Charcoal in the cave paintings at France’s Font-de-Gaume overturns the long-held assumption that these paintings lacked the carbon needed for radiocarbon dating, according to recent study findings.
Published in the Proceedings of the National Academy of Sciences (PNAS), the research identifies the first direct radiocarbon dates for the cave’s artwork. For over a century, archaeologists have studied Font-de-Gaume, but the exact age of its images had remained uncertain before now.
Font-de-Gaume is located in the Dordogne area of south-western France, close to Les Eyzies in the Vézère Valley. The region is famous for the large number of prehistoric sites it contains, including 25 decorated caves such as Lascaux. The cave was found in 1901 by Denis Peyrony and includes more than 200 painted and engraved figures, all of which have been carefully recorded by researchers. Currently, it is one of the few decorated Ice Age caves in the area that is still open to tourists. Although visitors cannot touch the cave walls, scientists can collect small samples for dating under strict guidelines.
In the past, these dating methods had little effect since it was believed that the black paintings at Font-de-Gaume had been made using only iron and manganese oxide pigments. As these minerals have no organic carbon, radiocarbon dating could not be carried out, and the ages of the black Paleolithic pictures could only be estimated by comparing their stylistic features. Until now, scientists had not established whether the pigments contained carbon at all.
Cracking a Century-Old Assumption
In 2023, Ina Reiche, a research chemist with the CNRS, and her team started to cast doubt on this long-standing assumption. Using non-invasive imaging, they found the first example of a charcoal-based cave painting in the main chambers of Font-de-Gaume; this discovery was published in Scientific Reports. The new study in PNAS extends this research by looking at two particular paintings discovered where the cave corridors meet: a bison and a mask-like face.
Reiche’s team carried out Raman microspectrometry and hyperspectral imaging to determine if charcoal was present in the black pigment. These techniques analyze the chemical composition of the painting using light and reflectance, allowing for a non-destructive examination. The researchers found charcoal distributed evenly along the lines of both figures rather than concentrated in particular areas. This even distribution ruled out later contamination from graffiti or visitors and confirmed that the charcoal formed part of the original artwork.
After confirming the presence of charcoal, the team received special permission to collect microscopic samples for radiocarbon dating using accelerator mass spectrometry. The technique is sensitive enough to provide accurate dates even when only a small amount of material is available.
A Modified Mask
Direct radiocarbon dating placed the bison between 13,461 and 13,162 calibrated years before 1950, likely in the Magdalenian period of the Upper Paleolithic. Radiocarbon dates are calibrated to account for the variations in atmospheric carbon-14 levels over time due to solar activity and changes in the Earth’s magnetic field.
The history of the mask-like painting was more complicated. Samples taken from various parts of the same mask yielded three different date ranges: one ranging from about 8,993 to 8,590 calibrated years before 1950, another from about 15,981 to 15,121, and a third lying between 15,297 and 14,246. These findings suggest that the mask may preserve multiple episodes of artistic activity rather than representing a single phase of painting.
This finding changes how archaeologists view decorated caves. Some may have remained active and meaningful places that later generations revisited and modified long after the original artists had finished their work.
A Blueprint for the Rest of the Region
The approach developed by Reiche’s team combines non-invasive chemical imaging with highly sensitive radiocarbon dating and could allow archaeologists to directly date artwork across the Dordogne region that had previously been considered impossible to date. The research involved collaboration among several French institutions, such as the CNRS’s national radiocarbon measurement facility, the Muséum national d’Histoire naturelle, the Centre des monuments nationaux, and the Centre de recherche et de restauration des musées de France.
It has not yet been determined whether or not other paintings in the area also have concealed charcoal; in that case, the present dating estimates will have to be revisited.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.