The Carrizozo volcanic field is a monogenetic

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

located in

New Mexico New Mexico is a state in the Southwestern United States, Southwestern region of the United States. It is one of the Mountain States of the southern Rocky Mountains, sharing the Four Corners region with Utah, Colorado, and Arizona. It also ...

, 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 cone A cinder cone or scoria cone is a steep, volcanic cone, conical landform of loose pyroclastic rock, pyroclastic fragments, such as volcanic ash, clinkers, or scoria that has been built around a volcanic vent. The pyroclastic fragments are forme ...

s. 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 Carrizozo is a town in Lincoln County, New Mexico, United States. It is the county seat, with a population of 996 at the 2010 census. Founded in 1899, the town provided the main railroad access for Lincoln County, and the town experienced signi ...

, 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 pr ...

between Sierra Blanca to the southeast and the Oscura Mountains 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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

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 White Sands National Park is a national park of the United States located in New Mexico and completely surrounded by the White Sands Missile Range. The park covers in the Tularosa Basin, including the southern 41% of a field of white sand ...

. The Carrizozo Woman's Club helped protect this state area. The lava flow is composed of

pāhoehoe 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 unde ...

lava that spread through

lava tube A lava tube, more rarely called a pyroduct, is a 'roofed conduit through which molten lava travels away from its vent'. If lava in the tube drains out, it will leave an empty cave. Lava tubes are common in low-viscosity volcanic systems. La ...

s. 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 ...

. 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 site Trinity was the first detonation of a nuclear weapon, conducted by the United States Army at 5:29 a.m. MWT (11:29:21 Greenwich Mean Time, GMT) on July 16, 1945, as part of the Manhattan Project. The test was of an implosion-type nuclear ...

, the first atomic bomb's 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 widesp ...

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 Chihuah ...

, a region of the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

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 (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

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 (geology), crust (at about under the oceans and about under the continents) and ends at the top of the lower mantle (Earth), lower man ...

. The lavas erupted were mildly

alkaline In chemistry, an alkali (; from the Arabic word , ) is a basic salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as a base that dissolves in water. A solution of a soluble base has a pH greater than 7.0. The ...

in composition, similar to the nearby

Jornada del Muerto Jornada del Muerto was the name given by the Spanish conquistadors to the Jornada del Muerto desert Endorheic basin, basin, and the almost waterless trail across the Jornada beginning north of Las Cruces, New Mexico, Las Cruces and ending sout ...

, 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