Sally Brockwell

Late Holocene climate change and human behavioural variability in the coastal wet-dry tropics of northern Australia: Evidence from a pilot study of oxygen isotopes in marine bivalve shells from archaeological sites

Abstract Previously it has been argued that midden analysis from three geographically distinct coastal regions of tropical northern Australia (Hope Inlet, Blyth River, Blue Mud Bay) demonstrates that changes through time in Aboriginal mollusc exploitation reflect broader coastal environmental transformations associated with late Holocene climatic variability (Bourke et al. 2007). It was suggested that, while a direct link between environmental change and significant cultural change in the archaeological record has yet to be demonstrated unambiguously, midden analysis has the potential to provide the as-yet missing link between changes in climate, environment and human responses over past millennia. We test this hypothesis with a preliminary sclerochronological analysis (i.e. of sequential stable isotopes of oxygen) of archaeological shell samples from all three regions. Our findings suggest the existence of variations in temperature and rainfall indicative of an increasing trend to aridity from 2000 to 500 cal. BP, consistent with previous palaeoenvironmental work across northern Australia.

Earth Mounds in Northern Australia: A Review

Abstract Although earth mounds are a common archaeological feature of the northern Australian coastal plains, there has been little systematic investigation of them. This paper aims to redress the balance by reviewing and synthesising investigations into earth mounds in northern Australia. I examine several themes raised in the literature that are relevant to research on earth mounds in relation to a number of case studies from northern Australia. These include location, morphology, origins, chronology and the role of mounds in the wider context of settlement systems. I conclude that earth mounds in northern Australia can be divided into two distinct types, coastal/estuarine and freshwater. Both types proliferated in the late Holocene and represent seasonally occupied sites at the junction of a number of resource zones that may also have had social significance as territorial markers.

Local and Indigenous management of climate change risks to archaeological sites

Hundreds of thousands of significant archaeological and cultural heritage sites (cultural sites) along the coasts of every continent are threatened by sea level rise, and many will be destroyed. This wealth of artefacts and monuments testifies to human history, cosmology and identity. While cultural sites are especially important to local and Indigenous communities, a stall in coordinated global action means adaptation at a local scale is often unsupported. In response, this paper produces a practical climate change risk analysis methodology designed for independent, community-scale management of cultural sites. It builds on existing methods that prioritise sites most at risk from climate impacts, proposing a field survey that integrates an assessment of the relative cultural value of sites with assessment of exposure and sensitivity to climate impacts. The field survey also stands as a monitoring program and complements an assessment of organisational adaptive capacity. The preliminary field survey was tested by Indigenous land managers in remote northern Australia at midden and rock art sites threatened by sea level rise, extreme flood events and a range of non-climactic hazards. A participatory action research methodology—incorporating planning workshops, semi-structured interviews and participant observations—gave rise to significant modifications to the preliminary field survey as well as management prioritisation of 120 sites. The field survey is anticipated to have global application, particularly among marginalised and remote Indigenous communities. Well-planned and informed participation, with community control, monitoring and well-informed actions, will contribute significantly to coordinated global and regional adaptation strategies.

The palaeo-environmental history of Big Willum Swamp, Weipa: An environmental context for the archaeological record

Abstract The environmental history of Big Willum (Waandriipayn) Swamp and the surrounding landscape is reconstructed for the last 8000 years through the analysis of pollen, charcoal and mineral magnetics. The data provide a Holocene record of vegetation and fire in an area where few records exist. Swamp initiation at Big Willum began prior to 8000 cal. BP, with swamp–like conditions maintained until 2200 cal. BP, after which it became a permanent deep water body, reaching its present day extent between 600–400 cal. BP. From 7000–1200 cal. BP the surrounding woodland was essentially stable. Fire is present throughout the record, with only one period of pronounced burning outside of the historic period, at around 1000 cal. BP, leading to a slightly more open understorey/woodland. The hydrological change at 2200 cal. BP that led to Big Willum becoming a more permanent water body overlaps with the end of the most intensive period of shell mound formation and the commencement of earth mound building at nearby Wathayn. This is suggestive that change in, or diversification of, mound types may in part be linked to environmental transformations in the late Holocene. One possibility is that greater water security allowed for increasing and more permanent exploitation of inland locations.