Abstract

GUTIERREZ, Pedro Raúl  and  BARREDA, Viviana D.. Palynology of the El Trampeadero f ormation (Upper Carboniferous), La Rioja province, Argentina: a biostratigraphic approach. Ameghiniana [online]. 2006, vol.43, n.1, pp.71-84. ISSN 1851-8044.

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 variornata (Menéndez and Azcuy) Menéndez and Azcuy, Ahrensisporites cristatus Playford and Powis, Anapiculatisporites argentinensis Azcuy, Apiculatisporites variornatus di Pasquo et al ., Convolutispora muriornata Menéndez, Cordylosporites sp. cf. C. Asperdictyus (Playford and Helby) Dino and Playford, Cristatisporites menendezii (Menéndez and Azcuy) Playford, C. stellatus (Azcuy) Gutiérrez and Limarino, Psomospora detecta Playford and Helby, Raistrickia sp. cf. R . accincta Playford and Helby, Reticulatisporites magnidictyus Playford and Helby, R. passapectus Ottone, Spinozonotriletes hirsutus Azcuy, Verrucosisporites patelliformis (Menéndez) Gutiérrez and Césari. 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-Westphalian) age is here proposed for the El Trampeadero Formation. The abundance of palynomorphs with affinities to higro and hidrophitic plants (Lycophyta, Filicopsidas) agree with the lacustrine environment suggested by sedimentological evidences.

Keywords : Argentina; La Rioja; Paganzo Basin; Upper Carboniferous; El Trampeadero Formation; Palynology; Biostratigraphy.