A Multidisciplinary Approach to the Study of Early Neolithic Pyrotechnological Structures. The Case Study of Portonovo (Marche, Italy)

The introduction of agricultural practices fostered the development of specific technologies for the new subsistence practices and the production of new artefacts. Pyrotechnological structures such as ovens are part of the Neolithic equipment and accompanied the spread of agriculture from the Near East across Europe and the Mediterranean Sea. Ovens located within settlements – mainly domed, aboveground structures – have been traditionally linked to cooking and baking. The function is usually deduced from techno-morphological traits, although experimental approaches or ethnoarchaeological observations have often been used. This article aims to demonstrate the effectiveness of the multidisciplinary approach to understand the function of fire structures. An integrated methodology that combines archaeological analysis, archaeometry, and experimental archaeology has been applied to study the underground ovens of the Early Neolithic site of Portonovo (Marche, Italy) dated to the sixth millennium BCE. Samples of hardened sediment of archaeological ovens’ inner surface and selected pottery fragments were analysed through X-ray powder diffraction to estimate the temperature reached. A life-size replica of an underground oven was then created to perform firing experiments, including pottery firing. Samples of the oven’s walls and experimental vessels were analysed with the same method, and the values were compared. Our results indicate that the Portonovo ovens are potentially multifunctional structures, built for about 700 years, always with the same technique exploiting the natural soil’s insulating properties

Glazed sgraffito ware from Torre Alemanna (Foggia, fifteenth to sixteenth century A.D.): technological aspects of a local production

The archaeometric investigation of 46 potsherds of “Torre Alemanna type” pottery aimed to define a compositional refer- ence group and to understand the technological characteristics of its production. Principal component analysis applied to bulk chemical data (XRF) of the ceramic body showed a strong compositional homogeneity. Their comparison with local clays and 6 fragments of bricks sampled from the ceramic kiln, on the one hand, revealed the use of alluvial clays as raw material and, on the other hand, proved their fractionation for the production of pottery. The mineralogical assemblages detected by X-ray powder diffraction analysis inferred maximum firing temperatures between 750 and 1000 °C for the ceramic body. Polarising optical microscopy and scanning electron microscopy with energy dispersive spectroscopy (SEM–EDS) investigations on coating revealed the presence of quartz-rich white engobe covered with a high lead transparent glaze. The polychromatic decoration was analysed by colorimetry and EDS to compare the colour characteristics through all the pot- sherds. A temperature range between 780 and 950 °C of liquidus temperatures was inferred from the ternary phase diagram of PbO-Al2O3-SiO2 system. Overlap of temperature ranges for sintering of the ceramic body and maturing glaze points to a single firing of the Torre Alemanna type ware. The results obtained define the reference compositional group and technol- ogy of the Torre Alemanna type ware, already attested in several archaeological contexts of southern Italy, and showed a technological continuity with the past about the use of local carbonate-rich clays to produce fine pottery

SiLiBA: Building the geological chert lithotheque

Lithotheques collect and exhibit raw material used by human communities for the manufacturing of objects during the Prehistory and represents an important tool of their knowledge. These collections are essential in the procuring and provenance study of archaeological lithic industries. This paper aims, firstly, to introduce SiLiBA, the lithotheque of the Earth and Geoenvironmental Sciences Department of the University of Bari Aldo Moro (Italy), as reference collection in the archaeological field studies, and secondly to propose guidelines and rules to build a lithotheque. The collection consists of about 900 pieces of geological cherts, which are the result of an expanded collecting action of primary and secondary cherts across Italy (Apulia, Basilicata, Sicily), Croatia, and Switzerland, belonging to formations from the Cretaceous to the Quaternary Period. All the chert samples were described according to the non-destructive multiparametric protocol for chert investigation (NM-PCI), providing a modular dataset of binary, ordinal and continuous variables which integrates petrographycal, micropaleontological, chemical and physical data. Such results were summarized in suitable reports, with also geographic coordinates, geological description and photographic documentation, in a digital database, which will be soon online. Cherts are grouped in 37 suitable boxes, following geographic hierarchical organisation and reporting informative labels. Some representative samples are exposed in the Earth Sciences Museum of the same University. Furthermore, the lithotheque is equipped by a dedicated laboratory which includes optical microscopes, a glossmeter and a spectrophotocolorimeter. The promotion in the last years was guaranteed by dissemination activities for educational and academic communities, including an interactive laboratory of experimental archaeology

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

Retrieval of phase relation and emission profile of quantum cascade laser frequency combs

