A methodology for qualitative archaeometallurgical fieldwork using a handheld X-ray fluorescence spectrometer

Abstract

Recent work aimed at provenancing metal slag from Sagalassos, south-west Turkey, as part of a study investigating the Roman iron industry in the area. Although previously samples of the slag material had been exported from the country for the purposes of analysis, a method of analysing the materials in-situ was required. It was decided that the best technique for achieving ‘in-the-field’ results would be handheld X-ray fluorescence spectrometry (HH-XRF). A series of laboratory based tests were first performed in order to determine the ideal working parameters for the HH-XRF and the best method for preparing the samples. The results indicated that different slag (i.e. Ti-rich/poor) could clearly be distinguished amongst the powdered samples. A total of 45 metal slag were analysed in the field in order to see whether the slag could be qualitatively characterised based on provenance. The results of the field study indicated two principle groups (a high Ti–Zr group and a low Ti–Zr group). The Ca and Mn contents also split the data into two groups but these were not consistent with the previous Ti–Zr groups. These differences could be related to the choice of ores and fluxes used for iron production.