Maastrichtian to Danian Atlantic transgression in the north of Patagonia: A dinoflagellate cyst approach

GULER, M. VERÓNICA; GONZÁLEZ ESTEBENET, M. SOL; NAVARRO, EDGARDO L.; ASTINI, RICARDO A.; PÉREZ PANERA, JUAN P.; OTTONE, E. GUILLERMO; PIERONI, DANIEL; PAOLILLO, MELISA A.

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Año: 2019 vol. 92 p. 552 - 564

0895-9811

The late Maastrichtian to early Paleocene marine successions in northern Patagonia and neighboring southwesternAtlantic Ocean Basins provided a valuable organic-walled dinoflagellate cysts record. Assemblagesaround the Cretaceous?Paleogene boundary and more pronounced in the Danian compare well with thosecoevals from lower latitudes sites (e.g. Brazil, Uruguay, Tunisia, Israel). Humid-warm climate prevailing inPatagonia together with counterclockwise oceanic circulation along the southwestern South Atlantic Oceanwould have favored the exchange of taxa of the marine biota with lower-latitude basins, and helped to explainthe similarities of the marine palynoflora from the southernmost part of South America and those from thewidely separated Tethyan domains. Quantitative data of Danian dinoflagellate cyts assemblages from the northof Patagonia were used to infer palaeoecological and paleoenvironmental conditions in terms of nutrientavailability, salinity, and coastal proximity, providing refined local paleogeography in an epicontinental context.Consistent with Tethyan sites records, assemblages from northern Patagonia exhibit high abundance or dominanceof the presumed heterotrophic dinoflagellate cysts, denoting a globally nutrient - enrichment of thewatermasses during the Danian.