Abstract

RUBINSTEIN, Claudia V.  and  STEEMANS, Philippe. New palynological data from the Devonian Villavicencio Formation, Precordillera of Mendoza, Argentina. Ameghiniana [online]. 2007, vol.44, n.1, pp.3-9. ISSN 1851-8044.

New terrestrial and marine palynomorphs of the lower part of the Villavicencio Formation, San Isidro Creek, Precordillera of Mendoza, Argentina, are evaluated. The palynomorph assemblage is dominated by miospores, and also contains acritarchs and scarce chitinozoans. Different processing methods have been tested due to the poor preservation state of the palynomorphs. The new slides provided abundant and diverse palynomorphs and allowed the recognition of 13 miospore species and two acritarch species. This review suggests a late Pragian to early Emsian age, thus confirming and refining previous palynological dating. The miospore assemblage may be correlated with the upper part of the Ems Biozone, in terms of the Devonian miospore zonation of the Brazilian Amazon Basin. Palaeogeographically, acritarchs show perigondwanan affinities. In the light of this refined age determination, the stratigraphic and phytogeographic inferences for the Precordillera land plants should be reconsidered.

Keywords : Devonian; Miospores; Acritarchs; Biostratigraphy; Palaeogeography; Precordillera; Mendoza; Argentina.