DETERMINATION OF PIGMENTS AND BINDERS IN POMPEIAN WALL PAINTINGS USING SYNCHROTRON RADIATION – HIGH‐RESOLUTION X‐RAY POWDER DIFFRACTION AND CONVENTIONAL SPECTROSCOPY – CHROMATOGRAPHY

The employment of synchrotron techniques complemented by conventional laboratory systems has allowed us to deepen and improve our knowledge of Roman wall painting procedures. The palette identified in wall paintings from Pompeii and Herculaneum from the second century bc includes goethite, hematite, cinnabar, glauconite, Egyptian blue, and other components such as calcite and aragonite. Proof of the use of organic binders is provided by FTIR and PY–GC/MS. Therefore, the possibility of the use of ‘a secco’ techniques cannot be ruled out. Pigments in wall paintings are usually found in small percentages and conventional X‐ray diffractometers do not detect them. Synchrotron radiation – high‐resolution X‐ray powder diffraction has allowed identification with only a few micrograms of sample.     

LEAD ISOTOPIC EVIDENCE FOR A MIXED PROVENANCE FOR ROMAN WATER PIPES FROM POMPEII*

Lead isotope analysis has been applied to the investigation of some Roman objects found in the town of Pompeii, consisting mostly of fistulae from the Augustan water supply system. The results of the analyses have produced ratios between 18.10 and 18.66 for ²⁰⁶Pb/²⁰⁴Pb, between 15.63 and 15.72 for ²⁰⁷Pb/²⁰⁴Pb and between 38.21 and 38.98 for ²⁰⁸Pb/²⁰⁴Pb. These data point to a fairly complex origin for the lead artefacts, probably involving several successive meltings and recyclings of a rather heterogeneous lead supply. The spread of lead isotope ratios can only be reconciled with a multiplicity of end‐members, at least three, but very probably more. There is one certain Sardinian ore, other indistinguishable Hercynian ores of Sardinia and/or Spain, and several different Alpine Mesozoic‐Tertiary mineralizations of the Mediterranean basin (Spain, Greece, Tuscany).     

MAPPING THE UNDISCOVERED RUINS OF POMPEII (NAPLES,ITALY) USING GROUND PENETRATING RADAR*

The ground penetrating radar (GPR) technique was tested in Pompeii, in an unexplored area where the Roman ruins are partially buried in the volcanic deposits. The method was also combined with time domain reflectometry (TDR) measurements to estimate the dielectric properties of the different volcanic units. In spite of the total thickness of the covering materials and the high signal attenuation measured in some layers, the radar was able to show a detailed image of the volcanic sediments and to locate the manmade structures hidden in the ash deposits. Moreover, the present study shows that the integrated use of GPR and TDR techniques could be successfully employed to evaluate the performance of the radar in specific terrains covering archaeological sites. Since it is unlikely that a large part of Pompeii will ever be excavated, GPR could be successfully used to produce detailed maps of the ruins still hidden in the subsurface, giving archaeologists the possibility of reconstructing the entire urban development of this unique ancient city.     

PROVENANCING OF LIGHTWEIGHT VOLCANIC STONES USED IN ANCIENT ROMAN CONCRETE VAULTING: EVIDENCE FROM ROME

This paper presents the geochemical analysis of lightweight scoria and pumice used in concrete vaults from ancient Rome. The geochemical signatures of dark scoria indicates a provenance of the 36–18 ka lavas of Vesuvius, as opposed to the more recent events on which Pompeii was built, as previously thought. The light‐coloured pumices analysed, which were originally thought to belong to the Sabatini volcanic system (north of Rome), corresponded instead to products from Campi Flegrei. These results provoke re‐evaluation of the trade and acquisition of these specialized materials destined for imperial projects in the capital city.     

CREEP OF LEAD DYEING VESSELS IN POMPEII: THE USE OF FINITE ELEMENT ANALYSIS TO ANSWER ‘UNANSWERABLE’ QUESTIONS

The scale of manufacture of the dyeing industry in Pompeii is a controversial subject. Previous studies have taken a theoretical approach. This study used full‐scale replicas of dyeing apparatus to investigate their operating parameters. To explore the physical effect within the materials during the dyeing cycle, a virtual replica was constructed. Finite element analysis was used to explore the long‐term mechanical effects of the dyeing process on the apparatus and on production as a whole. These combined methods have given an understanding of the significance of the industry and this new method has provided a foundation for further work.     

FRESCO AND LIME‐PAINT: AN EXPERIMENTAL STUDY AND OBJECTIVE CRITERIA FOR DISTINGUISHING BETWEEN THESE PAINTING TECHNIQUES

Identification of the painting technique adopted by an artist is often debated in studies on the characterization, restoration and conservation of mural paintings. However, objective criteria to identify the two main lime‐based painting techniques, fresco and lime‐paint, have not yet been systematically verified on replicas. Replicas were painted following both fresco and lime‐painting techniques. A comparison of microstratigraphic sequences and distribution of chemical elements reveals systematic differences between the two techniques, providing objective distinguishing criteria. Samples from the Abbey of Chiaravalle (Milan, Italy) and Pompeii were also analysed, and the results were compared with experimental data to validate the recommended criteria.     

THE SUPPLY OF CAMPANIAN‐MADE SIGILLATA TO THE CITY OF POMPEII

Pompeii is an important temporal reference in the study of Roman ceramics, yet until now the origins of red slip tableware or sigillata found in the city have largely been classified by visual evaluations of the pottery. This investigation employs petrographic and elemental analyses to establish the provenance of sigillata found in two pre–ad 79 contexts of Pompeii. In contrast to previous studies, the results suggest that pottery workshops in the vicinity of Somma‐Vesuvius played a vital role in the supply of sigillata to the city.