Fruit carbonate in archaeological sites: a new proxy for reconstructing agricultural systems of early societies

• Applicant: Privatdozentin Dr. Simone Riehl
• Subject Area: Egyptology and Ancient Near Eastern Studies ; Mineralogy, Petrology and Geochemistry ; Prehistory and World Archaeology
• Term: from 2018 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 404630470

Fruit carbonate in archaeobotanical assemblages bears a hitherto underestimated potential for archaeological research. In contrast to common charred archaeobotanical macroremains, the CaCO3-enriched fruits contain relatively high amounts of oxygen and strontium. These are suitable for estimating paleoclimate parameters (delta 18O, Delta 47) as well as provenance analysis (87Sr/86Sr), providing a basis for better understanding the early agricultural dynamics. The central goal of this project is to create foundations for the use of fruit carbonate as a palaeoenvironmental proxy of early agroecosystems. The project design involves two research phases. A pilot study will be performed on modern material sampled in collections and grown in laboratory experiments. This study will fulfill the following tasks: (1) to assess potential reservoir effects in 14C-dating of fruit carbonate, (2) to reveal the correlation between delta 18O values of fruit carbonate and local climate parameters (precipitation and temperature), (3) to establish the dependence of Delta 47-values of fruit carbonate ('clumped isotope thermometry') on local temperatures, (4) to evaluate the relationship between 87Sr/86Sr-ratios of fruit carbonate and those of soils at growing locations.In the main study, the established geochemical relationships will be applied to archaeobotanical material. The fruit carbonate has to serve as a palaeoenvironmental proxy to approach two key questions in Near Eastern archaeology: (1) the former moisture availability (climate or irrigation?) and (2) localization of the former sites of plant growth leading to reconstruction of the cultivation areas. The expected results from analyzing this multifunctional proxy will provide a broad spectrum of applications for archaeology and the geosciences.

• DFG Programme: Research Grants