The Sierra de Los Tuxtlas (Tuxtlas Mountains) are a

volcanic belt A volcanic belt is a large volcanically active region. Other terms are used for smaller areas of activity, such as volcanic fields or volcanic systems. Volcanic belts are found above zones of unusually high temperature () where magma is created ...

and

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have aris ...

along the southeastern

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

Gulf coast The Gulf Coast of the United States, also known as the Gulf South or the South Coast, is the coastline along the Southern United States where they meet the Gulf of Mexico. The coastal states that have a shoreline on the Gulf of Mexico are Tex ...

in Eastern Mexico. The

Los Tuxtlas Biosphere Reserve The Los Tuxtlas Biosphere Reserve or Biósfera Los Tuxtlas, is a biosphere reserve located in the coastal and higher elevations of the Sierra de los Tuxtlas, in Los Tuxtlas of Veracruz state, in south eastern Mexico. Ecoregion The area is notabl ...

(Biósfera Los Tuxtlas) includes the coastal and higher elevations of the Sierra de Los Tuxtlas. The volcanic mountains were used as a

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 ...

source by the

Olmec The Olmecs () or Olmec were an early known major Mesoamerican civilization, flourishing in the modern-day Mexican states of Veracruz and Tabasco from roughly 1200 to 400 Before the Common Era, BCE during Mesoamerica's Mesoamerican chronolog ...

culture during the Early Formative period (). Quarried basalt was transported by raft through a network of rivers, to sites in the

Olmec heartland The Olmec heartland is the southern portion of Mexico's Gulf Coast of Mexico, Gulf Coast region between the Tuxtla mountains and the Olmec archaeological site of La Venta, extending roughly 80 km (50 mi) inland from the Gulf of Mexico coastline ...

for use in creating monuments, including colossal heads.

Geography

Peaks in this range include Volcano Santa Marta and Volcano San Martín Tuxtla, both rising above 1,700 meters. San Martín Tuxtla is the only recently active volcano in the belt, erupting in 1664 and again in May 1793. It is a broad

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 ...

shield volcano A shield volcano is a type of volcano named for its low profile, resembling a shield lying on the ground. It is formed by the eruption of highly fluid (low viscosity) lava, which travels farther and forms thinner flows than the more viscous lava ...

with a one kilometer wide summit. Hundreds of smaller

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 are prevalent throughout the Sierra. Other,

extinct volcano A volcano is commonly defined as a vent or fissure in the Crust (geology), crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface. On Earth ...

es include San Martin Pajapan (1,160 meters) and Cerro El Vigia (800 meters). The Sierra de Los Tuxtlas volcanoes are an insular anomaly. The volcanoes are separated from the nearest volcano in the

Trans-Mexican Volcanic Belt The Trans-Mexican Volcanic Belt (), also known as the Transvolcanic Belt and locally as the (''Snowy Mountain Range''), is an active volcanic belt that covers central-southern Mexico. Several of its highest peaks have snow all year long, and dur ...

to the west by about 150 miles (250 km), and from the Central American Volcanic Belt to the southeast by almost 200 miles (330 km).

Natural history

The upper flanks of the San Martin Tuxtla and Santa Marta volcanoes are covered with the

Neotropical The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone. Definition In biogeogra ...

Sierra de los Tuxtlas tropical rainforest

ecoregion An ecoregion (ecological region) is an ecological and geographic area that exists on multiple different levels, defined by type, quality, and quantity of environmental resources. Ecoregions cover relatively large areas of land or water, and c ...

, of the

tropical and subtropical moist broadleaf forests Tropical and subtropical moist broadleaf forests (TSMF), also known as tropical moist forest, is a subtropical and tropical forest habitat type defined by the World Wide Fund for Nature (WWF). Description TSMF is generally found in la ...

biome. The lower portions are covered with stunted pastures and grasslands. The Tuxtla quail-dove (''Zentrygon carrikeri'') is

endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

to the ecoregion. The Volcan San Martin rainfrog, '' Craugastor vulcani'', is an

endangered An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching, inv ...

frog endemic to rain and cloud forests of Sierra de los Tuxtlas. The area is also home to an endemic species of giant scarab beetle, '' Dynastes moroni'', described in 2005.Ratcliffe, B. C., R. D. Cave, and E. Cano. 2013. The dynastine scarab beetles of Mexico, Guatemala, and Belize (Coleoptera: Scarabaeidae). Bulletin of the University of Nebraska State Museum 27: 1-666.

References

* (in Spanish) * {{cite gvp , vn=341830 , name=San Martín Pajapan

External links

Los Tuxtlas Biosphere Reserve
Tuxtlas Landforms of Veracruz Ecoregions of Mexico Neotropical tropical and subtropical moist broadleaf forests Geography of Mesoamerica Volcanic belts Volcanism of Mexico Important Bird Areas of Mexico

Geography

Natural history

See also

References

External links