Nosams whoi carbon dating
: Under present procedures, samples less than 9 µmol and as small as 2 µmol are processed automatically using small-sample techniques. Mc Nichol to discuss your research goals prior to submission of samples in this category.
Largely because special standards are required, an additional fee applies to samples in this size range. See submission details in the table above for more size-specific information.
Plant/wood and charcoal samples undergo a series of heated acid-base-acid leaches to remove inorganic carbon and mobile organic acid phases. We will repeat up to 20 base leaches; even if the solution is not clear after 20, we stop the base treatment and move on to a final acidification.
Sediment samples undergo the acid pretreatment only.
Ages are rounded according to the convention of Stuiver & Polach, shown below.
There are two situations that limit an age; the first is that the measured Fm is smaller than that of the corresponding process blank measured in the same suite of samples on the AMS.
Fraction Modern is a measurement of the deviation of the C is also affected by natural isotopic fractionation.
One other situation that limits the age (if not already limited by the background age) is the error of the AMS result.For calendar year 2016, the estimated added variance for samples of the process type OC (Organic Carbon) or HY (Hydrolysis) is 2.6‰ for samples containing Reporting of ages and/or activities follows the convention outlined by Stuiver and Polach (1977) and Stuiver (1980).Ages are calculated using 5568 years as the half-life of radiocarbon and are reported without reservoir corrections or calibration to calendar years.For freeware programs, we suggest that you look at the following web site for a list of programs that will calibrate radiocarbon results to calendar years (including making reservoir corrections).[ Radiocarbon-Related Information Sources] The error in the age is given by 8033 times the relative error in the Fm .Therefore a 1% error in fraction-modern leads to an 80 year error in the age.