Thermoluminescence dating of sediments
As a crystalline material is heated during measurements the process of thermoluminescence starts.
Thermoluminescence emits a weak light signal that is proportional to the radiation dose absorbed by the material. The technique has wide application, and is relatively cheap at some US0–700 per object; ideally a number of samples are tested. The destruction of a relatively significant amount of sample material is necessary, which can be a limitation in the case of artworks.
Most excited electrons will soon recombine with lattice ions, but some will be trapped, storing part of the energy of the radiation in the form of trapped electric charge (Figure 1).
The clay core of bronze sculptures made by lost wax casting can also be tested.
Different materials vary considerably in their suitability for the technique, depending on several factors.
Once all components of the radiation field are determined, the accumulated dose from the thermoluminescence measurements is divided by the dose accumulating each year, to obtain the years since the zeroing event.
Thermoluminescence dating is used for material where radiocarbon dating is not available, like sediments.
Search for thermoluminescence dating of sediments:
In the process of recombining with a lattice ion, they lose energy and emit photons (light quanta), detectable in the laboratory.