For the first time, scientists have accurately dated prehistoric cave paintings inside Font-de-Gaume, a famous decorated cave near Les Eyzies in France’s Dordogne region.
The groundbreaking study provides reliable dates for two black images—a bison and a masklike figure—and shows that sections of the artwork may have been created thousands of years apart. The findings offer archaeologists a valuable new method for determining when prehistoric people entered decorated caves, created paintings, and returned to modify or add to them.
Why Prehistoric Cave Paintings Are Difficult to Date
The Dordogne is home to some of Europe’s most important prehistoric art, including the renowned paintings at Lascaux. However, accurately determining when many Ice Age cave paintings were made has remained a major scientific challenge.
Radiocarbon dating measures carbon-14, a radioactive form of carbon that gradually declines after an organism dies. Charcoal, which is produced by burning organic material, can often be dated using this technique. Mineral pigments, by contrast, generally contain no carbon and cannot normally be analyzed through radiocarbon dating.
For decades, researchers believed that many of the region’s black cave paintings were made exclusively with iron and manganese oxides. Although these naturally occurring minerals create dark pigments, they do not contain the organic carbon required for carbon-14 analysis.
Consequently, many prehistoric paintings were considered impossible to date directly. Scientists, however, had not conclusively proven that the pigments contained no carbon whatsoever.
Scientists Search for Hidden Charcoal in Black Pigment
To investigate the possibility, researchers examined the chemical composition of two black figures at Font-de-Gaume. One image represents a bison, while the other is widely known as a mask.
The research team used Raman microspectrometry and hyperspectral imaging, two advanced, minimally invasive techniques that can identify materials without causing noticeable damage to the ancient artwork.
Raman microspectrometry uses light to analyze molecular vibrations, creating a chemical fingerprint that helps identify pigments and other substances. Hyperspectral imaging captures subtle variations in color and reflected light across an image, allowing scientists to determine which compounds are present.
Hyperspectral imaging is increasingly used in cultural heritage research because it can reveal details that are difficult to detect with the naked eye. The technology is also used in biomedical research, agriculture, environmental monitoring, and astrophysics.
Both analytical methods detected traces of charcoal within the black pigment used to create the Font-de-Gaume paintings.
The charcoal appeared consistently throughout the black lines forming the figures. This distribution was significant because it indicated that the carbon was part of the original pigment, rather than later contamination caused by graffiti, visitors, or tourism inside the cave.
Microscopic Samples Reveal the Age of the Paintings
After confirming the presence of charcoal, the researchers received exceptional permission to remove extremely small samples from the paintings for carbon-14 dating.
Working with such tiny samples is technically demanding. Researchers must extract enough carbon to produce a dependable measurement while preserving as much of the prehistoric artwork as possible.
The results confirmed that the bison was created during the Upper Paleolithic, the later part of the Old Stone Age when anatomically modern humans produced many of Europe’s best-known cave paintings.
The bison was dated to between 13,461 and 13,162 calBP.
CalBP stands for Calibrated Before Present, with “present” conventionally set at 1950. Radiocarbon results must be calibrated because atmospheric carbon-14 levels have changed over time. These fluctuations can be influenced by factors such as solar activity and variations in Earth’s magnetic field.
The new radiocarbon date places the Font-de-Gaume bison slightly later than earlier estimates.
The Font-de-Gaume Mask May Span Multiple Periods
The masklike figure produced a more complex result. Samples taken from different parts of the image produced three separate date ranges.
One section was dated to between 8,993 and 8,590 calBP. A second section dated to between 15,981 and 15,121 calBP, while a third was placed between 15,297 and 14,246 calBP.
These findings suggest that the figure may include elements created at widely separated times. Instead of being completed by one artist during a single visit, the mask may preserve several episodes of artistic activity separated by thousands of years.
This possibility provides a more complex understanding of prehistoric cave art. Decorated caves may not always have been created or completed during one period. Some may have remained important places that later communities revisited, altered, or interpreted in new ways.
A New Method for Dating Prehistoric Cave Art
The research was led by a scientist from the Laboratoire de développement instrumental et de méthodologies innovantes pour les biens culturels (Chimie ParisTech-PSL/CNRS/Ministère de la Culture). The study was published in PNAS.
The project brought together specialists from several French scientific and cultural institutions.
Contributors included researchers from the Laboratoire de mesure du carbone 14 (CEA/CNRS/IRD/ASNR/Ministère de la Culture), a national platform affiliated with the Laboratoire des sciences du climat et de l’environnement (CEA/CNRS/Université de Versailles Saint-Quentin-en-Yvelines). Scientists from the Histoire naturelle des Humanités préhistoriques laboratory (CNRS/MNHN/Université de Perpignan Via Domitia), the Centre des monuments nationaux, and the Centre de recherche et de restauration des musées de France also participated.
By combining chemical imaging with highly sensitive radiocarbon analysis, the team has developed a technique that could be used to date other prehistoric paintings previously considered impossible to analyze.
More accurate dates could help archaeologists identify which cave paintings were created during the same period, track changes in prehistoric artistic styles, and determine whether different generations repeatedly returned to the same caves. Ultimately, this evidence may reveal more about the communities that created the images and the cultural significance these underground spaces held for thousands of years.
Source: www.sciencedaily.com