Boring Lava Field

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Boring Lava Field
Bobs mountain.jpg
Bob's Mountain in Washington State
Location Oregon and Washington, U.S.
Coordinates 45°18′N 122°30′W / 45.3°N 122.5°W / 45.3; -122.5Coordinates: 45°18′N 122°30′W / 45.3°N 122.5°W / 45.3; -122.5
Highest point
 – elevation
 – coordinates
Larch Mountain[1]
4,061 feet (1,238 m)
45°18′N 122°30′W / 45.3°N 122.5°W / 45.3; -122.5
Geology Volcanic field[2]
Age Pleistocene[2]
Last eruption > 300,000 years[2]
Locations of Boring vents

The Boring Lava Field is an extinct Plio-Pleistocene volcanic field zone with at least 32 cinder cones and small shield volcanoes lying within a radius of 13 miles (21 km) of Kelly Butte, which is approximately 4 miles (6 km) east of downtown Portland, Oregon, in the United States. The name is derived from the town of Boring, Oregon, which lies just to the southeast of the most dense cluster of lava vents. The zone became active at least 2.7 million years ago, and has been extinct for about 300,000 years.[2]

The Portland metropolitan area, including suburbs, is one of the few places in the continental United States to have extinct volcanoes within a city's limits; Bend, Oregon is another; for example Pilot Butte is a 500 foot high cinder cone located within the Bend city limits.

Oregon vents[edit]

The following vents are in Oregon:

Washington vents[edit]

The following vents are in Washington:

  • Battle Ground Lake - Elevation 509 feet (155 m)[12] (miniature crater lake)
  • Bob's Mountain - Elevation 2,110 feet (643 m)[3] (contains intact summit crater)
  • Bob's Mountain (N) - Elevation 1,775 feet (541 m)[3]
  • Bob's Mountain (S) - Elevation 1,690 feet (515 m)[3]
  • Brunner Hill - Elevation 680 feet (207 m)[3] (2 vents)
  • Green Mountain - Elevation 804 feet (245 m)[3] (logged off during World War I)
  • Mount Norway - Elevation 1,111 feet (339 m)[3]
  • Mount Pleasant - Elevation 1,010 feet (308 m)[3]
  • Mount Zion - Elevation 1,465 feet (447 m)[3]
  • Nichol's Hill - Elevation 1,113 feet (339 m)[3]
  • Pohl's Hill - Elevation 1,395 feet (425 m)[3]
  • Prune Hill (W) - Elevation 555 feet (169 m)[3]
  • Prune Hill (E) - Elevation 610 feet (186 m)[3] (overlooks Camas, Washington)
The buttes of the Boring Lava Field are visible toward the center of this panorama of Portland, Oregon

References[edit]

  1. ^ a b "Larch Reset". NGS data sheet. U.S. National Geodetic Survey. Retrieved 2008-11-18. 
  2. ^ a b c d Wood, Charles A.; Jűrgen Kienle (1990). Volcanoes of North America. Cambridge University Press. pp. 170–172. 
  3. ^ a b c d e f g h i j k l m n o p q r Allen, John E. (September 1975). "Volcanoes of the Portland Area, Oregon". The Ore Bin (Portland, Oregon: State of Oregon Department of Geology and Mineral Industries) 37 (9): 150. Retrieved 2009-06-16. 
  4. ^ a b c Allen, John E. (September 1975). "Volcanoes of the Portland Area, Oregon". The Ore Bin (Portland, Oregon: State of Oregon Department of Geology and Mineral Industries) 37 (9): 151. Retrieved 2009-06-16. 
  5. ^ "Powell Butte". NGS data sheet. U.S. National Geodetic Survey. Retrieved 2008-04-02. 
  6. ^ "Rocky Butte Reset". NGS data sheet. U.S. National Geodetic Survey. Retrieved 2008-04-02. 
  7. ^ "Mount Scott". Geographic Names Information System, U.S. Geological Survey. 
  8. ^ "The Boring Lava Field: Portland, Oregon". United States Geological Survey. Retrieved May 21, 2010. 
  9. ^ "Sylvania Reset". NGS data sheet. U.S. National Geodetic Survey. Retrieved 2008-11-17. 
  10. ^ "Feature Detail Report ID 1136814: Mount Tabor Summit". 
  11. ^ "Mount Talbert". Geographic Names Information System, U.S. Geological Survey. 
  12. ^ "Battle Ground Lake". Geographic Names Information System, U.S. Geological Survey. Retrieved 2012-05-03. 

External links[edit]