SPEED DATING: A RAPID WAY TO DETERMINE THE RADIOCARBON AGE OF WOOD BY EA-AMS

Radiocarbon measurements in tree rings can be used to estimate atmospheric C-14 concentration and thereby used to create a C-14 calibration curve. When wood is discovered in construction sites, rivers, buildings, and lake sediments, it is unclear if the wood could fill gaps in the C-14 calibration curve or if the wood is of historical interest until the age is determined by dendrochronology or C-14 dating. However, dendrochronological dating is subjected to many requirements and C-14 dating is costly and time consuming, both of which can be frivolous endeavors if the samples are not in the age range of interest. A simplified C-14 dating technique, called Speed Dating, was thus developed. It can be used to quickly obtain C-14 ages as wood samples are neither chemically treated nor graphitized. Instead, wood is combusted in an elemental analyzer (EA) and the CO2 produced is carried into an accelerator mass spectrometer (AMS) with a gas ion source. Within a day, 75 samples can be measured with uncertainties between 0.5-2% depending on the age, preservation, and contaminants on the material and Speed Dating costs about one-third of conventional AMS dates.