Test of the partial bleach methodology as applied to the infra-red stimulated luminescence of an alluvial sediment from the Danube

Abstract

A sample of fine-grained distal sediment deposited by the River Danube in Romania was selected for luminescence measurements using infra-red diodes for stimulation. To obtain the equivalent dose (ED) a partial bleach approach was applied using a restricted spectrum in an attempt to replicate bleaching conditions underwater. The results, and those of the thermoluminescence measurements, gave an age in agreement with the archaeological evidence, suggesting that this sample was well bleached at deposition. A more rigorous test was devised using a simulation experiment and the results suggested that the partial bleach method may not be able to date correctly sediments that have had only part of their infra-red stimulated luminescence (IRSL) signal removed at deposition. Additional types of measurement are required to detect incomplete resetting of the IRSL signal at deposition.