## 3 Results and Discussion
### Isotopic Analysis in Modern Mammals
#### 3.2.2 \(\delta^{34}\)S Values of Various Mammals
Considering the geological structure of Crete, higher values of sulfur isotopes would be expected, particularly in the central and the southern parts of the Island, where [PERSON] et al. [81] analyzed archaeological fauna bones from Apodoulou (South Crete, Middle Minoan period). In these areas, the Messinianevaporites are more prevalent and have a wider geographical distribution. These evaporitic formations were deposited during the Messinian Salinity Crisis (MSC), which resulted in the extensive formation of evaporitic deposits throughout the Mediterranean Sea [89; 91]. In other parts of Crete, such as the western provinces of Chania and Rethymno, evaporites are relatively rare. Instead, they are replaced by other deposits relevant to desiccation, such as shallow water carbonates, partly traverting- and microbial-mat-type deposits, and Lago Mare [91]. Therefore, in these areas, lower sulfur values are expected. However, contrary to what is observed, higher sulfur isotopic values are detected in Chamalevri (\(\delta^{34}\)S of sheep range from 12.6 to 13.5%) compared to Apodoulou (\(\delta^{34}\)S of sheep range from 10.0 to 10.9%) according to [PERSON] et al. [81]. It appears that sulfur derived from the geological substrate (evaporite minerals) in the soil was not sufficient to outweigh the contributions of marine aerosols and rainfall. The closer proximity to the sea and the lower altitude of Chamalevri (80 m, 13 km from Rethymno) make it more susceptible to the influence of marine aerosols, which--in other words--may contribute to elevated sulfur values. In contrast, Apodoulou (430 m, 54 km from Rethymno), being further inland and at a higher elevation, experiences a reduced impact from marine aerosols. This suggests a competitive role of marine aerosols in relation to soil sulfur contributions in the distribution of sulfur at these locations. In conclusion, a major problem with sulfur isotopic values is the degree of overlap between freshwater and terrestrial species. It appears that locations with complex surface geology, geography and topography, like Greece, produce a diverse terrestrial \(\delta^{34}\)S composition, which is reflected in terrestrial floral and faunal \(\delta^{34}\)S. Such diverse terrestrial \(\delta^{34}\)S values result in difficult discrimination between freshwater and terrestrial species. Nevertheless, until now, sulfur isotopic values of recent plants, mammals, and fishes, which could potentially help in the paleo diet, paleomobility, and paleoecology reconstruction, had been lacking from Greece. The sulfur isotope is an important tool because it has the potential:  
(a) To refine palaeodietary profiles by lending support to conclusions based upon \(\delta^{13}\)C and \(\delta^{15}\)N;  
(b) To identify better the participation of marine protein in diets;  
(c) To distinguish between freshwater and terrestrial dietary sources, enabling better recognition of the paleo diet human profile;  
(d) To exclude potential foods with very different \(\delta^{34}\)S relative to those of humans;  
(e) To provide information about human mobility and migration because the sulfur values are connected with the geological background of a geographical region;  
(f) To detect other factors (such as regional soil differences, salinity, and aerosol) that can influence sulfur isotopes;  
(g) To recognize agricultural practices (intensive exploitation and systematic cultivation) and the anthropogenic factors (atmospheric pollution) that influence sulfur isotopes (such as atmospheric pollution);  
(h) To trace animal husbandry (sulfur isotope values provide evidence of the impact of husbandry methods) practices (such as care production, nutrition, breeding, potential mobility, or grazing on different lands). Sulfur isotopic analysis also has the potential to differentiate between local animals and those imported from or raised in other locations. Isotope analysis promises to be a useful addition to support archaeometric studies (palaeodietary, paleomobility, and migration examination).