Text Box: Appalachian Plateaus Introduction | Glaciers | Allegheny Plateau | Cumberland Plateau | Resources
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
The Appalachian Plateaus province extends from central New York, beginning generally at the southern edge of the Adirondack Mountains, running southwestward to the Fall Line (junction with the Atlantic-Gulf Coastal Plain) in northwestern Alabama.  The province is the northwesternmost of the five Appalachian provinces.  It varies in width from slightly more than 200 miles near its central portion in Ohio and West Virginia, to 30 miles in Tennessee.  The province generally slopes upward from west to east; the western edge typically lies at an elevation of about 1,000 feet, and the eastern edge in places attains heights exceeding 4,500 feet.
 
General Structure
This province is primarily an elevated section of nearly horizontal or gently folded strata, consisting mostly of sandstone, conglomerates and shale.  Significant erosion in several places, coupled with minor folding, especially in the eastern portion, have produced deep and relatively steep-walled valleys, resulting in a mountainous topography.  However, the province is considered a region of plateaus because nearly all of the rock layers are mostly horizontal, unlike the much more folded Ridge and Valley province to the east and south, and because it is generally higher than the provinces to the west.  Although the rock layers appear primarily horizontal on a local scale, on a large-scale there is a slight synclinal nature throughout most of the province.  The upturned edges, along the eastern and western sides, which are capped with relatively resistant sandstone, have yielded escarpments that clearly delineate the borders of the province along nearly the entire periphery.  The escarpment along the eastern edge has a variety of local names.  In New York it is referred to as the Helderbergs (Helderberg Mountains).  In Pennsylvania it is the Allegheny Front, a very prominent segment of the escarpment that is mostly 500-1,000 feet tall.  Dans Mountain is the name of the feature in Maryland, but it is again called the Allegheny Front in northern West Virginia, and Allegheny Mountain along the Virginia-West Virginia border.  The continuation of this escarpment along the southeastern portion of the province is called the Cumberland Front (or Escarpment or Mountain) in Kentucky and along most of the province border in Tennessee; it is called Walden Ridge along the southernmost segment of the Tennessee portion of the boundary, and Sand Mountain in Alabama.  Most of the western border of the province is much less prominent, and is called the Knob Belt in many places.  Only in north-central Ohio is there no escarpment delineating the province boundary, but even here there is a clear distinction between the more rugged terrain of the Appalachian Plateaus and the much flatter topography of the Central Lowlands to the west. 
 
 Appalachian Plateaus Introduction | Glaciers | Allegheny Plateau | Cumberland Plateau | Resources