A new dating method finally is allowing archaeologists to incorporate rock paintings -- some of the most mysterious and personalized remnants of ancient cultures -- into the tapestry of evidence used to study life in prehistoric times.
“If we are able to date depictions of livestock and material goods associated with incoming groups, we may be able to start unravelling the nature of interactions between groups in this early contact,” says David Pearce, an archaeologist and director of the Rock Art Institute at the University of the Witwatersrand in Johannesburg, South Africa, and a co-author of the latest study.
They lack the high levels of organic material needed to assess a pictograph's age using radiocarbon dating, the standard archaeological technique for more than a half-century.
Rowe describes a new, highly sensitive dating method, called accelerator mass spectrometry, that requires only 0.05 milligrams of carbon (the weight of 50 specks of dust).
Many experts had assumed that the black paint used in African pictures was based on manganese compounds and that the rock art would therefore have contained too little carbon to be reliably dated, he says.
As a result, techniques developed in Europe and elsewhere have not previously been applied in Africa.