Luminescence dating depends on the ability of minerals to store energy in the form of trapped charge carriers when exposed to ionising radiation. Stimulation of the system, by heat in the case of thermoluminescence TL , or by light in the case of photo-stimulated luminescence PSL , or optically stimulated luminescence OSL. Following an initial zeroing event, for example heating of ceramics and burnt stones, or optical bleaching of certain classes of sediments, the system acquires an increasing luminescence signal in response to exposure to background sources of ionising radiation. Luminescence dating is based on quantifying both the radiation dose received by a sample since its zeroing event, and the dose rate which it has experienced during the accumulation period. 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. Luminescence dating can be applied to the age range from present to approximately , years, thus spanning critical time-scales for human development and quaternary landscape formation. Luminescence dating techniques can also be used for dose reconstruction, following accidental exposure to ionising radiation, and to assess thermal exposure for example of concrete structures subject to fire damage.
At the Netherlands Centre for Luminescence dating we develop new and improved luminescence dating methods, and we apply luminescence dating in collaboration with NCL partners and external users. We develop new and improved luminescence dating methods, and we apply luminescence dating in collaboration with NCL partners and external users. The Netherlands Centre for Luminescence dating is a collaboration of six universities and research centres in The Netherlands. Luminescence dating determines the last exposure to light or heat of natural minerals, mainly quartz and feldspar.
Thereby the method can be used to determine the time of deposition and burial of sediments, or the time of baking of ceramic artefacts pottery, brick.
Tammy Rittenour, Lab Director. Lab Description. The USU Luminescence Lab is equipped with two automated TL/OSL dating systems (Model Risø TL/OSL-DA-.
It is one of the main methods used to establish the timing of key events in archaeology and human evolution, landscape and climate change, and palaeobiology in the latter half of the Quaternary. The age is obtained by measuring the radiation dose received by the sample since it was last bleached by sunlight and dividing this estimate by the dose rate from environmental sources of ionising radiation.
Past and present research interests span a wide geographic compass, including Africa, Asia, Australia, Europe and North America, and topics as diverse as the evolution and behaviour of humans Homo sapiens, Homo floresiensis and Homo neanderthalensis , their response to climatic changes over the past , years, and their interaction with the indigenous fauna and flora.
The OSL dating laboratory is also at the forefront of technical advances in the analysis and interpretation of OSL data collected from single sand-sized grains of quartz, building on the pioneering research of Roberts and Jacobs in this field. The state-of-the-art laboratory consists of separate rooms for the preparation and measurement of quartz and feldspar grains, as well as storage rooms for quarantined material.
School of Geography and the Environment, University of Oxford
a glacial moraine (OSL dating) or alternatively the erosion and/or uplift rate of a mountain (OSL thermochronology). The OSL laboratory is presently equipped.
Introduction How do we measure the OSL signal? How do we measure the radiation dose rate? Another way of dating glacial landforms is optically stimulated luminescence dating OSL. OSL is used on glacial landforms that contain sand, such as sandur or sediments in glacial streams. The OSL signal is reset by exposure to sunlight, so the signal is reset to zero while the sand is being transported such as in a glacial meltwater stream.
Once the sand grain has been buried and it is no longer exposed to sunlight, the OSL signal starts to accumulate. OSL works because all sediments have some natural radioactivity, caused by the presence of uranium, thorium and potassium isotopes in heavy minerals such as zircons. We analyse the quartz or feldspar minerals in sand deposits.
Luminescence dating lab
The Vienna luminescence lab was founded in the year The lab was build with the perspective of elaborating key questions of environmental and Quaternary research, as e. Markus Fiebig markus.
Luminescence Research Laboratory. Dating. Luminescence dating depends on the ability of minerals to store energy in the form of trapped charge carriers.
The Heidelberg Luminescence Laboratory at the Institute of Geography conducts optical dating of sediments and stone surfaces as well as scientific and technological development of the optical stimulated luminescence technique. Luminescence dating is a dosimetric dating technique based on the steady decay of radionuclides present almost everywhere in the natural environment and the steadily increasing radiation damage caused in non-conductors, like mineral grains. The natural radioactivity functions as a driving clockwork and the mineral grains serve as a readable clock.
The clock ticks within sedimentary deposits and other archives which are used by researchers in the palaeo-environmental and archaeological sciences to reconstruct the evolution of a landscape, the history of an archaeological site or the interaction of man and his environment in the geological and historical past, in disciplines such as geomorphology , geoarchaeology and archaeometry. As a result of the radioactive decay of the radionuclides mainly 40 K and 87 Rb and the radioactive decay chains mainly from U, U and Th present in a sedimentary deposit, an ionizing radiation is emitted which leads to measurable radiation damages within the crystal lattices of the quartz and feldspar minerals Fig.
