Inverted Topography: Germany Valley, West Virginia

May 01, 2013

Inverted Topography_2 copy (2)

Photographer: James Van Gundy
Summary Author: James Van Gundy

When the African and North American lithospheric plates collided in Carboniferous (Pennsylvanian) and Permian times, beginning about 325 million years ago, the rocks of the Appalachian region were faulted and folded into a lofty range of mountains. The folding produced an alternating series of upfolds (anticlines) and downfolds (synclines) in the region that's now called the Appalachian Valley and Ridge province. While one might expect an upfold to produce a ridge and a downfold to produce a valley, this isn't always the case. During folding, rocks tend to be compressed and strengthened along the trough of a syncline and stretched and weakened along the crest of an anticline. As a consequence of this, subsequent erosion may leave the compacted rocks of a syncline behind as a topographic high (ridge), and the stretched and cracked rocks of an anticline behind as a topographic low (valley). This has been referred to as "inverted topography".

Germany Valley in eastern West Virginia is a classic example of an anticlinal valley in which the Wills Mountain Anticline has been breached by erosion to form the picturesque valley viewed above. The Wills Mountain Anticline is a major Appalachian fold structure that extends for nearly 200 mi (320 km) through parts of Pennsylvania, Maryland, West Virginia and Virginia. Photo taken on June 12, 2010.

Photo details: Camera Maker: SONY; Camera Model: DSLR-A100; Focal Length: 18.0mm (35mm equivalent: 27mm); Aperture: f/10.0; Exposure Time: 0.0063 s (1/160); ISO equiv: 100; Software: DSLR-A100 v1.02.