Q-band ESR spectra as indicators of fossilization in tooth enamel

To test this, modern tooth enamel was artificially fossilized by prolonged heating in a buffered aqueous solution. To test if the teeth had developed characteristics typical in naturally fossilized teeth, the samples were analyzed by HPLC and GC to determine their amino acid racemization (AAR) ratios. Although the Q-band spectra from artificially fossilized teeth did not entirely mimic those from natural fossilization, similar ESR signal broadening occurred and correlated with the aIle/Ile ratios from the AAR analyses. Therefore, fossil diagenesis appears to cause distorted HAP crystals, which would make teeth more likely to absorb U through microcracks in the enamel. This suggests that samples exhibiting a broad peak might have absorbed much of their U relatively recently, and that accurate ESR dating requires a recent uptake model.