Palynology and paleoenvironmental significance of the Tunal Formation (Danian) at its type locality, quebrada El Chorro (Salta, Argentina).

VOLKHEIMER, W.; NOVARA, MARTÍN; NARVÁEZ, P.L; MARQUILLAS, R.A.

AMEGHINIANA

Asociación Paleontológica Argentina

Lugar: Buenos Aires; Año: 2006 vol. 43 p. 567 - 584

0002-7014

The palynologic investigation of samples from the Tunal Formation at El Chorro creek (Salta, Argentina) resulted in the recovery of terrestrial assemblages of pollen and spores associated with freshwater algae (Pediastrum spp. and Scenedesmus sp.). Of the 43 species of sporomorphs identified for the Tunal Formation so far, 28 species are cited here for the first time. The spores and pollen indicate a Danian age at the type locality. Sedimentary proxidata including abundant evaporites suggest intervals of at least seasonal arid environmental conditions. In contrast, the palynologic assemblages recovered from the organic rich dark shales indicate the presence of swampy areas and forests surrounding them. The dominance of Verrustephanoporites simplex Leidelmeyer (corresponding to the modern Phyllostylon, Ulmaceae) indicates abundant seasonal rainfalls, warm humid conditions and subtropical climate.