Volcanic evolution of the Pacific Northwest: 55 million year history

Active volcanoes in the Pacific Northwest result from a varied tectonic setting. Ocean-ridge rifting produces submarine volcanism offshore. Northwest subduction of the young Juan de Fuca Plate creates the arc of Cascades volcanoes. Hot-spot volcanism drives the Yellowstone caldera system. Continental extension plus a northward migrating triple junction add to the complex volcanic history. To look at the development of volcanism in the Pacific Northwest we will go back 55 million years to a time prior to stretching of the continent by Basin-and-Range extension and when Mesozoic subduction, compression, and crustal thickening had waned. At the end of the Cretaceous, […]

Read more