Fossilized wood samples dated by CIRAM lab
CIRAM recently dated two pieces of fossilized wood: a "morta" oak and a marsh yew. Both were found buried in the same location, in the Bessin and Cotentin marshes in Normandy…

Luminescence dating, including thermoluminescence (TL) and optically stimulated luminescence (OSL), can be used to date materials that have been heated or exposed to natural light.
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Luminescence dating is a method of dating method based on the measurement of energy accumulated in quartz or feldspar crystals present in certain materials. This energy comes from natural exposure to environmental radioactivity and is released when heat (TL) or light (OSL) is applied. It can be traced back to the last "instant zero" undergone by the material:
This method makes it possible to date materials over periods of up to 700,000 years, depending on sediment type and conservation conditions. CIRAM rigorously adapts its protocols according to the context (museum or excavation), the type of object, and the method chosen (TL test, TL or OSL dating).
Contact our teamsThe quality of thermoluminescence (TL) or optically stimulated luminescence (OSL) dating rests on three pillars:
CIRAM is currently the only private laboratory in Europe to offer TL/OSL dating comparable to the protocols used by public research centers.
Request a quoteThe archaeological dose, or equivalent dose, corresponds to the energy accumulated since the last heating or exposure. This measurement is carried out in our laboratories using the LexsygSmart system, after rigorous sample processing.
To obtain absolute dating, we need to know not only the equivalent dose, but also the annual dose of irradiation received by the object. This dose comes from three sources: the object itself (self-irradiation), its surroundings (up to 1 metre away), and cosmic radiation.
CIRAM combines complementary methods with TL/OSL dating, depending on the case:
Thanks to its scientific expertise and rigorous protocols, CIRAM has become a benchmark for radiocarbon datingbut also in luminescence dating. And with good reason: CIRAM is one of the few private laboratories to offer a complete range of TL and OSL dating services, with protocols as rigorous as those applied in public laboratories.
Our expertise lies in two main areas:
The TL test is a preliminary examination to assess whether a sample is old or not. TL dating, on the other hand, involves in-depth analysis with a rigorous protocol, including the precise calculation of archaeological dose and annual dose to provide a reliable absolute age.
Accuracy depends on the context and condition of the sample. In general, it varies between 5 and 10% of the estimated age.
TL is used to date heated ceramics, terracotta, porcelain and minerals. OSL is used for sediments and minerals exposed to light.
A TL test takes a maximum of 2 weeks, whereas TL or OSL dating takes 4 to 6 months. Turnaround times may vary according to the type of sample, the complexity of the analysis and the volume of requests.
The cost of TL/OSL dating depends on the nature of the sample, the complexity of the analysis and the number of samples to be analyzed. Please contact us for a personalized quotation.
CIRAM recently dated two pieces of fossilized wood: a "morta" oak and a marsh yew. Both were found buried in the same location, in the Bessin and Cotentin marshes in Normandy…
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