The Basin and Range Province is a particular type of topography that covers much of the southwestern United States and northwestern Mexico that is typified by elongate north-south trending arid valleys bounded by mountain ranges which also bound adjacent valleys. Death Valley is a good example of a modified basin and range valley. Image File history File links NPS image from http://www. ... For discussion of land surfaces themselves, see Terrain. ... Fljótsdalur in East Iceland, a rather flat valley In geology, a valley (also called a vale or dale) is a depression with predominant extent in one direction. ... For exotic financial options, see Mountain range (options). ... For other uses, see Death Valley (disambiguation). ...

The basins are down-fallen blocks of crust and the ranges are relatively uplifted blocks, many of which tilt slightly eastward at their tops. The normal arrangement in the basin and range system is that each valley (i.e., basin) is bounded on each side by one or more normal faults that are oriented along or sub-parallel to the range front. Old fault exposed by roadcut near Harrisburg, Pennsylvania. ...

This arrangement is very similar to the horsts and grabens seen in divergent plate boundaries such as the Mid-Atlantic Ridge or in failed rifting areas such as the Western Rift of the Great Rift Valley in East Africa. However the extent of the rifting in the Basin and Range is not concentrated into a single valley but is spread out over a very large area creating much smaller grabens laying roughly parallel to each other in a north-south direction (which leads to a rain shadow effect resulting in exceedingly dry conditions in this province). USGS image In physical geography and geology, a horst is the raised fault block bounded by normal faults. ... USGS image A graben is a depressed block of land bordered by parallel faults. ... In plate tectonics, a divergent boundary (divergent fault boundary or divergent plate boundary) is a linear feature that exists between two tectonic plates where the plates are moving away from each other. ... Courtesy USGS The ridge was central in the breakup of Pangaea that began some 180 million years ago. ... Northern section of the Great Rift Valley. ...  Eastern Africa (UN subregion)  East African Community  Central African Federation (defunct)  geographic, including above East Africa or Eastern Africa is the easternmost region of the African continent, variably defined by geography or geopolitics. ... For the television series see Rain Shadow. ...

Geography

The province extends east from the Sierra Nevada all the way to the Colorado Plateau and extends south over northern parts of the Baja California Peninsula. This covers parts of the U.S. states of Arizona, California, Idaho, New Mexico, Texas, Oregon, and Utah and almost all of Nevada. Basin and Range topography also dominates large parts of the Mexican states of Sonora, Chihuahua, and Baja California. The arid Great Basin is part of this province as well as most of the Sonoran Desert and the Chihuahuan Deserts. This article is about the mountain range in the Western United States. ... The Colorado Plateau, also called the Colorado Plateaus Province, is a physiographic region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. ... Baja California Peninsula (highlighted) The Baja California Peninsula or Lower California is a peninsula in the west of Mexico. ... A U.S. state is any one of the 50 states which have membership of the federation known as the United States of America (USA or U.S.). The separate state governments and the U.S. federal government share sovereignty. ... Official language(s) English Spoken language(s) English 74. ... This article is about the U.S. state. ... For other uses, see Idaho (disambiguation). ... Capital Santa Fe Largest city Albuquerque Largest metro area Albuquerque metropolitan area Area  Ranked 5th  - Total 121,665 sq mi (315,194 km²)  - Width 342 miles (550 km)  - Length 370 miles (595 km)  - % water 0. ... For other uses, see Texas (disambiguation). ... This article is about the U.S. state. ... This article is about the U.S. state. ... This article is about the U.S. State of Nevada. ... Sonora is a state in northwestern Mexico, bordering the states of Chihuahua to the east, Sinaloa to the south, and Baja California to the northwest. ... This article is about the state in Mexico. ... Location within Mexico Municipalities of Baja California Country Capital Municipalities 5 Largest City Tijuana Government  - Governor José Guadalupe Osuna Millán (PAN)  - Federal Deputies PAN: 8  - Federal Senators Alejandro González (PAN) Rafael Díaz (PAN) Fernando Castro (PRI) Area Ranked 12th  - Total 69,921 km² (26,996. ... Drainage map showing the Great Basin in orange Various Definitions of the Great Basin (NPS) Wheeler Peak in Great Basin National Park, Nevada. ... Map of the Mojave and Sonoran deserts. ... Map of the Chihuahuan Desert. ...

Geology

This unique topography has formed as the result of extension (literally the Earth's crust is being pulled apart) that is thought to be caused by the effect of the Pacific Plate moving north relative to the North American Plate (this is the same force behind the creation of the San Andreas Fault) and by other forces (see below). The crust here has been stretched up to 100% of its original width. In fact, the crust underneath the Basin and Range, especially under the Great Basin, is some of the thinnest in the world. Along the roughly north-south-trending faults mountains were uplifted and valleys down-dropped, producing the distinctive alternating pattern of linear mountain ranges and valleys of the Basin and Range province. A map showing these stretch marks, and noting their association with earth movements, is at the USGS report on the Pleasant Valley (Nevada) Earthquake. Chasm redirects here. ...  The Pacific plate, shown in pale yellow The Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean. ...  The North American plate, shown in brown The North American Plate is a tectonic plate covering most of North America, extending eastward to the Mid-Atlantic Ridge and westward to the Cherskiy Range in East Siberia. ... View of the San Andreas Fault on the Carrizo Plain in central California, 35°07N, 119°39W The San Andreas Fault is a geological fault that runs a length of roughly 800 miles (1300 kilometres) through western and southern California in the United States. ... Drainage map showing the Great Basin in orange Various Definitions of the Great Basin (NPS) Wheeler Peak in Great Basin National Park, Nevada. ...

