Gif Natural Radiocarbon Measurements VII
1972; Cambridge University Press; Volume: 14; Issue: 2 Linguagem: Inglês
10.1017/s0033822200059373
ISSN1945-5755
AutoresGeorgette Delibrias, M. T. Guillier, J. Labeyrie,
Tópico(s)Geology and Paleoclimatology Research
ResumoC 14 dates reported below were obtained mainly at the end of 1968 and during 1969 on archaeologic and geologic samples. Techniques of measurement used are unchanged. Since 1968, 4 complete routine sets have been running, each equipped with a 1 L CO 2 proportional counter. One is made of stainless steel with a background of 2.70 cpm at pressure 1 atm and the others are of OFHC copper with a background of either 1.10 or 1.30 cpm for a corresponding pressure of, respectively, 1 or 2 atm. For age calculation, 95% activity of NBS oxalic acid is used as the modern standard and the value of 5570 ± 30 years is used for the half-life of C 14 . Dates are expressed in years b.p. (before a.d. 1950).
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