Neolithic pottery from the Trieste Karst (northeastern Italy): A multi-analytical study

A group of Neolithic potsherds from caves of the Trieste Karst (northeastern Italy) belonging to the Vlaška Group has been studied through a multi-analytical approach mainly based on non-destructive X-ray computed microtomography (μCT) and portable X-ray fluorescence (XRF), combined with X-ray diffraction (XRD) and optical microscopy (OM) to investigate both manufacture technology and provenance of the vases. Most samples, probably produced using a modelling technique, were made using clay-silt size paste containing quartz inclusions, tempered with the addition of abundant calcite and some limestone fragments. Calcite minerals, very common in the karstic environment, were probably obtained by grinding speleothems. This peculiar paste seems to be typical of the Karst area since prehistoric times. One single sample (5880), characterized by an unusual shape recalling those of the Fiorano culture (present in Emilia-Romagna and Veneto), shows a fine-grained fabric with numerous grog fragments, quartz, minor feldspar but without calcite. The 2D and 3D μCT-derived fabric parameters, reflecting the manufacture technology, are also quite different from those of the local vases. These features suggest that sample 5880 was manufactured elsewhere and later reached the Karst, directly or indirectly. The combined use of conventional techniques and non-destructive XRF and μCT, which allows the quantification of clay material, lithic inclusions and porosity, has proved to be an effective approach to investigate both technology and provenance of ceramic materials.