Differential Effects of Bioturbation on Benthic Foraminiferal Distribution Across the Cretaceous–Palaeogene (K–Pg) Boundary at Bidart (Southwestern France)

Abstract

To assess the role of tracemakers in the reworking of benthic foraminifera across the Cretaceous–Palaeogene (K–Pg) interval, we studied benthic foraminifera present in the material infilling trace fossils (Planolites, Thalassinoides, and Zoophycos) and in the surrounding sediment observed in the uppermost Maastrichtian in the Bidart section (southwestern France). Deposition took place in the upper part of the slope during the uppermost Cretaceous and lower Danian at Bidart, as inferred from benthic foraminifera from the background sediment (not affected by burrows). Our results support the significance of tracemakers for reworking benthic foraminiferal assemblages, as previously suggested by calcareous nannofossil assemblages.