Osl dating ppt
Crystalline rock types and soils collect energy from the radioactive decay of cosmic uranium, thorium, and potassium-40.
Electrons from these substances get trapped in the mineral's crystalline structure, and continuing exposure of the rocks to these elements over time leads to predictable increases in the number of electrons caught in the matrices.
The term luminescence refers to the energy emitted as light from minerals such as quartz and feldspar after they've been exposed to an ionizing radiation of some sort.
Luminescence dating (including thermoluminescence and optically stimulated luminescence) is a type of dating methodology that measures the amount of light emitted from energy stored in certain rock types and derived soils to obtain an absolute date for a specific event that occurred in the past.
But when the rock is exposed to high enough levels of heat or light, that exposure causes vibrations in the mineral lattices and the trapped electrons are freed.
The exposure to radioactive elements continues, and the minerals begin again storing free electrons in their structures.
See Liritzis et al.'s excellent 2013 book on Luminescence Dating for more information on these processes.
Artifacts which can be dated using these methods include ceramics, burned lithics, burned bricks and soil from hearths (TL), and unburned stone surfaces that were exposed to light and then buried (OSL).
During the 1960s and 70s, the Oxford University Research Laboratory for Archaeology and History of Art led in the development of TL as a method of dating archaeological materials.