Using a novel Laser Ablation U-series dating technique, researchers have successfully dated mineral crusts covering rock art in the Atacama Desert to 15,500 years ago. This study, published in the Proceedings of the National Academy of Sciences (PNAS), provides the oldest direct date for figurative art in the Americas. The paintings depict extinct megafauna and geometric symbols, suggesting a complex belief system among the continent's earliest inhabitants.
The new methodology allows for dating without damaging the pigments, as it analyzes the microscopic layers of calcium carbonate that form over the art. This breakthrough is expected to revolutionize archaeological dating in arid regions where organic material for carbon dating is rarely preserved alongside petroglyphs.