Lifetime determination of OSL signals from potassium feldspar

Lifetime determinations for both IRSL and GLSL signals were carried out using a method of pulse annealing with different heating rates. For a sedimentary K-feldspar sample and ambient temperature of 10 degrees C, lifetimes of 6.6 x 10(8) and 1.3 x 10(6) years were obtained for IRSL and GLSL signals respectively. The differences in thermal stability for IRSL and GLSL are supported by results from an isothermal annealing experiment. The difference in lifetime is interpreted by different groups of traps being sampled by both stimulation sources. The implications for optical dating limits are discussed. (C) 1997 Elsevier Science Ltd.