Sorting, texture and structure

Abstract

SynopsisSands are sorted by the actions of air and water. A mathematical–physical model for the ensuing spatial and temporal variations in the size distributions of the sand grains is outlined. A crucial element in aeolian sorting and transport of sand is the process that takes place when a saltating grain impinges on the sand surface. This raises the problem of describing the texture of sand surfaces. Some initial empirical and mathematical findings concerning this problem are discussed. A closely connected question is that of how the grains in a sand deposit are packed and how this relates to the size distribution. Voronoi tesselations in combination with random point processes seem to offer one useful approach to the question.