Fossiliferous Quaternary lacustrine deposits of the Lake Eyre Basin are exposed in escarpments along the margins of Lake Eyre, North and were intersected in shallow boreholes in the area. These are described in detail and their distribution shown on the geological maps. The elevation of these earlier lake deposits above the present lake level, and their presence beneath a veneer of drift sand in the longitudinal ridges bordering the lake, have led to the conclusion that lake and dune formation are dual effects of wind erosion fallowing desiccation in Early Recent Times. Evidence is presented that a channelling effect of the wind played a major role in initiating dune development.