The progress of soil development at Swan Hill has been examined by the comparison of four successively older soil profiles which have all developed on aeolian materials at different times in history. The initial development is one of homogenization effected by biotic agencies that obliterates the depositional fabric and structure. There are found to be several other trends in profile differentiation which have advanced further in each older soil. These trends include the leaching of lime from the surface and its concentration into concretions, and the removal of clay from the surface and its deposition as coatings to grains, pores, and peds and as a dense matrix.