The unit consists mainly of undulating plains with east-west elongated sand dunes and interdune swales. Due to the scale of mapping, however, areas with sand sheets and non-orientated sand rises have been also included in this unit. In the present survey, the main occurrence of this landform is limited to some localities in the Charlton district, occupying about 4 000 hectares.
The main soils included in this unit have been mapped in the Ledcourt association.