The Shape of Pebbles, Grains and Pores

This short chapter offers a wealth of material, many of them recent developments. We discuss and tabulate (Table 7.2) the different classification schemes and numerical formulae used to describe the shape of grains, pebbles and rock fragments; acquaint the Reader with the efforts of a Hungarian research group (of Professor Gábor Domokos) to find the evolution equationEvolution equation that explains the characteristic ovoid shapeOvoid shape of beach pebbles. Further topics include the number of stable and unstable points of equilibriumStable and unstable points of equilibrium of a pebble or rock fragment, dependence of the settling velocitySettling velocity of sediments in water on particle shape, and the physical–mathematical fundamentals of the techniques measuring surface roughnessSurface roughness and surface fractal dimensionSurface fractal dimension of irregular particles.