Optimisation of preparation and measurement protocols for luminescence dating of small samples from a suite of porcelains and faiences

Abstract

Experiments designed to evaluate protocols for preparation and luminescence measurement of small samples (<100 mg) from high fired ceramics are described. These include: additive TL of untreated material; multiple stimulation (Predose TL, OSL, TL) of hydrofluoric washed fragments; Simplified Predose and SAR OSL of silicate powders from hydrochloric and fluorosilicic acid treatment. The 110°C TL signal in the Simplified Predose technique minimised required sample size, but growth with cumulative predose was sub-linear. For exponential extrapolations 11/26 faience samples yielded results within 1σ of typological expectations, but substantial scatter was interpreted as relating to radiation quenching effects. Extrapolation errors were investigated by deactivating samples and regenerating their predose responses. Acid treatment of cores drilled from sherds enabled preparation of mineral and grain-size fractions while avoiding crushing effects, and damage to or contamination by the glaze and decoration. Results of luminescence measurements indicate that future work should focus on the use of open detection filter combinations to increase signal levels, to enable quenching corrections in predose measurements and the use of high temperature TL signals. © 2010 MAA Printed in Greece. All rights reserved.