Characterisation and provenance of stones used in the mosaics of the domus dei Coiedii at Roman Suasa (Ancona,Italy)

The mosaics covering the floors of the rooms of the domus dei Coiedii at Suasa (Ancona, Italy) may be dated archaeologically and artistically between the late republican-Augustan age (end of the first century B.C.-beginning of first century A.D.) and the second century A.D.-first half of third century A.D. The floors were made mostly in opus tessellatum, only one in opus sectile. Tesserae used in opus tessellatum are made mainly of local stones, belonging to the so-called Umbro-Marchigiana Sedimentary Sequence: the white to pinkish and reddish tesserae consist prevalently of limestones belonging to the ‘Scaglia Rosata’ Formation (Late Turonian-Middle Eocene), and subordinately to the ‘Calcare Massiccio del Burano’, which is part of the ‘Calcare Massiccio s.l.’ Formation (Late Triassic-Early Lias). Most dark to black tesserae are composed of not fossiliferous marls and marly clays, which probably derive from the local ‘Marne a Fucoidi’ Formation; a number of them are made of very fine grained sandstones, which are found as pebbles in the alluvial sediments of the Cesano river close to Suasa, and, some, of aphyric leucite-bearing basanites from the potassic Quaternary magmatic province of central-southern Italy. Artificial glasses (red and green, rich in Pb and low in Sb; light blue, low in Pb and high in Sb), containing microliths of Pb-rich phase(s) and of wollastonite, were also used in some floors. The stones used in opus sectile are (1) sedimentary: nodular limestones belonging to the ‘Rosso Ammonitico’, which occurs in the Umbro-Marchigiana Sedimentary Succession; black marls and marly clays similar to those used in opus tessellatum; onyx marble; (2) magmatic: porphyrites (‘porfido verde antico’) and gabbros (ophite); (3) marbles: different kinds of coloured marbles, comprising ‘marmo cipollino’, ‘rosso antico’, ‘pavonazzetto’, ‘portasanta’, ‘giallo antico’, ‘bigio antico’, ‘brecce coralline’. White marbles from Marmara and Carrara were also employed.     

Volubilis (Meknes,Morocco): Archaeometric study of the white and coloured marbles imported in the Roman age

The ruins of the Roman town of Volubilis, located in the Middle Atlas, near Meknes, between Fez and Rabat, constitute the most important Roman archaeological site in Morocco and are included in the UNESCO World Heritage List. Volubilis became the headquarters of the Mauritania Tingitana limes after the annexation of the kingdom of Mauritania to the Roman Empire in AD 42. Evacuated by the Romans after the second half of the 3rd century, the town became the capital of the kingdom of Idriss I in AD 789.The results of an archaeometric study of the marbles imported into Volubilis during the Roman age are reported herein the sixth framework program of the European Union.Of the few coloured lithotypes that have been found, all are of Greek origin with the exception of the so-called “Portuguese pink”, a pale pink marble exploited by the Romans near Vilaviçosa in the Lusitania which, till now, has not yet been identified outside Iberia. As regards the white marbles employed in the statuary, petrographic study in thin section and the δ¹³C and δ¹⁸O isotopic data emphasize the frequent use of Lunense and Pentelic marbles. The latter also features among the white marbles used for crustae and architectural elements together with the dolomitic variety of Thasian marble, Parian marble from Lakkoi, Proconnesian marble from the island of Marmara, an unknown marble most probably of local origin, and a variety of the so-called “greco scritto” whose provenance still remains unclear. In fact, its petrographic and geochemical features do not match those known for the classical “greco scritto” from Cap de Garde, near Annaba (Algeria).     

