Cumberland Plateau
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The names
The Cumberland Plateau is technically an extension of the Allegheny Plateau, known by a local name. In the southern United States, where usage of Cumberland Plateau is the common term, usage of the term includes much of eastern Kentucky and western West Virginia in the United States, and also stretches in a band across Tennessee to include a small portion of northern Alabama. Portions of the Allegheny Plateau illogically not included in the Cumberland are those along the same latitudes of the parts of West Virginia in Ohio, thus the term is imprecise and conventional vice totally formal and well defined—as is further evidenced by inclusion of West Virginia by both terms.It is a deeply dissected plateau, with topographic relief commonly of about four hundred feet (120 meters), and frequent sandstone outcroppings and bluffs. Many coal seams are present in the area, and the Cumberland Plateau has for many years been heavily mined. At the Pottsville Escarpment, which is the transition from the Cumberland Plateau to the Bluegrass in the north and the Pennyrile in the south, there are many spectacular cliffs, gorges, rockhouses, natural bridges, and waterfalls. In Tennessee it borders the Highland Rim east of the Nashville Basin. In Kentucky, the appearance and height of the resulting hills increases dramatically from northwest to southeast, with the hills in the westernmost areas of the plateau having a relief of around 200 feet and an appearance very similar to the knobs region, whereas areas near Cumberland Mountain have a spectatular relief that can exceed 1500 feet.
It is contiguous with the Allegheny Plateau on the northern side, the only real difference being local naming. The sedimentary rocks that compose both plateaus are of Mississippian and Pennsylvanian geological age, composed of near shore sediments washed westward from the original Appalachian Mountains. Some rock layers were laid down in shallow coastal waters, some, including bituminous coal seams were laid onshore in swampy environments. These are interlaced with delta formations of cross-bedded sandstones and occasionally conglomerate. There are numerous discontinuities in the beds, where they were raised high enough to be eroded, then lowered to have more sediments added on top.
Though the plateau is not composed of true mountains (although that is the local name for them), and nowhere is very high, it has some of the most rugged terrain in the eastern United States. Inhabitants of eastern Kentucky and western West Virginia mostly live in very narrow V-shaped valleys with little bottom land. Buildings and roads built along the bottom of the valley are susceptible to floods, while any structures on the steep slopes are subject to slumping. Roads are serious engineering challenges, and expensive to maintain. There are few locations available for agriculture; most people make their livelihoods from mining, timbering, or services.
The plateau contains some of the largest stretches of contiguous forest in the eastern United States; however, the rich, native deciduous forests are increasingly being converted to monoculture pine plantations. Ecologically, it is a part of the Appalachian mixed mesophytic forests ecoregion.
See also: Geology of the Appalachians
External links
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