Luminescence dating method
Ionizing radiation excites electrons from the valence band, or ground state, across an energy gap to the conduction band where they are free to move about.
Energy levels within the gap cannot normally be occupied, but crystalline defects resulting in localized charge deficiencies allow occupation of metastable energy levels within the gap.
The time lag can be understood by reference to solid state energy band theory. 1996-2001: age determination of the Late Pleistocene loess of eastern Belgium with TL 1997- 1998: Age determination of tropical sand dunes with TL 1999 - present: implementing OSL dating and age determination of the Dutch coversands 2002 - present: TL and IRSL dating of Chinese loess deposits Luminescence dating is based on the measurement of the amount of light that is released upon thermal or optical stimulation, by minerals such as quartz and feldspar. In general, the activities of the group have developed as follows: 1992-1995: implementing the thermoluminescence laboratory, performing authenticity testing and dating of ceramics.(Go in About Luminescence Dating) Luminescence is the emission of light from crystalline materials following the absorption of energy from an external source.It is distinguished from other light emissions such as fluorescence by a time interval between absorption and emission, an interval of sufficient duration to permit dating on an archaeological time scale.