Orogeny which developed in continental detachment systems at converged plate margins. Orogeny An orogeny is an event that leads to both structural deformation and compositional differentiation of the Earth's lithosphere (crust and uppermost mantle) at convergent plate margins. An orogen or orogenic belt develops when a continental plate crumples and is pushed upwards to form one or more mountain ranges; this involves a series of geological processes collectively called orogenesis. Orogeny is the primary mechanism by which mountains are built on continents. The word "orogeny" comes from Ancient Greek (, , + , , ). Although it was used before him,
Alpine orogeny Carpathian orogeny for the Carpathians, Hellenic orogeny for the Hellenides or the Himalayan orogeny for the Himalayas. The Alpine orogeny has also led to the formation of more distant and smaller geological features such as the Weald–Artois Anticline in southern England and northern France, the remains of which can be seen in the chalk ridges of the North and South Downs in southern England. Its effects are particularly visible on the Isle of Wight, where the Chalk Group and overlying Eocene strata are folded to near-vertical, as seen in exposures at Alum Bay and Whitecliff Bay, and on the Dorset