Pelican Butte
Pelican Butte | |
---|---|
Highest point | |
Elevation | 8,037 ft (2,450 m) NAVD 88[1] |
Prominence | 2,196 ft (669 m) |
Coordinates | 42°30′48″N 122°08′43″W / 42.513428508°N 122.145281964°W[1] |
Geography | |
Location | Klamath County, Oregon, U.S. |
Parent range | Cascades |
Topo map | USGS Pelican Butte |
Geology | |
Age of rock | Pleistocene |
Mountain type | Shield volcano |
Volcanic arc | Cascade Volcanic Arc |
Last eruption | Pleistocene[2] |
Climbing | |
Easiest route | Dirt road |
Pelican Butte is a steep-sided
Pelican Butte is within the
Geography
Pelican Butte is located in
While still part of the Cascade Range,[4] Pelican Butte is disconnected from the main axis, having formed above a network of normal faults that mark the eastern border of the Cascades.[9] The volcano reaches an elevation of 8,037 feet (2,450 m).[1][a] Pelican Butte has steep sides, and despite erosion from glaciers, its original shape is mostly preserved. During the Pleistocene epoch, glaciers formed a canyon and a cirque on the northeastern side of the volcano; they also reduced the summit elevation several tens of meters and carved out an intrusive conduit in the volcano.[10] The volcano is no longer heavily glaciated.[11]
Pelican Butte has a large volume at 4.8 cubic miles (20 km3), making it one of the bigger
Ecology
On the volcano, at about 4,430 feet (1,350 m) elevation,
Animals that live in the Sky Lakes Wilderness include
Geology
Pelican Butte is part of the Quaternary Mount McLoughlin Reach,[18] a volcanic vent zone that runs from the volcano to Aspen Lake, encompassing 33 vents over an area of 357 square miles (925 km2).[19] The vent zone ranges from 9.3 to 15.5 miles (15 to 25 km) in width. Compared to the nearby vent zone surrounding Mount Mazama, it has a lower density of volcanic vents, no dacitic or silicic volcanic rock, and a lower volume of eruptive material produced during the Quaternary.[18] Basaltic andesite is the predominant volcanic rock in the McLoughlin Reach,[18] though Pelican Butte is andesitic in composition along with nearby Brown Mountain and the dissected Devils Peak volcanic cone.[20]
The continuity of the Quaternary Cascade arc is interrupted at several points, including a potential gap between Pelican Butte and the Big Bunchgrass shield volcano to the north.[21][22] Running for 11 miles (17 km) in length, the reach has fewer volcanic vents than the rest of the Quaternary Cascades, including 10 eroded mafic vents that have been dated to the Pliocene or early Quaternary. Northward of this reach, the Quaternary Cascades run continuously for 310 miles (500 km).[21][22]
Pelican Butte is a shield volcano. It sits on basaltic andesite erupted during the Pliocene and early Pleistocene. Samples from the volcano have 58 to 60 percent
Eruptive material at the volcano includes
There is one distinct geochemical sample with a higher nickel and chromium content than other lava erupted by the volcano, which may reflect heterogeneity in the source for the erupted material.[23] The volcanic rock in the intrusive conduit in Pelican Butte's central vent is identical to the lava flows found in the Pelican Butte deposits.[11]
A fault scarp sits adjacent to lava flows on the western flank of the volcano, though the fault did not move the deposits, suggesting this lava was erupted 1.17 million years ago.[9]
Nearby features
Imagination Peak is a scoria cone with lava flows northwest of Pelican Butte. Imagination Peak and Brown Mountain are both part of the McLoughlin Reach with Pelican Butte. [24] Brown Mountain is also a shield volcano with a volume of 1 cubic mile (4.2 km3).[13] Dated to between 60,000 and 12,000 years old, it produced basaltic andesite lava flows that have not been heavily eroded, but during Pleistocene glacial advance, ice streams on the volcano ate away at the cinder cone that formed Brown Mountain's summit. This formed a glacial cirque with a bowl shape on the northeastern flank.[13]
The Global Volcanism Program of the Smithsonian Institution does not list any specific subfeatures for Pelican Butte.[2]
Eruptive history
