Leonardo da Vinci, the Renaissance genius who lived from 1452 to 1519, studied geology not only with a view to improve the background details in his drawings and paintings but also as a science for its own sake. Many of his works, such as Landscape with Waterfall, Ravine with Waterbirds, and Virgin of the Rocks depict nuances of his geological research such as sedimentary layers and rock formations carved out by wind and water. Other Renaissance painters studied his artwork so that they could better craft geological details with accuracy.
Da Vinci's contributions to geology are not so well known because he did not publish them. However, more than 10,000 pages of his written notes survive to the present. Some document observations he made during his travels, and some are sketches he made as an engineer assisting in the building of irrigation canals.
The findings of da Vinci in the field of geology refuted Biblical explanations prevalent at the time concerning the age of the Earth. For instance, he came to the conclusion that fossils were the petrified remains of animals that had previously been alive. He deduced that shells discovered on the tops of mountains showed that natural forces moved and shaped the landscape over a long period of time. He recognized the movement of water upon the landscape as a cyclical pattern that eroded older rocks and transported sediment to the sea and that mountains then formed from former ocean floors, thus depositing shells and other marine materials on high elevations. To da Vinci, the parts of the Earth were interconnected just as a human body was the sum of its parts, and water was the circulatory system that fed and shaped the living Earth.
To sum up, da Vinci's geological discoveries were centuries ahead of their time. They demonstrate a grasp of concepts that would be published long afterwards when they would be rediscovered by others, and some of these concepts are geological basics that we still study today.