Characterisation of clayey raw materials for ceramic manufacture in ancient Sicily.

It is well known that mineralogical, petrographic and chemical analyses can successfully support provenance studies of archaeological ceramics. The characterisation of a ceramic paste, the assessment of its technology of production and its provenance assignment related to a specific production centre or to a geographical and/or compositional space, are all tasks that can be performed even more accurately if the clayey raw materials used in pottery production are also studied. For that reason the identification of the clay deposits exploited in a given ceramic workshop often plays a key role in the archaeometric reconstruction of the production cycle where geology, mineralogy, petrography and chemistry are equally involved in a sort of ‘integrated approach’. Archaeological excavations in Sicily, especially those that have been accomplished in the last 25 years, have brought to light kilns designed for ceramic manufacture in a number of sites, attesting the relevant impact of this activity on the earliest economy in this region of the Western Mediterranean. The geological predisposition of the territory which is characterised by several clayey formations certainly promoted the straightforward development of such a thousand-year old productive tradition. The present research is a detailed study of textural, compositional and technological properties of nine clayey formations cropping out in the territory of Western and Central Sicily, which are already recognised as having been, or as potentially having been used as raw materials for ceramic production. Several compositional and textural markers for distinguishing the clays and therefore, potentially useful to identify the provenance of local/regional ceramic products have been successfully identified.