Geologist
A geologist studies Earth’s materials, structure, processes, and history using field observations, laboratory analysis, and geological models.
Mineralogy: The study of minerals, including their composition, structure, properties, and formation. Mineral properties help geologists identify the materials that make up rocks.
Plate tectonics: The theory that Earth’s lithosphere is divided into moving plates whose interactions shape the surface. It unifies explanations of earthquakes, mountain building, and seafloor formation.
Economic geology: The study of Earth materials that can be extracted and used economically. It guides evaluation of mineral and energy resources.
James Hutton: A Scottish geologist whose work helped establish uniformitarian thinking and an ancient Earth. His arguments made slow geological processes central to explaining deep time.
Geophysics: The application of physical principles and measurements to investigate Earth and its environment. Geophysics often probes Earth indirectly, while geology also interprets rocks and field relationships.
Petrology: The study of rocks, their origins, composition, and transformations. Petrology connects rock samples to the processes that formed them.
Radiometric dating: A method of determining age from the decay of radioactive isotopes in a material. It gives numerical ages to rocks and events that field relationships place in sequence.
Hydrogeology: The study of groundwater, its movement, distribution, and interaction with geological materials. Aquifer assessments apply geological knowledge to water supply and contamination.
Charles Lyell: A British geologist known for Principles of Geology and his defense of uniformitarianism. His influential synthesis shaped nineteenth-century geological interpretation.
Geochemistry: The study of chemical composition and reactions in Earth materials and systems. Geochemistry emphasizes chemical evidence within questions shared with geology.