Editing Cascade Range (section)

==Geology==
[[File:Cascade Range plate tectonics-en.svg|thumb|upright=1.15|Geology of the Cascade Range-related plate tectonics.]]
{{See also|Geology of the Pacific Northwest|Cascade Volcanic Arc}}

The Cascade Range is made up of a band of thousands of very small, short-lived volcanoes that have built a platform of lava and volcanic debris. Rising above this volcanic platform are a few strikingly large volcanoes, like Mount Hood and Mount St. Helens, that dominate the landscape.<ref name="cascade1">{{USGS|url=http://geomaps.wr.usgs.gov/parks/province/cascade1.html|title=Pacific – Cascades Volcanic Province}}</ref>

The Cascade volcanoes define the Pacific Northwest section of the [[Pacific Ring of Fire|Ring of Fire]], an array of volcanoes that rim the Pacific Ocean. The Ring of Fire is also known for its frequent earthquakes. The volcanoes and earthquakes arise from a common source, namely [[subduction]]. In this case, the dense [[Juan de Fuca Plate]] plunges beneath the [[North American Plate]] at the [[Cascadia subduction zone]].<ref name="cascade2">{{USGS|url=http://geomaps.wr.usgs.gov/parks/province/cascade2.html|title=Pacific – Cascades Volcanic Province}}</ref> As the [[oceanic plate|oceanic slab]] sinks deep into the Earth's interior beneath the continental plate, high temperatures and pressures allow water molecules locked in the minerals of solid rock to escape. The water rises into the pliable mantle above the subducting plate, causing some of the mantle to melt. This newly formed magma rises toward the Earth's surface to erupt, forming a chain of volcanoes (the Cascade Volcanic Arc) above the subduction zone.<ref name="cascade2" />