Radiocarbon dating requires two destructive steps: acid-base-acid pretreatment and combustion. As a non-destructive alternative to combustion, ~50ºC oxygen plasmas remove sub-milligrams of organic carbon from surfaces of perishable archaeological artifacts for dating. Multiple AMS dates (and stable carbon isotopic analyses) are possible from successive plasmas on bulk artifacts without visible change, even under a microscope. Accurate radiocarbon ages were determined for previously dated materials with plasma extractions of ~100 µg carbon. AMS dating traditionally required removal of milligram-size samples (or larger) from archaeological artifacts that are destroyed during chemical pretreatment and combustion. Sometimes, it is unacceptable to remove even a small portion of an artifact for destructive analysis (i.e., depending on ratio of artifact size to amount removed, information content of sample structure, rarity or intrinsic value of object). Non-destructive plasmas were variously tested: on charcoal, TIRI wood, FIRI textile, six different materials from a naturally mummified infant burial bundle from Texas, and other previously dated materials. Agreement is generally good between non-destructive and traditional AMS radiocarbon dates. For truly non-destructive radiocarbon dating, it now remains to replace the destructive acid-alkali-acid pretreatment with a non-destructive one.
See more of Poster Session II
See more of The 10th International Conference on Accelerator Mass Spectrometry (September 5-10, 2005)