Optically stimulated luminescence dating laboratory
In addition to radiation from the surrounding sediment, OSL samples are affected by a cosmic dose rate, which reduces as the amount of sediment the sample is buried under increases. The cosmic dose is useful in other situations, as it can be used to determine how long rocks, for example, have been exposed on the Earth’s surface using Cosmogenic Nuclide Dating.
This page was contributed by Dr Georgina King from the Aberystwyth Luminescence Research Laboratory in the Institute for Geography and Earth Sciences. OSL is used on glacial landforms that contain sand, such as sandur or sediments in glacial streams. We prepare the sample through treating it with acids to remove any calcium carbonate or organic material, and sieve it to get a specific grain size (usually between 0.018 – 0.025 mm diameter), which we then measure in a specialised instrument. In the Aberystwyth Luminescence Laboratory our instruments are made by a Danish manufacturer and are called “Risø OSL/TL readers”. The technique can be applied to a wide variety of heated materials, including archaeological ceramics, burnt stones, burnt flints, and contact-heated soils and sediments associated with archaeological or natural events.Optically bleached materials of interest to quaternary science include aeolian, fluvial, alluvial, and marine sediments.