Thermoluminescence dating pottery

22 Nov

This paper reports the results of studying four sherds from the archaeological site in Teotenango Mexico where the Matlatzinca culture blossomed before the Spanish arrival in America.

The determination of the age, was carried out with the thermoluminescence (TL) method.

Two forms of luminescence dating are used by archaeologists to date events in the past: thermoluminescence (TL) or thermally stimulated luminescence (TSL), which measures energy emitted after an object has been exposed to temperatures between 400 and 500°C; and optically stimulated luminescence (OSL), which measures energy emitted after an object has been exposed to daylight.

To put it simply, certain minerals (quartz, feldspar, and calcite), store energy from the sun at a known rate.

In this work it is demonstrated that it is possible to obtain in the laboratory an artificial glow curve identical to the archaeological one.

From the conditions of the laboratory experiment (temperature of irradiation and dose rate), under which the identity is achieved, it is possible to estimate the archaeological age of the sample.

Another sample, however, showed a larger peak at 365°C and could not be dated because of serious fading.The theory of the method is presented and experimental results are given.Six ceramics and two baked soil samples collected from the famous Xian Terracotta Army Site have been dated by using fine grain (2–8 μ) TL technique.TL ages of 1.93 ± 0.13 ka and 2.20 ± 0.19 ka have been also obtained from the baked soil samples with a plateau between 300 and 350°C.The TL dates of the ceramics and baked soil are consistent with C-14 dates on charcoal samples taken from the same layer in Xian Terracotta Army Site.