The preservation and interpretation of δ34S values in charred archaeobotanical remains

The measurement of sulphur isotope (δS) values in charred plant remains has the potential to inform understanding of the spatial configuration and ecology of crop production. We investigated the effects of charring, manuring, oxidation and anaerobic soil conditions on modern cereal grain/pulse seed δS values, and assessed the effect of chemical pre-treatment on charred modern and archaeobotanical grain/seed δS values. We used these results to interpret δS values in archaeobotanical material from Neolithic Çatalhöyük. Our results suggest that δS values can be reliably preserved in charred grain/seeds but are subject to influence by anaerobic soil conditions, the effect depending on the timing of flooding in relation to S assimilation