A drawing of an outcrop of stratified rock lying horizontally, with grass and a stunted tree growing on top of it. On the left the stratum is thrust up at a more acute angle. In the foreground is a rocky hillock. Leonardo had a profound awareness of geological processes. He wrote about the immense forces that formed mountain ranges, and the huge periods of time over which they weathered. Leonardo also made many drawings of rock formations; some were imaginary, but here he made a careful record of an outcrop of stratified rock bursting out of the earth.