Most of the 14C measurements reported here were made between October 1982 and October 1983. Equipment, measurement, and treatment of samples are as reported previously (R, 1968, v 10, p 36–37; 1976, v 18, p 290; 1980, v 22, p 1045).
Age calculations are based on a contemporary value equal to 95% of the activity of NBS oxalic acid standard (No. 4990A) and on the conventional half-life for 14C of 5568 yr. Results are reported in years before 1950 (years bp). Errors quoted with the dates are based on counting statistics alone and are equivalent to ± 1 standard deviation (±σ).