ANALYSIS OF NATURAL IRSL AND TL EMISSION-SPECTRA OF POTASSIUM-RICH FELDSPARS WITH REGARD TO DATING APPLICATIONS

The spectral composition of thermally and infrared stimulated luminesc ence (TL, IRSL) of three potassium-rich feldspar samples from a dune i n the Upper Rhine Graben, Germany, is reported. All TL and IRSL emissi ons are dominated by wavelengths around 400-420 nm and 540-600 nm; TL shows additional emissions at 280 nm, approximate to 620 nm and at app roximate to 770 nm (due to the limited detection band of the Freiberg spectrometer, not yet investigated in IRSL). The emission at 400-420 n m shows no significant shift with temperature or stimulation time. The emission band at 540-600 nm seems to be composed of more than one pea k and cannot unequivocally be identified, but is more prominent in TL than in IRSL. Samples were dated with IRSL using detection bands of 39 3-412 nm and 536-557 nm. Results agree with the expected age of 11-13 ka, and with results from TL dating.