Ancient aqueduct carbonates: accurate archives of the environment and archaeological events

• Applicant: Dr. Gül Sürmelihindi
• Subject Area: Palaeontology ; Classical, Roman, Christian and Islamic Archaeology
• Term: Funded in 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 434934785

Understanding our environment and the way it changes due to natural and human causes is crucial for the survival of society. Studies of palaeoenvironmental archives are pivotal in this respect and provide insights for scenarios of future nature-human interactions. We will use calcium carbonate deposits from Roman aqueducts as an innovative archive to obtain high-resolution palaeoenvironmental and archaeological data for the Mediterranean realm. The carbonate archive stores key information on groundwater quantity and composition and indirectly on rainfall, air temperature and extreme environmental events at subannual resolution. It also documents human interference with these antique water supply systems such as cleaning, maintenance and restructuring with concurrent dynamics of changing local socio-economic conditions. In this way, the archive builds a direct link between environmental stress and Roman social and economic development.The study focuses on three aqueduct systems in Provence, southern France, that served two major roman cities, Nîmes and Arles. The aim is to retrieve local climate and environmental data from the Roman Imperial period (27 BCE to 476 CE). Samples of the aqueduct deposits will be studied using petrography, stable isotope and trace element geochemistry, and spectrofluorescence. Chemostratigraphies will be constructed for each carbonate sample for extraction of environmental data, such as temperature and water composition variations. The cyclicity of the oxygen isotope data reveal the annual layer structure, which can be used to determine the number of years the aqueducts were operated. Comparison of carbonate samples along the same aqueduct will help to distinguish variations in water composition of the spring from changes that developed along the aqueduct channel. A particular focus of the project will be on geochemical markers of extreme environmental events such as droughts, floods and earthquakes. Such events not only provide information on local climate extremes but also allow correlation between carbonate samples of different aqueducts. 230Th/U dating and dating using historical sources will be attempted to obtain absolute ages for the aqueducts. The final aim is to create a baseline for present climate and environmental studies and to investigate to what extent local Roman communities were exposed to environmental stress and how they reacted to that. Understanding the way Roman society adapted to climate and environmental stress will help us to cope with the types of water stress that will likely be encountered in the near future in the Mediterranean.

• DFG Programme: Research Grants
• International Connection: Austria, United Kingdom
• Cooperation Partners: Professor Dr. Christoph Spötl; Professor Dr. Andrew Wilson