Cave Formations

Stalactites
Stalagmites
Flowstone
Draperies
Helictites
Columns

The age of a speleothem (a stalactite or stalagmite) can be determined. The calcite in a speleothem contains traces of radioactive uranium. The uranium decays at a constant rate and makes dating by radiometric methods possible. These dates help determine the cave's age. They also provide a timeline for environmental changes that are recorded in the cave's formations.

Speleothems can tell us about rainfall. They have concentric bands of growth similar to tree rings. During wet periods, the bands are thicker; during droughts, the bands are thinner. The layers can be dated, and help us reconstruct rainfall patterns through time.