Recent advances in delta sedimentology are briefly summarized. Most of the review is based on data that have been published elsewhere. Some new information is presented concerning the Rhǒne delta, e.g., the distribution of its marine environments (Fig. 2) and the regional variations in differentiation of the mollusc shell assemblages (Fig. 3). The bulk of the sediments in deltas of the Rhǒne type are formed in marine environments. The volumetric proportions between deposits of different facies, as found in many recent deltas, may be very dissimilar to those in fossil (pre-Quaternary) deltas, formed under “non-glacial” conditions (cf. Fig. 7).