Andean orogeny Andean orogeny The Andean orogeny () is an ongoing process of orogeny that began in the Early Jurassic and is responsible for the rise of the Andes mountains. The orogeny is driven by a reactivation of a long-lived subduction system along the western margin of South America. On a continental scale the Cretaceous (90 Ma) and Oligocene (30 Ma) were periods of re-arrangements in the orogeny. Locally the details of the nature of the orogeny varies depending on the segment and the geological period considered. Subduction orogeny has been occurring in what is now western South America since the break-up
Svecofennian orogeny and thick continental crust collapsed under the influence of gravity and spread out. By 1850 millions years ago this collapse had evolved to a dynamic of extensional tectonics. In this extensional milieu short-lived sedimentary basins formed. The Svecobaltic orogeny developed when subduction bought the Fennoscandian Craton into an oblique collision with the Sarmatian Craton. The mentioned sedimentary basins were destroyed by basin inversion 1830 million years ago. This last event of basin inversion was associated with a period of metamorphism in southern Finland that peaked about 1820 million years ago. Two models exist regarding the origin of the Nordic orogeny: