Scotia lies within the Murray Basin, which contains thin and generally flat-lying sedimentary rocks of Cainozoic age. The landscape consists of level and gently undulating plains and dunes with soils largely of aeolian origin
Two landforms predominate at Scotia. The first consists of parallel sand dunes with narrow sandy swales and small to large open calcareous swales. The dunes travel in an east-west direction, are up to 10 m in height and 200 to 1,200 m apart. Individual dunes may form an unbroken line to 6 km in length. Slopes are gentle with the south-facing side generally slightly steeper than the northern.
There are also patches of sandy interdune plains up to 20 km2 in area. On Scotia the dunes, which are almost wholly stabilised, are composed of red earthy sands and sandy solonised brown soils overlying sandy clays. The other dominant landform type is flat extensive plains of calcareous loamy sands overlying light clay sub-soil. They consist of loam or sandy loam solonised brown soils often with limestone nodules at the surface. Surface flow of water is limited due to the sandy nature of the soils, and no watercourses are evident on Scotia. However, moisture accumulates in the swales and open flats where the soil texture is heavier.
Scotia’s vegetation is dominated by four communities: two Eucalyptus shrubland (mallee) communities, one with a spinifex understorey, the other with an understorey comprising a variety of shrubs; belah woodlands and mixed shrubland, the latter being a stage in the regeneration of previously cleared mallee or belah woodland. A number of other vegetation communities occur as small patches. Community distribution is largely determined by the influence of minor changes in topography and associated soil type on soil water relations, and history of disturbance: Eucalyptus shrublands are confined to sandy soils on the dunes and sandy swales, while Casuarina woodlands are found in the swales and calcareous plains of loamy solonised brown soils.