Abstract

The Cretaceous/Paleogene boundary (K/Pg) event, associated with a meteorite impact at Chicxulub, Mexico, is globally recognized as one of the largest mass extinctions in natural history, marking the end of the Mesozoic Era. However, most of the outcrops with records and geochemical evidence of this boundary are distributed in the Northern Hemisphere and at mid -latitudes. Here, aiming to contribute to the knowledge of this event at high southern latitudes, we characterize a single iridium anomaly correlated with the K/Pg boundary, present within a carbonaceous mudstone level in a continental depositional environment in the Rio de las Chinas Valley, Chilean Patagonia. High -resolution geochemical and palynofacies analyses were performed on a stratigraphic section from the top of the Dorotea Formation. Results showed that the iridium enrichment coincides with an anomaly of other platinum group elements. In addition, the palynofacies analysis showed a disturbance in the depositional environment, marked by an abrupt change from non -degraded phytoclasts (e.g., cuticles) to pseudoamorphous and degraded cuticles, and by an increase in the abundance of spores at the same level. The Rio de las Chinas Valley locality provides new evidence for the comprehensive study of the endCretaceous event, from the poorly represented continental environments of high southern latitudes. (c) 2024 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.