Arizona transition zone

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Simplified Arizona geographic regions. Physiographic regions of Arizona.svg
Simplified Arizona geographic regions.

The Arizona transition zone is a diagonal northwest-by-southeast region across central Arizona. The region is a transition from the higher elevation Colorado Plateau to the northeast in Northeast Arizona and the Basin and Range region of southwest and south regions of lower elevation deserts.

Arizona state of the United States of America

Arizona is a state in the southwestern region of the United States. It is also part of the Western and the Mountain states. It is the sixth largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona shares the Four Corners region with Utah, Colorado, and New Mexico; its other neighboring states are Nevada and California to the west and the Mexican states of Sonora and Baja California to the south and southwest.

Colorado Plateau plateau in the southwestern United States

The Colorado Plateau, also known as the Colorado Plateau Province, is a physiographic and desert region of the Intermontane Plateaus, roughly centered on the Four Corners region of the southwestern United States. This province covers an area of 336, 700 km2 (130,000 mi2) within western Colorado, northwestern New Mexico, southern and eastern Utah, and northern Arizona. About 90% of the area is drained by the Colorado River and its main tributaries: the Green, San Juan, and Little Colorado. Most of the remainder of the plateau is drained by the Rio Grande and its tributaries.

Northeast Arizona

Northeast Arizona is a region of the U.S. state of Arizona commonly including Apache County and Navajo County. Some notable towns there are St. Johns, Eagar, Holbrook, Show Low, Winslow, Window Rock, Fort Defiance, Ganado, Chinle, and Kayenta.

Contents

Northwest Arizona transitions to the higher elevation Mojave Desert of southern California, Nevada and Utah, with an indicator species of Joshua trees and other species, and southwestwards regions of the Sonoran Desert, along the Lower Colorado River Valley; in Arizona's south, all of central and eastern desert Sonoran Desert regions merge southwards into Sonora Mexico. The transition zone includes the Mogollon Rim and the White Mountains and extends into western New Mexico.

Mojave Desert desert in southwestern United States

The Mojave Desert is an arid rain-shadow desert and the driest desert in North America. It is in the southwestern United States, primarily within southeastern California and southern Nevada, and it occupies 47,877 sq mi (124,000 km2). Very small areas also extend into Utah and Arizona. Its boundaries are generally noted by the presence of Joshua trees, which are native only to the Mojave Desert and are considered an indicator species, and it is believed to support an additional 1,750 to 2,000 species of plants. The central part of the desert is sparsely populated, while its peripheries support large communities such as Las Vegas, Barstow, Lancaster, Palmdale, Victorville, and St. George.

California State of the United States of America

California is a state in the Pacific Region of the United States. With 39.6 million residents, California is the most populous U.S. state and the third-largest by area. The state capital is Sacramento. The Greater Los Angeles Area and the San Francisco Bay Area are the nation's second and fifth most populous urban regions, with 18.7 million and 8.8 million residents respectively. Los Angeles is California's most populous city, and the country's second most populous, after New York City. California also has the nation's most populous county, Los Angeles County, and its largest county by area, San Bernardino County. The City and County of San Francisco is both the country's second-most densely populated major city after New York City and the fifth-most densely populated county, behind only four of the five New York City boroughs.

Nevada State of the United States of America

Nevada is a state in the Western United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast and Utah to the east. Nevada is the 7th most extensive, the 32nd most populous, but the 9th least densely populated of the U.S. states. Nearly three-quarters of Nevada's people live in Clark County, which contains the Las Vegas–Paradise metropolitan area where three of the state's four largest incorporated cities are located. Nevada's capital, however, is Carson City.

In the Arizona ecoregion section, the Arizona transition zone is the major section of the EPA designated, Level III ecoregion, Arizona/New Mexico Mountains ecoregion . The other two outlier subregions to the transition zone in Arizona, are the Kaibab Plateau of the North Rim of the Grand Canyon, and associated ranges of the Chuska Mountains region of the northeast Arizona and northwest New Mexico.

Arizona/New Mexico Mountains ecoregion ecoregion

The Arizona/New Mexico Mountains ecoregion is a Level III ecoregion designated by the United States Environmental Protection Agency (EPA) in the U.S. states of Arizona and New Mexico.

Kaibab Plateau

The Kaibab Plateau is located in northern Arizona in the United States. The plateau, part of the larger Colorado Plateau, is bordered on the south by the Grand Canyon and reaches an elevation of 9200 feet above sea level. The plateau is divided between Kaibab National Forest and the "North Rim" portion of Grand Canyon National Park. Tributary canyons of the Colorado River form the plateau's eastern and western boundaries, and tiers of uplifted cliffs define the northern edges of the land form. Winter snowfall is often heavy, and this creates opportunities for backcountry Nordic skiing and snow camping.

