Palynology of the El Trampeadero Formation (Upper Carboniferous), La Rioja Province, Argentina:: a biostratigraphic approach

PALYNOLOGY OF THE D. TRAMPEADERO FORMATION (UPPER CARBONIFEROUS), LA RIOJA PROVINCE, ARGENTINA: A BIOSTRATIGRAPHIC APPROACH. A diverse and relatively well preserved palynological assemblage recovered from El Trampeadero Formation (Upper Carboniferous, Paganzo Basin) is here described. This assemblage is composed by elements of continental origin: woody particules, cuticules, spores, pollen grains and algae. The dominant spore species are Apiculiretusispora varioniata (Menendez and Azcuy) Menendez and Azcuy, Ahrensisporites cristatus Playford and Powis, Anpiculatisporites argentinensis Azcuy, Apiculatisporites variornatus di Pasquo et al., Convolutispora muriornata Menendez, Cordylosporites sp. cf. C. asperdictyus (Playford and Helby) Dino and Playford, Cristatisporites menendezii (Menendez and Azcuy) Playford, C. stellatus (Azcuy) Gutierrez and Limarino, Psomospora detecta Playford and Helby, Raistrickia sp. cf. R. accincta Playford and Helby, Reticulatisporites magnidictyus Playford and Helby, R. passapectus Ottone, Sphiozonotriletes hirsidus Azcuy, Verrucosisporites patelliformis (Menendez) Gutierrez and Cesari. Moreover, Dibolisporites disfacies Jones and Truswell was recorded for the first time for the Paganzo Basin. Monosaccate (Plicatipollenites spp., Cannanaropollis spp.) and bisaccate (Alisporites sp., Limitisporites sp.) pollen grains were also recognized for this unit. Considering the known chronostratigraphic ranges of some key species, a Late Carboniferous (late Namurian-Westplialian) age is here proposed for the El Trampeadero Formation. The abundance of palynomorphs with affinities to higro and hidrophitic plants (Lycophyta, Filicopsiclas) agree with the lacustrine environment suggested by sedimentological evidences.