Residues on Stone Artefacts: State of a Scientific Art

Article excerpt

At the 1996 Society for American Archaeology meeting in fabulous New Orleans, residues and functional analysis of stone artefacts were the specific focus of offerings scattered through the programme in posters (e.g.D. Lee, T. Murphy, L. Hooper and R. Donahue), workshop (N. Tuross, M. Wachowiak, R. Evershed, C. Kolman), at least two symposia (B. Hardy, B. Kimura & B. Hardy, T. Loy, D. Hyland, Charters et. al., Cummings et al., Tuross et al., C. Heron, H. Ceri and M. Newman) and several general sessions (E. Lohse, J. Furby & R. Fullagar, B. Williamson, M. Newman). We could not see them all, and we know some presenters listed in the programme did not show. A symposium (sponsored by the Conservation Analytical Laboratory at the Smithsonian Institution) and a workshop (sponsored by the Conservation Analytical Laboratory at the Smithsonian Institution and the National Center for Preservation and Training, National Park Service, Natchitoches, Louisiana) were dedicated to residue analysis. Both, organized by Noreen Tuross, were a success with lively debate. In dealing with much broader issues, the presentations seemed to portray conflicting views on the veracity of scientific techniques, and on the achievements of integrated functional analysis of stone artefacts. While papers presented in the general sessions assumed the validity of the methodologies being used, some in the sponsored workshop and symposium cast doubt on:

* the distinctiveness of microscopic residues;

* the integrity/reactivity of ancient bio-molecules;

* the viability of the current methodologies;

* and consequently on the reliability of taxonomic identifications on ancient stone artefacts.

Archaeologists could be forgiven for being both confused whether residues survive on stone tools, or whose technique is best. As archaeologists with one foot in the lab and one in the field, we were both stimulated and depressed by the workshop and sponsored symposium. We offer here our post-conference views on residues, on functional analysis of stone tools and on where consensus seems to lie.

Stone artefact function

Stone artefact function has been investigated by diverse lines of evidence in many theoretical contexts for over a century. Many articles summarize these notions and review lines of evidence, which include tool design, raw material characteristics, use-wear, residues, context, ethnography and the study of long-term trends (e.g. Hayden 1979; Kamminga 1982; van Gijn 1990; Yerkes & Kardulias 1994). In truth, artefact function rarely, if ever, is determined from a single line of evidence, although many claim use-wear or residues provide sufficient evidence of tool function. The rise and rise of residue studies can be correlated with the increased availability of specialized techniques in biochemistry for analysing low concentration samples. We think time-consuming techniques of observing and recording visible residues have been neglected, a casualty of the high-tech methods now available for targeting the particular species of animal or plant contact material.

Detailed microscopic observations and recording are essential pre-requisites to any residue analysis. In contrast to the impressions offered at the workshop, microscopically visible organic structures are common under optimal preservation conditions. Many residue analysts do 'whole tool' extractions in the process of analysis, a procedure which is often inappropriate for archaeological material as it is both destructive and does not target particular residues with their visible structures and associations with utilized edges.

Survival, detection and taxonomic identification of animal related residues

Blood, hair, bone and cartilage are the residues most often preserved on the surfaces of stone artefacts used in butchering animals. These and other traces have been documented by micro-wear analysts and in specific residue studies (Briuer 1976; Anderson 1980; Keeley 1980; Kamminga 1982; Loy 1983; Fullagar 1986; van Gijn 1991; Furby 1995). …