Erosion removes rock material from the sides of this mini-canyon, causing the pressure on the adjacent rock to be reduced. As the pressure is lowered, the rocks expand outward, creating fractures subparallel to the canyon walls. Curved slabs of rock then 'peel off' along the fractures, giving the mini-canyon a parabolic cross section. Only one wall of the canyon is shown in this photo.

© 2001
Photo by David J. Leveson