Libby realized that the residual carbon 14 of some samples would be thus affected and suggested that some materials would be more accurate for dating than others.

He predicted that charcoal would be the most effective, shell, the least.

Residues or solutions which do migrate can usually be washed out of the structural matrix of the sample with various chemicals.

contamination dating radiocarbon-60

He suggests that this radiocarbon is residual from the material’s creation.

If true, his claims would have far-reaching implications for the ages of these materials. The first is a set of 90 previously published radiocarbon AMS dates of old samples (most 100k years) that he has re-analyzed.

There are several things that you might want to check for.

Fortunately for you, there's a spreadsheet that I (Becky) have written which does these things.

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The second is a set of new samples that the RATE team collected and sent to a leading radiocarbon AMS laboratory to be dated.