Rock of ages: Australia's oldest artwork found

An archaeologist says he has found the oldest piece of rock art in Australia and one of the oldest in the world: an Aboriginal work created 28,000 years ago in an outback cave.

The dating of one of the thousands of images in the Northern Territory rock shelter, known as Nawarla Gabarnmang, will be published in the next edition of the Journal of Archaeological Science.

The archaeologist Bryce Barker, from the University of Southern Queensland, said he found the rock in June last year but had only recently had it dated at the radiocarbon laboratory of New Zealand's University of Waikato.

He said the rock art had been made using charcoal, so radiocarbon dating could be used to determine its age; most rock art is made with mineral paint, so its age cannot accurately be measured.

Barker said the work was "the oldest unequivocally dated rock art in Australia" and among the oldest in the world.

The oldest known rock art is in Spain, where hand stencils and red discs made by blowing paint on to the wall in El Castillo cave are at least 40,800 years old, according to scientists using a technique known as uranium-thorium dating.

Sally May, an archeologist from the Australian National University who is not involved with Barker's research, said his find was "incredibly significant".

"I don't think it will surprise anyone that rock art is that old in Australia because we know people have been here a lot longer than that, and there's no reason to believe they weren't producing art," she said.

Barker said he had found evidence that the cave where he found the rock art had been occupied for 45,000 years.