EGU22-9898
https://doi.org/10.5194/egusphere-egu22-9898
EGU General Assembly 2022
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

The late Eifelian (Middle Devonian) Kačák event and its effects on rugose coral palaeobiodiversity (Ardennes, Belgium)

Valentin Jamart1 and Julien Denayer2
Valentin Jamart and Julien Denayer
  • 1AnomLab, University of Lausanne (UniL), Institute of Earth Sciences (ISTE), Géopolis, 1015 Lausanne, Switzerland (vjamart.phd@gmail.com)
  • 2Evolution & Diversity Dynamics Lab, U.R. Geology, Université de Liège (ULiège), 14 Allée du Six-Août, B18, Sart Tilman, 4000 Liège, Belgium (julien.denayer@uliege.be)

Of the many biocrises that occurred during the Devonian period, the most studied ones are the end-Devonian Kelwasser event (Frasnian-Famennian Boundary) and the Hangenberg event (Devonian-Carboniferous Boundary). However, the Middle Devonian crisis are receiving an increasing attention. The crisis occurring immediately before the Eifelian-Givetian Boundary (ensensis conodont zone) is known as the Kačák event. It has essentially been identified by time-specific lithofacies in deep-environment settings where pelagic faunas (conodonts, ammonoids, dacryoconaridids) suffered extinctions. On the Belgian neritic carbonate shelf system the Kačák event has been identified, in the lower part of the Hanonet Formation where a complex faunal turnover took place but with few changes in the depositional settings as known in deeper environments. The event is also recognised on a palaeobiological base as the pre-crisis Old World Realm fauna-dominated assemblages are suddenly facing the invasion of East American Realm fauna such as siphonophrentid and heliophillid rugose corals. After the crisis, these corals are very uncommon and the Old World Realm assemblages become largely dominant again. This palaeobiological criterion is proposed to help, especially when the typical pelagic guides are missing, in the identification of the Kačák event.

How to cite: Jamart, V. and Denayer, J.: The late Eifelian (Middle Devonian) Kačák event and its effects on rugose coral palaeobiodiversity (Ardennes, Belgium), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9898, https://doi.org/10.5194/egusphere-egu22-9898, 2022.

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