Rubification, i.e, the reddening of the soil due to oxidation of Fe-bearing minerals is often observed in Aridisols. Soil moisture conditions in arid regions favors oxidation over redoxidation.
The processes deflation and deposition are responsible for the development of 'desert pavement' (surface pebble layers). Deflation is the sorting out, lifting, and removal of loose, dry, fine grained soil particles by the turbulent action of the wind. It is assumed that vertical sorting of stones, i.e., the gradual upward migration of pebbles that have been heaved up by swelling clay, with local supplement action by frost, growth of salt crystalls, and expansion of entrapped air, with preferential collapse of fines into voids too small to accept pebbles during subsequent desiccation support developing a surface pebble layer. The pavement serves as a dust trap but inhibits loss of soil particles by wind erosion.