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

到目前为止，考古植物学组合中的碳酸果果具有被低估的考古研究潜力。与常见的烧焦的考古植物大型遗骸相比，富含CaCO3的水果含有相对较高的氧气和锶。该方法适用于古气候参数(三角洲18O、三角洲47)的估算和物源分析(87Sr/86Sr)，为更好地了解早期农业动态奠定了基础。该项目的中心目标是为利用碳酸盐水果作为早期农业生态系统的古环境替代品奠定基础。项目设计包括两个研究阶段。将对从收集中取样并在实验室实验中生长的现代材料进行试点研究。本研究将完成以下任务：(1)评估水果碳酸盐14C测年中潜在的储集层效应；(2)揭示水果碳酸盐的delta18O值与当地气候参数(降水和温度)的相关性；(3)建立水果碳酸盐的delta47值与当地温度的依赖关系；(4)评估水果碳酸盐的~(87)Sr/~(86)Sr-比值与生长地点土壤的关系。水果碳酸盐必须作为古环境的替代物来研究近东考古学中的两个关键问题：(1)以前的水分可获得性(气候或灌溉？)(2)原有植物生长地点的本地化，导致种植区的重建。分析这一多功能替代物的预期结果将为考古学和地学提供广泛的应用。

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.