An orogeny is an event that leads to a large structural deformation of the Earth's lithosphere (crust and uppermost mantle) due to the interaction between plate tectonics. An orogen or orogenic belt develops when a continental plate crumples and is pushed upwards to form one or more mountain ranges; this involves many geological processes collectively called orogenesis. The word comes from Ancient Greek (ὄρος, óros, lit. 'mountain' + γένεσις, génesis, lit. 'creation, origin').
