The alternating topography of the area is the result of two main factors. First, during the collision with Europe and Africa, the crust of the North America was compressed, forming fold-like structures called anticlines and synclines. These structures are analogous to a tablecloth that has been pushed across a table. The second factor in forming the Valley and Ridge is found in the type of rocks found here. Unlike the piedmont, this region is composed entirely of sedimentary rocks sandstone, shale, and limestone.
Sandstones are the predominant ridge former.
They cap all the peaks found in western Virginia and West Virginia. Shales and limestones are much less resistant and tend to underlie the valleys and constitute the flanks of the ridges. In terms of environment, western Virginia has nearly seen it all. The geology of the region tells the story. The various limestones, sandstones, and shales of the Shenandoah Valley and the Valley and Ridge province formed in settings still found on earth.