Delta-C-13
Definition
The ratio of carbon-13 to carbon-12 in a biological sample, expressed relative to a standard (VPDB). Distinguishes C3 plant diets (wheat, rice; delta-C-13 around -25 per mil) from C4 plant diets (maize, millet; delta-C-13 around -12 per mil). Used in forensic provenance to distinguish dietary traditions associated with different agricultural regions.
- Measures
- Carbon-13 to carbon-12 ratio
- Reference standard
- VPDB
- C3 plant diet
- Around -25 per mil
- C4 plant diet
- Around -12 per mil
Common questions
Why does delta-C-13 reveal what someone ate rather than where they were born?+
Carbon isotope ratios are laid down in tissue from dietary intake, so the value reflects long-term diet composition, primarily C3 versus C4 plant staples, rather than a direct geographic signal on its own.
How is delta-C-13 combined with other evidence for provenance?+
It is typically paired with other isotope ratios, such as nitrogen or strontium, and with skeletal or facial evidence, because diet alone narrows a population but does not pinpoint a specific region.
Related terms
- Delta-N-15
- The ratio of nitrogen-15 to nitrogen-14, expressed relative to atmospheric nitrogen. Increases by approximately 3-4 per mil with each step up the...
- FaceLab
- The digital facial approximation software developed at the University of Manchester and extended at Liverpool John Moores University by Caroline Wilkinson's group....
- Gerasimov Method
- The Russian anatomical facial approximation technique developed by Mikhail Gerasimov from the 1930s, in which the facial muscles are individually reconstructed on...
- Isoscape
- A map of isotope ratio variation across a geographic area, derived from systematic sampling of soil, water, plant, or mineral material; used...
- Manchester Method (IFRG)
- The combined-anatomy facial approximation protocol developed by Richard Neave and systematised by Caroline Wilkinson (2004, 2010), which reconstructs masticatory muscles anatomically and...
- Operation Hammerhead (Adam Case)
- The Metropolitan Police investigation (2001-ongoing) into the murder of an unidentified Nigerian child whose torso was recovered from the River Thames in...
- Strontium Isotope Ratio (Sr-87/Sr-86)
- The ratio of radiogenic strontium-87 to stable strontium-86 in a geological or biological sample, which reflects the age and composition of the...
- Tissue-Depth Method
- The American facial approximation technique (Krogman, Iscan) in which tissue-depth pegs are placed at standardised landmarks using population-mean depth data from cadaver...
- Trophic Enrichment Factor
- The per-mil increase in delta-N-15 per trophic level in the food chain, approximately 3-4 per mil. A marine fish consumer has a...