The science of the origin, history, and structure of the Earth is called geology. It examines rocks, minerals, fossils, landforms, and the physical processes that have shaped the planet over deep time.
Geologists study both Earth’s surface and its interior. Their work includes stratigraphy, which analyzes rock layers; paleontology, which uses fossils to reconstruct past life; geochemistry, which investigates Earth’s chemical composition; and geophysics, which uses measurements such as seismic waves to probe the planet’s interior.
The field has ancient roots, but modern geology developed through figures such as Nicolas Steno, James Hutton, and Charles Lyell. Radiometric dating places Earth’s formation at about 4.54 billion years ago, while plate tectonics explains how moving lithospheric plates create mountains, earthquakes, ocean basins, and volcanoes. Geology is broader than simply studying rocks: it helps explain natural hazards, climate history, groundwater, and the distribution of mineral resources.