Riken Natural Radiocarbon Measurements VII

Abstract

The C¹⁴ dates given below are continued from our previous list (R., 1970, v. 12, p. 559–576), and results obtained mainly during 1970 are described. A 2.7 L stainless steel counter and a 3.3 L copper counter are used, yielding background counting rates of 5.5 and 8.5 cpm, respectively, when filled with dead CO₂ at ca. 1.8 atm. Dates have been calculated on the basis of the C¹⁴ half-life of 5568 yr and 95% of NBS oxalic acid as modern standard.