Member Login. The following was included in TCTA's 2015-16 Survival Guide, the ultimate reference tool for Texas educators, and is current as of September 2015 but is subject to change.
The Allegheny Mountains run diagonally from the southwest to the northeast with piedmont and coastal plains in the southeast triangle. The Allegheny Front, as it's called, cuts a diagonal line across the state. In the northwest, the plateau falls to the Lake Erie lowlands and, finally, Lake Erie. ( Pennsylvania Close-up)
The Appalachian Mountains include from west to east: the Appalachian Plateau, Valley and Ridge, the Blue Ridge Province, and the Piedmont Region. The Blue Ridge Province is bounded on the west by the Great Smokies Fault near the Tennessee boundary and on the east by the Brevard Fault Zone. The mountains grew out of stacking and shuffling of thin horizontal sheets in several orogenies. The thrusting, shuffling rock sheets mixed the rocks like a deck of cards.