Tectonic Processes and their Impact on the Geography of Mexico

The Earth's surface is constantly shaped and reshaped by the movements of its underlying tectonic plates. These plates, which are in constant motion due to convection in the Earth's mantle, interact with each other at their boundaries, giving rise to a variety of geological processes and features.

In this text, we will examine how these processes have shaped the geography of Mexico, a unique country that encompasses all three types of plate boundaries. From the collision of tectonic plates to the creation of a new oceanic crust, we will look at how these powerful geological forces have changed the topography and landscape of Mexico.

Mexico: Where Tectonic Plates Meet, Shape, and Create

In the Earth system, all natural things are linked or connected. For example, things that happen on the surface of the planet are caused by things that happen inside the planet. High pressures and temperatures are put on the inside of the planet. This makes the minerals behave like they are plastic as if they were melted.

This lets them move in the form of convection cells, which are caused by temperature differences. In these convection cells, the movement of the mantle material drags the thin layer of solid rock, called the lithosphere, which covers the Earth. The lithosphere is made up of pieces of both the continental and oceanic crust, and its thickness ranges from 5 to 70 kilometers.

By sending these movements to the lithosphere, the crusts break and move, forming tectonic plates, which in turn cause different processes. Convergent boundaries are the places where two plates meet and move together. If these two are continental crusts, they will crash into each other and make big mountain ranges. When an oceanic plate and a continental plate hit each other, the oceanic plate sinks into the mantle beneath the continental plate. This is called subduction.

When convection currents in the Earth's mantle cause the plates to separate, this is called a divergent plate boundary. When this happens, magma rises to the surface through a large crack and forms a new oceanic crust as it cools. These cracks are called rift zones. At some boundaries, the plates only move from side to side. These are called transforms, and no new crust is made or destroyed at them.

The way the continents are located and the shape of the land are both affected by these processes at the plate boundaries. Mexico is the only country in the world with all three types of plate boundaries, which is a very interesting fact.

The Baja California peninsula is the only part of Mexico that is on the Pacific tectonic plate. The rest of Mexico is on the southwestern part of the North American tectonic plate. Also, a small part of the border between Chiapas and Guatemala is on the Caribbean tectonic plate, while the patrimonial sea zone in the west is on the Pacific, Rivera, and Cocos plates.

Mexico's topography and most important geological features are the results of how the tectonic plates interact with each other along their edges. When tectonic plates break apart, crash into each other, or move next to each other, they create surface relief. This gives rise to three types of mountain ranges, which are:

• The "wrinkling" of materials, which are called orogenic chains or orogens on a regional scale.
• The movement of big cracks, which are called "block mountains".
• The building up of lava and ash from magma that rises to the surface, also known as magmatic mountains.

In simple terms, the Earth's surface is constantly changing because of the movements of the tectonic plates under the ground. Mexico is a special country because it has all three types of these plate boundaries, which interact with each other and create mountains and other geological features. This shows how things happening inside the planet can have a big impact on the shape of the land on the surface.

INAH, México, grandeza y diversidad, 2021, pp.40-41.