Teacher and Student Information
The Shenandoah Caverns family of attractions offers an exciting and varied opportunity to combine earth science, history, and simple mechanics in one field trip experience. This teacher packet will provide you with some important resources to enhance the experience before your visit and in follow up classroom activities.
What is karst and and why is it important?(courtesy of Cave Conservancy of Virginia)
Karst is a landscape that includes topographic depressions such as sinkholes and caves caused by the underground dissolution of limestone bedrock. This landscape features underground streams and aquifers that supply the wells and springs providing drinking water to communities. The hollow nature of karst terrain means it has a very high potential for pollution. That’s because streams and surface runoff that enter sinkholes and caves bypass the natural filtration through soil and will move quickly through underground networks delivering contaminants to wells and other sources of drinking water. Approximately 10% of the Earth’s surface (20% of the United States) is composed of karst. However, about 25% of the population lives in those areas, indicating the importance of pollution control.
How karst and caverns were formed(courtesy of Cave Conservancy of Virginia)
Hundreds of millions of years ago, the area now occupied by the eastern United States was covered by a calm, shallow, tropical sea. Over eons, the deposits of calcium-rich shells and skeletons solidified into the bedrock we call limestone, dolomite and gypsum. These rocks are soluble in dilute acids. Water becomes slightly acidic when it takes up carbon dioxide while passing through the atmosphere and through organic soils. The interaction of acidic water with soluble rock produces the landscape known as karst.
During the Appalachian Orogeny, a series of mountain-building events in the central and eastern United States, rocks were alternately buried, uplifted, faulted, folded and fractured. This activity created cracks and fissures through which water flowed, dissolving the organic limestone. Within the past ten million years, caves, conduits and underground drainage systems have been carved into the rock by moving water.
As the cracks enlarge, they eventually meet, grow larger and form a funnel-shaped hole. As the funnel becomes larger, it allows more water to move through. The water begins moving sideways between layers of stone, always dissolving the limestone and enlarging the holes. The cracks become crevices. The crevices become channels. The channels become tunnels.
Resources & Links
- Class Exercise - Download and print a class exercise for your students to complete while touring the caverns. The free Acrobat reader is required, download that here.
- US Geological Survey (A Teachers Guide to Caves)
- American Geological Society (Earth Science Week materials)
- Cave Conservancy of the Virginias: 13131 Overhill Lake Lane, Glen Allen, VA 23059 804-798-4893
- National Caves Association: 4138 Dark Hollow Road, McMinnville, TN 37110 931-668-3925
- Virginia Cave Week