Primera evidencia palinológica en la Formacion El Paso, Paleozoico superior, Precordillera argentina

VERGEL, M., CISTERNA, G.A. & STERREN, A.F.

San Miguel de Tucumán

Jornada; Segundas Jornadas Geológicas de la Fundación Miguel Lillo; 2008

Fundación Miguel Lillo, Area Geología

ABSTRACT: The glacial marine deposits of the El Paso Formation are located to the southermost part of the Barreal hill in the San Juan province, Calingasta-Uspallata basin. Associated to this sequence, two fossiliferous intervals characterized by a rich invertebrates marine fauna (brachiopods, bivalves, gastropods, ortoconic nautiloids and crinoids), have been identified. However the age of this fauna is also discussed by different authors. Because the recent field works, the first palynological record for the El Paso Formation is herein proposed. The palynological assemblage, identified in the lower fossiliferous marine interval of this section, is composed of trilete spores with a bad preservation, high carbonization and abundant phytoclasts. The species recognized are Punctatisporites sp., Calamospora smileyana Menéndez, Cristatisporites menendezii (Menéndez y Azcuy) Playford, C. rolleri Ottone, C. spinosus (Menéndez y Azcuy) Playford, C. stellatus (Azcuy) Gutiérrez y Limarino, Reticulatisporites sp. This association, dominated by Cristatisporites rolleri, suggests preliminarily a pennsylvanian (late Bashkirian) age. It can be also related with other associations from different localities of the central western Argentinean basins included in the Raistrickia densa-Convolutispora muriornata biozone (Subzone A).