RELIEFS OF MEXICO: PLAINS, PLATEAUS, MOUNTAINS, MOUNTAIN RANGES, VOLCANOES - GEOGRAPHY

The reliefs of Mexico range from extensive mountain ranges with wide valleys and plateaus to coastal plains facing the Atlantic and Pacific Oceans. This includes at least 6 major mountain ranges and an extensive volcanic plateau that sets the boundary between North and Central America.

The maximum height is the Citlaltépetl volcano or Pico de Orizaba with 5,610 meters above sea level, located east of the Neovolcanic Axis, between Puebla and Veracruz. While the lowest area in the country is the Laguna Salada in Baja California to the northwest, 12 meters below sea level.

Pico de Orizaba (Mexico). Source: _Pico_de_Orizaba_1.jpg: pacomexicoderivative work: Ricraider (talk) enhanced zoom / CC BY (https://creativecommons.org/licenses/by/2.0)

The Mexican territory geologically is shared between the North American plate and the Caribbean plate that carries Central America. The contact limit of both plates has generated strong volcanic activity forming the Neovolcanic Axis that crosses Mexico from west to east.

Plains

Mexico has extensive plains to the north and east of its territory, including the Sonoran Plain and the Northern Plain. As well as the penetration into its territory of the Great Plain of North America and the plains of the coast of the Gulf of Mexico.

Sonoran plain, (Coahuila de Zaragoza, Mexico). Source: panza.rayada / CC BY-SA (https://creativecommons.org/licenses/by-sa/3.0)

On the coast of the Pacific Ocean there are coastal plains that are wider in the north with approximately 500 km between the Gulf of California and the Sierra Madre Occidental. While further south these plains extend only about 50 km wide.

The Sonoran plain

It is made up of a series of systems of hills and small mountain ranges between which large plains extend. In this region the Pinacate volcano is located, whose summit at 1,600 meters above sea level is made up of a wide circular caldera.

Great Plains of North America

It consists of a system of plains and hilly areas that is part of the North American plains region that extends to Canada.

Yucatan peninsula

It is a calcareous platform that emerged from the sea and presents a relief of plains and low hills called the Sierrita de Ticul. On the other hand, due to its calcareous geology, the subsoil of Yucatán presents a network of caves and channels through which water circulates and natural wells called cenotes open up.

Plateaus

Central Plateau

The most prominent plateau in Mexico is the Central Plateau or Mexican highland, stretching between the Sierra Madre Occidental and the Sierra Madre Oriental. This plateau is oriented from northwest to southeast and is divided into two sections called the Mesa del Norte and the Mesa del Sur.

Central Plateau (Mexico)

The Mesa del Sur is the highest with an average elevation of 2,000 meters, while the Mesa del Norte has an average elevation of 1,100 meters.

Chiapas Central Plateau

This plateau is part of the Sierra Madre de Chiapa and Oaxaca, and reaches an average altitude of 2,000 meters above sea level. It extends from the coastal plains of the southern Gulf of Mexico to Guatemala for 250 km.

Cordilleras and mountains

Sierra de Baja California

This mountain range is a continuity of the Sierra de California in the territory of the USA, extending for 1,430 km in the Baja California peninsula in Mexico. This mountain range decreases in altitude from north to south, from an average of 2,200 meters above sea level to 250 meters above sea level.

The eastern slope that falls into the Sea of Cortez is much steeper than the western slope that faces the Pacific Ocean. They are recognized in this mountain range, the Sierra de Juárez to the north and the Sierra de San Pedro Mártir to the south.

Sierra Madre Occidental

This mountain range forms the same system with the Sierra Nevada of California (USA), presenting a discontinuity between California and northern Mexico. The Sierra Madre Occidental extends for 1,250 km from Sonora to Jalisco in the Neovolcanic Axis in the south.

Sierra Madre Occidental (Mexico). Source: Christian Frausto Bernal / CC BY-SA (https://creativecommons.org/licenses/by-sa/2.0)

The Sierra Madre Occidental is a geological formation of volcanic origin with various plateaus and canyons up to 1,000 m deep. Its maximum height is reached in Cerro Gordo with 3,352 meters above sea level.

