The fractional glow technique was applied for the investigation of trap occ
upation in optically bleached K-feldspars separated from sediments. Various
bleaching times and two spectra ranges of sunlight simulator were used. Fo
ur trap groups exhibit different sensitivities to the bleaching. The influe
nce of the spectrum range of the stimulation light on the bleaching efficie
ncy is presented. (C) 2001 Elsevier Science B.V. All rights reserved.