Stratigraphy and structural geology are two fields in which Earth scientists try to interpret the stories told by rocks. Stratigraphers compare vertical sequences of rock layers from different areas to piece together the geologic history of a region. For example, rock sequences from the Grand Canyon, Bryce Canyon, and Zion National Parks show similar layers, indicating that all three places experienced some of the same episodes of erosion and deposition.

Structural geologists also carefully observe and interpret layers of rock. They study the way Earth's crust is deformed by mountain-building processes. Structural geologists study clues at Earth's surface that reveal the underlying structure and geologic history of an area.