Mount Eddy and Ultramafic Boulders

The Klamath Mountains, which extent into southwestern Oregon, are rugged, generally north-south trending ridges from 6,000 feet (1,830 meters) to 9,000+ feet (2,740+ meters) above sea level. They formed over 100s of millions of years (Early Paleozoic Era through the Cretaceous Period) as sections of the seafloor repeatedly slammed into the North American Plate. The episodes resulted in at least seven roughly north-south mountain belts composed of accreted terrane (slices of oceanic continent that stuck to the North American Plate) and/or uplifted blocks of the continent. Each belt is characterized by a unique assemblage, which include a variety of plutonic, metamorphic, volcanic, and/or sedimentary rocks. This view of 9,025-foot Mount Eddy is in the Eastern Klamath Belt. The mountain is composed of complex metamorphic and ultramafic rocks, some of which include rare minerals like chromite and asbestos.

Print No. A99NW-24-4.

More images from the Klamath Mountains/Trinity Alps.