Although there are other types of faults in the Basin and Range province, the extension and crustal stretching that have shaped the present landscape produce mostly normal faults. The upthrown side of these faults form mountains that rise abruptly and steeply, and the down-dropped side creates low valleys. The fault plane, along which the two sides of the fault move, extends deep in the crust, usually at an angle of 60 degrees. In places, the relief or vertical difference between the two sides is as much as 10,000 feet (just over 3000 m). Old fault exposed by roadcut near Harrisburg, Pennsylvania. ...

Kingston Range

Subsequent to the mountain building episode a large part of the mountain belt created in the Laramide orogeny and previous orogenies (the Sevier, and part of the Nevadan) went through a long period of extension that persists today. Image File history File links Download high resolution version (1800x1200, 236 KB) Looking southeast from Emigrant Pass in the Nopah Range towards Kingston Range, Mojave Desert, California, taken March 2005 by User:Stan Shebs File links The following pages link to this file: Mojave Desert Basin and Range ... Image File history File links Download high resolution version (1800x1200, 236 KB) Looking southeast from Emigrant Pass in the Nopah Range towards Kingston Range, Mojave Desert, California, taken March 2005 by User:Stan Shebs File links The following pages link to this file: Mojave Desert Basin and Range ... The Laramide orogeny was a period of mountain building in western North America, which started in the Late Cretaceous, 70 to 80 million years ago, and ended 35 to 55 million years ago. ... The Sevier orogeny was a mountain-building event that affected western North America between aproximately 140 million years ago (Ma), and 50 Ma. ... The Nevadan Orogeny was a major mountain building event that took place along the western edge of ancient North America between the Mid to Late Jurassic(between about 180 and 146 million years ago). ...

As the rocky ranges rise, they are immediately subject to weathering and erosion. The exposed bedrock is attacked by water, ice, wind and other erosional agents. Rock particles are stripped away and wash down the mountain sides, often covering young faults until they rupture again. Sediment collects in the adjacent valleys, in some places burying the bedrock under thousands of feet of rock debris. Rock redirects here. ... Weathering is the decomposition of rocks, soils and their minerals through direct contact with the Earths atmosphere. ... For morphological image processing operations, see Erosion (morphology). ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... This article is about water ice. ... For other uses, see Wind (disambiguation). ...

There are several hypotheses trying to explain how the continental crust of North America responded to the great deal of compaction it went through with the Laramide orogeny. There is at least some evidence to support all of these ideas but it is very possible that more than one is correct: The thickness of the Earths crust (km). ...

1. Movement of the Pacific Plate is stretching the North American Plate toward the West.
2. As the spreading center (divergent plate boundary) of the subducting Farallon Plate moved beneath the North American plate, it formed a "slab gap", which caused heat from the mantle plume feeding the spreading zone to thin out the continental crust above it and cause the spreading (see slab gap hypothesis).
3. After the Laramide orogeny, the crust under the Rockies got overthickened and the Great Basin spread out in response.
4. The continental root of the proto-Rockies was so deep that the bottom part broke off and was incorporated into the asthenosphere.

 The Pacific plate, shown in pale yellow The Pacific Plate is an oceanic tectonic plate beneath the Pacific Ocean. ...  The North American plate, shown in brown The North American Plate is a tectonic plate covering most of North America, extending eastward to the Mid-Atlantic Ridge and westward to the Cherskiy Range in East Siberia. ... In plate tectonics, a divergent boundary (divergent fault boundary or divergent plate boundary) is a linear feature that exists between two tectonic plates where the plates are moving away from each other. ... The Farallon Plate is an ancient tectonic plate which began subducting as Pangaea broke apart during the Jurassic period. ... A lava lamp illustrates the basic concept of a mantle plume. ... In geology, the slab gap hypothesis is one of the explanations put forward to explain several instances of crustal extension that occur inland near former subduction zones. ... Drainage map showing the Great Basin in orange Various Definitions of the Great Basin (NPS) Wheeler Peak in Great Basin National Park, Nevada. ... This article does not cite any references or sources. ...

Mineral resources

The Basin and Range province supplies nearly all the copper and most of the gold, silver, and barite mined in the United States. A small amount of petroleum is produced within the province, in Nevada. For other uses, see Copper (disambiguation). ... GOLD refers to one of the following: GOLD (IEEE) is an IEEE program designed to garner more student members at the university level (Graduates of the Last Decade). ... This article is about the chemical element. ... Baryte with Cerussite from Morocco Baryte with Galena and Hematite from Poland Barite (BaSO4) is a mineral consisting of barium sulfate. ... Petro redirects here. ... This article is about the U.S. State of Nevada. ...

See also

• Geologic timeline of Western North America
• Copper mining in Arizona
• Silver mining in Arizona
• Silver mining in Nevada

A timeline of significant geological events in the evolution of western North America. ... Copper mining in Arizona, a state of the United States, has been a major industry since the 1800s. ... Silver mining in Arizona was a powerful stimulus for exploration and prospecting in early Arizona. ... Silver mining in Nevada, a state of the United States, began in 1858 with the discovery of the Comstock Lode, the first major silver-mining district in the United States. ...

References

• Steven M. Stanley, Earth System History (W.H. Freeman and Company; 1999) pages 537, 540-543, 545 ISBN 0-7167-2882-6
• Plummer, McGeary, Carlson, Physical Geology, Eight Edition (McGraw-Hill: Boston, 1999) pages 321, 513, 514 ISBN 0-697-37404-1
• USGS - Geologic Provinces of the United States: Basin and Range Province (adapted public domain text)

Further reading

• Basin and Range by John McPhee, Noonday Press, 1990. ISBN 0-374-51690-1
• Geology of the American Southwest : A Journey Through Two Billion Years of Plate Tectonic History by W. Scott Baldridge, Cambridge University Press, 2004. ISBN 0-521-01666-5