Pelican Butte last erupted within the past 700,000 years.[10] Dating for its last eruptive activity is unclear; it has clearly not erupted since it was covered by glaciers about 12,000 years ago, though it probably has not erupted for 60,000 years. According to Wood and Kienle (1990), most eruptions took place less than 200,000 years ago.[9] However, Gorman (1994) reports that K–Ar dating of the summit places the volcano at 540,000 years old.[4] According to the Global Volcanism Program, Pelican Butte has not erupted since the Pleistocene.[2] In general, Pelican Butte and other andesitic volcanoes in the McLoughlin reach are not thought to be long-lived eruptive centers, though when combined their erupted material surpasses the eruptive volume of longer-lived mafic volcanoes like Mount McLoughlin.[25] It is unclear whether the volcano is extinct or dormant.[5][26]
Eruptions at Pelican Butte built a summit cone with tuff breccia and lapilli during pyroclastic eruptive activity,[27] which was mostly covered by lava flows before it was eroded over time[9] by glaciation, which lowered the cone's elevation significantly. Eruptive activity at Pelican Butte was mildly explosive, later switching to thinner flows with ʻaʻā and block lava.[28]
Human history
Pelican Butte is named after nearby Pelican Bay. It was also known by Native Americans as Mongina; the United States Coast and Geodetic Survey previously listed it under the name Lost Peak.[3][29]
Ancestral Native American groups related to the Klamath and Takelma people first hunted and gathered huckleberries in the area thousands of years ago. Mountains in the Cascades sometimes served as the setting for the rite of passage vision quests among young Klamath Native Americans. When white settlers reached the area, they began hunting, trapping beaver and marten, and grazing stock in the Sky Lakes wilderness area. The United States Forest Service began building trails and fire lookouts during the early 20th century.[8]
Pelican Butte has a fire lookout that first consisted of an L-4 lookout on a cable pole tower. It was replaced in 1954 by a timber tower, which was replaced again in 1966 with an R6 lookout on a timber tower. The current metal lookout tower was built in 1986 and is maintained by the United States Forest Service. Located at an elevation of 7,994 feet (2,437 m), it was voted the ugliest fire lookout in the state of Oregon by members of the Forest Fire Lookout Association.[30]
The United States Congress designated the Sky Lakes Wilderness area in 1984. The area includes the Waldo Tree,[6][7] which was inscribed by politician and Oregon Supreme Court Chief Justice John B. Waldo in 1888,[31] as well as Twin Ponds Trail, which follows the same route as a military wagon road from the 1860s.[6][7][8]
Recreation
A gravel road runs all the way to the summit of the mountain, branching north off Oregon Route 140. The road is only open during snow-free months during the summer. The last few miles of the road are steep and narrow, but they are accessible by vehicles with high ground clearance. The peak of Pelican Butte offers a 180 degree view of the Cascades stretching from south of Crater Lake to Mount McLoughlin.[9] A winter use trail for the volcano is operated by the Klamath Basin Snowdrifters Snowmobile Club.[32] The Pacific Crest Trail passes through the Sky Lakes wilderness area, running about 35 miles (56 km) in length.[6]
Pelican Butte has been the focus of perennial efforts to develop a
Notes
- [a] ^ The U.S. National Geodetic Survey lists the elevation of Pelican Butte as 8,037 feet (2,450 m). However, the Geographic Names Information System lists its elevation as 8,015 feet (2,443 m),[29] and the Global Volcanism Program of the Smithsonian Institution lists the Pelican Butte summit elevation as 8,035 feet (2,449 m).[2]
References
- ^ a b c "Pelican". NGS Data Sheet. National Geodetic Survey, National Oceanic and Atmospheric Administration, United States Department of Commerce. Retrieved 2008-04-01.
- ^ a b c d "Pelican Butte". Global Volcanism Program. Smithsonian Institution. 2013. Retrieved March 20, 2023.
