Plasma Micro-Sampling in Radiocarbon Dating: Approaching a Non-Destructive Model

Summary

The development of low-energy plasma oxidation as a sampling technique has created new opportunities for applying radiocarbon dating. Plasma oxidation can be carried out at energies below the threshold of carbonate and oxalate dissociation, dramatically reducing the need for pretreatment and subsequent loss of sample volume. Radiocarbon sample size can be reduced toward the minimum of the 40-100 millionths of a gram of carbon that is actually needed for standard AMS dating. This allows the dating of remarkably small samples, and it results in the imperceptible removal of carbon from more traditionally-sized samples, such as a charred maize kernel (the botanist will never know a dating sample has been removed). A surface-active technique, plasma oxidation preferentially samples carbon molecules from object exteriors, allowing repeated stratigraphic sampling through accumulations such as soot on fragments of cave or rockshelter ceilings and the interpretation of sequential dates. Masking techniques can focus sampling on only portions of artifacts, and other innovative applications include the dating of organic pottery pigments, residues on artifacts, and organic binders in mineral pigments. Low temperature plasmas allow superficially non-destructive sampling of museum specimens, while higher plasma energies can sample carbide from the surfaces of historic metals.

This Resource is Part of the Following Collections

• Society for American Archaeology 83rd Annual Meeting, Washington, DC (2018)

Keywords

Record Identifiers

Abstract Id(s): 22366