Ancient Arctic sediments revise understanding of wildfires in the Early Triassic

by Robert Schreiber
Berlin, Germany (SPX) Nov 18, 2025

Researchers have identified new evidence of ancient wildfires that alters established views on the Early Triassic epoch. An international consortium, including Heriot-Watt University in Scotland, found molecular traces of charred vegetation in sediments dating back roughly 250 million years. The research contradicts longstanding assumptions about a global charcoal gap following the Permian-Triassic extinction.

For years, the scarcity of visible charcoal in geologic layers led scientists to believe wildfires nearly vanished after the Great Dying, which eliminated most marine and terrestrial species. However, new findings published in Communications Earth and Environment reveal the presence of polyaromatic hydrocarbons, chemical markers formed during combustion, in 30 sediment samples from Svalbard in the Norwegian Arctic.

Dr Clayton Magill of Heriot-Watt explained, "A lot of folks have not found the normal evidence of fire such as charcoal, ash, burnt fossils so the consensus was that fire wasn't happening." He added, "What our colleague Dr Franziska Blattmann's work showed is that even without the big pieces of evidence, the microscopic signals are still there. You just need to know where to look."

The detected PAHs indicate widespread burning of fresh plant material. These results suggest that wildfires occurred during the Early Triassic, even though conventional fossil charcoal records provided little direct evidence.

The group combined sediment analysis with advanced climate and vegetation modeling, employing the open-source General Circulation Model (MITgcm) from MIT. This approach enabled them to test the interactions among climate, ecosystems, and wildfire regimes after the mass extinction event. Dr Magill noted, "By using models, we can run our data through theory and test whether it holds up. It doesn't just say 'trust me' - it shows you the evidence." He emphasized the value of open-source tools: "Open science allows everyone to compete at the highest level."

Leading the project, Dr Franziska Blattmann of the University of Lausanne stated, "This study came together through the collaboration of a multidisciplinary team of scientists, working together even amid the challenges of the COVID-19 pandemic. The research highlights how longstanding scientific questions can be advanced and how unexpected discoveries can emerge when collaboration is open, creative and supportive."

The research provides valuable perspective on climate variability and ecosystem recovery in deep time. Lessons from the Early Triassic, marked by environmental stress and recovery, may inform current responses to global climate challenges.

Research Report:Wildfire, ecosystem, and climate interactions in the Early Triassic