Karst Landscapes of the Ridge and Valley

Sinkhole Map

The Ridge and Valley Province, and particularlyits Great Valley, is one of the major karst regions of the United States. Many famous commercial caverns, such as Luray, Shenandoah, and Endless, occur in the Shenandoah Valley of Virginia. Two other famous karst features in this region are Natural Bridge and Natural Tunnel. Although the exact means by which these two features evolved are not agreed upon, both are the remnants of cave passages.

The Ridge and Valley of Tennessee also provides excellent examples of karst (Shofner and others 2001). These karst areas are generally covered with thick terra rossa, and have topographies characterized by sinkholes, sinking streams, and caves. In eastern Tennessee, all carbonates have considerable karst development, but units with the most development include the Knox Group, some formations of the Chickamauga Group and the Honaker Dolomite.

Burkes Garden, near the southwestern end of the Central Appalachians, is a dramatic topographic feature that provides excellent examples of both structural control and karst development. Structurally the elliptical basin is a dissected dome. The basin is almost completely rimmed by Garden Mountain, a high ridge composed of Clinch Sandstone. The basin is floored with Ordovician carbonates, and the streams form a centripetal pattern that converges on an outlet through a water gap on the north side of the rim. Many of the streams sink before reaching the center of the basin, however (Thornbury, 1965).