Limestone
Limestone caves form from weathering when the limestone is dissolved by acid groundwater, or from acid rainwater. Once such a cave is formed from the acid rain and water, stalactites and stalagmites may begin to form.
Physical Weathering
Caves may be formed from weather effects such as deep cold and intense freezing. This may cause cracking, frost heaves, and splits in the rock, leading to caves.
Exfoliation
Over time, rocks may cleave or slough off in sheets. This is called exfoliation. Caused by wind, temperature shifts and gravity, exfoliation may cause caves to form.
Thermal Expansion
With the repeated daily heating and cooling of rock, cave formations take place over time. Heat causes expansion in the rock and cooling causes contraction. The two opposing forces crack the rock and allow for cave formations to take place.
Oxidation and Biological Weathering
Many rocks and caves have iron content. With exposure to water vapor, oxidation or rusting takes place and helps form caves. Biological weathering takes place when lichens and mosses attach to the rock of cave walls and slowly decompose them.
Article Written By Eric Cedric
A former Alaskan of 20 years, Eric Cedric now resides in California. He's published in "Outside" and "Backpacker" and has written a book on life in small-town Alaska, "North by Southeast." Cedric was a professional mountain guide and backcountry expedition leader for 18 years. He worked in Russia, Iceland, Greece, Turkey and Belize. Cedric attended Syracuse University and is a private pilot.