Within the non-conductors the activated electrons are lifted from the valence band to the conduction band and may be trapped at lattice defects where they are stored in meta-stabile states Fig. The larger the amount of trapped electrons is, the longer was the time during which mineral grains were exposed to the ionizing radiation. By supplying energy, the trapped electrons are released from their meta-stable states whereupon they recombine by emitting a cold light: the luminescence signal Fig.
Laboratory of optically stimulated luminescence (OSL Laboratory)
Optically Stimulated Luminescence OSL dating has emerged within the last 20 years as a key Quaternary absolute dating tool, with a wide range of terrestrial and marine applications. Optical dating techniques employ ubiquitous quartz or feldspar grains to directly date the deposition of sedimentary units. As such, the optical dating methods allow the systematic chronological evaluation of Quaternary-age sedimentary sequences.
OSL is an acronym for Optically-Stimulated Luminescence. Optically-Stimulated Luminescence is a late Quaternary dating technique used to date the last time.
Luminescence dating is used to identify when a sample was last exposed to daylight or extreme heat by estimating the amount of ionising radiation absorbed since burial or firing. This equation very simply expresses the calculations necessary, but it is important to be aware of the factors influencing the two values used. Heterogeneous sediments and radioactive disequilibria will increase errors on Dr, while incomplete bleaching of the sample prior to burial, anomalous fading in feldspars, and the estimation of past sediment moisture content may all also add to increased errors.
The dating of sediments using the luminescence signal generated by optical stimulation OSL offers an independent dating tool, and is used most often on the commonly occurring minerals of quartz and feldspar and, as such, has proved particularly useful in situations devoid of the organic component used in radiocarbon dating. Quartz has been used for dating to at least ka, while the deeper traps of feldspar have produced dates as old as 1 ma.
The use of fine-grain dating for samples such as pottery, loess, burnt flint and lacustrine sediments, and coarse-grain dating of aeolian, fluvial and glacial sediments is regularly undertaken. While thermoluminescence TL, the generation of a luminescence signal generated by thermal stimulation is still conducted on pottery and burnt flint samples, the bulk of luminescence dating now uses optical stimulation as this releases a signal that is far more readily zeroed than that re-set by heat.
Analysis of fully bleached samples is preferred as this ensures that associated errors are kept to a minimum. Despite this, procedures exist with which to identify and take account of partially bleached grains, as may be seen in fluvial, or more likely glacial sediments, where light exposure may have been attenuated by turbid or turbulent conditions. It is important to observe certain conventions when collecting samples in order to reduce errors as much as possible. By taking samples from well-sorted sediment structures problems with heterogeneous dose rates may be avoided, and all grains are more likely to have undergone the same depositional history.
Any areas of disturbance such as soil formation, groundwater leaching, bioturbation or slumping, should be avoided to remove the potential for post-depositional mixing of grains.
Optically stimulated luminescence
Directed by Professor Mark D. Bateman, the Sheffield Luminescence Dating Facility was established in In recent years samples from all around the world have been dated, including archaeological sediments from the USA and South Africa, relict cold-climate desert sands from Arctic Canada, dune sands from Zambia, Zimbabwe, The Netherlands and UK and lake sediments from Mexico.
Both quartz and many feldspar minerals act as dosimeters recording their exposure to this ionizing radiation. After being exposed to radiation these minerals, when stimulated by either heat or light, emit light.
Laboratory irradiated quartz has a TL emission band below °C in the region of – nm. Figure 6. Examples of TL (a, b) and OSL (c, d).
Luminescence dating is a geochronological technique that spans the Late Quaternary. It is particularly useful for minerogenic sediments, for example as optically stimulated luminescence OSL dating of quartz and infrared stimulated luminescence IRSL dating of feldspar. Thermoluminescence TL dating can also be used to determine the age of pottery. The Lund Luminescence Laboratory was established in , as the first of its kind in Sweden. In the adjoining rooms mechanical and chemical preparation of samples can be carried out under darkroom conditions.
Map marking study sites of the Lund Luminescence Laboratory. Click the pins on the map for links to the specific studies. Laboratory staff Helena Alexanderson Head of laboratory, professor. Git Klintvik Ahlberg Technician. Skip to main content. Browse aloud. Activate BrowseAloud.