This template should be placed at the bottom of articles about volcanoes in Oregon (see Category:Volcanoes of Oregon), to allow easy one-click navigation between them in some reasonable geographic order. Please add any missing or new volcano articles in the appropriate sections of the template, in north-south order for each of the Cascade sections and west-east order for the Basin and Range section.
Sections edit
The High Cascades include volcanoes which are members of the main Cascade volcanic arc and located on or near the Cascade Crest, the main hydrologic divide along the length of the Cascade Range.
The Western Cascades include volcanoes on the west side of the range, most of which are very old eroded remnants (examples: Coffin Mtn, Iron Mtn), but there are also some more recent volcanoes such as the Boring Lava Field.
The Eastern Cascades or Cascade Back-Arc includes volcanoes in the back-arc on the east side of the range. This second, somewhat discontinuous, volcanic arc is about 20-30 miles east of the Cascade Crest, and it includes both older volcanoes (several million years old) and more recently active ones such as Newberry Volcano and its numerous associated cinder cones.
The Basin and Range includes volcanoes in eastern Oregon which are primarily the result of crustal extension or other mechanisms, in contrast to the Cascade volcanoes which are the result of subduction along the Cascadia subduction zone. Some of the volcanoes in this area, like Steens Mountain, are in the Columbia River Basalt Group and can even have their own dike swarms.
In Eastern Oregon, several of the most notable eastern volcanoes are within the Basin and Range border. However, several extinct volcanoes in northeast Oregon and the border between the two regions are also there, including the Miocene Strawberry Mountain stratovolcano and the also Miocene Tower Mountain caldera. Some of the volcanoes within this region overlap the Columbia River Basalt Group, another large volcanic province.
The Columbia Plateau includes a large igneous province of flood basalt, the Columbia River Basalt Group.
The Pacific Coast does not have any volcanoes in Washington. However, Oregon has several volcanic capes, heads, and landforms on its coast. Most of these volcanic structures are either extinct volcanoes or eroded lava flows. There are some exceptions for upheaved submarine volcanoes, like Cascade Head and Mount Hebo.
The Juan de Fuca Ridge has caused land volcanoes to erupt throughout Washington and Oregon. However, sometimes the ridge, along with the plate, create submarine volcanoes off the states' coasts. Significant members, like the Axial Seamount and the Brown Bear Seamount, are more active. In fact, Axial has erupted numerous times, with the most recent being in 2015. Scientists expect its next eruption will be between 2020 and 2024, however this might end being wrong and the volcano's eruption will be delayed.