Thermoluminescence dating of quaternary sediments using total bleach and regeneration methods

Thermoluminescence (TL) dating of sediments inconjunction with accelerator-mass-spectrometry (AMS) radiocarbon dating of organic materials have been carried out on Quaternary samples from Ban Bom Luang trench, northern Thailand and Thung Tuk archaelogical site, southern Thailand. These two sites permit detailed comparisons of thermoluminescence and radiocarbon chronologies. Both techniques produce self-consistent chronologies for the colluvial deposits (Ban Bom Luang trench) and beach sand deposits with the ancient remain (Thung Tuk archaeological site). In case of TL dating focuses are placed on problems connected with equivalent dose (ED) estimation. The dated results obtained by using two techniques: regeneration and total bleach techniques were compared with AMS radiocarbon dating. The obtained results show that the ED values are strongly dependent on the applied technique. Most of TL ages obtained by the regeneration technique were confirmed by AMS radiocarbon ages while total blench technique seems tobe discrepancy. The discrepancy dates evaluated by total bleach technique effect from supralinear (underestimation), superlinear (overestimation) and saturation (overestimation). In order to make the TL-dating results more reliable and accurate, we compared the TL-age dating results with those of the radiocarbon ages and the widely accepted other ages from selected samples of the same sedimentary layers from various places in Thailand. The calibration curve of TL and other dating results displays a good positive correlation with the linear regression of about 0.992. This strongly advocates that our current TL-age dating results are more consistent with that of the AMS radiocarbon dating than that of the conventional radiocarbon dating. Moreover, the TL dating method is more powerful than the AMS radiocarbon dating in a sense that the TL data are well applicable to the fine-grained quartz-rich sediments of up to 2 Ma and tektite samples of about 0.7 Ma