Calcrete or Caliche is a type of sedimentary rock often found in arid and semiarid regions. It is composed of calcium carbonate with bits of gravel, clay and silt. It is found in Australia, Kalahari Desert, Sonoran and Mojave desert. Note that caliche does not form through dissolution and reprecipitation of rainwater. Rather, it forms when water from the ground rise above through capillary action, bringing up minerals from the ground into the surface.