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 / 44.099°N 121.541°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
editHow 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
editThe 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]
See also
editExternal links and references
editReferences
edit- ^ a b c Ross, Erin. "Oregon Public Broadcasting". Oregon Public Broadcasting.
- ^ a b "Smithsonian".
- ^ *Harris, S. L. (2005). "Chapter 13: The Three Sisters". Fire Mountains of the West: The Cascade and Mono Lake Volcanoes (Third ed.). Missoula, Montana: Mountain Press Publishing Company. p. 33. ISBN 978-0-87842-511-2.
- ^ Plummer, Charles C.; McGeary, David (1988). Physical Geology (4th ed.). Dubuque, Iowa: Wm. C. Brown Publishers. p. 54. ISBN 978-0-697-05092-2.
- ^ Faculty of the School of Geography, Geology and Environmental Science (2006). "Rhyolite". The University of Auckland. Retrieved November 29, 2017.
- ^ Klemetti, Erik (July 31, 2019). "The Hidden Volcanoes of Central Oregon".
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