REPOSITORY > RESULTS

Abstract

This dissertation aimed to explore the potential of Sr isotope ratio analysis, combined with multi-elemental profiling, as a tool for geographic discrimination, focusing on two projects: tracing the provenance of cheese/milk from Naxos, Greece (Project 1), and wood in the Eastern Carpathians, Romania (Project 2). The goal was to understand how the Sr isotope ratio and elemental composition are transferred along the chain of soil – water – plant – animal – animal-derived product (milk), the factors influencing this transfer, and the main sources of Sr isotopes in the final products.
The first project highlights the geochemical authentication of PDO Graviera Naxos cheese, a complex dairy matrix where the Sr isotopic and multi-elemental analyses face challenges due to the diverse sources contributing to the final product, including seasonal variations in milk composition and external inputs such as sea salt and rennet. Despite these complexities, this study successfully demonstrated strong correlations between the Sr isotopic signatures of milk and local environmental factors, such as feed and water, showcasing the potential of Sr isotopes in tracing the geographical origin of dairy products. This project not only enhances our understanding of Sr isotopic variation but also contributes to the broader application of creating detailed isoscapes, which are essential for forensic and archaeological investigations. The second project documents the temporal variability in Sr isotopic and multi-elemental signatures of Norway spruce trees across the Rodna, Rarău, and Călimani Mountains over the past 50 years, revealing how environmental factors influence the geochemical profiles of timber. Through the analysis of wood core segments, the research tracks changes in elemental concentrations and Sr isotopic ratios, illustrating fluctuations within these geochemical signatures across time. This segment of the research highlights the transmission of unique geochemical signatures from the environment to the wood, offering promising avenues for timber provenance verification. Both studies emphasize the importance of considering the entire environmental context, from the composition of bedrock, soil, water, and atmospheric deposits, to plants and, in the case of dairy, further to animals, for accurately interpreting the Sr isotopic signature of a material. Instead of attributing the Sr isotopic signature solely to the geological substrate, our findings show that the Sr isotopic composition of the final product (wood, milk) or the derived product (cheese) depends on various factors, such as soil properties, plant uptake capacity, and Sr concentration at each stage. The collected data on elemental and Sr isotopic composition in wood, milk, and cheese, as well as environmental samples, form the basis for further efforts in safeguarding the geographical origin of Carpathian timber and Naxos cheese.
The presented dissertation fills a gap in understanding the contributions of different Sr sources, providing insights into the complexity of linking geological and environmental Sr isotopic and multi-elemental fingerprints with final products. Additionally, the results of this study have improved the quality of Sr isoscapes for Europe, covering both bioavailable Sr in soils and Sr in surface and groundwater.