Chauvet Cave researchers discover natural calcite glaze protecting ancient art

Scientists from Sorbonne Université and the French National Center for Scientific Research (CNRS) have discovered that the 37,000-year-old cave paintings in France’s Chauvet Cave are protected by a thin, translucent film of calcite. This natural glaze has acted as a preservative for millennia, maintaining the exceptional condition of depictions of rhinoceroses, mammoths, lions, and horses.

To study the fragile artworks without disturbing the cave floor, which contains intact prehistoric human and animal footprints, the team developed a non-contact method using ultraviolet (UV) fluorescence. Researchers utilized a portable spectrometer mounted on a carbon-fiber pole with a three-meter fiber-optic bundle. By projecting a 365-nanometer UV beam onto the walls from a distance of approximately 2.5 meters, they were able to analyze the mineral deposits and the artists' techniques through the emitted fluorescence.

The findings, published in the journal ACS Omega, provide new insights into how Upper Paleolithic art has survived in subterranean environments and offer a way to monitor such delicate sites without physical contact.