Menan Buttes
Encyclopedia
The North and South Menan Buttes in southeastern Idaho
are two of the world's largest volcanic tuff
cones. The two cones, with four smaller associated cones, align along a north-northwest line and comprise the Menan Complex. The buttes rise about 800 feet (250 m) above the surrounding Snake River
plain and are late Pleistocene
in age, dating to approximately 10,000 YBP. The buttes are the remains of the only volcanic eruptions that have occurred in freshwater within the boundaries of the modern United States. The South Menan Butte is currently in private hands, however North Menan Butte is publicly owned and has been designated as a National Natural Landmark
and a Research Natural Area by the United States Congress
. The US Bureau of Land Management
designated the North Butte as an Area of Critical Environmental Concern
(ACEC).
The volcanoes forming the two major Menan Buttes were created when basaltic magma came into contact with a shallow aquifer
or with the precursor of the modern Snake River. Particles of volcanic glass called tachylite were created as the water turned to steam and explosively fragmented the hot magma. The cone shaped deposits are fairly uniform and consist primarily of tuff in lapilli
-size particles. Some deposit layers preserve indentations, designated as “bomb sags”, made as larger pyroclastic particles landed on soft layers of tuff.
The Menan Buttes stand at an elevation of 5,619 feet (1,713 m.) and are very similar in size and shape. North Menan Butte is slightly larger and elliptical, with axes 3.5 and 2.5 km in length. South Menan Butte measures 3 km x 2 km. The crater of the North Menan Butte is about 3,000 feet (900 m) in diameter and the cone is about 6,000 feet (1,800 m) in diameter. The North Butte’s volume is 0.16 cubic miles (0.70 cubic km) and the South Butte measures at 0.07 cubic miles (0.30 cubic km). In comparison, the better known tuff cone Diamond Head
on Oahu
has a volume of 0.15 cubic miles (0.6 cubic km). The larger buttes in the Menan Complex are asymmetrical. Each has a greater accumulation of material on the northeast, presumably due to strong southwest winds during the initial eruption.
The Menan Buttes are located in Madison County
, with lower slopes extending westward into Jefferson County
. Nearby communities include Menan
, Rigby
, Rexburg
and Idaho Falls, Idaho
.
Idaho
Idaho is a state in the Rocky Mountain area of the United States. The state's largest city and capital is Boise. Residents are called "Idahoans". Idaho was admitted to the Union on July 3, 1890, as the 43rd state....
are two of the world's largest volcanic tuff
Tuff
Tuff is a type of rock consisting of consolidated volcanic ash ejected from vents during a volcanic eruption. Tuff is sometimes called tufa, particularly when used as construction material, although tufa also refers to a quite different rock. Rock that contains greater than 50% tuff is considered...
cones. The two cones, with four smaller associated cones, align along a north-northwest line and comprise the Menan Complex. The buttes rise about 800 feet (250 m) above the surrounding Snake River
Snake River
The Snake is a major river of the greater Pacific Northwest in the United States. At long, it is the largest tributary of the Columbia River, the largest North American river that empties into the Pacific Ocean...
plain and are late Pleistocene
Pleistocene
The Pleistocene is the epoch from 2,588,000 to 11,700 years BP that spans the world's recent period of repeated glaciations. The name pleistocene is derived from the Greek and ....
in age, dating to approximately 10,000 YBP. The buttes are the remains of the only volcanic eruptions that have occurred in freshwater within the boundaries of the modern United States. The South Menan Butte is currently in private hands, however North Menan Butte is publicly owned and has been designated as a National Natural Landmark
National Natural Landmark
The National Natural Landmark program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only natural areas program of national scope that identifies and recognizes the best examples of biological and geological features in...
and a Research Natural Area by the United States Congress
United States Congress
The United States Congress is the bicameral legislature of the federal government of the United States, consisting of the Senate and the House of Representatives. The Congress meets in the United States Capitol in Washington, D.C....
. The US Bureau of Land Management
Bureau of Land Management
The Bureau of Land Management is an agency within the United States Department of the Interior which administers America's public lands, totaling approximately , or one-eighth of the landmass of the country. The BLM also manages of subsurface mineral estate underlying federal, state and private...
designated the North Butte as an Area of Critical Environmental Concern
Area of Critical Environmental Concern
Areas of Critical Environmental Concern is a conservation ecology program in the western United States, managed by the Bureau of Land Management. The ACEC program was conceived in the 1976 Federal Lands Policy and Management Act , which established the first conservation ecology mandate for the BLM...
(ACEC).
The volcanoes forming the two major Menan Buttes were created when basaltic magma came into contact with a shallow aquifer
Aquifer
An aquifer is a wet underground layer of water-bearing permeable rock or unconsolidated materials from which groundwater can be usefully extracted using a water well. The study of water flow in aquifers and the characterization of aquifers is called hydrogeology...
or with the precursor of the modern Snake River. Particles of volcanic glass called tachylite were created as the water turned to steam and explosively fragmented the hot magma. The cone shaped deposits are fairly uniform and consist primarily of tuff in lapilli
Lapilli
Lapilli is a size classification term for tephra, which is material that falls out of the air during a volcanic eruption or during some meteorite impacts. Lapilli means "little stones" in Latin. They are in some senses similar to ooids or pisoids in calcareous sediments.By definition lapilli range...
