Dating of freshwater fossil shells in the archaeological sites at Cliff Deva Thoud-Ta Thoud-Yai, Songkhla Province of Thailand with thermoluminescence.

Archaeological evidence indicates that a group of humans arrived in the southern region of Thailand around 40,000 years ago. This hypothesis is based on the discovery of human and animal bones, beads, and ceramics, as well as fossilized freshwater shells. This current study used thermoluminescence (TL) to date freshwater fossil shells from the archeological sites at Cliff Deva Thoud-Ta Thoud-Yai in Songkhla province of Thailand. Organic compounds having unpaired electrons trapped by crystal defects are required for TL dating. The method needs two factors for precise dating: the annual dose and the accumulated doses. We estimate the annual dose using the Dose Rate and Age Calculator (DRAC). Regarding the accumulated dose, we used glow-curve deconvolution (GCD) for general orders of the kinetics. The accumulated dose is determined by the relationship between the TL radiation intensity and the accumulated gamma radiation. Using linear regression, the dependency of TL intensity on dose was modeled. All fossil shells were dated at a temperature of 350°C for TL, and their ages were estimated to be 9485.96 ± 564.13 year. This outcome will ultimately help us understand more about how people in that region lived. [ABSTRACT FROM AUTHOR]