Sedimentary structures, both primary and diagenetic, have always interested students of sedimentary rocks, although in early times interest centered on fossils rather than on inorganic structures.
Pioneer studies of sedimentary structures were concerned with qualitative description and the use of structures for indicating the conditions under which the rocks were formed. The early observations were summarized by Gkabau (1913), amongst others, and included two outstanding papers by H. C. Sorby (1859b, 1908). There followed a period of more intensive description of sedimentary structures, stimulated partly by the early experimental studies of Gilbert (1914) and the work on Recent water and sand waves of Cornish (1914), but mainly by the increasing realization in the 1920’s and 1930’s, that sedimentary structures are valuable indicators of way up in folded strata. The prewar literature on structures as environmental or structural criteria is summarized in volumes by Twenhofel (1926,1932, 1939) and Shrock (1948).
The post–war period has seen a further rapid growth of interest in sedimentary structures. In 1950, Kuenen and Migliorini revealed the importance of turbidity currents in forming graded bedding, and subsequently numerous workers have systematically described the range of structures which are commonly associated with graded beds. Much progress has now been made in understanding these structures in spite of the severe handicap that very little is known about them from experiment or from Recent sediments. Furthermore, the mapping of these structures by