datation

Datation, in archaeology and geosciences, is the process of determining the age of an object, event, or layer. It encompasses methods that provide either absolute calendar ages or relative orderings of events.

Relative dating establishes a sequence without assigning an exact date, using principles of stratigraphy and typology. Key methods include stratigraphy (superposition, original horizontality), biostratigraphy based on fossil associations, and cross-dating of artifacts across sites.

Absolute dating seeks a numerical age. Radiometric techniques measure the decay of radioactive isotopes. Carbon-14 dating is widely used for organic materials up to about 50,000 years. Other systems include potassium-argon and argon-argon dating for volcanic rocks, uranium-series dating for calcium carbonates, and fission-track dating; luminescence dating such as thermoluminescence and optically stimulated luminescence measures the last time minerals were heated or exposed to light. Dendrochronology uses tree-ring sequences to date wooden objects or events with annual precision in some regions.

Calibration, contamination control, and context are critical. The accuracy depends on the material, the dating method, and the geologic or historical setting. Results are typically reported with an uncertainty range and, when possible, corroborated by multiple methods.

Applications include building archaeological chronologies, reconstructing past climates, dating geological events, and informing historical timelines. Datation intersects with the epistemology of dating, cultural heritage management, and scientific communication by providing a framework to place findings in time.