The study of the physical material of the Earth dates back at least to ancient Greece when Theophrastus (372-287 BCE) wrote the work Peri Lithon (On Stones).
The awareness of this vast amount of time opened the door to new theories about the processes that shaped the planet.
The most significant advances in 20th century geology have been the development of the theory of plate tectonics in the 1960s, and the refinement of estimates of the planet's age.
Hutton published a two-volume version of his ideas in 1795 ( Vol. Sir Charles Lyell first published his famous book, Principles of Geology, in 1830.
The book, which influenced the thought of Charles Darwin, successfully promoted the doctrine of uniformitarianism.
Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates.