Wasp nests used to date ancient Australian rock art

Mud wasp nests have helped establish a date for one of the ancient styles of Aboriginal rock art in the Kimberley, Western Australia. University of Melbourne and ANSTO scientists put the Gwion Gwion art period around 12,000 years old.

Wasp nests near the paintings have given scientists a major breakthrough
on Kimberley rock art [Credit: Damien Finch]

"This is the first time we have been able to confidently say Gwion style paintings were created around 12,000 years ago," said PhD student Damien Finch, from the School of Earth Sciences at the University of Melbourne. "No one has been able present the scientific evidence to say that before."

One wasp nest date suggested one Gwion painting was older than 16,000 years, but the pattern of the other 23 dates is consistent with the Gwion Gwion period being 12,000 years old.

The rock paintings, more than twice as old as the Giza Pyramids, depict graceful human figures with a wide range of decorations including headdresses, arm bands, and anklets. Some of the paintings are as small as 15cm, others are more than two metres high.

The details of the breakthrough are detailed in the paper 12,000-year-old Aboriginal rock art from the Kimberley region, Western Australia, now published in Science Advances.

Two classic Gwion human figures with headdresses and arm
and waist decorations [Credit: Mark Jones]

More than 100 mud wasp nests collected from Kimberley sites, with the permission of the Traditional Owners, were crucial in identifying the age of the unique rock art.

"A painting beneath a wasp nest must be older than the nest, and a painting on top of a nest must be younger than the nest," Mr Finch said. "If you date enough of the nests, you build up a pattern and can narrow down an age range for paintings in a particular style."

Lack of organic matter in the pigment used to create the art had previously ruled out radiocarbon dating. But the University of Melbourne and ANSTO scientists were able to use dates on 24 mud wasp nests under and over the art to determine both maximum and minimum age constraints for paintings in the Gwion style.

The project was initiated by Professor Andy Gleadow and Professor Janet Hergt, from the School of Earth Sciences, and started in 2014 with funding from the Australian Research Council and the Kimberley Foundation. It is the first time in 20 years scientists have been able to date a range of these ancient artworks.