The invisible cities.
Transformations and persistence of the ancient urban structures: the building materials.
Centuries of architectural transformations have changed the aspect of cities, at the point that much of the ancient shape is often invisible. Only scattered testimonies of the past survive in the contemporary urban fabric, with few elements that stand out in the architectural palimpsest. The aim of the project is to investigate the transformations of the urban space of the city of Pisa during the Roman period and the late antiquity (3rd century BC – 5th century AD), by means of archaeometric analysis on building materials
The evolution of the settlement will be investigated through the analysis of the architectural elements referable to the Roman period, both in the case of the few structures preserved entirely, and re-used elements incorporated into later structures. The study of construction materials, in particular of stones and bricks, will be conducted by combining the description of construction techniques with the systematic collection of geochemical data on the surface of the masonry. This methodology represents a novelty in archaeological sciences and can provide crucial data for the understanding of the construction phases of the city and the economic and productive context to which they are linked. Through the use of portable and non-invasive analytical instruments (XRF, NIR, Raman), combined with digital documentation (photogrammetry, 3D GIS) and statistical data processing, it will be possible to compile a catalog of construction materials used in Pisa during the Roman period. Geochemical analyses will also be carried out on clay sediments, ancient quarry fronts and outcrops, allowing to determine the provenance of raw materials.
The data collected in the urban area and in the surrounding territory will make it possible to evaluate the supply and use of building materials during a period of strong political and social change, providing an important indicator for understanding some changes in the Roman economic-administrative system in Pisa in a diachronic perspective.
The project aims at creating a new replicable protocol for the in situ collection of archaeometric data on building materials. The analytical data will also be implemented in an online database and released as an open data to promote collaborative practices in archaeological sciences.