High-precision AMS C-14 results on TIRI/FIRI turbidite

Unleached aliquots of TIRI/FIRI turbidite were analyzed by accelerator mass spectronomy (AMS) over a timespan of 18 months. Individual analyses ranged from 18,090-18,245 yr BP with reported errors between 30-50 yr. The weighted average fraction modem (FM) of these 28 measurements is 0.10378 +/- 0.00008 (which equates to 18,199 +/- 8 yr BP) and the measurements show a I standard deviation scatter of 0.00044 (+/-35 yr). The fractional error of these results indicates reproducibility of individual measurements at the 4parts per thousand (1sigma) level, which is consistent with the quoted counting-statistics-based errors. Laboratories engaged in the determination of C-14 results at reasonably high precision should consider taking advantage of the TIRI and FIRI sample materials in the role of process standards. Additional suites of high-precision data are necessary to refine the accuracy of these sample materials.