Frasnian–Famennian (Upper Devonian) conodont biofacies and global events in the compte section (Central Pyrenees, Spain)

Abstract Detailed studies on conodont biofacies from upper Frasnian to middle Famennian in the Compte section (Central Pyrenees area) allow recognition of different eustatic fluctuations and the Kellwasser, Nehden, and Condroz events. Five conodont biofacies have been identified: Palmatolepis , Palmatolepis – Polygnathus , Polygnathus – Palmatolepis , Palmatolepis – Icriodus and the new Icriodus – Palmatolepis biofacies. The evolution of conodont biofacies during the end Frasnian reflects a sudden regressive episode at the base of FZ13b subzone and a maximum transgressive trend at the top of FZ13b subzone, which aligns with the Upper Kellwasser Event. The Kellwasser crisis dramatically reduces the conodont biodiversity, which recovers during the lower Famennian. A transgressive trend is recorded during the Palmatolepis crepida – Palmatolepis gl. prima zone interval, which may be referred to as the Nehden Event. Within La Mena Formation two regressive trends are identified by sharp conodont biofacies changes in the Palmatolepis rhomboidea and Palmatolepis gr. gracilis zones: the lower and upper Condroz Events.