Luminescence dating of burnt materials: effects of preheat treatment on OSL and consequences for dating procedures

摘要

For dating purposes, OSL experiments were carried out on a variety of silicate materials extracted from ceramics and kiln fragments which were already dated by TL. In order to check the thermal stability of signals, a study of the variation of OSL with preheat temperature showed, in a majority of cases, that OSL, recorded at room temperature, increases above 200 degreesC before the normal thermal drainage at higher temperature, at more than 250 degreesC. According to our data, preheat treatments at a temperature which induces an increase of OSL, lead to underestimated measures of equivalent doses (ED). So, dating protocols avoiding sensitivity changes by preheating have been carried out, using the more appropriate conditions of preheat and stimulation that get rid of unstable components, determined by preliminary studies. A good agreement between OSL and TL results is then obtained when no change in sensitivity occurs during the irradiation/optical bleaching cycles performed in ED measurements. (C) 2001 Elsevier Science Ltd. All rights reserved. [References: 19]