MODELING THE DEVELOPMENT OF NON-PERIGLACIAL SORTED NETS

Theoretical model experiments demonstrate that non-periglacial sorted nets can develop on any piece of unobstructed ground surface that has little or no gradient, if it bears a loose, discontinuous cover of pebble-sized stones and if these particles are moved on the surface in small steps in any direction of the compass with equal probability. The physical causes of these movements are not important for the establishment of the sorted net. The model experiments also show that both the time required to establish a stable sorted net pattern from an initially disordered state and the diameters of the sorted polygons that have develop during this time are negative exponential functions of the cover density. Furthermore, there are certain cover density thresholds below which coherent polygon networks cannot be established or maintained.