Geology: The Grand Canyon
Geology started out with the simple curiosity of the earth, its rocks, how and when they formed. “William Strata Smith first recognized in the early 1800s that the fossil record had systematically changed through time.” This lead scientists, namely geologists from all over the world to make divisions of geological time known as a relative time scale. In order to get a generalized date they placed rocks and fossils into eras and periods. With a relative time scale, scientists were able to work together to establish a timeline they could use to categorize the age in which the rock or fossils existed.
John Wesley Powell discovered the Grand Canyon on one of his expeditions and called it “the greatest exposure of rock record on the content.