Understanding of rivers and their sediments, both as modern systems and as ancient counterparts in the geological record, has progressed steadily but markedly over the past several decades, with contributions by practitioners in divers fields of geosciences and engineering. This book contains 31 papers, with authors from 13 countries, who participated in the Sixth International Conference on Fluvial Sedimentology held in Cape Town, South Africa, in 1977. True to the nature of these quadrennial conferences, the papers in this book discuss a broad range of fluvial subjects that include the character of bedforms and sediment transport in river channels, morphological and sedimentological features of modern fluvial environments, modern and ancient avulsions, internal and external controls on the behaviour of river systems, and the facies and architectural organization of alluvial deposits.