Groundwater (Part 3)
Karst Topography
• Karst topography forms when groundwater dissolves soluble rocks. Karst features include caves, sinkholes, disappearing or sinking streams, and natural bridges and tunnels.
Caves
Left: Pulaski County cave (photograph by Phyllis Newbill); right: Shenandoah County cave (photograph by Parvinder Sethi)
Caves are defined as cavities large enough for people to enter. The cave entrance shown above left is in Pulaski County. The cave shown above right is in Shenandoah County.
Sinkholes
• Sinkholes are surface depressions caused by the collapse of underlying dissolved rocks.
Sinkhole on a golf course in Giles County (Photograph by Robert Whisonant)
Sinkholes are caused by the collapse of the underlying caverns. In the photo above, this sinkhole forms a natural water hazard in a golf course in Giles County. Note people and golf cart (oval) for scale.