Luminescence dating: where it has been and where it is going

The luminescence properties of common minerals, such as quartz and potassium-rich feldspars, allow them to be used to measure depositional ages for late Quaternary sediments. The optically stimulated luminescence (OSL) signals currently used are appropriate for mineral grains whose previous radiation history was erased by exposure to sunlight immediately prior to deposition. However, the concepts relating to grain size and long-term stability of the signals established when using the thermoluminescence signals should not be forgotten. Recent technological advances and the development of new laboratory measurement procedures for obtaining the equivalent dose have resulted in more widespread and more confident use of OSL for dating using smaller samples, even down to the single grain level. Ages can now be obtained for samples only a few hundred years old, and new luminescence signals are being investigated in order to extend the age range back by an order of magnitude from ∼100 kyr to ∼1 Myr.