Intrasite studies of the spatial arrangements of archaeological materials to interpret structures in activity areas is an important facet of archaeology. As post-depositional processes move these materials from their original position it is imperative that the effect of these processes are evaluated before interpretations about the use of space by humans living at the site are made. In this study we conclude that most of the sediment starch and charcoal from a sandstone rockshelter in New South Wales derives from a cultural source. An evaluation of the effect of seven physical characteristics of the site on the horizontal distribution of the starch and charcoal remains suggests that, at least at this rockshelter, and unlike their effect on stone artefacts, these characteristics have not obscured the general pattern of original distribution at the site. The distribution pattern can, therefore, be interpreted as representative of past human use of space at the rockshelter.