Optically Stimulated Luminescence (OSL) Dating

Please reference: Mallinson, D. Optically stimulated luminescence is a method of determining the age of burial of quartz or feldspar bearing sediments based upon principles of radiation and excitation within crystal lattices, and stems from the fact that imperfections in a crystal lattice have the ability to store ionizing energy Aitken , ; Botter -Jensen et al. Radiation within sediments comes from alpha, beta, and gamma radiation emitted during the decay of U, U, Th, 40 K, and 87 Rb, and their daughter products, both within the mineral grains and in their surroundings Lian , , and from cosmic rays Figure 1. Under controlled laboratory conditions, assuming the sample was collected under light-restricted conditions, controlled exposure of the sample to photons yields a luminescence response the equivalent dose, D e , the intensity of which is a function of the dose rate within the sediment, and the length of time the sample was exposed to the background radiation. In order to measure the age, two factors must be known; 1 the environmental dose rate, and 2 the laboratory dose of radiation that produces the same intensity of luminescence as did the environmental radiation dose the equivalent dose. Dividing the equivalent dose by the dose rate yields time.

The principles of Luminescence Dating

The possible role of environmental change, especially sea level change, as a stimulus for the development of human residence and migration is poorly understood. We investigate this problem by showing a record of sea-level change and coastal transformation based on a sediment core FN1 core and a Neolithic site Pingfengshan site obtained from the Funing bay on the northeast coast of Fujian, China.

Samples from FN1 core and Pingfengshan site were taken for grain size ananlyses and for optically stimulated luminescence OSL dating.

CABAH’s Professor Zenobia Jacobs specialises in Optically Stimulated Luminescence (OSL) dating, a technique that can date objects further.

Portable Spectrofluorimeter for non-invasive analysis of cultural heritage artworks using LED sources. Luminescence spectroscopy – Spatially resolved luminescence – Time resolved luminescence – Electron spin resonance ESR. Flint and heated rocks – Ceramics and pottery – Unheated rock surfaces – Tooth enamel and quartz grains – Sediment dating. LexEva is a newly released evaluation software developed for analysis in luminescence research and dating.

Few years depending on signal intensity and sensitivity of equipment for which the lexsyg systems are especially developed. Radiation Measurements 32, This Website uses cookies Our website uses cookies and the web analytics tool Google Analytics according to our privacy policy. By continuing to browse these pages, you agree.

Luminescence Dating Laboratory

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.

Principles of Luminescence Dating. Optically stimulated luminescence was developed.

Jack Rink about a new technique that he using to determine the age of the Crystal River archaeological site. He began his education in Florida where he received his Ph. After working on projects in Africa, Europe and Asia, Dr. Rink returned to Florida several years ago to work on the Salt Springs site near Palatka. He has since worked at sites around the state including several shell middens on St.

Rink and his associates specialize in a special type of geochronology called Optical Stimulated Luminescence—or OSL for short—that is used to date archaeological sites and geological features. OSL dating is a system of sampling and measuring the amount of energy that is trapped within soils. Quartz and quartzite accumulate energy in them through time. The rate of breakdown and energy release is relatively constant.

Optically Stimulated Luminescence dating

Up to now not a single dating technique has been developed for in-situ planetary exploration. The only information on the age of extraterrestrial planetary surfaces comes from the “crater-counting” method. This method has an inherent large error and low resolution and is completely inadequate for local geology. Luminescence dating has possibly the potential to open up a completely new discipline in planetary in-situ exploration.

This assessment has a strategic value for the development of a new generation of in-situ instrumentation. Sedimentation processes on Mars are completely unexplored.

The basic premise of mortar dating by optically stimulated luminescence (OSL) is that quartz in the sand used for making mortar has been.

Optical : Relating to the use of visible or near-visible light. Stimulated : To excite with a stimulus light or heat. Optically stimulated luminescence : The emission of light from crystalline materials when stimulated by light following previous absorption of energy from radiation. Luminescence dating consists of a family of analytical methods, most of which are used in archaeological research.

They can be applied to samples ranging in age from just a few years to several hundreds of thousands of years beyond the range of radiocarbon dating , and they are, therefore, able to cover a time interval that includes important turning points in the evolution of humans. The choice of luminescence method depends on the availability of appropriate minerals, the time period of interest, and the nature of the target event. When one technique is not suitable to a particular situation, another technique often is.

