Ridge-and-valley Appalachians
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The Ridge-and-Valley Appalachians, also called the Ridge and Valley Province or the Valley and Ridge Appalachians, are a physiographic province of the larger Appalachian division and are also a belt within the Appalachian Mountains extending from northern New Jersey westward into Pennsylvania and southward into Maryland, West Virginia, Virginia, Tennessee, and Alabama. They form a broad arc between the Blue Ridge Mountains and the Appalachian Plateau physiographic province (the Allegheny and Cumberland Plateaus).
These mountains are characterized by long, even ridges, with long, continuous valleys in between. From a great enough altitude, they look almost like corduroy, except that the widths of the valleys are somewhat variable and ridges sometimes meet in a vee.
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[edit] Geography
The two great mountain ranges constituting the middle portion of the Ridge and Valley Province are the Alleghenies and the Cumberlands.
The eastern edge of the Ridge and Valley region is marked by the Great Appalachian Valley, which lies just west of the Blue Ridge. The western side of the Ridge and Valley region is marked by steep escarpments such as the Allegheny Front, the Cumberland Mountains, and Walden Ridge.
[edit] Geology
These curious formations are the remnants of an ancient fold-and-thrust belt, west of the mountain core that formed in the Alleghenian orogeny (Stanley, 421-2). Here, strata have been folded westward, and forced over massive thrust faults; there is little metamorphism, and no igneous intrusion.(Stanley, 421-2) The ridges represent the edges of the erosion-resistant strata, and the valleys portray the absence of the more erodible strata. Smaller streams have developed their valleys following the lines of the more easily eroded strata. But a few major rivers, such as the Delaware River, the Susquehanna River, and the Potomac River are evidently older than the present mountains, having cut water gaps that are perpendicular to hard strata ridges. The evidence point to a wearing down of the entire region (the original mountains) to a low level with little relief, so that major rivers were flowing in unconsolidated sediments that were unaffected by the underlying rock structure. Then the region was uplifted slowly enough that the rivers were able to maintain their course, cutting through the ridges as they developed.
Valleys may be synclinal valleys or anticlinal valleys.
These mountains are at their highest development in central Pennsylvania, a phenomenon termed the Pennsylvania climax.
[edit] References
| This article or section relies largely or entirely upon a single source. Please help improve this article by introducing appropriate citations of additional sources. |
- Stanley, Steven M. Earth System History. New York: W.H. Freeman and Company, 1999. ISBN 0-7167-2882-6
[edit] Significant ridges
| Name | State |
|---|---|
| Bays Mountain | Tennessee |
| Clinch Mountain | Tennessee and Virginia |
| Sleepy Creek Mountain | West Virginia |
| North Mountain | Virginia and West Virginia |
| Powell Mountain | Tennessee and Virginia |
| Cacapon Mountain | West Virginia |
| New Creek Mountain | West Virginia |
| Knobly Mountain | West Virginia |
| Mill Creek Mountain | West Virginia |
| Patterson Creek Mountain | West Virginia |
| South Branch Mountain | West Virginia |
| Spruce Knob | West Virginia |
| Sideling Hill | West Virginia, Maryland, and Pennsylvania |
| Bald Eagle Mountain | Pennsylvania |
| Nittany Mountain | Pennsylvania |
| Tussey Mountain | Pennsylvania |
| Blue Mountain | Pennsylvania |
| Kittatinny Mountains | New Jersey |
| Shawangunk Ridge | New York |
| Red Mountain | Alabama |
[edit] See also
General sub-fields of Physical Geography | |
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| Image:Flag of Maryland.svg | State of Maryland Annapolis (capital) |
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| Topics | |
| Regions |
Allegheny Mountains | Atlantic Coastal Plain | Baltimore‑Washington Metro Area | Blue Ridge | Chesapeake | Cumberland Valley | Delaware Valley | Delmarva Peninsula | Eastern Shore | Piedmont | Ridge and Valley | Southern Maryland | Western Maryland | Western Shore |
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| Counties |
Allegany | Anne Arundel | Baltimore City | Baltimore County | Calvert | Caroline | Carroll | Cecil | Charles | Dorchester | Frederick | Garrett | Harford | Howard | Kent | Montgomery | Prince George's | Queen Anne's | St. Mary's | Somerset | Talbot | Washington | Wicomico | Worcester |
Categories: Articles lacking reliable references from December 2007 | Geography and place-related navigation templates | Physical geography | Geology of Alabama | Geology of the United States | Regions of New Jersey | Regions of Tennessee | Regions of Virginia | Regions of West Virginia | Mountain ranges of Maryland | Mountain ranges of New Jersey | Mountain ranges of New York | Mountain ranges of Pennsylvania | Mountain ranges of West Virginia | Mountain ranges of Tennessee | Mountain ranges of Virginia | Physiographic provinces
