The Trans-Pecos Volcanic Field is a

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 western

Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...

in the counties of Brewster, Jeff Davis,

Presidio A presidio ( en, jail, fortification) was a fortified base established by the Spanish Empire around between 16th and 18th centuries in areas in condition of their control or influence. The presidios of Spanish Philippines in particular, were cen ...

, and extends into northern Mexican states of Chihuahua and Coahuila. It is the southernmost volcanic field to be documented and recorded in the

continental United States The contiguous United States (officially the conterminous United States) consists of the 48 adjoining U.S. states and the Federal District of the United States of America. The term excludes the only two non-contiguous states, Alaska and Hawaii ...

. The field started volcanic activity around 48 million years ago in the middle

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

epoch, and ended around 17 million years later in the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

epoch. The Volcanic field is the result of Ancient Subduction off the western portion of the continent at the time. Most of the volcanoes in the field are

caldera A caldera ( ) is a large cauldron-like hollow that forms shortly after the emptying of a magma chamber in a volcano eruption. When large volumes of magma are erupted over a short time, structural support for the rock above the magma chamber is ...

s. Some of the volcanoes are: *In Big Bend National Park, the Christmas Mountains caldera complex and Pine Canyon caldera complex *In

Big Bend Ranch State Park Big Bend Ranch State Park is a state park located on the Rio Grande in Brewster and Presidio counties, Texas. It is the largest state park in Texas. The closest major town is Presidio, Texas, where the state park's head office is located.

, the Bofecitos mountains center and the

Solitario The Solitario (''El Solitario'') is a large geologic formation in Big Bend Ranch State Park (Texas), Big Bend Ranch State Park in West Texas. When viewed from above, it suggests an impact crater; though it is actually the eroded remains of a lacco ...

*Near

Alpine Alpine may refer to any mountainous region. It may also refer to: Places Europe * Alps, a European mountain range ** Alpine states, which overlap with the European range Australia * Alpine, New South Wales, a Northern Village * Alpine National Pa ...

, the Paisano Volcano *In northern Jeff Davis County, the Davis Mountains Caldera Complex *In central

Presidio County Presidio County is a county located in the U.S. state of Texas. As of the 2020 census, its population was 6,131. Its county seat is Marfa. The county was created in 1850 and later organized in 1875. Presidio County (K-5 in Texas topological ind ...

, the Chinati Mountain Caldera Complex, and the Oak Hills Center. The field is currently undergoing geological studying and researched by several colleges and the

United States Geological Survey The United States Geological Survey (USGS), formerly simply known as the Geological Survey, is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, ...

References

{{coord, 29.225, -103.499, type:landmark_globe:earth_region:US-TX, display=title Volcanic fields of the United States Volcanism of Mexico Eocene volcanism Oligocene volcanism Miocene volcanism