The Earth is a dynamic planet.
Atmospheric phenomena, the gravitational energy and the agents of erosion form the external processes. These processes modify and erode the earth's surface causing the material eroded from higher areas to move into lower areas.
• The geological cycle.
The set of transformations of destruction and construction of the relief.
1. Orogeny is the formation of mountains as a result of internal processes.
2. Gliptogénesisà relief is wear that occurs when materials are eroded and transported to marine basins. Occurs by the processes and external agents.
3. Lithogenesis is the process of forming new stones caused by internal and external processes.
The relief is modified because of forces or energies that produce opposite effects: the internal processes generated by the internal energy of the earth are responsible for the new surface, and external processes generated by external energy are causing the destruction of reliefs , eroding mountains and filling the depressions.