Rottnest Island artifacts and palaeosols in the context of greater Swan Region prehistory

The prehistoric record of Rottnest Island 19 km offshore the Swan Region, Western Australia, consists solely of three stone artifacts. Two are Eocene fossiliferous chert flakes probably deriving from palaeosols in the Tamala Limestone cliffs at Fish Hook Bay and Little Armstrong Bay. A third is a calcrete flake from a siliceous dune blow-out near Fish Hook Bay. A feldspar pebble in situ in a palaeosol intercalated between aeolian calcarenite units at City of York Bay is probably a manuport. The age of the Little Armstrong Bay and City of York Bay palaeosols is estimated to be 15 000 to 50 000 years old. Similarities in pedology and in stratigraphic position suggest that these two palaeosols belong to a single palaeosol unit extending along Rottnest Island's northern shore, a possibility that could give scope to further prehistoric investigations on the island. Prehistoric remains could also be in situ in palaeosols and sandy sediments infilling solution pipes and other Tamala Limestone features on the island's littoral and submerged offshore. Palaeoenvironmental and archaeological site distribution data from the emergent continental shelf are used in the appraisal of pre-transgression terrestrial environments and prehistoric occupation in the Rottnest locality and elsehwere in the Greater Swan Region. -from Authors