Optical dating of single sand-sized grains of quartz: sources of variability

Optically stimulated luminescence (OSL) measurements have been made of over 3000 sand-sized grains of quartz. Analysis at this scale highlights the va riability in the luminescence sensitivity and the dose saturation character istics of individual quartz grains. Using a new instrument capable of measu ring single grains it is feasible to routinely measure the equivalent dose from many hundreds of grains from each sample. Analysis of such datasets re quires assessment of the uncertainties on each equivalent dose since these may vary significantly. This paper assesses the significance of signal inte nsity, dose saturation characteristics and instrument uncertainty in equiva lent dose calculation. (C) 2000 Elsevier Science Ltd. All rights reserved.