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May 11th 2020

Wasp Nests Re-Date Aboriginal Rock Art

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Scattered across the rocky, arid landscape of Western Australia’s Kimberley region are thousands of paintings known as Gwion Gwion art, striking and elegant images created thousands of years ago by ancestors of the Aboriginal people of Australia.

The paintings, reports Smithsonian magazine, mostly show human figures dancing, often wearing elaborate headdresses and holding boomerangs or spears. These Gwion Gwion images form a distinctive tradition, quite different from other Aboriginal rock art.

A Dating Mystery

The Gwion Gwion artwork is certainly very old. But while features of the paintings (such as the boomerangs) remain familiar to modern Aboriginals, neither they nor academic researchers have been able to say confidently how long ago the paintings were created.

Until wasps, or more precisely their nests, recently provided a clue.

The most common method of dating ancient artifacts or remains is radiocarbon dating, also called carbon-14 dating. The method relies on measuring a sample containing carbon and determining the proportion of radioactive carbon-14 to more common and non-radioactive carbon-12. The lower the proportion of carbon-14 atoms, the older the sample.

But this method can’t be used directly on Aboriginal rock art, for the simple reason that the paint used by the artists didn’t contain any carbon. Thus, the paintings themselves have nothing for radiocarbon dating technique to measure.

Enter the Wasps

This is where wasps come in. For most archeologists, disturbing a wasps’ nest is just one more minor hazard of field work. But wasps use carbon-rich organic materials to build their nests. In arid climates like that of Kimberley, traces of these nests can last thousands of years. And, says Smithsonian, these traces can be radiocarbon dated.

That tells us how long ago an ancient wasps’ nest was built, but how does that help us to date Aboriginal rock art? The answer is both simple and profoundly subtle. If ancient wasps built their nest on top of an existing Gwion Gwion painting, we know that the Gwion Gwion art was there first, and must be at least as old as the wasps’ nest that partly covers it.

If, on the other hand, the artist painted over the remnants of a wasps’ nest that was already there, we know that the painting cannot be any earlier than the nest, and possibly much later.

The Art of Interpreting Scientific Results

As Science Daily relates, a team of Australian scientists, working in cooperation with the Aboriginal owners of the site, gathered traces from more than 100 ancient wasp nests found either above or beneath Aboriginal rock art figures, and were able to determine radiocarbon dates for 24 of them.

The research team determined that 23 of the 24 dateable wasp nests ranged in age from 11,300 years ago to 13,000 years ago, which indicates that the same age range applies to the Aboriginal rock art. However, according to Ars Technica, one painting had a nest on top of it that dated to 16,600 years ago — meaning that the painting should be at least that old, comparable to a previously suggested age of around 17,000 years.

On the other hand, every individual measurement is subject to uncertainty, and Ars Technica notes that this particular sample date is only considered moderately reliable. Further investigation will be needed to determine if other Gwion Gwion art can be “wasp-nest dated” to a similar age. If so, it will indicate that the Aboriginal rock art in the Gwion Gwion style continued to be produced for 5,000 years or more.

Whatever the final results turn out to be, the saga of Gwion Gwion art and wasp nests reveals both thousands of years of artistic talent and the ingenuity that modern investigators have used to study it.

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