If I remember correctly, NaCl atoms are packed pretty closely together in crystallized form. They seem to be only looking at large crystalline structures, whic

If I remember correctly, NaCl atoms are packed pretty closely together in crystallized form. They seem to be only looking at large crystalline structures, which do not have evidence of disruption. Of course, they also said they used the same method with modern salt, and the O2 levels were lower than atmosphere by 9.2% for one of those samples. It seems fairly legit but it would be great if they could test salt from the same period but from a different mine.