Alleghanian orogeny the Allegheny and Cumberland Plateau, which in some areas are popularly called mountains, but are actually simply uplifted and eroded plateaus. A portion of the Alleghanian mountain system departed with Africa when Pangaea broke up and the Atlantic Ocean began to form. Today, this forms the Anti-Atlas mountains of Morocco. The Anti-Atlas have been geologically uplifted in relatively recent times, and are today much more rugged than their Alleghanian relatives. Alleghanian orogeny The Alleghanian orogeny or Appalachian orogeny is one of the geological mountain-forming events that formed the Appalachian Mountains and Allegheny Mountains. The term and spelling Alleghany orogeny was
East African Orogeny supercontinent (today known as Rodinia), a process that eventually culminated in the relatively short-lived Gondwanan supercontinent. Two partly incomparable scenarios have been proposed for this assembly. In one model, the EAO evolved from an accretionary orogeny involving the amalgamation of arcs and evolved into a collisional orogeny when the Neoproterozoic continent Azania collided with the Congo-Tanzania-Bangweulu Block at . In another model, the assembly of East Gondwana was a multiphase process which included two main periods of orogenesis: the older EAO ( ) and the younger Kuunga Orogeny ( ). In the former scenario the Kuunga Orogeny of the latter