The Carrizozo volcanic field is a monogenetic

volcanic field A volcanic field is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes ...

located in

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

, US. The volcanic field consists of two lava flows, the Broken Back flow and the Carrizozo lava flow (Carrizozo Malpais), the second youngest in New Mexico. Both lava flows originated from groups of cinder cones. The Broken Back flow is approximately long and the Carrizozo, one of the largest in the world, is long, covering with a volume of .

Carrizozo Malpais

The Carrizozo Malpais is a large lava flow on the west side of Carrizozo, New Mexico, on the northern part of the

Tularosa Basin The Tularosa Basin is a graben basin in the Basin and Range Province and within the Chihuahuan Desert, east of the Rio Grande in southern New Mexico and West Texas, in the Southwestern United States. Geography The Tularosa Basin is located prim ...

between Sierra Blanca to the southeast and the

Oscura Mountains Oscura Mountains, originally known to the Spanish as the ''Sierra Oscura'', are a ridge of mountains, trending north and south, east of the Jornada del Muerto and west of the Tularosa Valley. It is located in Socorro County and Lincoln County, N ...

to the west. The

lava Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

making up the flow came from Little Black Peak, about north-northwest of Carrizozo. It reached about south-southwest along the bottom of

in two active flows. Initial age estimates ranged from 1,000 to 1,500 years ago, but recent cosmogenic dating techniques revealed the eruption date is 5200 ± 700 years ago. At their southern end, the lava flows are about north of the dune fields of White Sands National Park. The Carrizozo Woman's Club helped protect this state area. The lava flow is composed of pahoēhoē lava that spread through lava tubes. The eruptions are estimated to have lasted about three decades, and the extent of the flow reflects this long eruptive duration rather than a high eruption rate. The Valley of Fires Recreation Area provides access to the Malpaís on its east edge, about west of Carrizozo on

U.S. Route 380 U.S. Route 380 (US 380) is an east–west United States highway. The highway's eastern terminus is in Greenville, Texas at an intersection with Interstate 30, of which the easternmost 3–4 miles are concurrent with US 69 in a loop around t ...

. The highway has several scenic overlooks where it crosses the Malpaís. The entire extent of the flow can be seen from higher elevations to the east on

. The Trinity (nuclear test), first atomic bomb detonation site, is northwest.

Broken Back flow

The Broken Back flow erupted from vents (a north-trending fissure, Broken Back Crater, and an unnamed cinder cone) located about northwest of Little Black Peak. The flow covered an area of about and is partially overlapped by the younger Carrizozo Malpais. This flow is significantly older than the Carrizozo Malpais, with an age estimated as 100,000 years, based on the degree of weathering and erosion. File:Carrizozo.jpg, The location of Carrizozo. File:Carrizozo Lava Flow.jpg, Satellite image of Carrizozo. File:Carrizozo Malpais Overview.jpg, An overview of the lava flows (Little Black Peak in distance). File:Carrizozo Malpais Closeup.jpg, A close-up view of the lava flows, showing pahoēhoē (Hawaiian for "ropey") lava flow structure. File:Carrizozo Malpais Juniper.jpeg, A

western juniper ''Juniperus occidentalis'', known as the western juniper, is a shrub or tree native to the Western United States, growing in mountains at altitudes of and rarely down to . It is listed as Least Concern on the IUCN Red List because it is a wides ...

tree grows out of the Carrizozo Malpaís.

Geology

The volcanic field is associated with the

Rio Grande Rift The Rio Grande rift is a north-trending continental rift zone. It separates the Colorado Plateau in the west from the interior of the North American craton on the east. The rift extends from central Colorado in the north to the state of Chihuahu ...

, a region of the Earth's crust that is being slowly pulled apart. This produces

faulting In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectonic ...

that provides paths for

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

to reach the Earth's surface from its

upper mantle The upper mantle of Earth is a very thick layer of rock inside the planet, which begins just beneath the crust (at about under the oceans and about under the continents) and ends at the top of the lower mantle at . Temperatures range from appr ...

. The lavas erupted were mildly alkaline in composition, similar to the nearby Jornada del Muerto, Hillsboro, and Black Mesa () flows. Seismic measurements in the region have detected a possible thermal anomaly associated with the volcanic field.

Notable vents

References

External links