Over the last 60 years, luminescence dating has developed into a robust chronometer for applications in earth sciences and archaeology. The technique is particularly useful for dating materials ranging in age from a few decades to around ,—, years. In this chapter, following a brief outline of the historical development of the dating method, basic principles behind the technique are discussed. This is followed by a look at measurement equipment that is employed in determining age and its operation. Luminescence properties of minerals used in dating are then examined after which procedures used in age calculation are looked at. Sample collection methods are also reviewed, as well as types of materials that can be dated.
This paper aims to provide an overview concerning the optically stimulated luminescence OSL dating method and its applications for geomorphological research in France. An outline of the general physical principles of luminescence dating is given. A case study of fluvial sands from the lower terrace of the Moselle valley is then presented to describe the range of field and laboratory procedures required for successful luminescence dating.
The paper also reviews the place of OSL dating in geomorphological research in France and assesses its potential for further research, by focusing on the diversity of sedimentary environments and topics to which it can be usefully applied. Hence it underlines the increasing importance of the method to geomorphological research, especially by contributing to the development of quantitative geomorphology. They are now largely used to date not only palaeontological or organic remains, but also minerals that characterise detrital clastic sedimentary material.
The Luminescence Dating and Dosimetry Laboratory is developing new techniques for application to the dating of artefacts and deposits from sites that range widely in terms of chronological period, geographic location and material type. Recent work as focused on optically stimulated luminescence OSL techniques, in particular a novel experimental approach to the measurement of single grain OSL.
A study produced, for the first time, absolute dates for a range of brick stupas located within the hinterland of Anuradhapura , contributing to the further development of a brick monument chronology for the region. Ongoing work is examining whether unfired clay bricks from various sites can be dated accurately. OSL techniques are being applied to date sediment sequences in stratigraphic contexts associated with irrigation systems.
In the absence of suitable organic samples for C dating, these systems are very difficult to date. New approaches are being applied to the dating of post-Roman irrigation systems in Spain to establish when they were created and used. Also, as part of a major investigation supported by the European Research Centre and led by Prof. Sauer at the University of Edinburgh, a PhD project has started to investigate the application of OSL and geomorphological techniques to establish the chronology of irrigation systems and settlement sites associated with the demographic growth at the frontiers of the Sasanian Empire.
The availability of chronologies for aeolian horizons obtained using OSL provides a valuable tool in the study of the evolution of coastal landscape and how past coastal communities responded to climate change.
All Research Projects
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.
OSL-method can be used for example when dating sand formations. In both methods the main idea is that the traps are emptied at the specific.
The impetus behind this study is to understand the sedimentological dynamics of very young fluvial systems in the Amazon River catchment and relate these to land use change and modern analogue studies of tidal rhythmites in the geologic record. Many of these features have an appearance of freshly deposited pristine sand, and these observations and information from anecdotal evidence and LandSat imagery suggest an apparent decadal stability. Signals from medium-sized aliquots 5 mm diameter exhibit very high specific luminescence sensitivity, have excellent dose recovery and recycling, essentially independent of preheat, and show minimal heat transfer even at the highest preheats.
Significant recuperation is observed for samples from two of the study sites and, in these instances, either the acceptance threshold was increased or growth curves were forced through the origin; recuperation is considered most likely to be a measurement artefact given the very small size of natural signals. Despite the use of medium-sized aliquots to ensure the recovery of very dim natural OSL signals, these results demonstrate the potential of OSL for studying very young active fluvial processes in these settings.
An important facet of the development of a geochronological technique is the investigation of potential age range.
Luminescence Dating: Applications in Earth Sciences and Archaeology
The stability of luminescence signals stimulated by IR at elevated temperature was first investigated by Thomsen et al. Buylaert et al. Based on studies of the source of the IR stimulated luminescence signal by Murray et al. They applied this revised protocol to samples of Japanese loess, one with age control, and were unable to detect significant signal instability. As a result of these early studies, the feldspar pIRIR signal is now widely used in dating both sand-sized extracts of K-feldspars and polymineral fine-grains Buylaert et al.
