Faster and More Accurate Processing of Samples for Microtephrochronology

Microtephrochronology is a stratigraphic dating method used by archaeologists and Quaternary scientists involving the location and characterisation of volcanic glass particles present in soils and sediments in sizes and amounts invisible to the unaided eye (e.g., Alloway et al. 2007; Turney and Lowe 2001). Accurate determination of the presence or absence of volcanic glass shards in a soil or sediment sample precedes quantitative analysis. This determination is typically accomplished using optical microscopy (Fig. 1) and is one of the most time-consuming and laborious steps in the process, with great potential for misclassification or miscounting error. Here we present a novel method of identifying and counting volcanic glass particles while simultaneously providing a rough geochemical characterisation of all the particles present in the sample (glass and non-glass), using an Aspex PSEM 3025 Particle Analyzer with Automated Feature Analysis (AFA) software (Fig. 2).