Mount St Helens
Merideth Beck, SC210-Davis, Feburary 27 2014
- Type: Active Stratovolcano
-Age of Rock: <40,000 years
-First Eruption: May 18, 1980
The volcano is located in the Cascade Range and is the part of the Cascade Volcanic Arc, which is a segment of the Pacific Ring of Fire that includes over 160 active volcanoes. Mount St. Helens is well known for its ash explosions and pyroclastic flows. Along with the volcano there is a National Volcanic Monument was created to preserve the volcano and allow for its aftermath to be scientifically studied. This volcano is a large eruptive cone consisting of lava rock interlayered with ash, pumice, and other deposits. It includes layers of basalt and andesite through which several domes of dacite lava have erupted. This volcano is considered to be the most active in the Cascades within the last Holocene (which is within the last 10,000 years or so).