Radiocarbon dating organic residues at the microgram level

[摘要] The relationship between submilligram sample size and C-14 activity for sample blanks (wood from Pliocene sediments) and a contemporary standard (oxalic acid [I]) for catalytically-reduced graphitic carbon have been examined down to 20 micrograms, The mean age of our 1 milligram wood sample blanks is now about 51.6 ka (0.162 pMC) while the mean for 20 microgram sample blanks is about 42.9 ka, So far, our lowest value for a 1 milligram wood sample blank is about 60.5 ka (0.056 pMC). We have determined a mean C-14 age of about 9.4 ka from a suite of seven organic extracts from hair, bone and matting from a naturally mummified human skeleton from Spirit Cave, Nevada, These data indicate that the Spirit Cave human is the third oldest directly-dated human skeleton currently reported from North America.

[发布日期] 1997-03-01

[效力级别]  Proceedings Paper