GIF-SUR-YVETTE, FRANCE—Spray-like paintings in Chauvet-Pont D’Arc Cave thought to be around 36,000 years old may be the oldest-known depictions of a volcanic eruption. Geoscientist Sebastien Nomade of the University of Paris-Saclay sampled rocks in three volcanic centers at the Bas-Vivarais volcanic field, which lies some 20 miles from the cave in southern France. He and his team members measured the levels of different isotopes of radioactive argon gas in the samples, and determined that the region had been lit up by a series of strombolian eruptions between 19,000 and 43,000 years ago. Strombolian eruptions, named for Italy’s Stromboli volcano, spew lava more than 200 yards into the sky. “You just have to climb the small hill on top of Chauvet, and looking north you see the volcanoes. During the night you could see them glowing and you could hear the sound of the volcanic eruption,” Nomade told Nature News. He adds that there’s no way to prove that the images depict volcanic eruptions, “but for us it’s the hypothesis which is the most probable.” For more, go to "A Chauvet Primer."