The orogenic theories have emerged to explain the origin of orogenic or mountain ranges. They can be grouped into two types:
- Fixist theories.
- Mobilist or horizontalist theories.
They have been the predominant ones until the beginning of the 20th century, and they affirm that both the continents and the oceans have not changed their position since the Earth was formed. They only admit that there can be vertical movements, which is why they are also called verticalist theories. Some of these theories are:
The Earth, as it cooled and contracted, folded and the mountain ranges were formed.
The mountain ranges were formed by the rise of granite magma from the mantle.