EGU23-14371, updated on 26 Feb 2023
EGU General Assembly 2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.

Collapse of Late Permian chert factories in the equatorial Tethys and the nature of the Early Triassic chert gap

Fen Yang1, Yadong Sun1,2, Patrick Frings3,4, Lin Luo1, Jingwen Eh1,5, Lina Wang6, Yafei Huang1, Tan Wang1, Johann Müller2, and Shucheng Xie1
Fen Yang et al.
  • 1State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Wuhan 430074, China (
  • 2GeoZentrum Nordbayern, Universität Erlangen-Nürnberg, Schlossgarten5, 91054 Erlangen, Germany (
  • 3Earth Surface Geochemistry, GFZ German Research Centre for Geosciences, Telegrafenberg, 14473 Potsdam, Germany (
  • 4Plants and Ecosystems (PLECO), Biology Department, University of Antwerp, Wilrijk, Belgium (
  • 5Qujiang Middle School, Shaoguan 512000, China (
  • 6School of Earth Sciences, Hebei GEO University, Shijiazhuang 050031, China (

The Permian witnessed the extensive development of cherts from the palaeoequator to the northern high latitudes. However, large-scale chert deposition was abruptly terminated in the latest Permian, resulting in the Early Triassic "chert gap". Deepwater sedimentary successions in South China across the Permian-Triassic transition recorded the shift from radiolarian- and spicule-bearing siliceous units to carbonate/siliciclastic facies in the equatorial Tethys. In order to constrain the onset time of the chert production crisis and understand its nature, we carried out sedimentological, palaeontological, and geochemical analyses on two deepwater sections along the northern margin of the South China Block. Our results suggest that chert production in equatorial latitudes was already weakened in the Clarkina changxingensis conodont zone. The final collapse of the chert factory occurred in the Clarkina yini - Hindeodus praeparvus/Clarkina zhangi Zone and was accompanied by a significant decrease in SiO2 content, which predated the negative carbonate carbon isotope excursion and climate warming but coincided with a sharp decline in primary productivity. Combined with Si box model results, our study suggests that global warming cannot maintain a multi-million-year chert gap. Instead, the loss of siliceous skeleton producers was the primary cause of the Early Triassic chert demise.

How to cite: Yang, F., Sun, Y., Frings, P., Luo, L., Eh, J., Wang, L., Huang, Y., Wang, T., Müller, J., and Xie, S.: Collapse of Late Permian chert factories in the equatorial Tethys and the nature of the Early Triassic chert gap, EGU General Assembly 2023, Vienna, Austria, 24–28 Apr 2023, EGU23-14371,, 2023.