What happened at 1500—1000 cal. BP in Central Australia? Timing, impact and archaeological signatures

Abstract

historic settlement away from the major drainage lines, involving changing relations between core and peripheral parts of the desert and new patterns of resource use, or whether it signals a more general increase in the human population of the region.Also at issue is the articulation (if any) of these socioeconomic shifts with climate-driven or human-driven changes in Central Australian environments. A related question concerns the impact of ENSO-driven climatic variability over this period: Aboriginal settlement in Central Australia appears to be expanding at a time when ENSO activity was at its highest in the current cycle (which began 4000-3000 years ago). This emphasizes the importance for arid zone prehistory of reconstructing palaeo-environmental variability, not simply long-term averages.Abstract: This paper reviews the late Holocene archaeology of Central Australia. The last 1500 years saw significant changes in the archaeological record in this part of the Australian arid zone, with shifts in settlement pattern, site histories, resource use, tool inventories and rock art. Much of the evidence points to regional population growth, beginning 1500-1000 cal. BP and coinciding with expansion of summer-rainfall grassland and more frequent palaeoflood events. Hunter-gatherer groups appear to have increased their use of marginal or outlying areas as these became seasonally accessible. Responses to the demographic changes, especially in the better-watered ranges, include more extended occupation of existing sites, more processing of acacia and grass seeds, and an increase in territoriality reflected in the greater differentiation of rock art complexes after 1500 cal. BP. The archaeological changes are not scaled commensurately with the modest environmental shifts at this time, indicating that human-environment interactions were not linear. A human-environment threshold may have been breached 1500-1000 years ago, with existing socio-economic or historical factors acting to amplify the effects of small environmental changes. However, it remains difficult to fully characterize the nature of these human-environment interactions, despite the fine-grained archaeological record now available. An unresolved problem for this emerging picture of climatic amelioration and population growth is that Aboriginal settlement in Central Australia was expanding at a time when ENSO-driven variability appears to have been at its highest.

Weaving the Common Threads of Simulation and Formation studies in Archaeology

“…Similar patterns in large radiocarbon databases around Australia have been identified, stoking longstanding debates over the population history of the continent and the presence or absence of a definable period of socioeconomic 'intensification' during the late Holocene (Smith and Ross, 2008;Williams, 2013). Alternatively, this pattern has been suggested to instead be the result of time-dependent decay on the archaeological record (Holdaway et al, 2008).…”

A continental narrative: Human settlement patterns and Australian climate change over the last 35,000 years

“…Whether corrected or uncorrected, the data indicate that this period saw significant population growth above anything previously observed in the past. Regional studies by Smith (1988), Smith and Ross (2008) and Veth (1993Veth ( , 1996Veth ( , 2006) also show that this trend is evident within archaeological records at local scales across the arid interior. While climate amelioration probably played a role, and especially increasing and intensified La Niña conditions at ~1.2ka (Williams et al, 2010;Veth et al, 2011;Goodwin et al, 2014), new organisational strategies and technological changes in the mid-to-late Holocene (6-2ka) may have facilitated stability in resource and food procurement.…”

“…Despite the data limitations outlined in Section 1.1, archaeologists regularly correlate past human activities with climate events, using a range of indices such as artefact discard rates , the emergence of new stone artefact technologies (Veth et al, 2011), changes in midden composition and frequency (Beaton, 1983;Nunn et al, 2007), sedimentation rates (Smith and Ross, 2008), ethnographic records (Keen, 2004), and changes in rock art phases (McDonald, 2008). One of the most recent and effective techniques for such correlations is the use of radiocarbon data as a proxy for human activity, generally in the form of sum probability or time-series analyses.…”

Reconstructing the dynamics of ancient human populations from radiocarbon dates: 10 000 years of population growth in Australia

“…These changes may also have provided the capacity for population growth [11], which created new potential for cultural and technological changes, leading to further population growth, and so on [14]. Intensified use of seed resources could have been a key element of this cascading process [11,37].…”