DYNAMICAL PROCESSES ON DESERT PAVEMENTS AND THE HEALING OF SURFICIAL DISTURBANCES

Mature desert pavements are traditionally regarded as hallmarks of sta bility, but their stability is dynamic, not static. In a study aimed a t documenting this dynamic stability and its role in healing surface d isturbances, experiments were performed over a 5-yr period on small cl eared patches, or plats, on pavement surfaces in Panamint Valley, Cali fornia, These experiments show that stones from plat edges begin to re surface the clearing at rates of about 1% per year on 40-cm-square pla ts and 10% per year on 10-cm-square plats, Stones contributing to the regenerated pavement have smaller average diameters than stones on the surrounding pavement, Cavities 5-10 cm deep, formed in mature pavemen t by removal of embedded boulders, fill by ravel and slope failure. Af ter five years, cavity depth has been reduced by as much as 60%, Forty -year-old boulder cavities are nearly completely refilled and have bee n repaved by smaller than average pavement stones, Gaps caused by remo val of small stones (2-3 cm) have completely healed in 5 yr, Displacem ent of surface stones by small animals is a major component of the hea ling process. (C) 1996 University of Washington.