Inadequate observation of sedimentary TRUSHKovA and KUKHARENKO'S "Atlas of structures has been responsible for incorrect Placer Minerals." The most comprehensive interpretation of the order of superposition atlas is the "Atlas of Textures and Struc- in deformed beds and this has led, in turn, tures of Sedimentary Rocks" edited by A. to gross errors in stratigraphy and structure. V. KHABAKOV (1962). Failure to recognize and utilize those Our Atlas is an outgrowth of our work on structures which indicate direction of cur- "Paleocurrents and Basin Analysis," a book rent flow has also led to incorrect, or at in which directional sedimentary structures least incomplete, understanding of basin are described and interpreted with special development. reference to the evolution of sedimentary We believe, therefore, that there is need for basins. That work, however, contains mini- a work which constitutes a field guide to the mal photographic material - just enough study of these structures - a book in to give the reader some concept of the sedi- which these structures, so difficult to mentary structures described.