Revista de la Asociación Geológica Argentina
versión impresa ISSN 0004-4822
KOUKHARSKY, Magdalena y OTTONE, Eduardo G. Fossil plants from the Choiyoi Group, Frontal Cordillera at the latitude of the Mendoza River. Rev. Asoc. Geol. Argent. [online]. 2011, vol.68, n.2, pp. 205-209. ISSN 0004-4822.
In this contribution we report the discovery of the first fossil remains in sedimentary strata belonging to the Tambillos Formation, Choiyoi Group, Cordillera Frontal of Mendoza. In the studied area the Tambillos Formation, which is formed dominantly by acid volcanics rocks of alleged Early to the Middle Permian, were deposited over an erosive unconformity on top of propilytic andesites of the Portezuelo del Cenizo Formation. The vegetal remains were found about 23 meters from the base of the formation, hosted in fine-grained sandstones and shales that were deposited in a fluvial environment (microdelta), along the borders of a lake during the first episodes of the rhyolitic volcanism of the region. The fossil flora includes abundant, poorly preserved impressions of Sphenophyta that does not permit to assign a precise age, although these forms are common in the Upper Carboniferous-Permian and Triassic of Argentina.
Palabras clave : Tambillos Formation; Portezuelo del Cenizo Formation; Sphenophyta.