University of Wisconsin Radiocarbon Dates II

This report summarizes the radiocarbon dates obtained at the University of Wisconsin since November 1964; the procedures followed have been described previously (Wisconsin I, 1965). The counting equipment has been supplemented with a second detector of 500 ml volume for which the nominal background at 1 std atm, 298.2° K, is 2.1 cpm as determined with petroleum methane (Phillips Petroleum Co.). The corresponding standard count for contemporary methane derived from NBS oxalic acid 95% A ox , is nominally 2.8 cpm at 1 std atm, 298.2° K. The additional counting equipment was also obtained from the Sharp Division of Beckman Instrument Co.