Description:
Giant desiccation cracks are common in southwestern U.S. playas and have been
reported in several areas of Arizona but they are much more common than previously
recognized. These giant cracks are similar to mudcracks or large soil cracks, but on an
enormous scale. The cracks themselves are up to 3 feet (1 m) wide, up to 9 feet (2 m)
deep (apparent depth), and a few are on the order of 1000 feet (300 m) long. They form
polygonal blocks that look identical to the shape of mudcracks, but the polygons are
characteristically 150-600 feet (45-180 m) across whereas typical mudcracks form
polygons 4-8 inches (10-20 cm) across and large soil cracks form polygons 2-6 feet (0.5-
2 m) across. Some giant desiccation cracks are large enough to be mistaken for earth
fissures that are caused by subsidence from groundwater pumping.