This paper deals with the archaeometric study of lime-based plasters found in the archaeological settlement of Scauri, located in the homonymous bay in the southwestern part of Pantelleria Island. Since 1999, archaeological surveys have led to the recovery of the huge remains of a Late Roman settlement dating back to the fourthfifth century AD. It is well known that the island of Pantelleria is entirely composed of volcanic rocks. Accordingly, the production of quicklime required calcareous rocks to be imported. Also, the selection criteria of the sandy aggregate are relevant and of interest to this study, to evaluate the achieved technological level. Within this context, a mineralogical and petrographic characterisation of the plasters was carried out using thin-section petrography, for the classification of the sand aggregate.Moreover, X-ray diffraction and scanning electron microscopy were performed to investigate the composition of the binder. The analytical results allowed the identification of different recipes for the manufacture of the studied plasters, obtained by the use of different types of aggregate (volcanic rock fragments, pumice, basaltic scoriae, and ceramic fragments) and highlighted the degree of pozzolanic reaction of the binder. Finally, the provenance of the calcareous raw material was inferred using a petrographic approach. K E Y W O R D S archaeometry, island of Pantelleria, Late Roman age, lime-based plasters, Mediterranean Sea

No abstract

This study presents the results of the examination and characterisation of the wall paintings that decorate the rupestrian church named Grotta del Crocifisso, which is located in the territory of Lentini (eastern Sicily, few tens of kilometres from Catania and Syracuse). The earliest mural paintings in the church date back to the twelfth century AD. A multi-analytical approach was adopted for the characterisation of stone materials, secondary degradation products, and pigments. For this purpose, the following techniques were used: reflected light microscopy (RLM), polarised light microscopy on thin sections (PLM), X-ray powder diffraction (XRPD), mercury intrusion porosimetry (MIP), portable X-ray fluorescence (p-XRF), scanning electron microscopy (SEM-EDS), Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy (RS). The lithic substrate and the plaster’s coating layers were thoroughly characterised from compositional and textural points of view, and the use of locally available raw materials was established. Similarly, the newly formed crystalline phases produced by alteration processes of the original materials were recognised. The red, yellow, brown, and green pigments were easily identified by p-XRF and SEM-EDS. The use of “earth pigments” widely available in the surrounding area (various types of ochre) was thus highlighted. The recognition of the dark blue pigment created some additional issues in its identification, making further diagnostic methods necessary. In fact, the use of the most common mineral pigments was categorically excluded by both p-XRF and SEM-EDS, since no chromophore metallic elements were highlighted with the exception of trace amounts of iron. A combination of detailed microscopic observations together with the application of FTIR and RS supported the use of an organic pigment obtained from the maceration of woad (Isatis tinctoria). The green pigment is the result of a mixture between woad and yellow ochre. Woad is even today easily available in Sicily, and some additional experimental tests were carried out on Isatis tinctoria that had been freshly collected in the area (treated with traditional procedures). Over the past centuries, woad was widely used for dyeing fabrics, but its practice for wall paintings has only been sporadically proven. The identification reported in this case study could be considered a novelty at least in the Sicilian panorama.