DOMUS AUREA,THE ‘SALA DELLE MASCHERE’: CHEMICAL AND SPECTROSCOPIC INVESTIGATIONS ON THE FRESCO PAINTINGS

In this paper, data collected from the wall fresco paintings of room 114, called the ‘Sala delle maschere’, of the Domus Aurea in Rome is analysed. The chemical composition of the efflorescence is investigated by infrared spectroscopy. The colour palette is determined by means of EDXRF, Raman spectroscopy and visible reflectance spectroscopy. EDXRF has allowed an extensive mapping of the elements present in the pigments and plaster; whilst in‐situ Raman spectroscopy has been determinant for attributing the molecular composition of the pigments in a number of doubtful cases. Most pigments identified are typical of Imperial Roman fresco paintings (first to fourth centuries AD) ( Ward‐Perkins 1981 ); more interestingly, we found evidence of fragments painted with Egyptian blue, which was normally used mostly in official rooms.     

Firewood economy during the 4th millennium BC at Lake Clairvaux,Jura, France

Abstract

This paper presents the results of charcoal analyses from two waterlogged sites located at Lake Clairvaux in the French Jura and dated to the period between 3700–3500 BC. The economy of firewood intended for domestic use was characterised in accordance with the spatial organisation of the sites on the lakeshore, the economic context and the environment. Because gathering modes mainly depend on the available biomass and resource proximity, charcoal spectra are representative of the exploited woodland. However, as firewood gathering is a major and vital activity, the Neolithic societies established a firewood economy closely linked to their social organisation and way of life and to the environment.     

Molluscan Total Assemblages across a Woodland–Grassland Boundary and their Palaeoenvironmental Relevance

Abstract

Molluscan total assemblages across a woodland-grassland boundary are described and analysed using a variety of numerical techniques. These demonstrate that although the Mollusca respond to the vegetation boundaries their response does not exactly parallel that of vegetation structure. In particular, some shade-preferential species have encroached from woodland into adjacent grassland, degree of encroachment being an individual species characteristic. The study indicates that the detection of boundaries in sub-fossil assemblages from buried soil surfaces will only be possible if spatially-oriented multi-sampling strategies are employed.     

The Use of Strontium Isotope Analysis to Investigate Tiwanaku Migration and Mortuary Ritual in Bolivia and Peru

Strontium isotope analysis is applied in South America for the first time in order to investigate residential mobility and mortuary ritual from ad 500 to 1000. While Tiwanaku‐style artefacts are spread throughout Bolivia, southern Peru and northern Chile during this time, the nature of Tiwanaku influence in the region is much debated. Human skeletal remains from the site of Tiwanaku and the proposed Tiwanaku colony of Chen Chen have been analysed to test the hypothesis that Tiwanaku colonies, populated with inhabitants from Tiwanaku, existed in Peru. Strontium isotope analysis supports this hypothesis by demonstrating that non‐local individuals are present at both sites.     

LITHIC RESOURCES IN THE EARLY PREHISTORY OF THE ALPS*

Rocks, which are ubiquitous in archaeological sites as chipped or polished tools, were important factors in the prehistoric Alpine economic system. Archaeometric characterization and identification of source areas open the path to a more detailed understanding of the production and diffusion mechanisms behind Alpine lithic industries. An overview of the situation from the eastern to the western Alps in the Mesolithic, the Neolithic and the Copper Age illustrates current debates and issues.     

Wavelength‐dispersive X‐ray fluorescence analysis of ancient glasses*

The application of X‐ray fluorescence to the study of the composition of ancient glasses has been limited by the large amount of material required for samples. In this paper the setting of a reduced sampling XRF method for the analysis of ancient glasses is described. The method involves the preparation of glass beads by melting the sample with lithium tetraborate flux. By means of reference and synthetic samples, the method allows regression curves to be set, covering broad ranges from ppm to high concentrations. By means of a single program, up to 31 elements of interest in the study of ancient glass are analysed. The reproducibility, sensitivity and reliability of the method are discussed. The results demonstrate that 0.2 g of glass is sufficient to obtain accurate and sensitive analyses for most of the elements of interest.     

