The origin, dispersal, deposition and burial of natural sediment grains is the central concern of sedimentology. The subject is truly inter- disciplinary, commands the attention of Earth scientists, is of consider- able interest to fluid dynamicists and civil engineers, and it finds widespread practical applications in industry. Sedimentology may be approached from two viewpoints: a descrip- tive approach, as exemplified by traditional petrography and facies analysis, and a quantitative approach through the physical and chemical sciences. Both approaches are complementary and must be used in...