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
Antler orogeny due to sea-level rise in the Cambrian rather than displacement from an ocean basin. The sedimentary effects of the Antler orogeny are well known and well described in many published reports, but the exact nature of that event and the driving force remain unsettled. Among the unanswered questions are these: what aspect of plate tectonics was involved; what effect did the Alamo impact event have; why did marine basins appear in the area of general uplift; why did the western facies assemblage, and not the eastern assemblage, include bedded chert, basaltic bodies, barite deposits, and sulfide deposits. Antler orogeny The