African terra sigillata from Henchir Es-Srira archaeological site, central Tunisia: Archaeological provenance and raw materials based on chemical analysis

• Provenance study of African terra sigillata from Henchir Es-Srira, central Tunisia
• Trace and REE patterns allowed recognizing the source area of the base-clay
• New reference group was defined at Henchir Es-Srira for terra sigillata chiara “C”

Terra sigillata from the Henchir Es-Srira archaeological site in central Tunisia was analysed by X-ray fluorescence (XRF), and chemical data were statistically treated by multivariate (principal component and cluster) analyses, which defined a geochemically homogeneous reference group. According to our results, potsherds from Henchir Es-Srira are compositionally compatible with the six reference samples from the same site already published in the literature, and form a single group. A larger reference group is now well established for this site. In addition, comparisons with previous data from other sites in both northern and central Tunisia show that terra sigillata from Henchir Es-Srira is chemically more similar to that of the northern sites than the central ones. Neutron activation analysis (NAA), an extremely valuable tool for provenance studies, was also performed on a set of selected potsherds from Henchir Es-Srira and clay materials collected nearby, with the aim of identifying the possible clayey raw materials used for this ceramic production. Comparisons of both bulk chemical composition and trace and rare earth element (REE) patterns show that most of the objects were locally produced from a Neogene base-clay, probably collected from the “Saouaf Formation”.