Chronology and palaeoenvironment of the Cranebrook Terrace (near Sydney) containing artefacts more than 40,000 years old

Abstract

There is growing scientific and popular interest in the chronology, habitational environment and spatial extent of early human occupation of Australia. Lunettes adjacent to lakes in the semi-arid interior near Lake Mungo appear to have been occupied by at least 35,000 BP (Bowler 1976) Alluvial sites in the upper Swan River in Western Australia (Pearce and Barbetti 1981) and possibly Keilor in Victoria (Joyce and Anderson 1976) were peopled by about 40,000 BP (see review by White and O'Connell 1982:32-42). The oldest reported archaeological finds for coastal NSW are what are believed to be a selection of choppers and steep-edged scrapers found in association with alluvial gravels at the base of the Cranebrook Terrace of the Nepean River (Fig.l). StoGkton and Holland (1974), who described the site, obtained radiocarbon dates of 26,700 + 1700/1500 BP (GaK 3014) and >31,8OO BP (GaK 3445) for logs buried within the gravels. However, we now have reason to believe that these dates are minimum ages resulting from the contamination of ancient wood with younger carbon mobile within the groundwater. In this paper GCN and RWY are responsible for the geomorphology, stratigraphy and chronology, EDS for the archaeology. Because the artefacts were not found in a clearly defined habitation site, but rather were scattered throughout what was possibly a reworked gravel unit, their authenticity has not been universally accepted, although it has never been seriously questioned. Yet it was not the intention of Stockton and Holland (1974) to critically establish the absolute authenticity or antiquity of early human occupation of the Cranebrook Terrace. Their paper examined 'sites ranging across the Blue Mountains'. The Cranebrook Terrace is essentially outside their study location and was poorly dated. This most eastern aspect of their work has not been followed up except for a recent paper on an alluvial site nearby (Kohen et al 1984).