Grand Canyon A steep-sided canyon carved by the Colorado River in Arizona, United States

The Grand Canyon is a steep-sided canyon carved by the Colorado River in Arizona, United States. The Grand Canyon is 277 miles (446 km) long, up to 18 miles (29 km) wide and attains a depth of over a mile.

The edge of the Mogollon Rim east of Pine, Arizona Mogollon Rim east of Pine.jpg
The edge of the Mogollon Rim east of Pine, Arizona

Geography

The transition zone is dominated by the Mogollon Plateau at the southern edge of the Coconino Plateau of the Flagstaff region and the San Francisco volcanic field; the Mogollon Rim borders the plateau which extends from Oak Creek Canyon on the west, to the east at the highest elevations of Arizona in the central and western White Mountains. [1]

The Mogollon Plateau or Mogollon Mesa is a pine-covered southern plateau section of the larger Colorado Plateau in east-central Arizona and west-central New Mexico, United States. The southern boundary of the plateau is the Mogollon Rim. The Mogollon Plateau is 7,000–8,000 feet (2,100–2,400 m) high. The plateau lends its name to the Mogollon tribe, part of the Cochise-Mogollan peoples who inhabited this and nearby areas from 5,000 to 2,500 years ago. Their descendants are believed to include the Anasazi.

The Coconino Plateau is found south of the Grand Canyon and north-northwest of Flagstaff, in northern Arizona of the Southwestern United States.

Flagstaff, Arizona City in Arizona

Flagstaff is a city in and the county seat of Coconino County in northern Arizona, in the southwestern United States. In 2015, the city's estimated population was 70,320. Flagstaff's combined metropolitan area has an estimated population of 139,097. The city is named after a ponderosa pine flagpole made by a scouting party from Boston to celebrate the United States Centennial on July 4, 1876.

List of mountain ranges of the Arizona transition zone

The Arizona transition zone map is similar to the yellow transition region shown above. [2]

Central mountain ranges

Western region ranges

Eastern region ranges

See also

Related Research Articles

Painted Desert (Arizona) desert in Arizona

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Intermontane Plateaus physiographic division of the United States

The Intermontane Plateaus of the Western United States is one of eight U.S. Physiographic regions (divisions) of the physical geography of the contiguous United States. The region is composed of intermontane plateaus and mountain ranges. It is subdivided into physiographic provinces, which are each subdivided into physiographic sections.

Sonoran Desert North American desert

The Sonoran Desert is a North American desert which covers large parts of the Southwestern United States in Arizona and California and of Northwestern Mexico in Sonora, Baja California, and Baja California Sur. It is the hottest desert in Mexico. It has an area of 260,000 square kilometers (100,000 sq mi). The western portion of the United States–Mexico border passes through the Sonoran Desert.

White Mountains (Arizona)

The White Mountains of Arizona are a mountain range and mountainous region in the eastern part of the state, near the border with New Mexico; it is a continuation from the west of the Arizona transition zone–Mogollon Rim, with the Rim ending in western New Mexico. The White Mountains are a part of the Colorado Plateau high country of Northeast Arizona, the Navajo Nation, with the rest of the Plateau in eastern Utah, northwest New Mexico, and southwestern Colorado. Nearby communities include Show Low, Pinetop-Lakeside, Greer, Springerville, Eagar, and McNary. Much of the range is within the Fort Apache Indian Reservation.

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Intermountain West geographic and geological region of the western United States

The Intermountain West, or Intermountain Region, is a geographic and geological region of the Western United States. It is located between the front ranges of the Rocky Mountains on the east and the Cascade Range and Sierra Nevada on the west.

<i>Fraxinus velutina</i> species of plant

Fraxinus velutina, the velvet ash, Arizona ash or Modesto ash, is a species of Fraxinus native to southwestern North America, in the United States from southern California east to Texas, and in Mexico from northern Baja California east to Coahuila and Nuevo León.

Lower Colorado River Valley

The Lower Colorado River Valley ("LCRV") is the river region of the lower Colorado River of the southwestern United States in North America that rises in the Rocky Mountains and has its outlet at the Colorado River Delta in the northern Gulf of California in northwestern Mexico, between the states of Baja California and Sonora. This north–south stretch of the Colorado River forms the border between the U.S. states of California/Arizona and Nevada/Arizona, and between the Mexican states of Baja California/Sonora.

Geography of Arizona

Arizona is a landlocked state situated in the southwestern region of the United States of America. It has a vast and diverse geography famous for its deep canyons, high- and low-elevation deserts, numerous natural rock formations, and volcanic mountain ranges. Arizona shares land borders with Utah to the north, the Mexican state of Sonora to the south, New Mexico to the east, and Nevada to the northwest, as well as water borders with California and the Mexican state of Baja California to the southwest along the Colorado River. Arizona is also one of the Four Corners states and is diagonally adjacent to Colorado.

