G o n z á l e z e t a l . G e o l o g i c a A c t a , 1 3 ( 4 ) , 3 4 5 3 6 1 ( 2 0 1 5 ) D O I : 1 0 . 1 3 4 4 / G e o l o g i c a A c t a 2 0 1 5 . 1 3 . 4 . 7 Upper Frasnian palynomorphs from the Catalan Coastal Chain 346 defined as Les Vilelles unit in the Priorat Massif (Sáez, 1982), is confusing. On the basis of the palynological content of two closely collected shale samples, Colodrón et al. (1979) dated Les Vilelles unit as Middle to Late Devonian (Eifelian to Famennian). Since then, some authors considered that the age of Les Vilelles unit spans the entire Middle to Late Devonian interval (Sáez and Anadón, 1989; VillalbaBreva and Martín Closas, 2009) while some others select an arbitrarily age range within such interval (Anadón et al., 1985b; García-Alcalde et al., 2002; Carls et al., 2004). The uncertainty about the age is enlarged with a second biostratigraphic study in the Priorat Massif. Raymond and Caridroit (1993) analyzed an assemblage of radiolarians and conodonts from two radiolaritic chert samples close to those analyzed by Colodrón et al. (1979) providing a Mississippian (Tournaisian to early Visean) age. Apart from being contradictory, the two biostratigraphic studies to date available at the “pre-Carboniferous” succession of the Priorat Massif are devoid of any taxonomic description or illustration and include a high number of species left in open nomenclature (“sp” and “cf”). In consequence, a detailed biostratigraphic study of this unit was required. The present study analyzes palynologically the upper part of the most representative section of Les Vilelles unit, previously studied by Sáez (1982) to define it providing a more solid age constraint. It includes illustrations of most of the reported palynomorphs together with the systematic-descriptive analysis of the newly established species as well as those left in open nomenclature. Although biostratigraphically oriented in essence, the study also provides insights into the relation between the pre-Carboniferous and Carboniferous series of the CCC.