Deciphering the Forest

Volcanic ash can be gentle and fine enough to preserve a leaf’s structure in great detail, and nearby 34 million-year-old Bridge Creek Flora fossils reveal many species of an ancient hardwood forest. This forest had a blend of trees found today only in parts of the Appalachians, China, and spots along the Pacific Coast. Fossils indicate that some types of trees changed little during the Age of Mammals. From that evidence and comparisons to modern trees and their settings, much has been learned about past ecosystems and climates. About 30 million years ago, during a period of significant global change, the air cooled and the seasons became more pronounced, causing the earlier near-tropical plants of the area to retreat southward. Many hardwoods and conifers replaced them, along with a whole new set of forest creatures.

Oregon · United States