Palaeoenvironmental changes across the Mid‐ and latest Maastrichtian events: Planktic foraminiferal inference from the Elles section (central Tunisia)

Abstract

Based on quantitative changes in the Maastrichtian planktic foraminiferal species distribution patterns from the Elles section (central Tunisia), δ13C, δ18O‐based palaeotemperature and inferred proxies (species diversity, ecological associations, and depth ranking), the palaeoenvironment is inferred. Based on Constrained Clustering and corroborated by Non‐metric Multidimensional Scaling (NMDS), four statistically significant intervals are identified. Interval 1 (lower–middle part of CF5 Zone) is marked by a warm, oligotrophic, stable, and well‐stratified upper water column. Interval 2 (upper part of CF5 Zone), here designated as the pre‐Mid‐Maastrichtian Event (MME) event, is marked by stressed, warmer, moderately mesotrophic, and weakly stratified surface waters with an unstable upper water column. Interval 3 (CF4 Zone) encompasses the MME and is marked by warm, stable, mesotrophic surface waters with a moderately well‐stratified upper water column. The upper part of Interval 3, designated as post‐MME, is also marked by mesotrophic conditions, but with increased surface water warming, unstable and stressed conditions. Interval 4 (CF3–CF1 zones) shows the effects of the Indian Deccan volcanism, and is marked by warmer surface waters, mesotrophic, unstable, stressed environmental conditions, with a weakly‐stratified upper water column.