Palynostratigraphic analysis of lower Cretaceous sediments in the Golfo San Jorge Basin, central Patagonia, Argentina

Abstract

Palynomorph assemblages were recovered from the “Neocomian deposits” and the Pozo D-129 Formation in the VOA.SC.CL.a-4005 well, Golfo San Jorge Basin, Argentina. The studied palynofloras comprise 67 spore species, 26 pollen taxa and, one algal taxon. Based on the presence of Densoisporites corrugatus, a Barremian age is proposed for the “Neocomian deposits”. Likewise, a Barremian age is inferred for the analyzed levels of the Pozo D-129 Formation, supported by the occurrence of Cicatricosisporites hughesii, Cyatheacidites tectifera, and Densoisporites corrugatus. This age assignment is further supported by a chronostratigraphic correlation with the Barremian tectifera-corrugatus Interval Zone of southern Patagonia. Multivariate statistical analysis comparing the studied assemblages with other Lower Cretaceous palynofloras from Patagonia reveal strong similarities with assemblages from the Las Heras Group and the Puesto Albornoz Formation, thereby confirming previous regional correlations. Overall, this study contributes to a more detailed understanding of the paleofloras and depositional history of the Golfo San Jorge Basin.