The birth of sedimentology: Henry Clifton Sorby and Johannes Walther

Sedimentology is the study of naturally occurring particulate matter with special emphasis on understanding the factors controlling the creation, distribution and accumulation of that matter. Consequently, sedimentology can, and does, embrace geomorphology and climatology, transport mechanisms, depositional environments and lithifaction processes. Its significance lies in the ability of practitioners of the subject—sedimentologists—to determine each and all of the foregoing through the study of samples of sediments and sedimentary rocks. It is, therefore, a basic discipline for the study of past and present environments on Earth, its satellite and its planetary neighbours. The long-standing contributions of two of the nineteenth century founders of the subject, Henry Clifton Sorby (1826–1908) and Johannes Walther (1860–1937), are discussed here.