Argon, a noble gas, is not commonly incorporated into such samples except when produced in situ through radioactive decay.
The date measured reveals the last time that the object was heated past the closure temperature at which the trapped argon can escape the lattice.
Many factors can spoil the sample before testing as well, exposing the sample to heat or direct light may cause some of the electrons to dissipate, causing the item to date younger.
Because of these and other factors, Thermoluminescence is at the most about 15% accurate.
For this reason, many archaeologists prefer to use samples from short-lived plants for radiocarbon dating.K–Ar dating was used to calibrate the geomagnetic polarity time scale.Thermoluminescence testing also dates items to the last time they were heated.In historical geology, the primary methods of absolute dating involve using the radioactive decay of elements trapped in rocks or minerals, including isotope systems from very young (radiocarbon dating with Radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes.Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age.
The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, allowing much older samples to be dated.