Identifying Chemical Activity Residues on Prehistoric House Floors: A Methodology And Rationale For Multi‐Elemental Characterization of a Mild Acid Extract of Anthropogenic Sediments

Archaeologists have employed sediment chemistry in site prospection for nearly a century. For example, phosphorus is a good indicator of human occupation, because it is a generic indicator of human activity. Recently, multi‐element studies of sediments have successfully identified specific activity areas by analysing other elements in addition to phosphorus. To reach its full potential, however, sediment chemistry must be undertaken with an understanding of how these residues are formed and of the chemical indicators that can be used to identify specific activities. Methodologies that optimize the extraction of specific residues must be employed. Not to do so is a naïve application of the technique.     

GC–MS ANALYSIS AND FATTY ACID RATIOS OF ARCHAEOLOGICAL POTSHERDS FROM THE WESTERN GREAT BASIN OF NORTH AMERICA*

The study of organic residues in archaeological pottery has focused on fatty acids due to their relative stability and longevity. However, even these compounds are subject to degradation, which makes assignment of residues to original foods problematic. This paper suggests that the use of ratios of fatty acids that degrade at roughly the same rate can be useful to identify very general categories of foods. It compares independent information on pot function based on ethnography and engineering/technological studies to that reconstructed based on extracted fatty acid ratios. The results support the notion that Great Basin pots were used primarily to boil seeds and that pot shape and pot function were related.     

GC/MS ANALYSIS OF FATTY ACIDS FROM ANCIENT HEARTH RESIDUES AT THE SWAN POINT ARCHAEOLOGICAL SITE*

Gas chromatography – mass spectrometry (GC/MS) is used to analyse soil residues from hearth sites in Swan Point, Alaska. An experimental hearth is also prepared by burning animal bones to study the characteristics of bone fires and the lipid residues that they leave embedded in soil. Hearth soil samples are derivatized with HCl in methanol to convert bound and unbound fatty acids into methyl esters. Concentrations of saturated fatty acid methyl esters in the samples are determined and their ratios analysed. The fatty acid patterns found in ancient campfires are consistent with burning bones of large ruminants as well as monogastric herbivores.     

DNA AND PROTEIN RECOVERY FROM WASHED EXPERIMENTAL STONE TOOLS*

Traces of protein and DNA are preserved on stone tools used to process animals. Previous research documents the identification of protein residues from tools sonicated in 5% ammonium hydroxide, but it remains untested whether the same treatment yields useable DNA. In this study we report both DNA and protein recovery using 5% ammonium hydroxide from residues on stone tools. We extracted 13‐year‐old residues from experimentally manufactured stone tools used to butcher a single animal. We also show that surface washing procedures typically used to curate stone tools remove only a small fraction of the DNA and protein deposited during animal butchery.     

FTIR AND SOLID‐STATE 13C CP/MAS NMR SPECTROSCOPY OF CHARRED AND NON‐CHARRED SOLID ORGANIC RESIDUES PRESERVED IN ROMAN IRON AGE VESSELS FROM THE NETHERLANDS*

In this study, solid‐state ¹³C magnetic resonance spectroscopy using cross‐polarization combined with high‐powered proton decoupling and magic‐angle sample spinning and Fourier transform infrared spectroscopy using a diamond anvil cell, are employed to give information about the organic functional groups present in charred and non‐charred solid organic residues and to give an insight into the degree of condensation of the chars. Residues were preserved in ceramic vessels recovered from the indigenous settlement of Uitgeest–Groot Dorregeest, dating back to the Roman period. In addition, the application of these solid‐state techniques is used for verification of earlier results obtained in analytical pyrolysis studies and to clarify the relationship between the already thermally degraded charred residues and the controlled heating fragmentation taking place during analytical pyrolysis and direct temperature‐resolved mass spectrometry.     

Evidence for Varying Patterns of Exploitation of Animal Products in Different Prehistoric Pottery Traditions Based on Lipids Preserved in Surface and Absorbed Residues

The excavation of a barrow at Upper Ninepence, Walton in the Welsh Borderlands, U.K., revealed two phases of occupation associated with two different ceramic traditions, namely Grooved Ware (2500bc) and Peterborough Ware (3000bc). The Grooved Ware and Peterborough Ware pits seem to have a mutually exclusive distribution on the site. Screening of the sherds for lipid residues has revealed the presence of remnant fats in a remarkably well-preserved state considering the age of the finds. Investigations of various chemical characteristics of the remnant fats from absorbed and carbonized residues have enabled distinctions to be drawn between fats from non-ruminant (e.g. porcine) and ruminant (e.g. ovine or bovine) origins. Significantly, both ruminant and non-ruminant fats are found associated with the Grooved Ware whereas only ruminant fats are found associated with the Peterborough Ware. The assignments are based upon the distributions of solvent-extractable lipid components and the compound-specific stable carbon isotope values of the major n -alkanoic acids. The results reveal differences in vessel use and indicate possible changes in patterns of animal exploitation or dietary preferences between the two phases of occupation. The results illustrate the importance of residue analysis in archaeological investigations, particularly at prehistoric sites where evidence from faunal remains is limited or absent.