Limestone: The Superstar of Cave Creation
Hulton Archive/Getty Images
Hulton Archive/Getty Images
Limestone is the superstar of cave creation, with most caves around the world formed in this rock type. This sedimentary rock is composed primarily of calcium carbonate, making it more susceptible to dissolution by acidic water.
The reaction between limestone and carbonic acid in water leads to the gradual formation of caves. Iconic cave systems like Mammoth Cave in Kentucky (pictured) and the Carlsbad Caverns in New Mexico owe their existence to limestone.