University of Rome Radiocarbon Dates XVII

Abstract

This list includes dates from Italy, Libyan Sahara, Niger and the Dahlak Islands, obtained from 1976 to 1980, using the benzene scintillation method. Chemical processing from sample to benzene follows procedures of Alessio et al (1978a). Standard pretreatment for wood and charcoal included boiling with 5-10% HCL. Pretreatment for a-labeled samples underwent leaching with 0.2N NaOH. Since the last date list, Lecroy NIM modules have replaced the original recording electronics for the liquid scintillation detection system, described in Alessio et al (1973, 1976). Benzene sample volumes up to 4.Sml, with appropriate amounts of NE 216 scintillator (Nuclear Enterprises, Ltd) yielded the best figure-of-merit (E2/B = 2300) for 2m1 benzene and an efficiency of 72%. Age calculations comply with standard Radiocarbon protocol, as Stuiver and Polach (1977) recommended, including normalization by mass spectrometrically determined S13C (Alessio et al 1969).