Mississippian Period............by R.E
It is the Appalachian Mountians. Which consist of: Taconic Orogeny (Ordovician);Acadian Orogeny (Devonian);Caledonian Orogeny (Silurian); Allegheny Orogeny (Pennsylvanian & Permian).
Ordovician period
Devonian Period
Allegheny Southern Railway ended in 1984.
Allegheny Athletic Association ended in 1896.
Allegheny Valley Railroad ended in 1891.
Allegheny Portage Railroad ended in 1857.
Trans-Allegheny Lunatic Asylum ended in 1994.
Mountains are formed by the process of orogeny.
The Allegheny Plateau was formed through a series of geological processes including uplift and erosion during the Appalachian orogeny, a period of mountain-building that occurred around 300 million years ago. This resulted in the creation of a broad, flat-topped region with steep cliffs and deep valleys that we see today in the eastern United States.
orogeny come from the Greek oros meaning 'mountain'
Taconian orogeny and Acadian orogeny