A multidisciplinary diagnostic approach for the restoration of the inside surfaces decorative plaster of the vault of the late seventeenth-century Sant'Angelo Church in Monopoli (Bari, Italy),

The metropolitan church of Sant’Angelo (Monopoli, Bari - Italy), rebuilt in 1675 (Bellifemine, 1979) on the pre-existing medieval church, shows numerous forms of decay; the church is decorated with stuccoes and painted plaster dating back to the first half of the eighteenth century. The liturgical space has been heavily altered by extensive biological formations and sulfation that covered decorations, and by surface gaps, due to copious infiltration of rainwater caused by the absence of maintenance of the church since 1920 and also the deprivation of the roof since 1972. The diagnostic of degradation was supported by mineralogical, petrographic, chemical, and biological investigations performed with optical UV/VIS and electron microscopy, visible spectrometry. Biological samples, scraped and collected from the church vault, were duplicated and isolated by spread plating on plate count agar medium. The total DNA was extracted and the PCR products were sequenced and DNA similarity check was performed using the Gene Bank and EMBL databases. The various specialist analyses foreseen in the diagnostic project, preliminary to the restoration intervention, have highlighted important correlations between the technologies and the materials used in the re-editions and formal enrichments, datable between the end of the eighteenth century and the first half of the nineteenth century, as well as the disasters suffered over time, remedial actions and the long phase of abandonment of the church starting from the Second World War. Finally, the use of infrared thermography and the detection of the decorative apparatus with a 1:5 scale 3D laser scanner, accompanied by monitoring the physical and microclimatic conditions of the environment, helped to define in detail the structural criticalities connected to the interface between the wall structure and the decorative apparatus for timely restoration. Scanning electron microscopy evidenced the presence of fungal and bacterial colonies whose characterization is currently in progres

Fumarolic Minerals: An Overview of Active European Volcanoes

The fumarolic mineralogy of the Icelandic active volcanoes, the Tyrrhenian volcanic belt (Italy) and the Aegean active arc (Greece) is investigated, and literature data surveyed in order to define the characteristics of the European fumarolic systems. They show broad diversity of mineral associations, with Vesuvius and Vulcano being also among the world localities richest in mineral species. Volcanic systems, which show recession over a longer period, show fumarolic development from the high-temperature alkaline halide/sulphate, calcic sulphate or sulphidic parageneses, synchronous with or immediately following the eruptions, through medium-temperature ammonium minerals, metal chlorides, or fluoride associations to the late low-temperature paragenesis dominated by sulphur, gypsum, alunogen, and other hydrous sulphates. The situation can be different in the systems that are not recessing but show fluctuations in activity, illustrated by the example of Vulcano where the high-temperature association appears intermittently. A full survey of the mineral groups and species is given in respect to their importance and appearance in fumarolic associations

Petroarcheometric Analysis on Obsidian Artefacts Found Within Some Neolithic – Eneolithic Period Caves of Southern Italy

AbstractIn the last twenty years, obsidian artefacts have been found in important and often extensive karst cavities in Southern Italy: three located in Calabria (Grotta della Monaca, and Grotta del Tesauro, in Sant'Agata di Esaro, Cosenza; Grotta Pietra Sant'Angelo in San Lorenzo Bellizzi, Cosenza), one in Puglia (Grotta di Santa Barbara in Polignano a Mare, Bari) and another in Campania (Grotta di Polla, Salerno). All these sites, that have returned a total of 151 obsidian tools, were connected to human frequentation of the underground environments that occurred during the Holocene, which can be precisely located in the vast period between the Neolithic and the Eneolithic (6th–4th millennium BC). They are mainly blades and bladelets, but also burins together with scrapers and cores, generally of small dimensions. SEM-EDS and WD-XRF absolutely non-destructive analyses carried out on these items have shown that all samples have a source area in the obsidian outcrops of the island of Lipari (Messina, Italy). These data confirm that the Aeolian island of Lipari furnished the privileged obsidian extraction outcrops for most of the Neolithic and Eneolithic archaeological sites of Southern Italy

XRF technique

The techniques of chemical investigation by X-ray fluorescence (XRF) are widespread since the 50s of the last century. Depending on the accuracy of the desired data and on the artifact characteristics, they can be used as partially destructive or as absolutely non-destructive and non-invasive techniques. The archeomaterials that can be analyzed are the most disparate: minerals, rocks, metals, building materials, pigments, and so on; practically almost everything that is solid, liquid or gelatinous can be analyzed by XRF. The theoretical physical principles and the main components of X-ray spectrometers, in energy dispersion (ED) and wavelength dispersion (WD), are described, also comparing the advantages and disadvantages of each analytical technique. In the last decades, the diffusion of the ED silicon drift detectors, together with the development of very accurate and high specialized software for quantitative analysis, has given a new impulse to the diffusion of the portable spectrometers offering new possibilities for in situ and very rapid archeomaterial characterizations. Case studies related to different artworks, like ceramics, necklaces, coins, obsidians and other lithic artifacts will also be presented: they show the important contribution that X-ray spectrometer technique gives to solve problems related to the characterization, restoration and to the source identification of the raw materials