Go to main content

University of Silesia in Katowice

  • Polski
  • English
Institute of Earth Sciences
Logo European City of Science 2024

Variable oxygenation conditions during a mid-Tournaisian anoxic event

10.05.2023 - 10:30 update 10.05.2023 - 10:37
Editors: lukaszmalarzewski

The May issue of Geological Magazine, one of the oldest geological journals, published an article, authored by researchers from the Institute of Earth Sciences at the University of Silesia in Katowice Michał Rakociński, Daria Książak, Agnieszka Pisarzowska, Michał Zaton and a researcher from the Université Toulouse III Paul Sabatier in France, Markus Aretz, on the record of a mid-Tournaisian anoxic event in the Montagne Noire in southern France. This event occurred about 355 million years ago and affected numerous groups of marine organisms as anaerobic conditions in the seas and oceans emerged on a global scale. However, as researchers have shown based on detailed geochemical and petrographic analyses, sediments forming in the southern France area at this time were formed in a better-oxygenated environment than in other areas previously studied in detail, i.e. the Polish Laurussian shelf (Holy Cross Mountains), and the Palaeotethys area (Carnic Alps, Austria). Large mercury spikes in the studied successions are indicative of increased submarine volcanism during this time. As shown, volcanic processes led to climatic changes that resulted in the deglaciation of Gondwana, global transgression, and the development of anoxic conditions in many sedimentary basins at this time. However, as has been shown, anoxic conditions in pelagic zones did not occur with the same intensity everywhere.

This paper is the result of the NCN OPUS grant implemented at the University of Silesia in Katowice (UMO-2014/15/B/ST10/03705) entitled Depositional environments during the Lower Alum Shale Event (Early Carboniferous) on the southern shelf of Laurussia in the light of integrated geochemical, paleoecological and facial investigation, led by Michał Rakociński (Institute of Earth Sciences, University of Silesia).


Rakociński, M., Książak, D., Pisarzowska, A., Zatoń, M., Aretz, M., 2023. Weak and intermittent anoxia during the mid-Tournaisian (Mississippian) anoxic event in the Montagne Noire, France. Geological Magazine 160(5), 831–854.


return to top