Archaeological implications of natural carbon-14 variations

Abstract

(p. 10)

De Vries (1958) was the first to report variations in the atmospheric 14C content which he indirectly observed in tree-rings from European and North American wood. Since then over thousand 14C analyses have extensively confirmed the fact that the natural 14C level has not been constant. These measurements have largely been carried out on North American dendrochronologically dated wood from Sequoia and Bristlecone Pine by the radiocarbon laboraties of the University of California at San Diego in La Jolla, the University of Arizona in Tucson and the University of Pennsylvania in Philadelphia; the results have on various occasions been reported by Suess (1970), Damon (1972) and Ralph (1973) and co-workers.