A 45-million-year-old forest preserved unmineralized, wood still brown and crumbly, at 80°N where nothing grows today. Dawn redwoods and swamp cypress grew in 24-hour summer sunlight. The logs are so well-preserved they can still burn.
A swamp forest at 80° North
Some 45 million years ago, during the Eocene epoch, Axel Heiberg Island was a vastly different place. Located at a similar high latitude as it is today, the island experienced months of continuous sunlight in summer and months of total darkness in winter. Despite the polar night, the climate was warm and wet, with average summer temperatures around 19°C. This environment supported a lush, temperate swamp forest dominated by large conifers.
The primary trees were the dawn redwood, Metasequoia, and a type of swamp cypress, Glyptostrobus. These deciduous conifers would shed their needles to survive the dark winters. The forest was dense, with some trees reaching heights of 50 meters and growing for up to 1,000 years. Stumps measuring over 2.5 meters in diameter have been found still rooted in the soil where they grew. The ecosystem was diverse, supporting trees and also plants like birch, alder, sycamore, and even grapes. Fossil evidence shows that alligators and turtles also inhabited this warm, high-latitude environment.
Mummified, not mineralized
The most remarkable feature of the Axel Heiberg forest is its state of preservation. The term "fossil forest" is inaccurate, as the organic material is not petrified; it has not been replaced by minerals. Instead, the wood, leaves, and cones are "mummified," retaining their original carbon-based material.
This unique preservation is the result of rapid burial. Periodically, perhaps every 10,000 years, floods would quickly cover the forest floor with thick layers of fine sediment and silt. This process cut off oxygen, preventing both decomposition and mineralization. At least 19 distinct forest layers are preserved in this way within a sediment deposit over 150 meters thick. The result is a record of the ancient ecosystem. Layers of leaf litter are preserved on the forest floor, and cones and seeds are often found intact. The wood itself is so well-preserved that its cellular structure can be studied, and pieces can still be split and burned.
The site was scientifically documented in 1985 by a geologist from the Geological Survey of Canada, after a helicopter pilot reported seeing a concentration of logs from the air.
💡Fun Facts
The forest grew during a period of peak global warmth known as the Early Eocene Climatic Optimum.
Because the wood is not mineralized, scientists can study the tree rings to analyze the climate conditions of individual years from 45 million years ago.
Some leaves are so perfectly preserved they can be peeled from the sediment as if they were recently pressed.
The dominant tree, *Metasequoia*, was first described from fossils and thought to be extinct until a living population was discovered in China in 1944.
The site is not open to the public. It is an extremely remote and protected scientific research area.
Admission
Access is restricted to permitted researchers. Some adventure tourism companies offer fly-by tours or landings, but these are infrequent and very expensive.
Accessibility
The terrain is a polar desert, accessible only by specialized charter aircraft. There is no public infrastructure.