The multi-disciplinary study of Early Copper Age lamps from Zgornje Radvanje (NE Slovenia)

Abstract This paper focuses on the analysis and identification of two prehistoric lamps from Zgornje Radvanje (NE Slovenia). The analysis of the organic residues and experimental archaeology allowed us to characterize the fuel source and the wick remains of oval-formed ceramic artefacts from the Copper Age settlement. Infrared spectroscopy (ATR IR), GC-MS and GC-C-IRMS were used to study organic compounds in two archaeological samples, with comparative composition data yielding experiments with modern wicks, linseed oil and animal fats. ATR IR showed traces of plant fibres in the sample of charred residues from one of the lamps. A comparably higher frequency of straight-chain compounds with odd numbers of carbon atoms provided the extracted lipids from the ceramics of the second oval-formed ceramic artefact. We interpret these to mean that carbonised organic residues from the inner surface of the ceramic object are the result of smouldering, with the identified residues of plant fibres probably associated with the remnants of the wick. The GC-MS analysis showed a higher frequency of straight-chain compounds with odd numbers of carbon atoms (especially C15:0 fatty acids) together with two double bond positional isomers of C18:1 in the second oval-formed artefact. The presence of C18:2 and C18:3 fatty acids that are typical for linseed oils was also detected. These analysis together with GC-C-IRMS analysis suggest a predominant use of ruminant fat as fuel for lighting possibly in combination with plant oils. Burns similar to those on the original artefact were observed on replicas of the artefact after they were used as lamps.