ROMANO‐EGYPTIAN RED LEAD PIGMENT: A SUBSIDIARY COMMODITY OF SPANISH SILVER MINING AND REFINEMENT*

Samples of red pigment from a group of seven Roman‐period Egyptian mummies, known as red‐shroud mummies, are investigated. Elemental analysis by inductively coupled plasma time‐of‐flight mass spectrometry (ICP–TOFMS) shows that the samples contain mostly Pb (83–92% by weight), along with 0.2–2.0% Sn. All of the samples are found to have similar trace element distributions when normalized to the continental crust, suggesting that they share a common geological origin. Lead isotope ratios are found to match the mixed lead sources typically associated with Rio Tinto, Spain – a site extensively mined for silver during the first century ad . Raman microspectroscopy identifies the major phase of each sample to be red lead (Pb₃O₄) with a minor phase of lead tin oxide (Pb₂SnO₄). Lead tin oxide does not occur naturally, and its incidental occurrence within the sample indicates that the material was heated under oxidative conditions at temperatures in excess of 650°C. In archaeological contexts, the high‐temperature oxidative treatment of lead is typically associated with metallurgical refinement processes such as cupellation. Based on this evidence, it is argued that the pigment was produced out of litharge associated with silver cupellation at the Rio Tinto site.     

CHEMICAL CHARACTERIZATION OF TIN‐LEAD GLAZED POTTERY FROM THE IBERIAN PENINSULA AND THE CANARY ISLANDS: INITIAL STEPS TOWARD A BETTER UNDERSTANDING OF SPANISH COLONIAL POTTERY IN THE AMERICAS*

Majolica pottery was the most characteristic tableware produced in Europe during the Medieval and Renaissance periods. Because of the prestige and importance attributed to this ware, Spanish majolica was imported in vast quantities into the Americas during the Spanish Colonial period. A study of Spanish majolica was conducted on a set of 186 samples from the 10 primary majolica production centres on the Iberian Peninsula and 22 sherds from two early colonial archaeological sites on the Canary Islands. The samples were analysed by neutron activation analysis (NAA), and the resulting data were interpreted using an array of multivariate statistical approaches. Our results show a clear discrimination between different production centres, allowing a reliable provenance attribution of the sherds from the Canary Islands.     

A SPECTROSCOPIC INVESTIGATION OF PIGMENT AND CERAMIC SAMPLES FROM COPÁN,HONDURAS*

A combination of micro‐Raman spectroscopy, micro‐infrared spectroscopy and SEM–EDX was employed to characterize decorative pigments on Classic Maya ceramics from Copán, Honduras. Variation in red paint mixtures was correlated with changing ceramic types and improvements in process and firing techniques. We have confirmed the use of specular hematite on Coner ceramics by the difference in intensities of Raman bands. Different compositions of brown paint were correlated with imported and local wares. The carbon‐iron composition of the ceramic type, Surlo Brown, was confirmed. By combining micro‐Raman analysis with micro‐ATR infrared and SEM–EDX, we have achieved a more comprehensive characterization of the paint mixtures. These spectroscopic techniques can be used non‐destructively on raw samples as a rapid confirmation of ceramic type.     

ICP–MS ANALYSIS OF GLASS FRAGMENTS OF PARTHIAN AND SASANIAN EPOCH FROM SELEUCIA AND VEH ARDAŠ?R (CENTRAL IRAQ)*

Forty‐one glass fragments were analysed by inductively coupled plasma – mass spectrometry, determining 40 major, minor and trace elements, including rare earth elements. The fragments came from excavations carried out at the archaeological sites of Seleucia and Veh Arda??r in modern Iraq, and were dated to the Parthian and Sasanian epochs. Analytical data indicate that all the samples are silica–soda–lime glasses. Magnesium and potassium oxide contents below 1% suggest that eight out of nine glasses from Seleucia, dating from between the first and the third century ad , could have been obtained by use of an evaporite as a flux; the same conclusion can be drawn for some of the Sasanian glasses dating from the fourth and fifth centuries ad . The other glasses from Veh Arda??r, as well as the remaining sample from Seleucia, are characterized by higher contents of magnesium and potassium, which suggests recourse to plant ash; different magnesium and phosphorus contents allow one to separate these samples into two main groups, pointing to the use of different kinds of plant ash. Aluminium and calcium contents, together with trace element data, may indicate that different sands were used for preparing glasses of different composition. Samples from Seleucia and Veh Arda??r are mainly blue–green and green to yellow–green, respectively; iron and manganese contents suggest that the furnace atmosphere was mainly responsible for the development of these hues.