The potential of carbonized grain to preserve biogenic (Sr)-S-87/(Sr)-S-86 signatures within the burial environment

Carbonized grains survive for millennia in many archaeological contexts. Their stable structure raises the possibility that they preserve biogenic strontium isotope signatures. This hypothesis was investigated using short-term, laboratory experiments with modern grain immersed in Chalk solution. HCl leaching removed > 95% of secondary alteration from charred grain, and isotope ratios close to the starting value were recovered. This could not be achieved with uncharred grains. HCl leaching of archaeological carbonized grains produced comparable levels of decontamination. Although preliminary, these results suggest that strontium isotope analysis of archaeological carbonized grains from calcareous burial contexts could be used to investigate ancient trade and agriculture.