The Highland Rim is a geographic term for the area in Tennessee, North Alabama, and Kentucky which surrounds the Central Basin.
The Highland Rim is a cuesta surrounding the basin, and the border where the difference in elevation is sharply pronounced is an escarpment.
[2] In the northern part of the Western Highland Rim, sinkholes readily occur in an area with a southern extension of the Pennyroyal plateau of Kentucky, where the karst is best developed on the Mississippian St. Louis Limestone and the Ste.
[4] The constituent bedrock is composed primarily of Mississippian aged St. Louis, and Warsaw limestones with Fort Payne chert underlain by Chattanooga Shale that forms a large part of the escarpment.
The stratigraphy of the Southern Highland Rim is primarily composed of flat-lying limestones, dolomites, and shales, and to a much lesser extent, of cherts, siltstones, mudstones, and very fine grained to conglomeratic sandstones.