What is the Basin and Range orogeny?
Basin and range topography is characterized by alternating parallel mountain ranges and valleys. It is a result of crustal extension due to mantle upwelling, gravitational collapse, crustal thickening, or relaxation of confining stresses.
What is Basin and Range System?
Basin and Range Province, arid physiographic province occupying much of the western and southwestern part of the United States. The region comprises almost all of Nevada, the western half of Utah, southeastern California, and the southern part of Arizona and extends into northwestern Mexico.
Why is it called Basin and Range?
The Basin and Range derives its name from the alternating north-south trending mountains and flat valley floors comprising the province. The valley floors of the Southern Basin and Range are low desert basins, which are continuously filling with sediments resulting from the erosion of the surrounding mountains.
What is Basin and Range faulting?
Geology. It is generally accepted that basin and range topography is the result of extension and thinning of the lithosphere, which is composed of crust and upper mantle. Extensional environments like the Basin and Range are characterized by listric normal faulting, or faults that level out with depth.
Where is the Basin and Range?
The Basin and Range province is familiar to anyone lucky enough to venture across it. Steep climbs up mountain ranges alternated with long treks across flat basins. This pattern extends from eastern California to central Utah and from southern Idaho to the state of Sonora in Mexico.
How was Basin and Range formed?
The basins (valleys) and ranges (mountains) are being created by ongoing tension in the region, pulling in an east-west direction. Over most of the last 30 million years, movement of hot mantle beneath the region caused the surface to dome up and then partially collapse under its own weight, as it pulled apart.
When was the Basin and Range formed?
However, the majority of the extension occurred around 20 ±10 million years ago. The extensional provinces in the northern part of the Basin and Range started generally earlier, while the southern portion (especially south of 40° north latitude) mostly started later, around 30 million years ago.
What is the basin and Range Province?
The Basin and Range Province is a vast physiographic region covering much of the inland Western United States and northwestern Mexico or from Mexico to Canada. It is defined by unique basin and range topography, characterized by abrupt changes in elevation, alternating between narrow faulted mountain chains and flat arid valleys or basins.
What is the difference between range and basin?
by Amanda Briney, Contributing Writer. Updated April 10, 2019. In geology, a basin is defined as a bounded area where the rock within the boundaries dips inward toward the center. By contrast, a range is a single line of mountains or hills forming a connected chain of land higher than the surrounding area.
What is an ancient orogeny?
It may also refer to a specific episode of orogeny during the geologic past. Even though tall mountain peaks from ancient orogenies may erode away, the exposed roots of those ancient mountains show the same orogenic structures that are detected beneath modern mountain ranges.
What causes Basin and range topography?
Causes of Basin and Range Topography. As they rise, they are immediately subject to weathering and erosion. The rocks are eroded by water, ice, and wind and particles are quickly stripped and washed down the mountain sides. This eroded material then fills the faults and collects as sediment in the valleys.