More specifically, they might be called a:
* Paleontologist: If they focus on fossils and ancient life.
* Stratigrapher: If they focus on the layers of rock and their relationships.
* Petrologist: If they focus on the composition and origin of rocks.
* Geochronologist: If they focus on dating rocks and events in Earth's history.
All of these specialists use rocks to piece together the story of our planet's past.
