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
Damara orogeny Damara orogeny The Damara orogeny was part of the Pan-African orogeny. The Damara orogeny occurred late in the creation of Gondwana, at the intersection of the Congo and the Kalahari cratons. The Damara orogeny involved the suturing of the Congo–São Francisco and Río de la Plata cratons at 580–550 Ma (together with India forming northern Gondwana) before the amalgamation of the Kalahari and Mawson cratons in the Kuunga–Damara orogeny at 530 Ma (southern Gondwana). The Adamastor Ocean closed southwards from the Araçuaı́ Belt (São Francisco Craton, now in South America) to the Kaoko Belt (Congo Craton, now in Africa) 580–550