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. The blue-light stimulated OSL signals were measured by the single aliquot regenerative dose SAR protocol to determine the ages of of the samples. The comparison of sea level change and Neolithic cultural periods presents a good relationship in coastal area of Fujian, China since about 7 ka before present. In detail, the cultural types of Keqiutou culture and Huangguashan culture all belong to coastal mountainous culture, of which flourishing periods corresponds to the higher sea level periods of mid-late Holocene. Tanshishan culture belongs to estuarine coastal culture, and most sites of this period correspond to a lower sea level located at lower altitudes. East coastal area of Fujian province, centring on the Funing bay, is a major concentrated area of Neolithic culture sites in the middle and lower reaches of Min River which is the longest river in Fujian province of China, with largest water and most extensive area. A large number of neolithic remains were found around this area.
The principles of Luminescence Dating
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.
Nowadays, OSL dating has proven that it is a reliable method to provide deposition Quaternary sediments in Brazil are suitable for luminescence dating in the.
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 most common methods applied to minerals are cosmogenic radionuclides, electron spin resonance ESR and luminescence techniques.
Optically Stimulated Luminescence
In luminescence dating, the signal accumulates within minerals over time as a function of low level, natural radiation exposure. The datable event is that point in time when the signal was reset to zero and started to grow again. The signal is essentially a dosimeter, converting to a chronometer by estimating the rate of dose absorption.
Luminescence dating refers to a group of methods of determining how long ago mineral grains were last exposed to sunlight or sufficient heating. It is useful to geologists and archaeologists who want to know when such an event occurred. It uses various methods to stimulate and measure luminescence. All sediments and soils contain trace amounts of radioactive isotopes of elements such as potassium , uranium , thorium , and rubidium. These slowly decay over time and the ionizing radiation they produce is absorbed by mineral grains in the sediments such as quartz and potassium feldspar.
The radiation causes charge to remain within the grains in structurally unstable “electron traps”. The trapped charge accumulates over time at a rate determined by the amount of background radiation at the location where the sample was buried. Stimulating these mineral grains using either light blue or green for OSL; infrared for IRSL or heat for TL causes a luminescence signal to be emitted as the stored unstable electron energy is released, the intensity of which varies depending on the amount of radiation absorbed during burial and specific properties of the mineral.
Most luminescence dating methods rely on the assumption that the mineral grains were sufficiently “bleached” at the time of the event being dated. Single Quartz OSL ages can be determined typically from to , years BP, and can be reliable when suitable methods are used and proper checks are done. In multiple-aliquot testing, a number of grains of sand are stimulated at the same time and the resulting luminescence signature is averaged .
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Optically Stimulated Luminescence (OSL) is a technique used for dating sand grains, Another way of dating glacial landforms is optically stimulated luminescence dating (OSL). Precision and accuracy in glacial geology.
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. The charge build-up manifests as electrons, mobilized in the quartz matrix by environmental radiation, which populate pre-existing energy minima that are called ‘traps’.
OSL dates represent the time since electron traps within the quartz grains were previously emptied or bleached by heating or exposure to sunlight. The equivalent dose D e of the sample is divided by the dose rate to calculate the age. Luminescence techniques applied to quartz can be used to obtain depositional ages up to years in certain environments. Several criteria need to be met in order to achieve accurate OSL results.
Luminescence dating utilises energy deposited in mineral lattices by naturally occurring ionising radiation to record information encoding chronology, depositional process information, and thermal history records in ceramics, lithics, and sedimentary materials. Precision of dating varies from sample to sample, and from context to context, depending on individual sample characteristics mineralogy, luminescence sensitivity, stability and homogeneity of the radiation environment, and the quality of initial zeroing.
A well calibrated laboratory can produce accuracy at the lower end of the precision scale. For high quality work it is important that the environmental gamma dose rates are recorded in-situ at time of excavation, which is most readily facilitated by involving the dating laboratory in fieldwork. The key importance of luminescence dating within Scottish Archaeology lies in the nature of the events represented by the various dating materials.
Luminescence dating is a rapidly expanding field. Recent advances in methodology and instrumentation have improved both its accuracy and precision, such.
Precision and accuracy in the optically stimulated luminescence dating of sedimentary quartz. T1 – Precision and accuracy in the optically stimulated luminescence dating of sedimentary quartz. E-mail: au au. Pages for all PhD students phd. Common pages for staff members at AU staff. Departments and faculties. Research units and facilities Departments and schools Research centres Research facilities Research support Find a researcher. Danish way of living Cost of living Family and work-life balance The Danes.
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Luminescence Dating, Uncertainties, and Age Range
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. This energy is lodged in the imperfect lattices of the mineral’s crystals.
distributions for age determination allows more accurate dating for some samples, but the nature of the distributions limits the resolution on others, conclusions.
Luminescence dating is a rapidly expanding field. Recent advances in methodology and instrumentation have improved both its accuracy and precision, such that it is now becoming an important player in Quaternary science. The advantage luminescence has over other techniques is the ability to date directly events of archaeological and geological interest: the last heating of ceramics and lithics and the last exposure of light for sediments. This often eliminates the need to establish a linkage between the dating event and the target event and thereby the loss of accuracy associated with such bridging arguments.
Luminescence is not as precise as some dating methods, but errors between 5 and 10 percent are commonly obtained. Go in About Luminescence Dating. Luminescence is the emission of light from crystalline materials following the absorption of energy from an external source. It is distinguished from other light emissions such as fluorescence by a time interval between absorption and emission, an interval of sufficient duration to permit dating on an archaeological time scale.
The external source of energy is naturally occurring, ionizing radioactivity alpha, beta, gamma and cosmic radiation. The time lag can be understood by reference to solid state energy band theory. Ionizing radiation excites electrons from the valence band, or ground state, across an energy gap to the conduction band where they are free to move about.
Energy levels within the gap cannot normally be occupied, but crystalline defects resulting in localized charge deficiencies allow occupation of metastable energy levels within the gap. Excited electrons or electron vacancies holes can thus become trapped at these defects.
Luminescence dating laboratory
Springer Professional. Back to the search result list. Table of Contents. Hint Swipe to navigate through the chapters of this book Close hint. Abstract Optically stimulated luminescence OSL dating is a versatile technique that utilises the two most ubiquitous minerals on Earth quartz or K-feldspar for constraining the timing of sediment deposition.
I The accuracy and precision of TL dates Radiocarbon, ceramic cross dating, and tree-ring dat- Thermoluminescence dating shows good potential.
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.