Yale Natural Radiocarbon Measurements IX

Abstract

The present list represents a major portion of the samples measured since publication of the last date list in 1963. As in previous lists, dates are reported in terms of the 5568 yr half-life. Infinite dates are reported as beyond a limit equal to 2σ above background. Nearly all of the samples were measured in one of three quartz counters with backgrounds of 0.7 to 1.2 cpm per liter of effective counting volume at working pressures of about two atmospheres. The age errors quoted are based only on the standard deviations in counting rates of sample and standards. The various C 14 projects of the Radiocarbon Laboratory have been supported by the National Science Foundation, Grants GP 4879 and GA 1157; the tree ring research has been supported by the Atomic Energy Commission under contract AT (30-1) 2652. Technical assistance has been provided by Carolyn H. Morgan and Terry C. Eisensmith.