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.
Saunders, who thought the thermoluminescence response of pottery shards could date the last incidence of heating. In , Aitken et al. In , the principles behind optical and thermoluminescence dating were extended to include surfaces made of granite, basalt and sandstone, such as carved rock from ancient monuments and artifacts. Ioannis Liritzis , the initiator of ancient buildings luminescence dating, has shown this in several cases of various monuments.
Optically stimulated luminescence dating method
The radiation dose rate is calculated from measurements of the radioactive elements K, U, Th and Rb within the sample and its surroundings and the radiation dose rate from cosmic rays. The dose rate is usually in the range 0.
The total absorbed radiation dose is determined by exciting, with light, specific minerals usually quartz or potassium feldspar extracted from the sample, and measuring the amount of light emitted as a result.
The photons of the emitted light must have higher energies than the excitation photons in order to avoid measurement of ordinary photoluminescence. A sample in which the mineral grains have all been exposed to sufficient daylight seconds for quartz; hundreds of seconds for potassium feldspar can be said to be of zero age; when excited it will not emit any such photons.
The older the sample is, the more light it emits, up to a saturation limit. The minerals that are measured are usually either quartz or potassium feldspar sand-sized grains, or unseparated silt-sized grains.
There are advantages and disadvantages to using each. For quartz, blue or green excitation frequencies are normally used and the near ultra-violet emission is measured. For potassium feldspar or silt-sized grains, near infrared excitation IRSL is normally used and violet emissions are measured.
Unlike carbon dating , luminescence dating methods do not require a contemporary organic component of the sediment to be dated; just quartz, potassium feldspar, or certain other mineral grains that have been fully bleached during the event being dated. In a study of the chronology of arid-zone lacustrine sediments from Lake Ulaan in southern Mongolia , Lee et al.
The sediments with disagreeing ages were determined to be deposited by aeolian processes. Westerly winds delivered an influx of 14 C -deficient carbon from adjacent soils and Paleozoic carbonate rocks, a process that is also active today. This reworked carbon changed the measured isotopic ratios, giving a false older age.
However, the wind-blown origin of these sediments were ideal for OSL dating, as most of the grains would have been completely bleached by sunlight exposure during transport and burial.
From Wikipedia, the free encyclopedia. Annual Review of Earth and Planetary Sciences. Retrieved February 8, Journal of Archaeological Science. Retrieved February 16, Retrieved March 15, Materials on the Quaternary Period of the Ukraine.
K-feldspars optical response stimulation spectra". Mediterranean Archaeology and Archaeometry. Canon of Kings Lists of kings Limmu.
In diagnostic imaging the increased sensitivity of the OSL dosimeter makes it ideal for monitoring employees working in low-radiation environments and for pregnant workers.
To carry out OSL dating, mineral grains have to be extracted from the sample. Occasionally other grain sizes are used. The difference between radiocarbon dating and OSL is that the former is used to date organic materials, while the latter is used to date minerals. Events that can be dated using OSL are, for example, the mineral's last exposure to sunlight; Mungo Man , Australia's oldest human find, was dated in this manner.
In archaeology, OSL dating is applied to ceramics: Recent OSL dating of stone tools in Arabia pushed the "out-of-Africa" date hypothesis of human migration back 50, years and added a possible path of migration from the African continent to the Arabian peninsula instead of through Europe.
From Wikipedia, the free encyclopedia.
Optically Stimulated Luminescence
Method of measuring radiation doses, often used in mineral dating. This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed.
Annual Review of Earth and Planetary Sciences. Financial Times requires registration. Archived from the original on January 3, Luminescence dating of quartz using an improved single-aliquot regenerative-dose protocol.Старейшей специализированный костяной инструмент атерийской культуры, Северной Африки ср. палеолита
Retrieved from " https: Particle detectors Dating methodologies in archaeology.