Buckaringa is part of a folded sedimentary sequence of sandstones, siltstones and shales. While the sandstones are relatively resistant to erosion, both the siltstone and shales are weak and easily eroded. The sandstone fold structures form the present pattern of ridges and ranges. On Buckaringa the quartzite of the ABC Range forms a hogback ridge, with a steep cliff along its eastern side. Buckaringa and Middle Gorges are formed where streams have cut through the ridge at right angles to the strata, forming steep-sided gorges with numerous crevices, caves and fallen boulder piles.
The remainder of the sanctuary consists of ridges and bedrock plains carrying shallow soils and rock debris, with deeper soils on the flatter alluvial areas away from the rock outcrops.