The basic principles of all the different luminescence dating techniques, and also electron spin resonance ESR dating, are the same: each relies on the effects of radiation exposure. Ages are obtained by measuring the cumulative effect of ionizing radiation on the crystal structure of certain minerals. The longer the duration since first exposure to radiation, the greater the amount of energy absorbed, and consequently, the greater the luminescent signal obtained, which is indicative of an older age for the material being investigated.

OSL Dating in Archaeology

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.

Under the direction of Dr. Jim Feathers, this laboratory provides dating service for ceramics, lithics, and sediments using optically-stimulated luminescence (OSL).

Optically stimulated luminescence dating of rock surfaces. N2 – There are many examples of rock surfaces, rock art and stone structures whose ages are of great importance to the understanding of various phenomena in geology, climatology and archaeology. Optically stimulated luminescence OSL dating is a well-established chronological tool that has successfully determined the depositional age of a wide variety of fine-grained sediments, from several years to several hundred thousands of years.

However, there is no routine OSL dating method applicable to larger clasts such as cobbles, boulders and other rock surfaces. Here the application of quartz OSL to the dating of rock surfaces is successfully tested by application to two different quartz-rich rock types sandstone and quartzite. Together with the measurement of infrared stimulated luminescence IRSL signals as a function of depth into the surface of different granites it is clear that both OSL and IRSL can be fully reset in the two mm closest to the rock surface.

Optically stimulated luminescence dating of young sediments and dusts

Williams, A. Journal of Archaeological Science: Reports, Here we present the results of a multi-phase compliance-based archaeological excavations of a new bridge crossing the Hawkesbury-Nepean River northwest Sydney.

Types of Luminescence Dating Techniques. Thermal (TL); Optically Stimulated (​OSL). Green Light (GSL) – Feldspar & Quartz; Blue Light (BSL) – Quartz; Red.

Optically stimulated luminescence dating at Rose Cottage Cave. A single-grain analysis demonstrates that the testing procedure for feldspar fails to reject single aliquots containing feldspar and the overestimate of age is attributed to this. Seven additional luminescence dates for the Middle Stone Age layers combined with the 14 C chronology establish the terminal Middle Stone Age deposits at 27 years ago, while stone tool assemblages that are transitional between the Middle Stone Age and the Late Stone Age are dated to between 27 years and 20 years ago.

Although there are inconsistencies in the Middle Stone Age dates, the results suggest that the Howiesons Poort at Rose Cottage Cave dates to between 70 years and 60 years ago. Much of the rich archaeological heritage in southern Africa is older than 50 years, which is the limit of the ubiquitous 14 C dating technique. In order to make appropriate inter-site comparisons of artefactual evidence, and further to compare the trajectory of human adaptation with external factors such as changing climates, it is necessary to establish a reliable chronological framework.

Optically stimulated luminescence OSL dating has become one of the foremost techniques in establishing this framework. OSL is based on the build-up and release of radiation energy in crystalline minerals, typically quartz.

Optically stimulated Luminescence dating of quartz

Luminescence dating including thermoluminescence and optically stimulated luminescence is a type of dating methodology that measures the amount of light emitted from energy stored in certain rock types and derived soils to obtain an absolute date for a specific event that occurred in the past. 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. As a result, there is no upper date limit set by the sensitivity of the method itself, although other factors may limit the method’s feasibility. To put it simply, certain minerals quartz, feldspar, and calcite , store energy from the sun at a known rate.

Oslo. ISSN Optically Stimulated Luminescence (OSL) dating allows age determinatio n of sediments deposited during the last glacial–interglacial cycle.

Luminescence dating, particularly using optically stimulated luminescence OSL , is revolutionizing Quaternary and archaeological science because it allows dating of sediments and artifacts that perhaps 10 years ago could not be dated. The lab has produced more than OSL ages from years to , years for aeolian, fluvial, lacustrine, and marine sediments, as well as pottery, artifacts and secondary carbonate. Chronologies have been developed for archaeological sites in Botswana and the U. As the OSL of a sediment is quickly lost when exposed to sunlight tens of seconds many sediments are bleached lack an OSL signal when deposited and buried.

After deposition these sediments accumulate luminescence which can be measured allowing the age of burial to be determined. There is now convincing evidence that many glacial, fluvial, aeolian, and even shallow marine sediments can be dated by OSL techniques. The upper limit of age by OSL is largely determined by the annual dose on the sediment which is related to it’s content of uranium, thorium and potassium. Low levels of radioactive isotopes in the sediment lead to very slow saturation of quartz and feldspar grains by released electrons and so ages in excess of ka may be possible.

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Luminescence Measurements demonstrated by Ed Rhodes