The Boot Heel volcanic field is located in the Bootheel region of southwest

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 ...

, adjacent areas of southeastern

Arizona Arizona is a U.S. state, state in the Southwestern United States, Southwestern region of the United States, sharing the Four Corners region of the western United States with Colorado, New Mexico, and Utah. It also borders Nevada to the nort ...

, and northwest

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. The field covers an area of more than 24,000 km².Baldridge, W. Scott, ''Geology of the American Southwest,'' Cambridge, 2004, pp. 219-223 The field includes nine

volcanic A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often fo ...

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcanic eruption. An eruption that ejects large volumes of magma over a short period of time can cause significant detriment to the str ...

s ranging in age from 26.9 to 35.3 Ma. Extrusive products include rhyolitic

ignimbrite Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surrou ...

s along with

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomina ...

, and

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture (geology), texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained matri ...

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 ...

flows. The major ash flow

tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock co ...

sheets produced, range in volume from 35 to 650 km³. Activity throughout most of the Boot Heel volcanic field paused between 33 and 28 million years ago. The earlier pulse of activity involved less

evolved Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...

magmas, while the later pulse was relatively depleted in

volatiles Volatility or volatile may refer to: Chemistry * Volatility (chemistry), a measuring tendency of a substance or liquid to vaporize easily ** Volatile organic compounds, organic or carbon compounds that can evaporate at normal temperature and pre ...

. The pause in activity has been interpreted as a period of tectonic reorganization along the west coast of North America, including the birth of the

San Andreas Fault The San Andreas Fault is a continental Fault (geology)#Strike-slip faults, right-lateral strike-slip transform fault that extends roughly through the U.S. state of California. It forms part of the tectonics, tectonic boundary between the Paci ...

, that temporarily shifted volcanism to the east. The field includes the Geronimo- Animas volcanic field and the Palomas volcanic field.

Geronimo volcanic field

The Geronimo volcanic field (also known as the

San Bernardino San Bernardino ( ) is a city in and the county seat of San Bernardino County, California, United States. Located in the Inland Empire region of Southern California, the city had a population of 222,101 in the 2020 census, making it the List of ...

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 ...

and a sub-section of the Boot Heel volcanic field in southeastern Arizona, US.

Calderas

The calderas of the Boot Heel field and their associated

s include: *

Pyramid Mountains The Pyramid Mountains are a 30 mi (48 km) long, mountain range in central-east Hidalgo County, New Mexico. The city of Lordsburg and Interstate 10 lie at its northern border. The range lies between the northeast corner of the north– ...

** Muir caldera 35.3 Ma (tuff of Woodhall Canyon) * Peloncillo Mountains ** Steins caldera 34.4 Ma (tuff of Steins) *

Animas Mountains The Animas Mountains are a small mountain range in Hidalgo County, within the " Boot-Heel" region of far southwestern New Mexico, in the United States. Location They extend north–south for about 30 miles (50 km) along the Continental Div ...

** Juniper caldera 33.5 Ma (Oak Creek Tuff) ** Animas Peak caldera 33.5 Ma (tuff of Black Bill Canyon) ** Tullous caldera 35.1 Ma (Bluff Creek Tuff) *

Chiricahua Mountains The Chiricahua Mountains massif is a large mountain range in southeastern Arizona which is part of the Basin and Range province of the west and southwestern United States and northwest Mexico; the range is part of the Coronado National Forest. T ...

** Geronimo Trail caldera 32.7 Ma (Gillespie Tuff) ** Clanton Draw caldera 27.4 Ma (Park Tuff) ** Portal caldera 27.6 Ma (tuff of Horseshoe Canyon) ** Turkey Creek caldera 26.9 Ma (Rhyolite Canyon Tuff)

References

{{DEFAULTSORT:Boot Heel volcanic field Volcanic fields of Arizona New Mexico Bootheel Volcanic fields of New Mexico Landforms of Hidalgo County, New Mexico Monogenetic volcanic fields Landforms of Cochise County, Arizona Calderas of Arizona Calderas of New Mexico Eocene calderas Oligocene calderas Volcanic fields of Mexico

Geronimo volcanic field

Calderas

See also

References