The soils are acid and have developed in a fine, sandy loam colluvium which has granules of similar composition to the lag. The landforms and the regolith types in the erosional regimes present a more complex picture reflecting active geomorphic processes. Deeper units of the weathered mantle, as well as country rock, are exposed. Gentle slopes occur as pediments below low breakaways. These slopes are mantled by acid red earths, developed in a pedisediment, and have a lag dominated by coarse, ferruginous saprolite, lithic fragments and quartz.
Erosion is active in such areas.
Some of the depositional tracts are being further modified by erosion, resulting in land-surfaces having regolith types comparable with those in other erosional regimes. The topographic relationships and regolith stratigraphies revealed by this study indicate a polyphase, multi-process history. Many of the regolith types resulting from this complex array of processes, have a distinctive pattern. The residual regimes at Bottle Creek are dominated by a regolith that is the result of intense in situ weathering, some of the uppermost regolith has been deposited by local colluviation. These areas have had a relatively stable geomorphic history.