Abstract

The Filo Negro Section, on Seymour Island (Antarctic Peninsula), is a fossiliferous section with great potential for Late Cretaceous-Paleogene studies, which also presents an iridium anomaly layer. However, it has not been thoroughly studied in terms of integrated high-resolution paleontological and multi-proxy records yet. Paly-nomorphs and geochemical proxies are used herein to assess paleoenvironmental and paleoclimatic changes recorded at this section during the Maastrichtian-Danian transition. In addition, statistical tests are applied to our numerical palynological data (cluster analysis, Mann Kendall Trend test and chi 2-test) in order to further support our interpretations. The P/G ratio (peridinioid/gonyaulacoid dinoflagellate cysts) was adopted as a paleoproductivity proxy, whereas the T/M ratio (terrestrial/marine palynomorphs) was used to infer proximal/ distal depositional settings. The sedimentary succession was divided into three intervals, based on a cluster analysis. We infer humid, relatively warm conditions for the latest Maastrichtian, and cool paleoclimates after the K-Pg transition. This is supported by the Fe/K ratio, which depicts a general trend toward drier climates in the early Danian. A marked increase in terrestrial palynomorphs, along with a general Ti/Al ratio increasing-upwards trend, implies more proximal settings above the maximum flooding surface, marked at 9.9 m. The P/ G and Ba/terrigenous elements ratios imply a marine paleoproductivity drop around the K-Pg transition, remaining low during the earliest Danian. We also refined the previous position of the K-Pg transition in this section, placing it within 9.5 to 9.6 m, based on dinoflagellate cysts biostratigraphical analysis and geochemical data (iridium anomaly and increase in siderophile elements).