Sierra Madre Oriental

It constitutes an extension of the Rocky Mountains of New Mexico and Texas, extending 1,350 km to the Cofre de Perote peak in the Neovolcanic Axis. This mountain range is formed by sedimentary rocks, being a product of the elevation of the seabed and its maximum height is Cerro El Potosí with 3,713 meters above sea level.

Neovolcanic Axis or Trans-Mexican Volcanic Belt

Although it is sometimes called Sierra or Neovolcanic Mountain Range, it is not a mountain range, it is really a system of stepped plains. This staggering of plains ranges from 500 to 2,600 meters above sea level, with a large number of volcanoes distributed there that form prominences above this limit.

This axis goes from the Pacific coast to the Atlantic, orienting from west to east, divides the Mexican territory in two, reaching 900 km in length and about 130 km in width. Its origin is in the tectonic activity of the Caribbean and North American plates, where the first subducts or submerges in the second.

In this mountainous system is the highest peak in Mexico, the Pico de Orizaba or Citlaltépetl volcano with 5,636 meters above sea level.

Sierra Madre del Sur

It is located to the south of the Neovolcanic Axis and parallel to this and to the Mexican southern Pacific coast. It extends for 1,200 km from the southwest of the Volcanic Axis to the Central American Mountain Range to the east, with about 100 km wide.

The highest point of this mountain range is Cerro Nube Flane at 3,720 meters above sea level. In addition, in this system the Sierra Madre de Oaxaca stands out, which begins in the Neovolcanic Axis and reaches the Isthmus of Tehuantepec.

Sierra Madre of Chiapas

It extends to the southeast through the states of Chiapas and Oaxaca parallel to the Pacific Ocean and includes deep canyons such as the Sumidero Canyon through which the Grijalva River circulates. It is a continuation of the Sierra Madre del Sur, but separated by the depression of the Isthmus of Tehuantepec.

Then it extends south to Guatemala with the name of Sierra Madre as part of the Central American Cordillera to Honduras. The most prominent elevation in Mexico is the Tacaná volcano on the border with Guatemala at 4,092 meters above sea level.

Valleys

In the rugged and varied geography of Mexico there are many valleys that stretch between the sierras and mountains.

Mexico's valley

The south central region of Mexico, between the Sierra Madre Occidental and the Sierra Madre Oriental, is generally referred to globally as the Valley of Mexico. However, it really is about 4 valleys, these are Cuautitlán, Apan, Tizayuca and the Anáhuac or Mexico Valley where Mexico City sits.

The area was an endorheic basin that was opened in colonial times by humans to drain the lakes that covered it.

Tlaxcala-Puebla Valley

Tlaxcala-Puebla Valley (Mexico). Source: Bodofzt / CC BY-SA (https://creativecommons.org/licenses/by-sa/4.0)

It is located to the center east in the Neovolcanic Axis, encompassing the states of Puebla and Tlaxcala, including the metropolitan area of Puebla and cultivated areas. This valley has an average altitude of 2,160 meters above sea level.

Bajío Valley

This valley covers areas of Jalisco, Guanajuato, northern Michoacán, southern part of San Luís de Potosí, Querétaro and Aguascalientes. It is an extensive plain limited by hills and mountains, located in central Mexico.

Tehuacan Valley

It forms an extensive elongated plain south of the state of Puebla, bordering the northern border of Oaxaca through which the Tehuacán River flows.

Chiapas Valley

It is located in the extreme south of the country, in the state of Chiapas, between the Central Plateau of Chiapas and the Sierra Madre de Chiapas.

Valleys of the Baja California Peninsula

Between the mountains of the Sierra de Juárez and San Pedro Mártir in the Baja California peninsula there are a series of valleys. Among them are the Ojos Negros Valley, the Trinidad Valley and the Chico-San Felipe Valley.

Volcanoes

Mexico is part of the so-called belt or ring of fire of the Pacific Ocean. At the same time its territory is in the geological transit between the North American plate and the Caribbean plate.

Due to this, in Mexico there is great volcanic activity, with around 11 large volcanoes. Even Orizaba Peak, the highest mountain in Mexico, is a volcano.

