Thermoluminescence dating archaeology
TL has a wide dating range; it has been used to date ceramics from a few hundred years old to geologic formations that are half a million years old.
The technique measures the small amount of energy that continually builds up in the mineral crystal lattice.
Two standard methods, the “fine-grain technique” and the “quartz inclusion technique”, and a new method, the pre-dose saturation exponential technique in thermoluminescence (TL) dating of ancient pottery and porcelain were reviewed, especially for the measurement of the paleodose and the annual dose.
The two standard methods have been acknowledged in domain of TL dating and are used widely for age determination in archaeology and geology.
Per questa ricerca è stata usata la tecnica della inclusione di quarzo ed il risultato dà una stima dell’età dei campioni del 603 a. con un errore di ± 250 anni in buon accordo con la stima ottenuta con metodi archeologici che dà una età compresa tra il 630 ed il 580 a.
Scientists in North America first developed thermoluminescence dating of rock minerals in the 1950s and 1960s, and the University of Oxford, England first developed the thermoluminescence dating of fired ceramics in the 1960s and 1970s.
Thus, preliminary X-ray or gamma radiography examination of the object can increase the amount of accumulated energy and thus give erroneous dating result.By heating the ceramic or mineral to above 500 degrees Celcius, these trapped electrons are released, creating a flash of light called thermoluminescence.When a laser light source is used to stimulate the release of electrons, the process is called optically stimulated luminescence.Most of the energy escapes as heat, but sometimes this energy separates electrons from the molecules that make up the minerals or ceramics.Usually the electrons will reconnect with the molecules, but some will not.