What is exfoliation in geological terms?

Exfoliation in geological terms refers to the process where layers of rock are broken off due to temperature changes, particularly the difference between day and night temperatures. This thermal expansion and contraction cause stress on the rock, leading to the peeling away of outer layers. It is particularly prevalent in areas with significant temperature fluctuations, where rocks can expand when heated during the day and contract when cooled at night. This phenomenon often creates a "exfoliated" appearance in rock formations, where the outer surfaces flake off, exposing new layers beneath.

The other options represent different geological processes. For instance, limestone pavement formation involves the weathering of soluble limestone, which is distinct from exfoliation. The melting of ice in rock crevices pertains to freeze-thaw weathering, while the movement of the Earth's crust relates to tectonic activity, none of which specifically describe the exfoliation process.