Optical dating: some luminescence properties of natural feldspars

Feldspars are widely used as dosemeters in dating archaeological and geological materials by luminescence methods, especially infrared stimulated luminescence, IRSL. Some fundamental problems of this luminescence phenomenon are still not solved satisfactorily and basic knowledge regarding emission wavebands, dose response, optical bleaching and stability of the different luminescence signals is of great interest. A series of measurements was carried out on defined feldspar fractions from sediments and museum specimens using a high sensitive TL/OSL spectrometer system built at the Freiberg luminescence dating laboratory and a modified Riso TL/OSL reader. The studies include spectral IRSL, TL and phosphorescence measurements, bleaching and dating experiments. Characteristic emission bands at 280, 330, 410, 560 and 700nm have been found and some dosimetric properties of it, relevant to luminescence dating, can be described. (author)