A pilot study into the geochronological and geomorphic context for the archaeology of Barrow Island, Western Australia

The island sanctuary of Barrow Island on the edge of the inner North-West continental shelf of Australia holds significant environmental as well as Indigenous and colonial cultural value. Insights on past occupation dynamics, particularly in response to Post-Glacial sea-level rise, continue to emerge from analysis of archaeological assemblages. However, there is limited temporal and landscape information from the wider island with which to better contextualise the physical site formation history of these cultural records. We present a new, modelled Post-Glacial sea-level curve for the region and new geochronological and sedimentological data (including rare earth element and quartz microtextural data) from non-archaeological site contexts to help infer changes in the coastal environment. This new data provides new insights on the island's paleogeography and evolution since approximately 80 ka BP in the context of inherited Last Interglacial features and highly dynamic oceanographic processes. Ongoing physical weathering processes have influenced dune building and reworking, such that neither colour nor numeric age are reliable indicators of sediment compositional and textural maturity. The results continue to emphasise how the continued integration of the island's geological, sedimentological and archaeological records help to understand aspects of cultural site formation, as well as expose some of the limiting factors in our understanding of past and present island physical dynamics.Ministry of Education (MOE)National Research Foundation (NRF)Submitted/Accepted versionThis study was made possible through a Research Collaboration Award from the University of Western Australia, with additional funding provided from an Australian Research Council Discovery Early Career Award to IW (DE180100601). Archaeological data was collected by the Barrow Island Archaeological Project funded by an ARC Discovery Grant (DP130100802) 2013–2015 awarded to PV and team. Department of Biodiversity Conservation and Attractions, Chevron Australia and WA Oil are thanked for their logistical and personnel support in the field, as also are Mick O’Leary and Peter Kendrick. We acknowledge the support of Buurabalayji Thalanyji Aboriginal Corporation. We thank Dick Peltier for providing the ICE-7G_NA ice model and Kurt Lambeck and Anthony Purcell for providing the ANU-ICE ice model. The global ANU-ICE combination model used in this study was kindly provided by Holger Steffen. Tanghua Li is supported by the Singapore Ministry of Education Academic Research Fund MOE2019- T3-1-004 and MOE2018-T2-1-003, the National Research Foundation Singapore, and the Singapore Ministry of Education, under the Research Centers of Excellence initiative. The GIA modelling is conducted in part using the research computing facilities and/or advisory services offered by Information Technology Services, the University of Hong Kong. This work comprises Earth Observatory of Singapore contribution no. 424. The authors also acknowledge the facilities, and the scientific and technical assistance of Microscopy Australia at the Centre for Micro- scopy, Characterisation & Analysis, the University of Western Australia, a facility funded by the University, State and Commonwealth Govern- ments. Acknowledgement is given to Mark Basgall David Zeanah and David Glover of Sacramento University for use of artefact distribution maps; and to Mick O’Leary for the DEM image of the Chair (Loop Beach)