Numerical model application for the restoration of the Racconigi Royal Park (CN, Italy)

After years of neglect and an almost complete lack of maintenance, the Racconigi Royal Park was in an inevitable and widespread state of decay. This decay also involved the waterways that were designed in the nineteenth-century by Xavier Kurten (1811–1840). The seasonal lack of water and the agricultural needs of the farms around the Park made it necessary, during the planning stage of the restoration project, to consider the practicability and the effectiveness of some measures that were conceived to optimize the operation of the restored waterways, without altering the historical structure of the system. The realization of a hydraulic numerical model of the system, which is briefly illustrated in the first part of this case study, resulted to be the most suitable tool to study different possible solutions of the problem. The model simulations in fact helped the restorers put into effect the right remedies to favour the correct flow of the water, to make the whole historical system more efficient and to make its future maintenance easier.     

Characterisation of 15 century red and black pastes used for wall decoration in the Qijmas El-Eshaqi mosque (Cairo, Egypt)

The use of coloured pastes for inlaying marble and limestone wall panels is one of the ornamental techniques that were widely used during the Mamluk period in Egypt (1250–1516 AD). Red and black pastes from Qijmas El-Eshaqe mosque (1482 AD) in Cairo were studied to identify their main components. The study of the samples involved the identification of the pigments, additive materials and organic binding media. The study was performed using various analytical methods such as polarising microscopy (PLM), scanning electron microscopy equipped with energy dispersive X-ray analyser (SEM-EDX), inductively-coupled plasma (ICP-AES), X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR). These complementary analytical techniques provide precise identification of inorganic and organic substances used in the pastes. The results indicated that the red pigment is mainly obtained from red ochre containing hematite, whereas amorphous carbon (bone black and charcoal) was used to obtain the black colour. Both samples contain calcium sulphate, which was used to give some hardness to the pastes. Beeswax was used as an organic medium in both pastes. The study provides the information required for the conservation of the coloured paste ornaments.     

The scientific investigation for the study and conservation of the wooden model of S. Maria della Consolazione's church (Todi,Italy)

The focus of this work is the wood polychrome model of the church of S. Maria della Consolazione in Todi, an artefact whose author and historical events are not completely known except a general reference to the construction period of the church (1508–1607 AD). In this study, original and additional materials were examined in order to provide a deeper understanding of the painting and assembly techniques, and a greater awareness of how well preserved the object is, as well as an analysis of previous preservation and conservation interventions. The samples from the painted surfaces were examined by means of micro-Raman spectroscopy, fourier transform infrared (FTIR) spectrometry and internal microstratigraphic analysis. Thin sections of the wood samples were examined under an optical transmission light microscope in order to identify the botanical species. The results shown in this paper suggest the possibility that the original painted layers are made of calcium carbonate white, red ochre and indigo and they were applied by protein binder without any ground layer. Some non-original pigments were found on the model surface like Prussian blue and chrome yellow. Concerning wood components, poplar was characterized both in the original and non-original parts of the model whereas pine species were detected only in the restoration elements.     

Different methods for soluble salt removal tested on late-Roman cooking ware from a submarine excavation at the island of Pantelleria (Sicily,Italy)

This paper deals with the comparative evaluation of different procedures of salt extraction designed for archaeological ceramics from submarine burial environments. The experimental work was carried out on a particular type of late-Roman cooking ware finds (Pantellerian ware) found in a shipwreck near the shoreline of the Island of Pantelleria (Sicily). The studied ceramic test-pieces were first recognised in terms of bulk characteristics (mineralogy, petrography and chemistry). SEM-EDS observation allowed verification of the presence of various secondary minerals at the surface and in the pore spaces formed after the prolonged permanence in seawater under oxidising or reducing conditions. Pore-size distribution was also determined in the same fragments that had been subjected to the salt extraction routines. Three salt extraction methods were tested: two methods based on diffusion processes (water immersion under stationary conditions and under mechanical stirring conditions) and one method based on both diffusive and advective processes (multiple packages of sepiolite). The obtained experimental data allowed us to identify strengths and weaknesses of the tested procedures with practical spin-off for archaeologists and restorers (efficiency, kinetics, compatibility with the ceramic substrate, costs and simplicity of use). Salt extraction under mechanical stirring was the most effective method and, for this reason, is suitable for laboratory fieldwork during or immediately after submarine archaeological excavations. Similar advantages are also intended for the preliminary treatments of the most precious findings prior to museum storage.     

