Mud wasps used to date Australia's aboriginal rock art

By Jonathan Amos

BBC Science Correspondent

5 February 2020

All the research has been conducted with the active participation of traditional owners

When the veteran telecoms engineer Damien Finch went on a three-week bush walk in Australia's Kimberley region, he became enthralled with its rock art.

On his return home, he tried to find out more about these enigmatic aboriginal paintings and engravings.

"I couldn't believe how little was known about them; we didn't even know how old they were," Damien said.

"It seemed disrespectful that scientists hadn't studied this stuff more; it was downplaying the importance of the culture," he told BBC News.

Now, 10 years on and in his 60s, Damien is putting that right.

He's approaching the end of his doctoral research on the topic, and in this week's Science Advances journal, has published his own efforts to age the Kimberley's so-called Gwion figures.

These feature finely painted human forms, often in elaborate ceremonial dress and carrying spears and boomerangs.

It was thought they were painted some 16,000 years ago, but the University of Melbourne investigator has been able to show the likely age is nearer in time - at about 12,000 years ago.

Dating rock art is really hard. Aboriginal artists use iron oxide pigments (ochre) which contain no organic material and are therefore resistant to any radiocarbon analysis.

Damien has got around this by studying instead the scraps of organic matter stuck on top of and underneath the paintings.

And for this, he's working with wasps. In particular, the ones that build nests out of mud. There's a wide group of these.

Some will enclose their prey - such as a paralysed spider or caterpillar - inside an earthen box. Before sealing the lid, the wasps lay an egg on the unfortunate victim. The developing larva then consumes the immobile spider or caterpillar, eventually digging its way out of the nest as an adult to carry on the cycle.

From Damien's point of view, when the female wasp gathers her mud supplies she inevitably picks up fragments of charcoal from the Kimberley's fire-prone landscape. And this charcoal can be radiocarbon dated.

Continued

Megafauna cave painting could be 40,000 years old

Emma Masters
May 31, 2010

Scientists say an Aboriginal rock art depiction of an extinct giant bird could be Australia's oldest painting.

The red ochre painting, which depicts two emu-like birds with their necks outstretched, could date back to the earliest days of settlement on the continent.

It was rediscovered at the centre of the Arnhem Land plateau about two years ago, but archaeologists first visited the site a fortnight ago.

A palaeontologist has confirmed the animals depicted are the megafauna species Genyornis.

Archaeologist Ben Gunn said the giant birds became extinct more than 40,000 years ago.

"The details on this painting indicate that it was done by someone who knew that animal very well," he said.

He says the detail could not have been passed down through oral storytelling.

"If it is a Genyornis, and it certainly does have all the features of one, it would be the oldest dated visual painting that we've got in Australia," he said.

"Either the painting is 40,000 years old, which is when science thinks Genyornis disappeared, or alternatively the Genyornis lived a lot longer than science has been able to establish."

Mr Gunn says there are paintings of other extinct animals right across the area including the thylacine, or tasmanian tiger, the giant echidna and giant kangaroo.

"It does give you a window back to a time that you can pinpoint, and in the case of the Genyornis it's a very long picture," he said.

The traditional owners of the land in the Northern Territory say they are excited the painting could be Australia's oldest dated rock art.

The Jawoyn Association's Wes Miller says the painting is one of thousands rediscovered across Arnhem Land in recent years.

"It verifies that the Jawoyn people were living in this country for a very, very long time," he said.

"People say it, but once again this is clearly a demonstration of how long Jawoyn people have been in this country and other Indigenous groups. It's great from that point of view. It's pretty exciting stuff."


http://www.abc.net.au/news/stories/2010/05/31/2913350.htm?section=justin

 
(Submitted by Chad Arment)