Mount Jefferson, Oregon

Mount Jefferson
height	3199  m
location	Oregon , USA
Mountains	Cascade chain
Coordinates	44 ° 40 '27 "  N , 121 ° 47' 58"  W Coordinates: 44 ° 40 '27 "  N , 121 ° 47' 58"  W.
Type	Stratovolcano , inactive
rock	Andesite , basaltandesite , dacite
Age of the rock	300,000 years
Last eruption	approx. 950 AD
First ascent	1888

Mount Jefferson is an inactive stratovolcano in the Cascade Range . At 3,199  m, it is the second highest mountain in the US state of Oregon . Its rock is essentially composed of andesite , basalt andesite and dacite .

Mt. Jefferson is very rugged and has several glaciers . Its west side is occupied by the Mount Jefferson Wilderness and Willamette National Forest . The east side has been part of the Warm Springs Indian Reservation since 1855 , although the area was originally settled by the Molala who now live further northwest in the Grand Ronde Indian Reservation .

The mountain was named in 1806 by the participants of the Lewis and Clark Expedition after President Thomas Jefferson , who commissioned the expedition. After further research at the beginning of the 19th century, two residents from Salem managed the first ascent in 1888 . Climbing the summit is technically very demanding and is difficult due to the steep, ice-encrusted rocks.

The last major eruption phase of Mount Jefferson itself was about 15,000 years ago. Volcanic activity seems to have shifted further south since then. Around 4500 BC BC and in the year 950 lava flows from the monogenetic vents Forked Butte and South Cinder Peak are recorded.

literature

• Stephen L. Harris: Fire Mountains of the West: The Cascade and Mono Lake Volcanoes. Mountain Press Publishing Company, Missoula 1988, ISBN 0-87842-220-X

Web links

Commons : Mount Jefferson  - collection of images, videos, and audio files

• Volcano Hazards Program - Mount Jefferson United States Geological Survey.
• The Vulcanoes of Lewis and Clark United States Geological Survey.

Individual evidence

1. ^ ^{A b} Volcano Hazards Program - Mount Jefferson. United States Geological Survey, accessed December 19, 2013 . 
2. ^ Volcano Hazards Program - Mount Jefferson Geology and History. United States Geological Survey, accessed December 19, 2013 . 
3. ↑ Fred Spicker: Mount Jefferson (Oregon): Climbing, Hiking & Mountaineering. In: SummitPost. September 21, 2001, accessed December 19, 2013 . 
4. ^ Joseph S. Walder, Cynthia A. Gardner, Richard M. Conrey, Bruce J. Fisher, Steven P. Schilling .: Volcano Hazards in the Mount Jefferson Region, Oregon . US Geological Survey Open-File Report, 99-24, 2000. ( online )