<i>Platanus wrightii</i> species of plant

Platanus wrightii, the Arizona sycamore, also in Spanish Álamo, is a sycamore tree native to Arizona and New Mexico with its range extending south into the Mexican states of Sonora, Chihuahua, and Sinaloa.

Black Hills (Greenlee County) mountain range in Greenlee County, Arizona

The Black Hills of Greenlee County are a 20 mi (32 km) long mountain range of the extreme northeast Sonoran Desert bordering the south of the White Mountains of eastern Arizona's transition zone.

Big Burro Mountains

The Big Burro Mountains are a moderate length 35-mile (56 km) long, mountain range located in central Grant County, New Mexico. The range's northwest-southeast 'ridgeline' is located 15 mi southwest of Silver City.

Chino Valley (Arizona)

The Chino Valley of Arizona is a large, 70-mi (113 km) long valley, centered on Seligman, Arizona in northwest Yavapai County and southwest Coconino County. The valley is located at the southwest of the Coconino Plateau and lies in the extreme northwest of Arizona's transition zone.

Aquarius Mountains

The Aquarius Mountains are a 45-mi (72 km) long mountain range in southeast Mohave County, Arizona. The range lies in the northwest of the Arizona transition zone, and at the southwest of the Coconino Plateau, a subsection of the Colorado Plateau.

Toroweap Fault

The Toroweap Fault of northwest Arizona and southwest Utah is part of a fault system of the west Grand Canyon region, Arizona, USA; also the west perimeter regions of the Coconino and Colorado Plateaus. The Hurricane Fault originates at the Toroweap Fault, in the region of the Colorado River, and strikes as the westerly expression of the Toroweap Fault. The Toroweap strikes northerly from the Colorado at the east of Toroweap Valley, and enters south Utah; from the Colorado River, the Hurricane Fault strikes north-northwest along the west flank of the small, regional Uinkaret Mountains, the west border of Toroweap Valley. The Hurricane Fault, and the Hurricane Cliffs strike into southwest Utah as part of the west, and southwest perimeter of the Colorado Plateau. The Hurricane Cliffs are made of Kaibab Limestone, an erosion resistant, cliff-forming rock unit.

The Pliocene to Late Neogene Bidahochi Formation, lies at an elevation of about 6,300 feet (1,920 m) to 6,600 feet (2,012 m) at the southeast of the Colorado Plateau; the deposits are from Bidahochi Lake,, and the deposits extend southwards to the region at the north perimeter of the White Mountains of central-east Arizona. Bidahochi Lake is thought to have been a single "large lake, or several shallow, and ephemeral ones." Various fossil types are found; also bird trackways.

Peacock Mountains

The Peacock Mountains are a small, 26-mi (42 km) long mountain range in northwest Arizona, USA. The range is a narrow sub-range, and an extension north, at the northeast of the Hualapai Mountains massif, which lies to the southwest. The range is defined by the Hualapai Valley to the northwest, and north and south-flowing washes on its east border, associated with faults and cliffs; the Cottonwood Cliffs are due east, and are connected to the Aquarius Cliffs southward at the west perimeter of the Aquarius Mountains; the cliffs are a result of the Aquarius Fault, which is an extension southward from the Grand Wash Cliffs and Grand Wash Fault which crosses the Colorado River at Lake Mead, and the west perimeter of the Grand Canyon/Colorado Plateau.

Shinarump Conglomerate

The early Late Triassic conglomerate called the Shinarump Conglomerate, formally the Shinarump Member of the Chinle Formation, is a highly resistant coarse-grained sandstone and pebble conglomerate, sometimes forming a caprock because of its hardness, cementation, and erosion resistance. The Shinarump is found throughout the Colorado Plateau with significant exposures as the canyon rimrock in the vicinity of Canyon De Chelly National Monument, at the north-northeast of the Defiance Plateau/Defiance Uplift. At Canyon De Chelly the Shinarump Conglomerate was laid down upon De Chelly Sandstone-(280 Ma, an erosion unconformity of 50 my), in a region at the west foothill region of the mostly north-south trending Chuska Mountains of northeast Arizona – northwest New Mexico.

References

  1. Hendricks, J. D.; Plescia, J. B. (1991). "A Review of the Regional Geophysics of the Arizona Transition Zone". Journal of Geophysical Research. American Geophysical Union. 96 (B7): 12,351–12,373. doi:10.1029/90jb01781.
  2. Luchhitta, 2001. Hiking Arizona's Geology, Part 2, "Map Graphic": Arizona Transition Zone, p. 143-145. (and Hikes: 18-26, p. 145-182) ISBN   0-89886-730-4