Análisis fitolítico de la Formación Tezanos Pinto (Pleistoceno Tardío- Holoceno Temprano) en el sector sudoeste de su área de distribución en la provincia de Entre Ríos (Argentina).

ERRA, G., ZUCOL A. F., KRÖHLING, D.M. Y C. A. GONZÁLEZ

AMEGHINIANA

ASOCIACION PALEONTOLOGICA ARGENTINA

Lugar: Buenos Aires; Año: 2013 vol. 50 p. 429 - 446

0002-7014

Loess deposits are the main component of the Late Quaternary sequences of the Pampa plains (South America). The Last Glacial Maximum loess represents a depositional unit of the Pampean Aeolian System that evidences the expansion of semiarid conditions to the northeast of the region. The Tezanos Pinto Formation is the typical loessic unit of the late Pleistocene?early Holocene of the northeastern Pampa region. Advances in the knowledge of the micropaleobotanical content of this geologic formation are presented in this work, especially the obtained results of the Southweastern area of Entre Ríos Province. The analyzed phytolith assemblages show a high homogeneity with some variations that allowed their quantitative differentiation across the analyzed sedimentary profiles. The presence of grass phytoliths jointly with palm, podostemoid and ciperoid elements allowed to make this characterization. The described phytolith assemblages, as previously observed in the northwestern part of the area covered by the loess in Entre Ríos, show high abundance of megathermic grasses, with a greater presence of xeric elements at lower levels, and with elements denoting warm-temperate episodes with major moisture principally in their middle and top sections. This is linked to the presence of a warm-temperate to temperate steppe with xeric conditions in the basal levels.