Glow curves and emission spectra of burnt flints

The thermoluminescence (TL) behaviour of a group of burnt flints from a pre historic site in North Italy has been studied. Due to incomplete burning or non-reproducible results only three samples could be reliably dated. The flints have been studied through electron microscopy with microprobe, X -ray diffraction and TL, also wavelength resolved. A new type of preparatio n using a hydraulic press avoids modifications of the natural TL signal. Th e effects of acid etching were also studied. All the samples turned out to be composed of microquartz and megaquartz. Th e glow-curves gave indication of incomplete burning through the appearance of a peak at about 450 degrees C (heating rate 8 degrees C s(-1)), contrary to the well-annealed samples that presented a composite peak in the 280-38 0 degrees C region. Encouraging results have been obtained in the analysis of the TL emission s pectra. Three emission regions have been detected: 260-330 nm, 350-500 nm a nd 580-640 nm. While only the middle one is usually detected by conventiona l 2D instrumentation, also the UV region could be probably proposed for dat ing burnt flint. (C) 1999 Elsevier Science Ltd. All rights reserved.