Crops in motion: Strontium isotope analysis of cereal provenance in a foraging-oriented Neolithic economy

Strontium isotope analysis offers a powerful tool for investigating mobility and provenance in prehistoric contexts, yet its application to archaeobotanical finds remains limited. This study applies ⁸⁷Sr/⁸⁶Sr analysis to charred cereal grains from Molino Casarotto, an Italian Middle Neolithic wetland site characterised by a foraging-oriented subsistence strategy and unusually limited cereal use compared to contemporary Neolithic farming sites. A locally defined bioavailable ⁸⁷Sr/⁸⁶Sr baseline was established through systematic sampling of modern plants across distinct lithological units surrounding the site. The isotope ratios of the archaeological cereals reveal a non-local and heterogeneous supply pattern, with values consistent with both regional fluvial units and more radiogenic extra-regional sources. These results provide direct evidence for a spatial decoupling between crop production and consumption and demonstrate the methodological viability of strontium isotopes for tracing cereal provenance. By extending isotopic provenancing to plant remains, this study contributes a new analytical framework for investigating crop circulation and provisioning systems in prehistoric societies. More broadly, it highlights the potential of archaeobotanical isotopic data to address fundamental questions concerning surplus, exchange, and the organisation of economic networks in non-state contexts.