- ^ a b McArthur & McArthur 1992, p. 658.
- ^ a b c d Gorman 1994, p. 1.
- ^ a b c d "Pelican Butte". Oregon Wild. 2019. Retrieved March 22, 2024.
- ^ a b c d e f g "Sky Lakes Wilderness: Fremont-Winema". United States Forest Service. 2024. Retrieved April 19, 2024.
- ^ a b c d e f "Sky Lakes Wilderness: Rogue River-Siskiyou NF". United States Forest Service. 2024. Retrieved April 19, 2024.
- ^ a b c "Sky Lakes Wilderness". United States Forest Service. Archived from the original on January 15, 2010. Retrieved April 19, 2024.
- ^ a b c d e Wood & Kienle 1990, p. 196.
- ^ a b c d e f g Wood & Kienle 1990, p. 195.
- ^ a b c d e f g h Smith 1988.
- ^ Hildreth 2007, p. 44.
- ^ a b c d Harris 2005, p. 131.
- ^ Cutler & Hays 1991, p. 66.
- ^ Cutler & Hays 1991, p. 67.
- ^ a b c Barnard, J. (July 5, 2002). "Snowcat skiing considered on Pelican Butte". Seattle Post-Intelligencer. Hearst Communications. Retrieved March 9, 2024.
- ^ "Wildlife: Klamath Sucker Fish". Oregon Wild. 2019. Retrieved March 9, 2024.
- ^ a b c Hildreth 2007, p. 33.
- ^ Hildreth 2007, p. 6.
- ^ Hildreth 2007, p. 34.
- ^ a b Hildreth 2007, p. 57.
- ^ a b Hildreth 2007, p. 59.
- ^ a b c d Gorman 1994, p. 2.
- ^ Hildreth 2007, p. 70.
- ^ Hildreth 2007, p. 64.
- ^ "Deschutes & Ochoco National Forests - Pelican Butte Volcano". US Forest Service. Archived from the original on May 12, 2011. Retrieved April 19, 2024.
- ^ Wood & Kienle 1990, p. 195–96.
- ^ Harris 2005, p. 132.
- ^ a b "Pelican Butte". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. November 28, 1980. Retrieved March 20, 2023.
- ^ "Pelican Butte Lookout". National Historic Lookout Register. 2024. Retrieved March 22, 2024.
- ^ "Judge Waldo Tree Loop Hike". OregonHikers.org. Trailkeepers of Oregon. July 1, 2023. Retrieved April 19, 2024.
- ^ "Pelican Butte Snow Trail". United States Forest Service. Retrieved March 16, 2023.
- ^ a b Liedtke, K. (February 28, 2017). "Rumor trail: No plans for Pelican Butte". Herald and News. Adams Publishing Group. Archived from the original on February 28, 2017. Retrieved March 9, 2024.
Sources
- Cutler, T.L.; Hays, D.W. (Autumn 1991). "Food Habits of Northern Spotted Owls in High Elevation Forests of Pelican Butte, Southwestern Oregon". Northwestern Naturalist. 72 (2): 66–69. JSTOR 3536802.
- Gorman, C. (April 1, 1994). Petrology and geochemistry of the Pelican Butte area, S. Oregon. North-Central Section of the Geological Society of America. OSTI 7141004.
- Harris, S. L. (2005). Fire Mountains of the West: The Cascade and Mono Lake Volcanoes (3rd ed.). ISBN 0-87842-511-X.
- Hildreth, W. (2007). Quaternary Magmatism in the Cascades, Geologic Perspectives. United States Geological Survey. Professional Paper 1744. Retrieved January 2, 2023.
- Wood, C. A.; Kienle, J., eds. (1990). Volcanoes of North America. ISBN 0-521-43811-X.
- ISBN 978-0-87595-237-6.
- Smith, J. G. (1988). Geologic map of the Pelican Butte quadrangle, Klamath County, Oregon (Map). 1:62,500. United States Geological Survey.
External links
- "Pelican Butte". SummitPost.org.