Visitors commonly note the rounded appearance of the back side of Half Dome. It was not polished by glaciers but rather fracture
d off in sheets much like how one might peel layers from an onion. This process occurs because these rocks formed at ~20–25 km depth, but have experienced a removal of confining pressure because they are now exposed at the surface What is this process called?
This process where the sheets might peel off like an onion is called exfoliation.
Rock exfoliation can be described as a process that occurs causing sheets of rocks to be peeled from the surface of a rock. The process is also describes as Onion skin weathering.
Pressure release that happens during erosion could also be responsible for this happening. Curved plates of rocks would be stripped from underneath.