Earthquakes and ancient leaning towers: Geodetic monitoring of the bell tower of San Benedetto Church in Ferrara (Italy)

In May–June 2012, several seismic events took place in the Po River Plane in northern Italy, with a maximum magnitude of M_W 5.86 (M_L 5.9)] and the epicentre located about 32 km from the centre of Ferrara. Many historical buildings were seriously damaged and others showed marked deformations or differential settlements. Therefore, it was necessary to place many of them under monitoring, using fast and safe measurement techniques to quickly obtain accurate information on ongoing structural deformation. This paper presents the case study of the bell tower of San Benedetto Church in Ferrara (17th century), which was already under monitoring at the time of the earthquake because of its remarkable leaning angle. Immediately after the seismic events, monitoring of the bell tower was repeated. Digital levelling indicated a marked differential settlement of the foundations with regard to the trend of secular movement, while terrestrial laser scanning (TLS) revealed a significant increase of the inclination of the tower's axis, confirming the results from levelling and showing good integration of both monitoring techniques.     

The wood of “C” and “F” Roman ships found in the ancient harbour of Pisa (Tuscany, Italy): the utilisation of different timbers and the probable geographical area which supplied them

During the excavation of the Etruscan and Roman harbour of Pisa, several shipwrecks were found. The wooden timbers constituting the ship C and ship F (which date back to the first and the second century A.D., respectively, as attested by archaeological findings) were selected in order to collect information about the technological knowledge of the time. Pinus pinaster Aiton was essentially utilised for the planking of ship C and Quercus sp. caducifolia for that of ship F. The choice of timber for the other parts of ship C hull was much more differentiated. Ship C seems to be built in a careful way and its characteristics when added to its overall lightness, seem to reflect its use as a higher capacity boat built for sea sailing. Ship F seems more linked to short voyages in inner fresh waters. The utilisation of different woods was linked not only to the technological characteristics of wood, but also to their easy availability. Palynological analysis, carried out on the clay sediments embedding the shipwrecks, has shown that the flora of Pisa area in that time period would have allowed the acquisition of all the timber species used for both the ships’ construction, with the exception of the fig wood. However, a foreign origin of the timber from somewhere else in the Northern Mediterranean area has not been excluded.     

Consolidation and protection by nanolime: Recent advances for the conservation of the graffiti,Carceri dello Steri Palermo and of the 18th century lunettes,SS. Giuda e Simone Cloister,Corniola (Empoli)

Nanolime dispersed in 2-propanol was extensively used for the consolidation of wall paintings. The knowledge of the advances of this methodology dealing with all the possible effects associated with the nanolime new material in conservation is fundamental to assess and improve the technique. In this paper, four different dispersions of Ca(OH)₂ nanoparticles were characterised by Small Angle X-rays Scattering technique (SAXS) and Transmission Electron Microscopy (TEM) in order to achieve information on size, shape, polydispersity, agglomeration, and crystal structure (by SAED patterns) of the particles. Once characterised, the dispersions were tested in two different case studies, the Carceri dello Steri in Palermo with their graffiti and the 18th century lunettes at the SS. Giuda e Simone Cloister, Corniola (Empoli) with their lime-based mural paintings. The treated samples were characterised in relationship to either their morphology and surface chemical composition by Scanning Electron Microscopy coupled with Energy Dispersive X-rays spectroscopy (SEM-EDX), or their water absorption and mechanical properties (resistance to material abrasion). The results obtained showed that all the dispersions were nanometrically structured and their application succeeded in recovering the mechanical properties of the painting or graffito layers, not altering their permeability to water and keeping perfectly the wall transpiration. However, the dispersions constituted of the nanoparticles obtained via a synthesis able to control size and shape of the Ca(OH)₂ particles resulted in a better performance in situ, even if the differences found by SAXS and TEM were slight.