Applying geoarchaeological principles to marine archaeology: A reappraisal of the “first marine” and “in situ” lithic scatters in the Dampier Archipelago, NW Australia

The absence of known prehistoric underwater cultural heritage (UCH) sites on the Australian inner shelf stands in stark contrast to the thousands of sites revealed elsewhere in the world. Two recent claims—Dortch et al. (D2019) and Benjamin et al. (B2020)—put forward the first in situ (i.e., primary context) UCH sites in the shallow waters of the Dampier Archipelago, North West Australia, each arguing that the stone artefact scatters are at least 7000 years old and are now submerged because of postglacial sea-level rise. We present new hydrodynamic modelling and data on coastal erosion and bathymetry, and reassess each site's sedimentary setting and archaeological site-formation history. D2019 and B2020 clearly present lithic cultural artefacts, but the arguments for their sites being of primary context and reflecting early Holocene land surfaces are mistaken. Rather, these sites occur in the intertidal zone, and many or all artefacts are likely to have been reworked. Sites of secondary context, if treated appropriately, can inform our understanding of site-formation process and change, and may support more powerful contributions to submerged archaeology than attempts to seek the first or the oldest.