Fine grained terraces that represent past episodes of valley aggradation are found in many of the world's arid regions, e.g. the Flinders Ranges of south Australia, the Anti Atlas mountains in Morocco, the Sinai Desert, and the Namib Desert. The sediment texture and facies of these paleo-valley fills contrast markedly with the modern channel and floodplain. Hypotheses for the depositional paleo-environment include lacustrine, wetland and paleoflood.