Análisis Panilofacial aplicado a cortejos sedimentarios del Jurásico medio en el sector suroccidental de la Cuenca Neuquina, Argentina

MARTÍNEZ, MARCELO A.; GARCÍA, VIVIAN M.; QUATTROCCHIO, MIRTA E.

REVISTA ESPAÑOLA de PALEONTOLOGÍA

Sociedad Española de Paleontología

Lugar: Oviedo; Año: 1999 p. 217 - 230

0213-6937

Palynofacies analysis was used to characterize the Depositional Sequences JC4.1 (uppermost Upper Toarcian - lowermost Lower Bajocian), JC4.2, JC4.3 and JC4.4 (middle Lower Bajocian), JC4.5 (middle Lower Bajocian - uppermost Lower Bajocian) and JC5 (uppermost Lower Bajocian - uppermost Upper Bajocian), recognized by Zavala (1993) in Los Molles and Lajas formations, Lohan Mahuida profile, southwestern of Neuquén Basin, Argentina. Highstand Systems Tract (HST), Transgressive System Tracts (TST) and Lowstand Systems Tract (LST) are recognized in each sequence. The studied palynoflora corresponds to the Callialasporites dampieri Zone (Late Toarcian - Oxfordian), Callialasporites turbatus Subzone (Late Toarcian - Early Bajocian) and Ischyosporites marburgensis Subzone (uppermost Early Bajocian - Late Bajocian), defined by Quattrocchio et al. (1996). The HST are characterized by high relative abundances of Cheirolepidiaceae, Araucariaceae and spores. The marine palaeomicroplankton have the highest diversity. Phytoclasts dominant over the amorphous. In the TST the Cheirolepidiaceae are associated with saccate pollen of Podocarpaceae and Caytoniaceae. Relative abundances of marine paleomicroplankton are lower than in HST. The amorphous have it highest abundance. The LST are characterized by Cheirolepidiaceae, Araucariaceae and spores; the highest diversity and abundance of acritarchs and translucent phytoclasts dominance.