Tumalo Volcanic Center
Source of large-volume Pleistocene ashflows in Oregon, United States
From Wikipedia, the free encyclopedia
The Tumalo volcanic center of Central Oregon is viewed as a source of large-volume Pleistocene ashflows, in the US state of Oregon.[2]
| Tumalo Volcanic Center | |
|---|---|
 | |
| Highest point | |
| Elevation | 1,955 ft (596 m) |
| Coordinates | 44°05′56″N 121°32′28″W |
| Geography | |
| Parent range | Cascade Range |
| Geology | |
| Rock age | More than 500,000 years[1] |
| Volcanic arc | Cascade Volcanic Arc |
| Last eruption | Pleistocene |
The eruption, ashflows included
How big was the volcanic eruption? Imagine a cube of lava, one that's 1.5 miles (2.4 km) long by 1.5 miles (2.4 km) wide by 1.5 miles (2.4 km) high.[1]
Ashflows include
- Desert Spring Tuff,
- Bend Pumice
- Tumalo Tuff, and
- Shevlin Park Tuff.
The area has many rhyolitic domes, such as Melvin Butte, plus andesitic cinder cones, including those of the Triangle Hill and Triangle Peak area, whose composition is similar to the Tumalo Tuff (and Bend Pumice), and Shevlin Park Tuff.[2]
This area has andesitic and mafic cinder cones, such as Lava Butte.[3] and rhyolite domes.[4] Viscous rhyolite domes extruded to the surface.[5]
Ways the Tumalo Volcanic Center's ashflows have been used
The Tumalo Volcanic Center's ashy pumice was quarried for concrete. This concrete effectively built the city of Bend, Oregon[1]
Pumice from the Tumalo Volcanic Center composes Oregon State University–Cascades's expansion, into a pumice mine.[6]