The major development recently undergone by quantum cascade lasers has effectively extended frequency comb emission to longer-wavelength spectral regions, i.e. the mid and far infrared. Unlike classical pulsed frequency combs, their mode-locking mechanism relies on four-wave mixing nonlinear processes, with a temporal intensity profile different from conventional short-pulses trains. Measuring the absolute phase pattern of the modes in these combs enables a thorough characterization of the onset of mode-locking in absence of short-pulses emission, as well as of the coherence properties. Here, by combining dual-comb multi-heterodyne detection with Fourier-transform analysis, we show how to simultaneously acquire and monitor over a wide range of timescales the phase pattern of a generic frequency comb. The technique is applied to characterize a mid-infrared and a terahertz quantum cascade laser frequency comb, conclusively proving the high degree of coherence and the remarkable long-term stability of these sources. Moreover, the technique allows also the reconstruction of electric field, intensity profile and instantaneous frequency of the emission.Comment: 20 pages. Submitted to Nature Photonic

The glass-melting crucibles of Derrière Sairoche (1699–1714 AD, Ct. Bern, Switzerland): a petrological approach

Forty-three sherds of crucible found in the pre-industrial (1699–1714 AD) forest glassworks of Derrière Sairoche (Ct. Bern, Switzerland) were studied in order to determine the nature of raw materials and the technological aspects of their production and use. The samples were analysed using optical microscopy, XRD, XRF, UV–VIS spectrometry and SEM/EDS. The crucibles were produced with local natural clayey sand and fired in two steps. After preliminary firing in a low-temperature furnace (800–1000 °C), the crucibles were brought to temperatures up to 1500 °C within the glass-melting furnace, before adding the glass batch. Using the structural order of cristobalite as an archaeothermometer, temperatures between 1370 and 1500 °C were estimated. The crucible surface shows corrosion by glass and furnace gases. Connections between glassmaking and crucible production are emphasised by this study

The glass-melting furnace and the crucibles of Südel (1723–1741, Switzerland): provenance of the raw materials and new evidence of high thermal performances

Fifty crucible fragments and 10 fragments of the melting furnace of the forest glassworks of Südel (1723–1741, Ct. Luzern), were analyzed by petrographic, mineralogical and chemical techniques in order to assess the temperature reached in the melting chamber and to find out which raw materials were used to make the crucibles and the melting furnace. Since the crucibles were used in the melting furnace, the temperature estimations were based on both the crucibles and the refractory fragments, as they were parts of the same system. The temperature range in the melting chamber, estimated by the structural order of the new-formed cristobalite, points to a temperature range between 1350 and 1500 °C. However, three crucible samples recorded extreme temperatures as high as 1650 °C, suggesting very high flame temperatures for wood fuel. The analyzed red bricks were made with local calcium-poor clay. One of them was tempered with refractory fragments, demonstrating an in-house production and the recycling of such a material after its use. The crucibles and the refractory bricks were made with the same refractory clay. The former using unprocessed clay and the latter blending clay with chamotte. A comparison with Sidérolithique clayey sand samples from the Swiss Jura, shows strong affinities which may rule out the archaeological hypothesis of an exclusive provenance of such clays from Germany, suggesting an import from the Swiss Jura mountains

Pre-industrial glassmaking in the Swiss Jura: the refractory earth for the glassworks of Derrière Sairoche (ct. Bern, 1699–1714)

Fragments of the melting furnace and several crucibles of the glassworks of Derrie`re Sairoche are compared with local raw materials. Principal component analysis (PCA) based on the chemical composition and on the grain-size distribution of the archaeological and natural materials demonstrates that the analysed samples were made from the same raw material and that local clayey sands (Hupper, Side´rolithique) were exploited. Availability in situ of good raw materials made tempering unnecessary. Their high melting point (c. 1600°C) allowed good performance in service conditions at temperatures up to 1500°C. Moreover, because of low Fe₂O₃tot concentrations, batch-glass contamination was avoided

Pottery kiln and drying oven from Aventicum (2nd century AD, Ct. Vaud, Switzerland): Raw materials and temperature distribution

Fireboxes of two pottery structures, excavated in 2002 at Aventicum (at present Avenches), the capital of Roman Switzerland, were studied to understand their function in the artisan quarter. Twenty-one oriented samples underwent petrographical, mineralogical and chemical analyses to determine the nature of the raw materials and the temperature distribution.Both structures are typologically different and show differing degrees of thermal impacts. Inferred maximum temperatures for kiln Structure 6, as deduced from phase associations, were as high as 1050–1200 °C. Such high temperatures are typically recorded in fireboxes of ceramic kilns. Structure 180 is proposed to have been a drying oven, as evidenced by: (1) its phase associations, pointing to maximum firing temperatures of c. 950–1050 °C, and (2) its unusual shape. Six out of seven clays from the artisan quarter revealed Ca-rich composition, but the Ca-poor one was preferentially used by Roman potters for bricks and clay binders to build the two structures. Such “refractory” clays are obviously better suited to withstand higher firing temperatures and for a longer period than Ca-rich clays