Welcome to the USGS Luminescence Dating Laboratory Site.
The age of the pottery, in principle, may then be determined by the relation Age = Accumulated dose / Dose per year Although conceptually straightforward, TL has proven to to be far from simple in practice.
When pottery is fired, it loses all its previously acquired TL, and on cooling the TL begins again to build up.
By comparing this light output with that produced by known doses of radiation, the amount of radiation absorbed by the material may be found.
The method is a direct dating technique, meaning that the amount of energy emitted is a direct result of the event being measured.
Better still, unlike radiocarbon dating, the effect luminescence dating measures increases with time.
The amount of luminescence is proportional to the original dose of radiation received.
In thermoluminescence dating, this can be used to date buried objects that have been heated in the past, since the ionizing dose received from radioactive elements in the soil or from cosmic rays is proportional to age.
Cord Luminescence Laboratory (DRILL) is located at DRI’s northern campus in Reno, NV and offers a broad spectrum of luminescence dating capabilities including optically stimulated luminescence (OSL) and thermoluminescence (TL) techniques.In some materials, these states are trapped, or arrested, for extended periods of time by localized defects, or imperfections, in the lattice interrupting the normal intermolecular or inter-atomic interactions in the crystal lattice.Quantum-mechanically, these states are stationary states which have no formal time dependence; however, they are not stable energetically.The effects of green light stimulation on the thermoluminescence (TL) of a sedimentary quartz from the Kimberley region of Western Australia are reported.The loss of TL at 310°C and the concomitant growth and decay of the photo-transferred TL (PTTL) at both 110 and 160°C are presented for optical stimulation of up to 200 s in a Risø TL/OSL reader.