How do rock shelters form beneath resistant sandstone layers?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

cave Stalactites and stalagmites in the Queen's Chamber, Carlsbad Caverns National Park, southeastern New Mexico.

Rock shelters, often found beneath resistant sandstone layers, form through a process of differential erosion. When a hard, resistant layer of rock—known as a cap rock—overlies a softer, more easily eroded material, the base of the slope is worn away more rapidly than the top.

As the softer material at the base is removed by weathering or erosive forces, the resistant cap rock is left unsupported, creating an overhang or a sheltered recess. This process is a common feature of cliff formation, where the resistance of the cap rock to uniform downcutting allows the underlying slope to retreat, resulting in the characteristic sheltered space beneath the ledge.1