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...