Sand-mining operations in Michigan have uncovered a true forest primeval—a 10,000-year-old spruce woods buried in sand.
The trees probably died after being flooded by retreating glaciers at the end of the last ice age, says Kurt S. Pregitzer, a forest ecologist from Michigan Technological University in Houghton, who led the forest excavation.
Sand and water quickly buried and preserved the forest. The trees, some up to 145 years old when they died, were still standing when the forest was discovered. Many sported bark and twigs. Spruce needles, pinecones, and mosses blanketed the floor.