Orogeny
![](/Images/godic/202501/28/World_geologic_provinces3619.jpg")
![Two processes that can contribute to an orogen. Top: delamination by intrusion of hot asthenosphere; Bottom: Subduction of ocean crust. The two processes lead to differently located granites (bubbles in diagram), providing evidence as to which process actually occurred.[4]](/Images/godic/202501/28/SubductionDelamination3620.JPG")
![Subduction of an oceanic plate by a continental plate to form a noncollisional orogen. (example: the Andes)](/Images/godic/202501/28/Active_Margin.svg3620.png")
![Continental collision of two continental plates to form a collisional orogen. However, usually no continental crust is subducted, only uplifted. (example: the Alps)](/Images/godic/202501/28/Continental-continental_convergence_Fig21contcont3620.gif")
Orogeny refers to forces and events leading to a large structural deformation of the Earth's lithosphere (crust and uppermost mantle) due to the interaction between tectonic plates. Orogens or orogenic belts (Fold mountains) develop when a continental plate is crumpled and is pushed upwards to form mountain ranges, and involve a great range of geological processes collectively called orogenesis.