AN INTERDISCIPLINARY APPROACH FOR CHARACTERIZING ANCIENT MATERIALS: BUILDING MATERIALS FROM THE HELLENISTIC-ROMAN CITY OF SOLUNTO (SICILY) AS A CASE OF STUDY

This presentation gives an overview of the advantages combining thin-section optical petrography with X-ray microdiffractometry (µ-XRD2) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS) for the analysis of well contextualised archaeological materials.

The Hellenistic-Roman city of Solunto (Sicily) offers an ideal case of study as the houses, in which typically lime based mortars and plasters are used, are well studied from a building history point of view.

To characterize this type of building materials in detail optical thin section petrography is a well-established tool not only regarding the minerals, but more important for determining textural and compositional features. However, optical microscopy has its limitations to characterize opaque phases or minerals below the optical resolution. This can be overcome using µ-XRD2, allowing non-destructive and local highly resolved structural analysis of the uncovered thin sections, where an identification of minerals with optical microscopy is not possible.

Pairing these two methods with SEM-EDS, results in a comprehensive study of the microstructural characteristics and chemical composition. This makes it possible to analyze not only the aggregates and inclusions but also the typically fine crystalline binder within this type of building material.

Our results, in combination with the analysis of the archaeological context, provide new insights into technology transfer in general, but also a better understanding of the different and interconnected strategies of selecting and processing local resources and the adaption of the used mortars to various architectural features.