Antarctica’s ancient forests left behind evidence of wildfires about 90 million years ago, according to a new study. Scientists examining ancient sediment from West Antarctica discovered tiny charcoal fragments showing that fires repeatedly burned through forests near the South Pole. The findings also reveal the oldest known coal-forming peat bog dominated by sphagnum moss.
The research, led by paleoecologist Ulrich Salzmann of Northumbria University in the United Kingdom, offers new insights into Antarctica’s environment during the Cretaceous period, when the continent was much warmer and largely free of ice.
Earlier research has also examined how falling carbon dioxide levels contributed to Antarctica’s transformation from a forested landscape into an ice-covered continent. Scientists have linked this long-term cooling to the formation of major Antarctic ice sheets about 34 million years ago.
Ancient charcoal reveals Antarctic forest fires
Researchers examined sediment collected in 2017 from Pine Island Bay in the Amundsen Sea. The drilling expedition recovered a 98-foot-long core containing ancient roots, pollen, spores, and a thin layer of coal.
Scientists first described evidence of the ancient forest in 2020. Further evidence emerged in 2024, when researchers discovered amber fragments in Antarctica for the first time. The latest study builds on those discoveries by examining charcoal preserved in the same sediments, which date to between 92 million and 83 million years ago.
Researchers found charcoal throughout the deposits, with higher concentrations in the upper layers. Some fragments were too large to have traveled far by wind, suggesting that fires occurred nearby. Microscopic analysis identified burned wood from podocarps, a family of conifer trees still found in the Southern Hemisphere.
Antarctica was once home to forests that caught fire!
Scientists have uncovered 90-million-year-old charcoal, revealing ancient wildfires near the South Pole. The discovery also points to the oldest known coal-forming moss bog. pic.twitter.com/QqnTQsU7HZ— Tom Marvolo Riddle (@tom_riddle2025) October 14, 2026
The charcoal also revealed the intensity of the fires. Researchers estimated temperatures between 700 and 750 degrees Fahrenheit (370 to 400 degrees Celsius), consistent with relatively mild fires spreading across the forest floor rather than through treetops. Similar fossil evidence has helped scientists reconstruct other prehistoric ecosystems, including the ancient petrified forest on the Greek island of Lesvos.
What sparked fires near the South Pole?
Scientists found little evidence that volcanic eruptions caused the fires. Instead, they suggest lightning and seasonal changes in moisture may have played a role. Although the region received substantial rainfall, seasonal drying could have made vegetation vulnerable to burning. Researchers also suggest that higher atmospheric oxygen levels may have helped fires spread.
Chemical traces associated with burning provided further evidence of recurring fires. However, the researchers could not determine exactly what ignited them. The fires occurred in a forest that experienced more than four months of continuous darkness each year, highlighting the unusual conditions of ancient Antarctica.
Fossils reveal the oldest known coal-forming moss bog
The sediment also revealed a major change in the ancient landscape. Fossil pollen and spores showed that a forested swamp gradually developed into a peat bog dominated by sphagnum moss. Waterlogged, acidic conditions helped preserve accumulating plant material that eventually formed coal.
Researchers identified the deposit as the oldest known coal-forming sphagnum peat bog, approximately 35 million years older than a comparable deposit in Germany. The discovery challenges earlier theories suggesting that sphagnum moss spread into the Southern Hemisphere much later.
Scientists believe recurring fires may have slowed tree growth and encouraged mosses and ferns to spread. However, the sediments cover roughly 9 million years, making it difficult to determine how quickly the landscape changed. The findings suggest that fire helped shape Antarctica’s ancient wetlands while raising new questions about the early history and spread of peat-forming mosses.
See all the latest news from Greece and the world at Greekreporter.com. Contact our newsroom to report an update or send your story, photos and videos. Follow GR on Google News and subscribe here to our daily email!
