Thermoluminescence Dating

In the last years, a laboratory for dating and authentication of archaeological finds and historical objects by means of thermoluminescence (TL) technique has been developed.

The technique is suitable for inorganic material like potteries, bricks, ceramics and bronze cores that contain quartz and feldspar crystals which have been heated at temperature of hundreds Celsius degree ("zeroing event"). A sampling is needed to perform the analysis.

The TL dating requires the measurement of two quantities: the total accumulated absorbed radiation dose in selected minerals (so-called palaeodose or archaeological dose) and the annual dose due to the natural radioisotope content of the sample and its surrounding environment. From these two measurements, the TL age can be subsequently calculated from the basic equation: age = (palaeodose)/ (annual dose).

The difference between a dating and an authentication of an object, is the accuracy of the result: in case of dating of material from an archaeogical site all the parameters of the age equation are known and the error associated to the final age is about 3-5%. Otherwise when an artwork from a museum or a private collection is analyzed all the information about the burial site and the surrounding environment are lost, then the paleodose is the only parameter measurable. In this case the result of a TL analysis is not the date of the last heating of the material, but a measure of compatibility between the obtained paleodose and the age proposed by archaeologist or historian.

The laboratory has already been used in many cases of authentication of artworks coming from museums and private collections and for dating in archaeological sites.

The main collaborations are with TecnArt S.rl., with Archaeomagnetic Dating researchers at INRIM (Dr. Enzo Ferrara) and at the Earth Science Department of the University of Torino (Dr. Evdokia Tema), with Chemist Department (Dr. Monica Gulmini) and with other Luminescence Dating Laboratory inside the INFN-CHNET network (Milano Bicocca, Catania and Bari).


E. Tema et al. "Archaeological, archaeomagnetic and thermoluminescence investigation of a baked clay kiln excavated at Chieri, northern Italy", Annals of Geophysics, 57, 5 (2014) G0528

E. Tema et al. "Combined archaeomagnetic and thermoluminescence study of a brick kiln excavated at Fontanetto Po (Vercelli, Northern Italy)", Journal of Archaeological Science 40 (2013) 2025-2035