Radiocarbon decays slowly in a living organism, and the amount lost is continually replenished as long as the organism takes in air or food.
In a stratigraphical context objects closer to the surface are more recent in time relative to items deeper in the ground.
Carbon-14 has a half-life of 5,730 ± 40 years— during the succeeding 5,730 years.
Because carbon-14 decays at this constant rate, an estimate of the date at which an organism died can be made by measuring the amount of its residual radiocarbon.
The method drastically reduces the quantity of datable material required.
SYNONYMS OR RELATED TERMS: amino-acid dating; aminostratigraphy; amino-acid racemization, amino acid racemization CATEGORY: technique DEFINITION: A method of absolute (chronometric) dating which is hoped to fill the gap between radiocarbon dates and potassium-argon dates.