-size particles. Some deposit layers preserve indentations, designated as “bomb sags”, made as larger pyroclastic particles landed on soft layers of tuff.
The Menan Buttes stand at an elevation of 5,619 feet (1,713 m.) and are very similar in size and shape. North Menan Butte is slightly larger and elliptical, with axes 3.5 and 2.5 km in length. South Menan Butte measures 3 km x 2 km. The crater of the North Menan Butte is about 3,000 feet (900 m) in diameter and the cone is about 6,000 feet (1,800 m) in diameter. The North Butte’s volume is 0.16 cubic miles (0.70 cubic km) and the South Butte measures at 0.07 cubic miles (0.30 cubic km). In comparison, the better known tuff cone Diamond Head
Diamond Head, Hawaii
Diamond Head is the name of a volcanic tuff cone on the Hawaiian island of Oahu and known to Hawaiians as Lēahi, most likely from lae 'browridge, promontory' plus ahi 'tuna' because the shape of the ridgeline resembles the shape of a tuna's dorsal fin...
on Oahu
Oahu
Oahu or Oahu , known as "The Gathering Place", is the third largest of the Hawaiian Islands and most populous of the islands in the U.S. state of Hawaii. The state capital Honolulu is located on the southeast coast...
has a volume of 0.15 cubic miles (0.6 cubic km). The larger buttes in the Menan Complex are asymmetrical. Each has a greater accumulation of material on the northeast, presumably due to strong southwest winds during the initial eruption.
The Menan Buttes are located in Madison County
Madison County, Idaho
Madison County is a county located in the U.S. state of Idaho. As of the 2000 Census the county had a population of 27,467 . The county seat and largest city is Rexburg. Madison County is part of the Rexburg, ID, Micropolitan Statistical Area.- History :The area was originally settled by members...
, with lower slopes extending westward into Jefferson County
Jefferson County, Idaho
Jefferson County is a county located in the U.S. state of Idaho. The county was established in 1913, and was named after Thomas Jefferson, the third U.S. President. As of the 2000 Census the county had a population of 19,155 . The county seat and largest city is Rigby...
. Nearby communities include Menan
Menan, Idaho
Menan is a city in Jefferson County, Idaho, United States. It is part of the Idaho Falls, Idaho Metropolitan Statistical Area. The population was 707 at the 2000 census.-History:Menan was the first settlement of Latter-day Saints in the Snake River Valley...
, Rigby
Rigby, Idaho
Rigby is a small city in and the county seat of Jefferson County, Idaho, United States. The population was 2,998 at the 2000 census.The larger "Rigby area" includes such outlying unincorporated communities as Annis, Garfield, Grant, Labelle, and Clark...
, Rexburg
Rexburg, Idaho
-Demographics:As of the census of 2000, there were 17,257 people, 4,274 households, and 2,393 families residing in the city. The population density was 3,534.4 people per square mile . There were 4,533 housing units at an average density of 928.4 per square mile...
and Idaho Falls, Idaho
Idaho Falls, Idaho
Idaho Falls is a city in and the county seat of Bonneville County, Idaho, United States, and the largest city in Eastern Idaho. As of the 2010 census, the population of Idaho Falls was 56,813, with a metro population of 130,374....
.
Additional sources
- Creighton, D.N., 1987, Menan Buttes, southeastern Idaho, in Beus, S.S., ed., Centennial Field Guide Volume 2 Rocky Mountain Section of the Geological Society of America, p. 109–111.
- Greeley, R., 1977, 5. Aerial guide to the geology of the central and eastern Snake River Plain, in Greeley, R., and King, J.S., eds., Volcanism of the eastern Snake River Plain, Idaho: A comparative planetary geology guidebook: NASA, Washington, D.C., p. 59–112.
- Hackett, W.R., and Morgan, L.A., 1988, Explosive basaltic and rhyolitic volcanism of the eastern Snake River Plain, in Link, P.K., and Hackett, W.R., eds., Guidebook to the Geology of Central and Southern Idaho: Idaho Geological Survey Bulletin 27, p. 283–301.
- Hamilton, W., and Myers, W.B., 1963, Menan Buttes, cones of glassy basalt tuff in the Snake River Plain, Idaho: U.S. Geological Survey Professional paper 450E, p. E114-E118.
- Stearns, H.T., Crandall, L., and Steward, W.G., 1938, Geology and ground-water resources of the Snake River Plain in Southeastern Idaho: U.S. Geological Survey Water-Supply Paper 774, 268 p.
External links
- North Menan Butte, A National Natural Landmark - Bureau of Land Management
- Satellite Image