Crustal Imaging and Characterization Team

USGS Luminescence Dating Laboratory

What is Luminescence Dating?

Luminescence dating is a form of geochronology that measures the energy of photons being released. In natural settings, ionizing radiation (U, Th, Rb, & K ) is absorbed and stored by sediments in the crystal lattice. This stored radiation dose can be evicted with stimulation and released as luminescence. The calculated age is the time since the last exposure to sunlight or intense heat. The sunlight bleaches away the luminescence signal and resets the time 'clock'. As time passes, the luminescence signal increases through exposure to the ionizing radiation and cosmic rays. Luminescence dating is based on quantifying both the radiation dose received by a sample since its zeroing event, and the dose rate which it has experienced during the accumulation period (See the Luminescence Age Equation). The principal minerals used in luminescence dating are quartz and potassium feldspar.

(LA-UR-01-6064)
Image used with permission of Dr. K. Lepper, http://www.ndsu.nodak.edu/ndsu/klepper/BreifOSL.html

Next: Applications of Luminescence

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