HIGH-PRECISION INTERCOMPARISON AT ISOTRACE

I conducted a high-precision comparison at the 0.2% to 0.3% level with samples supplied by the radiocarbon laboratory of the Quaternary Research Center at the University of Washington (QRC). Four samples with ages ranging from modern to >50 000 BP were dated in a blind test. The absence of cosmic-radiation background in AMS dating is a major advantage for dating samples >35 000 BP. The reliability of AMS dates >35 000 BP depends entirely on understanding the contamination processes. -from Author