Effects of migration of soil lipids on organic residues associated with buried potsherds

Abstract

Ceramics are one of the major loci for the survival of organic residues of archaeological interest. The effects of post-depositional intrusion of soil organic matter on organic residues retained in the porous walls of pottery vessels has hitherto been largely overlooked. Gas chromatography (GC) and GC/mass spectrometry ( GC MS ), have been used to examine lipid constituents from freshly excavated potsherds and burial soil freed from the sherd surface. The GC analyses afford “fingerprint” profiles for these sherd/soil pairs, while GC MS allows characterization of individual lipid constituents present. The results show that in the majority of cases clear qualitative and quantitative distinctions can be drawn between the lipid constituents of the soil, arising from the decay of higher plants and micro-organisms, and those absorbed in the sherd during its period of use. These results lend further credence to the hypothesis that organic residue analysis can be used in conjunction with conventional ceramic data and contextual information to define vessel function.