Exfoliation can happen in thin layers on individual boulders, or it can take place in thick slabs as it does here, at Enchanted Rock in Texas.
The great white granite domes and cliffs of the High Sierra, like Half Dome, owe their appearance to exfoliation. These rocks were emplaced as molten bodies, or plutons, deep underground, raising the Sierra Nevada range. Erosion then unroofed the plutons and took away the pressure of the overlying rock. As a result, the solid rock acquired fine cracks through pressure-release jointing. Mechanical weathering opened up the joints further and loosened these slabs.
