Charles Lyell and Johannes Walther are the 19th century founders of comparative sedimentology, and their philosophies and methods are the basis for most of the advances of the 20th century.

A principal result of the post-World War II expansion of comparative sedimentology initiated by the petroleum industry is the increased understanding of sedimentary features in carbonates--textures, structures, and organic elements. Examples of advances include the origin and environments of algal stromatolites, synsedimentary development of dolomite on tidal flats, geometry and internal structure of ooid sand bodies, and early diagenesis in subaerial and submarine environments. The vitality of the comparative approach is attributed to the continuing comparisons of recent and fossil examples. In retrospect, many earlier interpretations of ancient sedimentary features could have been used as guides to finding their recent analogues, i.e., supratidal dolomite, submarine cement in reefs. /P>

The postwar expansion of research on facies in carbonates is as lively and productive as that on sedimentary features. The five contributions of this collection explore comparisons of facies from different ages; their leadings and advances in understanding sedimentary features are used to predict future developments in (1) diagenetic facies; (2) facies anatomy of Holocene-Quaternary reefs and platforms; and (3) comparisons of facies patterns within and between geologic periods.