Tag Archives: Subduction

An aerial view of the Cascade volcanic peaks in Oregon, with the Three Sisters in the foreground, and Mts. Washington, Jefferson, Hood, and Adams extending northward
c. 30-10 Million BCE: The Cascade Volcanoes – A Tectonic Phenomenon

The Cascade Volcanoes in the Pacific Northwest are formed by the subduction of oceanic plates beneath the North American continental plate, resulting in a series of major volcanic peaks and vents along the Cascade volcanic [...]