Published online by Cambridge University Press: 18 July 2016
This list includes mainly the results of datings done from 1967 to 1969. Methods are essentially the same as those described in Radiocarbon, 1966, v. 8, p. 46–53, 1967, v. 9, p. 38–42, and 1969, v. 11, p. 15–21. Samples synthesized to benzene and counted by liquid scintillation spectrometry. Age calculations are based on 95% of the activity of the NBS oxalic acid standard and computed from the Libby half-life of 5570 yr and reference A.D. 1950. The error listed is the one-sigma statistical counting error. Most samples were counted for 2000 to 3000 min. HCL and NaOH pretreatments were applied to samples as required.