Platypus Rockshelter (KBA:70), S.E. Queensland: chronological changes in site use

Platypus Rockshelter is a multicomponent archaeological site set into a conglomerate cliff on the Brisbane River near Fernvale, S.E. Queensland.  Excavation revealed seven stratigraphic units in the smaller of two weathered cavities and these date from some 300 BP to younger than 540 BP.  An abundance of bone, freshwater mussel shell, charcoal and a lesser amount of other organic material (e.g. feathers, hair, plants) was found associated with numerous stone artefacts. This good organic preservation, when linked with an internally consistent C14 dating series, a model of site formation and an initial understanding of site disturbance processes, makes it feasible to investigate variability in prehistoric human use of Platypus Rockshelter.  Details concerning the site's complex stratigraphy, dating and site formation are the focus of a separate paper in this issue of QAR (Hall et al 1988).  In accordance with the aims of the Moreton Region Archaeological Project - Stage II (Hall and Hiscock 1988), this companion paper presents data on the assemblage content and discard patterns in order to discuss changing site use during the Holocene.  In particular we raise the issue of how the changing morphology of the shelter may have influenced the temporal pattern of cultural discard and follow with a discussion of how the nature of assemblages may be employed to tease out some factors relating to temporal changes in site use.  We also offer the caveat that changes in the discard rate of cultural material through time do not necessarily reflect shifts in "occupational intensity".