“The finest workers in stone are not copper or steel tools, but the gentle touches of air and water working at their leisure with a liberal allowance of time.” ~Henry David Thoreau
Thoreau refers to the process of erosion. Erosion is the process by which soil and rock are removed from the Earth’s surface by exogenetic processes such as wind or water flow, and then transported and deposited in other locations. The result is a rock or mountainside with evidences of the effects left by the water and air.
…there are innumerable examples of erosion to be found. Water is truly a powerful natural force, capable of inspiring awe and admiration.