Dating of Ancient Cerarmics by Thermoluminescence. III

Thermoluminescent (TL) dating of ancient ceramics was undertaken by a TL technique named the large grain method. Because the sources of alpha particles were embedded mainly in the clay fabric and the range of the particle is less than 23 μm for quartz, the contribution to TL from alpha particles could be neglected by the treatment of hydrofluoric-acid etching on the surface layer of the sample grain. The accumulated radiation dose from beta and gamma rays originating from the pottery itself and the surrounding soil was measured by means of high sensitive thermoluminescent dosimeter CaSO4:Tm. In the present investigation, the colourless grains of greater than 250μm in diameter obtained from Thai and Japanese potteries were used as samples. The experimental results showed fairly good agreements with the known ages for Japanese potteries