Roman settlement in Sardinia: archaeometric contribution to the excavation of Santa Filitica Villa (Sorso, Italy)

The complex settlement of Santa Filitica, which is located in north-western Sardinia, consists of the remains of an imperial Roman villa (and its annexed thermal plant). The site was reutilized from late 5th-6th century A.D. until Byzantine period (Rovina, 2003). Its complexity therefore makes it a particularly interesting site for reconstructing the history of Sardinia during a poorly known time span. This work focuses on archaeometric investigations conducted on ceramics (pottery and bricks), slags and mortars in order to characterize their composition, structure, provenance and technology. The results obtained from a combination of techniques (thin section Optical Microscopy, X-Ray Diffraction, X-Ray Fluorescence, Scanning Electron Microscopy), in addition to the statistical analysis, allowed us to formulate hypotheses about the provenance of raw materials or of pottery and on manufacturing tradition of the workshops. Among the findings pottery, bricks, mortars and slags reveal an heavy use of local raw materials including marly clays and local lime, as major content of the mortars, and iron ore. Noteworthy are the textural and chemical features of the Santa Filitica slags that, contrary to what was thought, point to blooming and forging at the same location. The abundance of wüstite and the absence of tapping-derived features also suggests (Miller et al., 1995; Senn et al., 2010) a low-efficacy reducing process and low-efficacy iron extraction, and the limited skills of the local smelters, which work, although not episodic, aimed to satisfy only local needs (Mameli et al., 2014).