geologies

Geology is the science that studies the Earth, including its materials, structure, and history. The plural term geologies is rarely used formally, but it may appear to refer informally to the various subfields or regional geologies that together comprise the discipline.

The field is commonly split into physical geology, which focuses on materials such as rocks, minerals, and soils and the processes that shape them (weathering, erosion, plate tectonics, volcanism); and historical geology, which interprets the geological record to reconstruct Earth's past.

Key subdisciplines include mineralogy (the study of minerals), petrology (igneous, sedimentary, and metamorphic rocks), geochemistry (chemical processes in Earth materials), geomorphology (landforms and their development), stratigraphy (layering of rocks), sedimentology (depositional environments and processes), paleontology (fossil life), volcanology (volcanoes and eruptions), hydrology or hydrogeology (water in the Earth), and geophysics (seismology, gravity, magnetism).

Researchers use field mapping, sampling, and laboratory analyses, including microscopic study and radiometric dating (such as uranium–lead, potassium–argon, and carbon-14 for recent events). They also employ remote sensing, geographic information systems (GIS), and geophysical surveys to study inaccessible areas.

Geology informs resource exploration, groundwater management, hazard assessment for earthquakes, landslides, and volcanoes, and the study of climate history and landscape evolution. The science intersects with physics, chemistry, biology, and mathematics and has evolved from natural philosophy to a modern Earth science with broad societal relevance.

Etymology: from Greek ge, earth, and logos, study.