Popocatepetl volcano (Mexico). Source:

The highest concentration of volcanic activity is in the Neovolcanic Axis or Trans-Mexican Volcanic Belt. Many of the Mexican volcanoes are active and have caused alarm in recent decades, such as Popocatepetl (1996) and Colima (1994).

Of these two, Popocatepetl represents the greatest concern due to its proximity to Mexico City and Puebla. A major eruption of this volcano would endanger 30 million inhabitants of these areas.

Depressions

The Balsas depression

It is the basin of the Balsa River, it is one of the largest in Mexico, covering almost 6% of its continental territory. It is located between the Sierra Madre del Sur and the Neovolcenic Axis, in a range between 300 and 600 meters above sea level.

The Salt Lagoon

It consists of a dry sandy depression that extends between the Sierra de Juárez and Sierra de Cucapá in a north-south direction. This plain is an intermittent lagoon, with widely spaced flood ranges, in fact the last time it was flooded was in 1999.

Slopes or large Mexican basins

Mexico has three large basins, which are the Pacific Ocean, the Gulf of Mexico and the Caribbean Sea. On the other hand, in the altiplano or Meseta del Centro there are various endorheic basins with rivers that flow into closed lakes that in Mexico are called pockets.

The longest river is the Bravo, which forms much of the border between Mexico and the US where they call it the Rio Grande. This river reaches 3,034 km in length and empties into the Gulf of Mexico.

The second river in Mexico in length is the Lerma or Grande de Santiago with 1,270 km, flowing into the Pacific Ocean. While in the basin of the Caribbean Sea are the Azul River, a tributary of the Hondo River that flows into the Bay of Chetumal.

Coastal, insular and underwater relief

Coastal relief

The most relevant coastal geographical features in Mexico are the Gulf of Mexico, the Bay of Campeche and the Yucatan Peninsula in the Atlantic. As well as the Gulf of Baja California, the Baja California peninsula, the Sea of Cortez and the Bay of Tehuantepec on the Pacific slope.

Island relief

There are notable differences between the islands under Mexican sovereignty in the Atlantic and those of the Pacific. Thus, in the Gulf of Mexico and the Caribbean Sea the islands are small and of reef origin without significant relief.

Revillagigedo Archipelago (Mexico). Source: Presidency of the Mexican Republic / CC BY (https://creativecommons.org/licenses/by/2.0)

While in the Pacific there are continental islands formed by mountainous outcrops and also oceanic islands such as the Revillagigedo archipelago. The islands of the latter are of volcanic origin and there is the Bárcena volcano.

Underwater relief

Due to the tectonic activity in which the Mexican territory is immersed, its marine relief is abrupt. In fact, both the Gulf of Baja California and the seafloor off the southern Pacific coast of Mexico are deep ocean trenches.

The one in the Pacific is called the Central American Trench and is the product of the subduction of the Cocos plate under the North American continental plate. While the Gulf of Baja California trench is the product of the tearing of the North American continental plate.

This is due to the fact that the contact between the Cocos plate and the North American plate is transformative, that is, they rub in opposite directions. On the other hand, the offshore platforms from Mexico to the Caribbean Sea end in chasms that reach up to 3,000 m deep.

Additionally, a large meteorite struck 66 million years ago in the Gulf of Mexico, an event to which the extinction of the dinosaurs is attributed. This left a large underwater crater near the northwest coast of the Yucatán Peninsula called Chicxulub, which is currently covered in layers of marine sediment.

References

Conabio, 1998. Map: general characteristics of the Mexican territory. Geographic information system. Mexico
INEGI (1991). Basic data on the geography of Mexico. National Institute of Statistics, Geography and Informatics (INEGI).
Geoinformation Portal 2020. National Biodiversity Information System (SNIB). (Viewed April 3, 2020). Taken from:
Tamayo, JL (2013). Modern Geography of Mexico. Threshing.
UNAM (1990). National Atlas of Mexico. Institute of Geography. Mexico.

RELIEFS OF MEXICO: PLAINS, PLATEAUS, MOUNTAINS, MOUNTAIN RANGES, VOLCANOES - GEOGRAPHY - 2025