Published in: Luminescence Dating in Archaeology, Anthropology, and The advent of optically stimulated luminescence (OSL) techniques and the potential for.
Optically-Stimulated Luminescence is a late Quaternary dating technique used to date the last time quartz sediment was exposed to light. As sediment is transported by wind, water, or ice, it is exposed to sunlight and zeroed of any previous luminescence signal. Once this sediment is deposited and subsequently buried, it is removed from light and is exposed to low levels of natural radiation in the surrounding sediment. Through geologic time, quartz minerals accumulate a luminescence signal as ionizing radiation excites electrons within parent nuclei in the crystal lattice.
A certain percent of the freed electrons become trapped in defects or holes in the crystal lattice of the quartz sand grain referred to as luminescent centers and accumulate over time Aitken, In our laboratory, these sediments are exposed to an external stimulus blue-green light and the trapped electrons are released. The released electrons emit a photon of light upon recombination at a similar site.
In order to relate the luminescence given off by the sample to an age, we first need to obtain the dose equivalent to the burial dose. Following the single-aliquot regenerative SAR method of Murray and Wintle , the dose equivalent De is calculated by first measuring the natural luminescence of a sample. Then, the bleached sample is given known laboratory doses of radiation, referred to as regenerative doses. The regenerative dose data are fit with a saturating exponential to generate a luminescence dose-response curve.
The De is calculated by the intercept of the natural luminescence signal with the generated curve. A curve is generated for each aliquot subsample , multiple aliquots are needed to obtain an accurate De.
4. Luminescence Dating of Archaeological Materials
Geochronology Group. The co-operating scientists at the INW are Prof. Frans De Corte and PhD. 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.
Enter your mobile number or email address below and we’ll send you a link to download the free Kindle App. Then you can start reading Kindle books on your smartphone, tablet, or computer – no Kindle device required. To get the free app, enter your mobile phone number. Optical dating is a rapidly developing technique, used primarily in the dating of sediments deposited in the last , or more years, and increasing numbers of Quaternary geologists, physical geographers, archaeologists, and anthropologists are now relying on the results.
Written by one of the foremost experts on optical dating, this book aims to bring together in a coherent whole the various strands of research that are ongoing in the area. It gives beginners an introduction to the technique while providing experienced practitioners with a valuable source of up-to-date references. The text is divided into three parts: main text, technical notes and appendices. In this way the main text is accessible to researchers with a limited knowledge of physics, while the technical notes provide the details for anyone wishing to understand the techniques completely.
The first part of the book presents basic notions and introduces the standard techniques, along with several illustrative case histories. The book then proceeds to discuss the limitations of the technique and the factors affecting reliability.
School of Geography and the Environment, University of Oxford
Emission of luminescence in response to exposing the sample to light. In the laboratory this light is normally restricted to a narrow range of wavelengths. Radioactivity is ubiquitous in the natural environment. Luminescence dating exploits the presence of radioactive isotopes of elements such as uranium U , thorium Th , and potassium K.
The premise of luminescence dating methods is that the dose–response of the natural luminescence signal can be reconstructed in the laboratory.
Optically stimulated luminescence and isothermal thermoluminescence dating of high sensitivity and well bleached quartz from Brazilian sediments: from Late Holocene to beyond the Quaternary? E-mail: andreos usp. E-mail: ligia. E-mail: ccfguedes gmail. E-mail: wsallu gmail. E-mail: assine rc. The development of optically stimulated luminescence OSL dating of sediments has led to considerable advance in the geochronology of the Quaternary.
OSL dating is a well established technique to determine sediment burial ages from tens of years to few hundred thousand years. Recent studies have shown that Quaternary sediments of Brazil are dominated by quartz grains with high luminescence sensitivity, allowing the determination of precise and reliable OSL burial ages.