University of Texas at Austin Radiocarbon Dates XII

Abstract

This list reports certain ¹⁴C measurements completed by November 1977; other projects completed by this time will be reported later. Age calculations are based on ¹⁴C half-life of 5568yr and modern standard of 95% NBS oxalic acid, supplemented by tree rings of pre-industrial wood from a log cut in the 1850's (Tx-540; R, 1970, v 12, p 249). Deviations reported are based on counting statistics of sample, background, and modern, and are ±1σ, except that when sample count approaches either modern or background, 2σ limits are reported. Unless noted, ¹²C/¹³C measurements were not made and results are not corrected for ¹³C fractionation. Our laboratory uses liquid scintillation counting of benzene, with Li₂C₂ and vanadium-activated catalyst in preparation; chemical yields range between 95% and 99%. Three counters are employed: a Packard Tri-Carb Model 3002 and 2 Beckman LS320 spectrometers obtained through a grant from the National Science Foundation.