and one of the founders of modern sedimentology, Kuenen’s participation in the Snellius deep-sea expedition to the Moluccas (1929–30) directed his attention to marine geology. One of the very few experimental geologists, he demonstrated the efficacy of high-density turbidity currents in transporting sand to deep-sea environments. In 1950 Kuenen, together with the Italian geologist C. I. Migliorini, interpreted the graded sandstone beds of ancient flysch sequences as turbidites. The study of their sedimentary structures has contributed much to palaeogeography. His most widely known book in the English language is the early classic on Marine Geology (1950).