Residue and Organic Archaeology

Organic residue analysis recovers and identifies the molecular remains of fats, oils, resins, and other substances absorbed in pottery and other artifacts, revealing what ancient vessels once held.

Definition

The chemical study of organic substances preserved in or on archaeological materials, using biomarkers to identify the commodities such as foods, fats, and resins that were processed, stored, or consumed.

Scope

This topic covers the extraction and identification of lipids, proteins, and other biomolecules preserved in ceramics, soils, and artifacts, chiefly through gas chromatography-mass spectrometry and compound-specific isotope analysis. It addresses the use of biomarkers to identify foodstuffs, beverages, and processing residues, and the issues of preservation and contamination that constrain interpretation.

Core questions

• What organic molecules survive in archaeological materials, and how?
• How are residues extracted and identified as specific commodities?
• What do biomarkers reveal about diet, cuisine, and resource use?
• How are contamination and degradation distinguished from genuine signals?

Key theories

Biomarker approach

The principle that specific organic compounds act as molecular fingerprints of particular substances, allowing degraded residues to be linked to commodities such as dairy fats, plant oils, or beeswax.

Compound-specific isotope analysis

The measurement of stable isotopes of individual compounds, such as fatty acids, to distinguish sources that share the same molecules, for example separating dairy from carcass fats.

History

Organic residue analysis developed from the 1970s onward as gas chromatography and mass spectrometry became available, and matured through the work of Richard Evershed and colleagues in what has been called an archaeological biomarker revolution. Compound-specific isotope analysis later allowed finer discrimination, notably in tracing the origins of dairying.

Debates

Contamination and preservation

Because residues are vulnerable to degradation, migration, and modern contamination, scholars debate criteria for authenticating ancient signals and the reliability of single-compound identifications.

Key figures

• Richard Evershed
• Carl Heron
• A. Mark Pollard

Seminal works

• evershed2008
• regertetal2000

Frequently asked questions

What can residue analysis tell us?

It can reveal what foods, drinks, oils, resins, or other substances were once held or processed in pots and other objects, even when nothing is visible to the eye.

How are residues identified if they have degraded?

Analysts look for characteristic surviving molecules, or biomarkers, and use isotopes of individual compounds to link the degraded remains to a likely original source.