Uncovering a new layer of history in southwest Victoria
Volcanic rocks of Tower Hill (pictured) and Budj Bim World Heritage site in southwest Victoria hold geological, archeological, and cultural significance. Dr Erin Matchan and her team explore all in this study. Image: Jo Condon
Recently, a collaborative research team at the University of Melbourne and Curtin University set out to confirm and constrain the age of volcanic rocks in southwest Victoria by a new and independent age-dating technique that is enabled by AuScope.
In the course of their research, the team uncovered archaeological evidence and the rich oral traditions of local Gunditjmara people, which, when combined with the pleasing results from geochronology analyses, enabled the team to suggest the possibility of human occupation in the area 37,000 years ago when volcanoes threw ash and lava across the landscape.
The geochronology study
Dr Erin Matchan and Prof David Phillips at the University of Melbourne, together with Prof Fred Jourdan and Dr Korien Oostingh at Curtin University, applied the Argon-argon (Ar-Ar) dating technique to two geological samples from the Newer Volcanics Province: one from Tower Hill, and one from the Budj Bim Volcanic Complex some 70 km to the northwest.
The team’s results revealed lava eruption ages of 36,800 ± 3,800 years and 36,900 ± 3,100 years for Tower Hill and the Budj Bim Volcanic Complex, respectively. After examining these dates in relation to important archeological and evidence and rich oral traditions of the local Gunditjmara people of this region, Erin and the team realised that their dates may have important archeological implications.
Investigating knowledge at Tower Hill
After gaining new geological age dates by the argon-argon dating method, the team sought to make a comparison with previously attained dates by other methods. They discovered that previous dates for Tower Hill (35,000 ± 3,000 years) and Budj Bim (39,600 ± 7,000 years) lined up well with the new dates, and also that they are consistent with ages of greater than 30,000 years (37,000 – 50,000 years) for the six earliest known human occupation sites in southeastern Australia.
They also discovered the story of the ‘Bushfield axe’, a basalt tool that was buried in the ash layers and discovered during the sinking of a post hole through a sequence of finely layered volcanic ash from Tower Hill and documented in the Proceedings of the Royal Society of Victoria in 1947. To our knowledge, this is the only documented report of a stone artifact being recovered from beneath (and not above) the Tower Hill ash, indicating that humans were present in the area during eruptions of the Tower Hill volcano.
Investigating knowledge at Budj Bim
Next, the team shifted their focus over to the Budj Bim Cultural Landscape World Heritage Site, the world’s oldest known aquaculture system built by the Gunditjmara People more than 6,000 years ago on the lava landform of the Budj Bim Volcanic Complex. They found that previous ages for the Budj Bim Volcanic Complex vary, depending on the sample type and that the new eruption age is relatively precise in comparison to historical studies. They also discovered Gunditjmara oral histories surrounding Budj Bim that have been previously interpreted to reflect observation of this volcanic activity.
Researchers were grateful to learn about rich Gunditjmara history in this study. Video: Gunditj Mirring
Combining evidence
The research team is pleased to shed new light on the earliest known human occupation sites in southeastern Australia, in the context of great interest globally in human migration routes. Dr Erin Matchan explains:
“Given the age of the Budj Bim Volcanic Complex, if oral traditions do indeed reflect witnessing volcanic activity, this could mean that these are some of the longest-lived traditions in the world.”
Reflecting on this new study
The research team is proud to contribute to the study of human occupation in Victoria and highlight the importance of considering Indigenous Ecological Knowledge in tandem with western scientific approaches.
Erin and the team feel that this study highlights the important role that investment into new infrastructure has on our ability to generate fresh scientific and cultural understandings:
“We also recognise the critical part that archeology and oral histories have played in piecing together the pieces of this new story. It is amazing what is possible when research combines different perspectives, and this study offers an exciting precedent for future studies in this area.”
Damein Bell, CEO of the Gunditj Mirring Traditional Owners Aboriginal Corporation says in this Science Mag article that the Gunditjmara community welcomes the new study, which highlights their deep link with their country:
“We’re always amazed by… new technologies that prove the brilliance of our ancestors.”
AUTHORS
Jo Condon and
Philomena Manifold
ACKNOWLEDGEMENTS
This study was supported by a University of Melbourne McCoy Seed Fund grant with Museum Victoria and an ARC Discovery Grant.
LEARN MORE
Dr Erin Matchan,
University of Melbourne