The following list covers some old measurements not included in previous lists and most of the samples measured at the Uppsala C14 laboratory since the last list (Radiocarbon, 1967, v. 9, p. 454-470); samples utilized for determining the increase of the C14/C12 ratio clue to explosion of nuclear devices are omitted

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 C14 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.