How do sheet joints and exfoliation domes form in granite plutons?

Sheet fractures are accurate fractures defining slabs of rock that range from 0.5 to 10 meters thick. They normally form in sets parallel to the Earth's surface but may form in convex-upward or concave-upward sets. The most popular hypothesis of the formation of sheet fractures is that they are the result of expansion and tangential fracturing consequent on erosion offloading or pressure release.