orógenos

In geology, orógenos (orogenic belts) are regions of the lithosphere that have undergone or are undergoing orogenesis, the process of mountain building associated with plate tectonics. The term covers belts and provinces formed by deformation, metamorphism, and magmatic activity as continents grow and oceans close. Orogenesis primarily occurs at convergent margins where tectonic plates collide, subduct, or accrete crustal blocks.

During orogenesis, crust is shortened and thickened, producing thrust faults, nappes, folds, and high‑grade metamorphism. Subduction can generate magmatic arcs and batholiths, while collision stacks crustal sheets and creates extensive structural belts. Orogenic belts may preserve a complex history of multiple tectonic events, including sutures, ophiolites, and terrane accretion.

Orogenic belts are topographically distinct, often forming mountain ranges with uplifted crust, deeply deformed rocks, and widespread metamorphism. They record stages of crustal growth and recycling at plate boundaries and contribute to ocean closure and continental assembly.

Examples include the Himalayan–Alpine belt, the Andes, the Alps, the Appalachians, and the Canadian and North American Cordillera. These belts illustrate different modes of orogenesis: continental collision, subduction-related arc magmatism, and accretionary processes.