Il quartiere edilizio ritrovato sotto la chiesa di Sant’Eulalia a Cagliari

The paper concerns the buildings under the church of St. Eulalia at Cagliari (Sardinia – Italy). Some ruins relating to the Late Antiquity and Early Middle Age put to light during the archaeological excavations from 1990 and 2008are very interesting to study the urbanism of the ancient town as well as the wall texture. The stone seems to be the most used through the different phases. In the last period they used also the opus africanum, coming from Africasince Punic age, but re-used in Vandal and Byzantine times. In wall textures as in structural/decorative parts (architraves, worked cornices, etc.) have been used mainly local sedimentary lithologies of the Cagliari Miocene series: i.e., "Pietracantone", "Tramezzario", "Pietra forte". The first two are the most used, but they have frequent decay problems due to their minero-petrographic characteristics and of high porosity. The biodeterioration of cultural heritage caused by different biological agents is very important and should always be considered in relation to environmental conditions such as temperature and humidity. The results of the research in the archaeological area of St. Eulalia showed that microbial contamination was represented by a multiplicity of bacteria and fungi, sometimes visible macroscopically.