Acadian orogeny Acadian orogeny The Acadian orogeny is a long-lasting mountain building event which began in the Middle Devonian, reaching a climax in the early Late Devonian. It was active for approximately 50 million years, beginning roughly around 375 million years ago, with deformational, plutonic, and metamorphic events extending into the Early Mississippian. The Acadian orogeny is the third of the four orogenies that created the Appalachian orogen and subsequent basin. The preceding orogenies consisted of the Potomac and Taconic orogeny, which followed a rift/drift stage in the Late Neoproterozoic. The Acadian orogeny involved the collision of a series of Avalonian continental
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