Isotope Analysis in Archaeology
Stable isotope analysis of bones, teeth, and other remains reconstructs ancient diet, breastfeeding, mobility, and environment from the chemical signatures laid down during life.
Definition
The measurement of stable isotope ratios in archaeological tissues and materials to reconstruct past diet, life history, environment, and the geographic origins and movements of people and animals.
Scope
This topic covers the use of stable isotopes of carbon, nitrogen, oxygen, strontium, and other elements in human and animal tissues to infer diet, weaning, climate, and residential mobility. It addresses the biological pathways by which isotopes enter tissues, the use of strontium and oxygen isotopes for provenance and migration, and the sampling and interpretive cautions involved.
Core questions
- How do dietary and environmental isotopes become fixed in body tissues?
- What do carbon and nitrogen isotopes reveal about ancient diet?
- How are strontium and oxygen isotopes used to study mobility?
- What confounding factors limit isotopic interpretation?
Key theories
- Dietary isotope reconstruction
- The principle that carbon and nitrogen isotope ratios in bone collagen reflect the kinds of plants and the trophic level of foods consumed, allowing reconstruction of past diet.
- Strontium and oxygen mobility tracing
- The use of strontium and oxygen isotopes, which reflect local geology and water, to identify individuals who grew up in a different region from where they were buried.
History
Stable isotope studies of ancient diet began in the late 1970s with carbon isotopes detecting maize agriculture, and expanded with nitrogen isotopes for trophic level and protein sources. From the 1990s, strontium and oxygen isotopes were applied to residential mobility, making isotopic analysis a standard tool in bioarchaeology and palaeodietary research.
Debates
- Equifinality in isotopic interpretation
- Because different diets or environments can produce similar isotope values, scholars debate how to resolve ambiguous signals and how heavily to rely on isotopes for claims about diet and migration.
Key figures
- M. Anne Katzenberg
- R. Alexander Bentley
- A. Mark Pollard
Related topics
Seminal works
- katzenberg2008
- bentley2006
Frequently asked questions
- What can isotopes tell us about ancient people?
- Isotopes in bones and teeth can indicate what kinds of foods people ate, whether they were breastfed, and whether they grew up in the region where they were buried.
- How do isotopes reveal migration?
- Strontium and oxygen isotopes in tooth enamel reflect the local geology and water of childhood, so values that differ from the burial location suggest the person moved during life.