Palinoestratigrafía y palinofacies de la Formación Lotena, Jurásico Medio de la Cuenca Neuquina

MARTÍNEZ, MARCELO A.; QUATTROCCHIO, MIRTA E.

AMEGHINIANA

Asociación Paleontológica Argentina

Lugar: Buenos Aires; Año: 2004 p. 485 - 500

0002-7014

Palynostratigraphy and palynofacies of the Lotena Formation, Middle Jurassic of the Neuquén Basin, Argentina. The palynological analysis applied to outcrop samples from the Lotena Formation, (integrated information from Portada Covunco section and previous data: Arroyo Picún Leufú section) allows to determine 29 taxa of sporomorphs (10 spores and 19 pollen grains) and 40 taxa of paleomicroplankton (2 Prasinophyceae, 15 acritarchs and 23 dinocysts). A marine paleoenvironment with a variable proximal-distal trend is suggested for both sections on the basis of the palynological/palynofacial analysis. This trend vary from distal (Portada Covunco section) to proximal conditions (Arroyo Picún Leufú). The presence of the Endoscrinium galeritum reticulatum Klement Zone associated with Gonyaulacysta jurassica (Deflandre) Norris and Sarjeant -Scriniodinium crystallinum (Deflandre) Klement emend. Riding and Fensome suggest an age not older than Late Callovian for the Lotena Formation at Portada Covunco locality, Neuquén province.