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
Malagasy orogeny Malagasy orogeny Malagasy orogeny is the name given to the Ediacaran to Cambrian orogeny that resulted as India collided with the already amalgamated African continent that consisted of Azania and the Congo-Tanzania-Bangweulu Block. The orogeny affected the parts of the East African Orogen that are now found in southern India, Madagascar and central Arabia. The term "Malagasy orogeny" was introduced by for the orogenisis between India and a series of Gondwanan cratonic blocks in present-day Africa (Congo/Tanzania/Bangweulu/Azania). In their reconstruction, India collided with Australia/Mawson in the Kuunga orogeny before the formation of Gondwana. They identified the Betsimisaraka suture in eastern