Rock art is much older than once thought

A new dating technique has allowed archaeologists to date southern African rock art, and what they found is surprising.

They discovered that some rock art in Botswana was painted at the time of the pyramids about 5500 years ago.

The oldest rock paintings in Lesotho and South Africa are 3000 years old.

"Dating has been one of the big problems we have had. We have just never known how old the stuff is," said Professor David Pearce of the Rock Art Research Institute at Wits University.

Researchers from Wits, Laval University in Canada and Oxford in the UK were involved in the study, which dated 43 sites across Southern Africa.

Dating rock art had been difficult, said Pearce, due to contaminants on rocks.

They were able to overcome this by identifying the contaminants and taking small samples of the art.

The researchers then used accelerator mass spectrometry radiocarbon dating to find out how old the paintings were.

Many were surprised.

"The view is that because these sites are exposed, they wouldn't last long," he said.

He believes that mineralisation on the rocks formed a type of cement that protected the art.

What the study also discovered was that Bushmen were returning to the same sites over hundreds and even thousands of years to paint.

"We know quite a lot about what the rock art is about and it is generally to do with religious belief," said Pearce.