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Tl dating

It includes techniques such as optically stimulated luminescence (OSL), infrared stimulated luminescence (IRSL), and thermoluminescence dating (TL)."Optical dating" typically refers to OSL and IRSL, but not TL.

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Crystalline rock types and soils collect energy from the radioactive decay of cosmic uranium, thorium, and potassium-40.This energy is lodged in the imperfect lattices of the mineral's crystals.Heating these crystals (such as when a pottery vessel is fired or when rocks are heated) empties the stored energy, after which time the mineral begins absorbing energy again.Thermoluminescence was first clearly described in a paper presented to the Royal Society (of Britain) in 1663, by Robert Boyle, who described the effect in a diamond which had been warmed to body temperature. The possibility of making use of TL stored in a mineral or pottery sample was first proposed by chemist Farrington Daniels in the 1950s. The potential of using thermoluminescence to date buried soils developed on colluvial and fluvial sediments from Utah and Colorado, U. Two forms of luminescence dating are used by archaeologists to date events in the past: thermoluminescence (TL) or thermally stimulated luminescence (TSL), which measures energy emitted after an object has been exposed to temperatures between 400 and 500°C; and optically stimulated luminescence (OSL), which measures energy emitted after an object has been exposed to daylight.

To put it simply, certain minerals (quartz, feldspar, and calcite), store energy from the sun at a known rate.

The exposure to radioactive elements continues, and the minerals begin again storing free electrons in their structures.

If you can measure the rate of acquisition of the stored energy, you can figure out how long it has been since the exposure happened.

It is useful to geologists and archaeologists who want to know when such an event occurred.

It uses various methods to stimulate and measure luminescence.

Luminescence dating is good for between a few hundred to (at least) several hundred thousand years, making it much more useful than carbon dating.