The underground geology of east Tennessee is equally as interesting as the geology on the surface. Because this area was under a shallow sea hundreds of millions of years ago, there is a thick layer of limestone bedrock. This limestone was made from the shells of ancient sea creatures. Limestone is weathered by slightly acidic water that seeps through cracks in the rock layer. Over time caves develop, some "decorated" with spectacular formations made of calcium carbonate. Ground water can collect deep beneath the surface and reappear as springs. As can be seen in this diagram, it is important not to contaminate surface water as it can eventually end up in ground water. Many people depend on this ground water when they drill wells for drinking and home use. Sinkholes should not be used as "dumps" because that trash could also contaminate well water.
are bizarre formations that seem to defy the laws of gravity. Note the strange horizontal growths coming out of some of the stalactites. The bright white dots are the reflections from water dripping from the stalactites.
is a small, hollow stalactite that is growing molecule by molecule of CaCO3 (calcium carbonate) with each drop of water. As the slightly acidic rainwater seeps through the limestone above the cave, it picks up calcium carbonate. When the water drips through the cave roof, it leaves behind small amounts of the mineral resulting in the soda straw. A wet cave is a "living" cave.
