Roman ceramics from Vicofertile (Parma, Italy): micro-Raman study of the heat diffusion during the production process

The present work focuses on the archaeometric characterization of Roman ceramics from Vicofertile (Parma, north-west Italy), with the main aim of defining the production systems, the surface finishing and the origin of the clays and to identify the production areas, through a multi-methodological approach. In 2008, during the two-year campaign of excavations in the area of Vicofertile, five Roman villas of the end of the first century AD, modified till the Imperial age with the addition of wineries and furnaces, were discovered. From the villas, twenty-eight samples of Roman ceramics were selected: amphorae with seals, terra sigillata pottery with in planta pedis seals, fragments of thin-walled ceramics, black painted pottery and an antefix. Fig.1: Raman maps obtained from the main bands of feldspar, hematite and quartz on a cross section of a red Roman ceramic; brighter shade means larger peak intensity. The samples were mineralogically and petrographically analyzed to characterize the composition of tempera ceramic body and decorations. The use of micro-Raman spectroscopy, in particular for the identification and understanding the structural changes during a fire treatment, is well established [Colomban et al. 2003; Colomban 2004; Bersani et al. 2010, Pešková et al. 2011; Zuluaga et al. 2012]. In this article, in addition to the standard characterization of the components of ceramic body and surface, Raman mapping was extensively carried out along the thickness of the ceramic samples to define the heat distribution during the production process. The collected data were compared with the peculiar shape of the ceramics and the ancient types of kilns to compare the real distribution of heat and its effect on the ceramic artifacts. KEY WORDS Ancient ceramic, Raman Spectroscopy, production process. REFERENCES Bersani D., Lottici P.P., Virgenti S., Sodo A., Malvestuto G., Botti A., Salvioli-Mariani E., Tribaudino M., Ospitali F., Catarsi M., Multi-technique investigation of archaeological pottery from Parma (Italy), Journal of Raman Spectroscopy 2012; 41: 1266-1271. Colomban P., Quang Liem N., Sagon G., Xuan Tinh H., Ba Hoành T. Journal of Cultural Heritage 2003; 4: 187-197. Colomban P. Applied Physics A 2004; 79: 167-170. Pešková Š., Machovič V., Procházka P. Ceramics – Silikáty 2011; 55: 410-417 Zuluaga M.C., Alonso-Olazabal A., Olivares M., Ortega L., Murelaga X., Bienes J.J., Sarmiento A., Etxebarria N. Journal of Raman Spectroscopy 2012; 43: 1811–1816.