Morphological analysis and radiocarbon dating of non-returning boomerangs from Cooper Creek/Kinipapa (Northeast South Australia)

Abstract

In this article we present the results of a morphological analysis of four mostly complete non-returning boomerangs and one shaped wooden fragment recovered in 2017 and 2018 from Cooper Creek near Innamincka in South Australia’s far northeast. This archaeological collection forms one of only six known/published wooden artefact assemblages in the country. We also detail the results of the direct accelerator mass spectrometry radiocarbon (AMS ¹⁴C) measurement of the artefacts which range from circa 275–175 BP (1650–1830 cal AD, median ages reported). Given that the age estimates obtained for the artefacts are from the recent period, we have complemented the morphological analysis by interpreting the assemblage within the context of ethnohistorical records and Traditional Owner knowledge. The assemblage reveals a variety of forms and functions representative of the diverse cultural activities and daily lives of the Aboriginal people who lived near significant waterholes in the Cooper Creek region during this period. The boomerangs also preserve manufacture and use-wear traces, providing insights into the life histories of each implement. In addition to their likely use as projectiles, our results indicate that the boomerangs were probably used for fighting, hunting, digging, fire management and possibly in ceremonies. Predictions for climate change in the region threaten to alter the conditions that allowed the preservation of these artefacts which may negatively affect the potential survival of other wooden objects that remain in the environment.

Keywords:

• Wooden technology
• boomerangs
• throwing sticks
• radiocarbon dating
• Cooper Creek
• waterholes
• South Australia

Acknowledgements

This research was approved by Flinders University’s Social and Behavioural Research Ethics Committee (Project Number: 8407). Permission to take samples from the objects was approved by the Yandruwandha Yawarrawarrka community and in accordance with the Aboriginal Heritage Act 1988. We thank Alice Beales from the South Australian Museum for the provision of relevant accession lists. We acknowledge the financial support from the Centre for Accelerator Science at ANSTO, through the Australian National Collaborative Research Infrastructure Strategy (NCRIS). We are grateful to Chantal Wight for her help in the Flinders University laboratories and Vito Hernandez for assistance with the microscope. Thanks also to Martin O’Leary from the South Australian State Herbarium for guidance on taxa and wood features and Antoinette Hennessy for the provision of maps. We also acknowledge National Parks and Wildlife South Australia for their support of this project.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.

Notes

1 Previously published unrounded Conventional Radiocarbon Ages (CRAs) were calibrated using the OxCal 4.3 program (Bronk-Ramsey) and applied the SHCal20 atmospheric curve (Hogg et al. 2020). Calibrated age-ranges at 84.9–95.4% probability are reported.

2 Boomerang blades are not aerodynamically equivalent. The blade whose edge outside the curvature traverses the greatest angle in the wake of the other is called the ‘attacking blade’. The other blade is referred to as the ‘following blade’. Travelling through one angle greater than the other, the ‘attacking blade’ also acquires an intrinsic aerodynamic lift effect, which is always greater than the ‘following blade’. The ‘attacking blade’, in Aboriginal Australia, is most often the gripping blade because it is the grip that generally gives the object the most rotation (Bordes and Freeman 2018:6).

3 The maximum value was measured at the elbow and the minimum value was measured at 30 mm away from the thinnest extremity.

3 The convexity in the case of this aerofoil type is more accentuated on the dorsal surface than on the ventral surface. This type of aerofoil can be considered as an intermediary between bi-convex and plano-convex types.

Additional information

Funding

This work was supported by the Centre of Accelerator Science at ANSTO with the financial provision through the Australian National Collaborative Research Infrastructure Strategy.