Intrepreting lipid residues in archaeological ceramics: preliminary results from laboratory simulations of vessel use

Abstract

• During the past four and a half years this group has been involved in a programme of development and testing of methods for the study of organic residues in archaeological ceramics. The analytical approach used is based on solvent extraction of powdered potsherds to release lipids absorbed in the ceramic fabric, with gas chromatography (GC) and combined gas chromatography/mass spectrometry (GC/MS) being used to characterise andquantify the individual components of the residues. Our most recent work has focused on an assemblage of more than sixty reconstructed vessels of Late Saxon/early medievaldate for which full or partial profiles were available. Analysis of potsherds sampled from different parts of these vessels, e.g. rim, body and base, have shown that different concentrations of lipid can exist in different parts of a vessel. This observation has important consequences for the sampling of potsherds for organic residue analysis. More significantly, these results indicate that the variation in the concentration of lipid in different parts of a vessel may reflect the way in which the vessel was used in antiquity. This paper discusses the results obtained from preliminary laboratory simulation experiments which have been carried out using replica vessels to provide supporting evidence for this potentially new approach to interpreting vessel use. Consideration will also be given to the possibility of using potsherds from these replica vessels in laboratory experiments aimed at simulating the decay of absorbed lipids during burial.