Alleghanian orogeny Province must have been even more intense; however, there is little evidence preserved. Rocks of Mississippian, Pennsylvanian, and Permian age are missing along the Eastern Seaboard. The mountains formed by the Alleghanian orogeny were once rugged and high, but in our time are now eroded into only a small remnant: the heavily-eroded hills of the Piedmont. Sediments that were carried eastward formed the coastal plain and part of the continental shelf. Thus, the coastal plain and Piedmont are largely the byproducts of erosion that took place from 150+ million years ago to the present. Sediments that were carried westward formed
Kibaran orogeny Kibaran orogeny The Kibaran orogeny is a term that has been used for a series of orogenic events in what is now Africa that began in the Mesoproterozoic around 1400 Ma and continued until around 1000 Ma when the supercontinent Rodinia was assembled. The term "Kibaran" has often been used for any orogenic rocks formed during this very extended period. Recently it has been proposed that the term should be used in a much narrower sense for an event around 1375 Ma and a region in the southeast of the Democratic Republic of the Congo (DRC). Regions that contain relics