Leonardo da Vinci’s Geological Secrets Revealed By Forensic Science

Forbes: “Forensic analysis of Leonardo da Vinci’s “landscape with waterfall” drawing revealed that it was created in two successive phases, suggesting that it is not the depiction of a real landscape, but rather a result of da Vinci’s geological research over the years. The drawing is dated to August 5, 1473, and many historians have previously identified the depicted landscape as the “Cascate delle Marmore” near Terni, the provincial capital of the Italian region of Umbria. The Marmore Falls is a series of man-made waterfalls created by the ancient Romans. Its total height is 541 feet, making it the tallest man-made waterfall in the world. The drawing is hosted today in the Uffizi Galleries in the historic center of Florence and rarely exhibited in public. Because in April 2019, a large exhibit of da Vinci’s work will open in his hometown of Vinci, Italian authorities allowed forensic investigations of some of his drawings for the very first time, including “landscape with waterfall.” Microscopic analysis under infrared light and X-rays revealed the chemical properties of the ink used by Leonardo. Apparently, he used two very distinct inks, one ink based on iron pigments and one ink based on carbon pigments, for his sketch. This observation suggests that da Vinci didn’t sketch the landscape at once, but rather added many details, like the rock layers, much later. It is therefore unlikely that the drawing shows a real landscape. Instead, it seems that da Vinci used it to sketch his geological research over the years. More than 10,000 pages of Leonardo’s notes survive, most dated between 1470 to 1519. Some contain observations about outcrops and rocks made during his travels in Tuscany and Romagna. As an engineer, he also supervised the construction of large irrigation canals, cutting through the sediments of the Apennines and Po Valley. Leonardo da Vinci was one of the first naturalists to both understand the origin of sedimentary rocks and recognize fossils as petrified remains of former living animals, as in his personal notes he writes, “…among one and another rock layer, there are the traces of the worms that crawled in them when they [the layers] were not yet dry.” It is likely that he came to this conclusion only after he sketched the waterfall and so decided to add the previously overlooked detail – the rock layers – to his early work. Leonardo da Vinci studied rocks and landscapes not only to satisfy his personal curiosity, but also to improve his paintings. The layers in his sketch, shown above the waterfall, are geologically correct. Turbidite layers, formed by submarine avalanches and later pushed by tectonic forces above the sea, are commonly spotted in rocky outcrops of the Apennines and are thin at the bottom and thick on the top, a result of the different rates of sedimentation under water…”