OPTICAL DATING OF YOUNG (MODERN) SEDIMENTS USING QUARTZ - RESULTS FROM A SELECTION OF DEPOSITIONAL-ENVIRONMENTS

Equivalent dose (ED) evaluations for quartz grains extracted from a number of modern or young samples collected from a range of depositional environments are reported. The signal used was optically-stimulated luminescence (OSL) with an argon ion laser tuned to 514 nm as a light source. Typical equivalent dose values were 0.05-0.3 Gy for the given samples which is substantially less than equivalent doses expected for similar sediments by conventional thermoluminescence (TL). The non-zero equivalent dose exhibited by the samples may be a product of relict OSL from incompletely bleached traps, sample pre-treatment procedures, or due to signal recuperation following bleaching during antiquity. The potential significance of each are discussed. A number of modifications to sample pre-treatment and processing are also described.