orogeneesi

Orogenesi, known in English as orogenesis, is the geological process that forms mountains through the deformation of the Earth's lithosphere as a result of plate tectonics. It encompasses the large-scale structural and metamorphic changes that shorten and thicken the crust, uplift it, and expose rocks at the surface through erosion and exhumation. Major mechanisms include compressional tectonics at convergent plate boundaries, subduction, and collision between continental plates. Shortening causes thrust faulting, nappe stacking, folding, and regional metamorphism; magmatic activity can generate plutons and batholiths that contribute to uplift. Orogenic belts develop when crustal blocks are accreted and welded to stable cratons, and when subduction zones are closed orogenic cycles begin. Orogeny often proceeds through several stages: precursor extension and magmatism, crustal thickening and deformation, uplift and erosion, and isostatic rebound of the thickened crust.

Time scales range from tens to hundreds of millions of years. The products include mountain ranges, igneous intrusions, metamorphic rocks, foreland basins, and suture zones where terranes welded together. Isostasy and climate influence the final relief: erosion lowers peaks, while uplift sustains precipitation and orographic rainfall. Well-known examples include the Alpine orogeny in Europe, the Himalayan orogeny in Asia, and the Andean orogeny along western South America. Orogenesis is a central concept in geology and tectonics, integrating structural geology, petrology, geochronology, and geophysics to explain how continents grow and transform through time.