Palynology of the Late Triassic Ischigualasto Formation, Argentina: Paleoecological and paleogeographic implications

CÉSARI, S. N.; COLOMBI, C.

PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 449 p. 365 - 384

0031-0182

In this study we describe and compare the palynological assemblages from the Carnian Ischigualasto Formationof westernmost Gondwana to those of eastern Gondwana, which have been referred to the Onslow and Ipswichphytogeographic provinces. The palynofloras studied contain many taxa common to both regions, as well asseveral species that are widely recorded in European Carnian successions and less frequently recovered inthe Carnian of the Southern Hemisphere. For the first time in Argentinean assemblages, we recognizeAnapiculatisporites spiniger, Cadargasporites granulatus, Cycadopites stonei, Ellipsovelatisporites plicatus,Enzonalasporites vigens, Ovalipollis pseudoalatus, O. ovalis, Patinasporites densus, Quadraeculina anellaeformis,Samaropollenites speciosus, Staurosaccites quadrifidus, ?Rimaesporites? aquilonalis, Vallasporites ignacii andZonalasporites cinctus. The new evidence extends the distribution of the Onslow palynoflora to include Carnianassociations formerly assigned to the Ipswich Province. The affinities of Argentinean palynofloras seem toindicate the existence of a similar flora extending from the northern Australian margin (West Timor), throughthe western Tethys coasts, to westernmost Gondwana during the Carnian. Moreover, the new data reinforcethe close relationship between some diagnostic species and humid environmental conditions.