Orogenesis

The orogénesis or orogenia is the process by which has been and continues turning construction of the mountains . This process can be studied as a tectonic structural event , as a geographic event , and as a chronological event , in which different orogenic events cause distinctive structural phenomena and related tectonic activity , largely affecting certain regions of rocks and crust. and that they occur in a certain time frame. The orogeny is often accompanied by folds and faultsof the strata, the development interruptions in the normal deposition of sedimentary rocks and the deposition of sediments in areas adjacent to the orogenic belt . It can be the result of subduction , the accumulation of land on the continents by oceanic plates, continental collisions and the overcoming of oceanic ridges by continents .

Etymology

The word orogenesis is made up of words or roots of Greek origin and means “study of the formation of mountains.” The word is composed of the prefix ” oros ” or ” ὄρος ” which means mountain, the suffix ” gen ” or ” γένεσις ” which means to produce or general , plus the suffix ” sis ” which means action .

History of orogenesis

According to scientists, orogenesis has remained very homogeneous over time. Gold-genetic processes have affected the formation of the earth since it has been known of its existence. It is considered that the different processes that characterize the tectonics of the world, started the evolution of the planet and that they have been maintained uniformly both in intensity and mechanics . The history of orogeny is based on three different processes or orogenies, which are those that have been responsible for the construction of the earth for more than 400 million years, these are:

• Caledonian orogeny : they were a series of tectonic movements from which the Caledonian chain arose
• Hercynian or Variscan orogeny : it occurred in different places on earth and the most important was the Caledonian folding .
• Alpine orogeny : it occurred in the tertiary period and is still in action. They are he formed the Himalayan alpine system .

What is orogenesis?

Orogenesis is a group of different processes that occur at the edges of the different tectonic plates that make up the planet and that, due to their movements, give rise to mountains or mountain ranges. In the ocean basins that limit the continents, a large amount of sediment accumulates which through convergent movements cause the deformation and metamorphism of the different materials that make it up. When one tectonic plate slides under the other, the earth’s crust thickens and mountain ranges emerge. While this process happens, a series of volcanic manifestations, mechanical or collision processes and thickening mantles can occur.

How is the proccess 

Orogeny is the process of mountain formation and occurs through the deformation of the different sediments found in a sediment basin . These sediments are fractured into pieces giving shape to the different types of relief on the earth. Produces a series of folded reliefs . The process takes place through three different steps: folding, which is the process in which soft materials are folded; the faulting , the process by which materials having a harder consistency are broken; and the thrust, process by means of which the materials move to their different positions. Orogeny tends to occur over a relatively short time and is capable of intense deformation. The regional metamorphism and magmatic activity are also often associated with orogenic event.

Types of orogenesis

There are two different types of orogenesis which are:

• Thermal orogenesis : This type of orogeny occurs when one tectonic plate subducts another plate underneath. In these processes there are a series of magmatic and volcanic processes as a consequence of the collision of the plates. According to this, thermal orogenesis has two different modalities:
• Arches of islands : consists of archipelagos, volcanic islands and trenches.
• Marginal mountain ranges : they occur when through subduction the oceanic lithosphere is broken at the edge of the continents.
• Mechanical or collision orogenesis : it occurs when tectonic plates drag a portion of the continent against another. The forces involved in this process are horizontal and mechanical, and volcanic processes are almost nil . The subduction of the plates is necessary for the process to take place and involves a phase of thermal orogenesis before the collision of the continents occurs.