Vertical facies changes form the fundamental basis of interpretation of many submarine turbidite systems. Some systems, however, do not show major vertical cyclicity over thicknesses of hundreds of metres, but rather display significant lateral changes. The late Proterozoic Amis River Formation of Namibia, which contains the facies typical of submarine turbidite systems, shows little vertical variation but has major lateral changes. In the west of the exposed area the sequence consists predominantly of bundles of facies C2 and D1 (facies scheme of Mutti and Ricci Lucchi, 1975) with interbedded packages of facies B1 beds, which become more common upwards. Only minor vertical cyclicity is observed, beds are laterally continuous for many kilometres and the sandstone: shale ratio is high. In the east largely thin-bedded facies D2 beds occur with a much lower sandstone: shale ratio than in the west. This system is interpreted here as developing largely by vertical accretion rather than progradation.