CHEMICAL AND MINERALOGICAL ANALYSES OF GALLO-ROMAN WALL PAINTING FROM DIETIKON,SWITZERLAND

Around 90 samples of Roman wall painting dating from the first to the third century AD were analysed using different analytical techniques: X-ray diffraction, X-ray fluorescence, infrared spectrometry, scanning electron microscopy, energy dispersive spectrometry, optical microscopy and physico-chemical tests. The identified pigments are: ash, calcite, carbon black, celadonite, cinnabar, Egyptian Blue, glauconite, goethite, hematite and red lead. Pigment mixtures were used to get other colours such as brown, pink or purple. Three types of plaster were used: a first, and most dominant, with river sand, a second with crushed tile for damp places and a third, to which cinnabar was exclusively applied, was prepared with crushed calcite crystals.     

METALLURGY OF BRONZE USED IN TOOLS FROM MACHU PICCHU,PERU*

Although the tin‐bronze artisans’ tools found at Machu Picchu appear to have been cast to their final shape, examination of their microstructures shows that they were forged and annealed. As found, the tools were broken or cracked due to poor ductility of the bronze. Rolling and annealing of samples of bronze formulated with sulphur and iron additions to replicate the metal used at Machu Picchu show that the minimum amount of deformation needed to induce the observed recrystallization is a 12% reduction in thickness. The sulphur and iron impurities retard nucleation of new grains during annealing, but do not inhibit subsequent grain growth. Tensile tests show that while up to 10% porosity in cast bronze has no effect on hardness or initial strain‐hardening rate, it reduces the tensile strength and ductility enough to embrittle the metal. Hardness is an inadequate indicator of the strength properties of cast bronze intended for use in tools or weapons. The results show that when the metalsmiths at Machu Picchu started making bronze tools for use by stone and woodworkers, they had not mastered the art of making metal with adequate strength properties for this service. The forging and annealing procedure they used did not enhance the mechanical properties of their tools, and may reflect an inherited metallurgical tradition.     

IBERIAN CERAMIC PRODUCTION FROM BASTI (BAZA,SPAIN): FIRST GEOCHEMICAL,MINERALOGICAL AND TEXTURAL CHARACTERIZATION

Ceramic fragments from the archaeological excavation of the Iberian–Roman city of Basti (Spain) were studied from a geochemical point of view and by applying a statistical tool to X‐ray fluorescence data to discover similarities between ceramic materials. The analysis of these samples was completed by performing a mineralogical analysis, textural observation, and by characterizing the porous system and the colour of the pieces. Our results enabled us to identify the source area of the clayey raw material in the surroundings of Basti and to estimate the firing temperature of the ceramics. Differences in the chemistry were confirmed by characteristics of the pastes and the mineralogical composition of the pieces. Some samples show black cores, which would suggest the presence of organic matter in the raw material and fast firing of the ceramics. The main types of temper were quartz grains and gneiss fragments, although carbonate grains were also identified. Our evidence suggests that most of the samples were well fired. New silicate phases were found to be present in several samples. The mercury intrusion porosimetry verified and confirmed the firing temperature of non‐carbonated samples. Colorimetry showed that the colour of the ceramics varied according to the amount of CaO that they contained.     

LEAD ISOTOPE ANALYSES OF ISLAMIC POTTERY GLAZES FROM FUSTAT,EGYPT*

Lead isotope analyses have been undertaken on a group of Islamic lead‐glazed pottery artefacts from Fustat, Egypt, spanning the period from the eighth to the 14th century ad , that had previously been the subject of a comprehensive typological, chronological, petrographic and technological study. Comparison of the lead isotope ratios for the glazes with those for lead ores from Egypt, Iran, Tunisia, Anatolia, Greece, Sardinia and Spain provided information on the possible sources of the lead used in the production of the glazes. The results show that the lead used in glaze production by the Islamic potters at Fustat was most probably obtained from distant ore sources in Iran or Tunisia, Sardinia, Spain and the Taurus Mountains. Different ore sources were favoured in different periods and, to a limited extent, for different types of pottery, but at no time did the Fustat potters use the potentially more accessible Egyptian ore sources.     

THERMOLUMINESCENCE AND STYLE IN THE AUTHENTICATION OF CERAMIC SCULPTURE FROM OAXACA,MEXICO

Oaxacan urns, the most characteristic esthetic expression of Zapotec culture in ancient Mesoamerica, are an important potential source of information for archaeologists and art historians, but relatively few exist with specific archaeological context and many are suspect as forgeries. This paper reports the thermoluminescent authenticity determinations of over one hundred Oaxacan urns as a first step toward confirmining a sequence previously determined by stylistic analysis. We tested a collection of 117 urns on loan to the St Louis Art Museum, mostly acquired after 1960, and another group of 6 from the Peabody Museum, Harvard, acquired before 1930. Our hypothesis that more recent collections would contain fewer forgeries was confirmed and a number of stylistic criteria for determining authenticity are critically examined in the light of the results.     

A FUNCTIONAL ANALYSIS OF MISSISSIPPIAN CERAMIC VESSELS FROM TOWN CREEK

Abstract

Vessel shape, size, and use-alterations are used to identify vessel types and vessel functions among Mississippian ceramics from the Town Creek site in central North Carolina. Possible functions are discussed for vessel types, and broad distinctions are made regarding vessels that possibly were used for cooking, serving and eating, or storage. The composition of the overall vessel assemblage at Town Creek indicates that it is generally comparable with other Mississippian assemblages. A consideration of the distribution of vessel types by context allows some insights into the association of different activities with different parts of the Mississippian community at Town Creek, namely, that the mound area was associated with distinctive vessel assemblages.     

PRE-COLUMBIAN METALLURGY: TECHNOLOGY,MANUFACTURE, AND MICROPROBE ANALYSES OF COPPER BELLS FROM THE GREATER SOUTHWEST*

Twenty-four cast copper crotals (commonly called bells), one 'spilled bell’, one tinkler bell and a number of minerals from locations throughout the Greater Southwest were analysed for their elemental composition by a PIXE nuclear microprobe at Los Alamos National Laboratory, New Mexico, USA. Sixteen bells contained minor and trace amounts of silver, antimony, arsenic, lead, and in some cases tin, strontium, and selenium. Nine bells contained little or no detectable amounts of these elements. This suggests that several workshops throughout the Greater Southwest and Mexico might have manufactured these bells.     

MOESSBAUER SPECTROSCOPIC,CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF IBERIAN POTTERY

Three types of Iberian pottery from the same excavation and archaeological level have been studied by Moessbauer spectroscopy, atomic absorption spectroscopy, X-ray diffraction, and transmitted-light polarizing microscopy. The results are compatible with a common origin, a firing temperature below 850 °C, and a different fabrication technique for each pottery type.     

INVESTIGATION ON ROMAN LEAD GLAZE FROM CANOSA: RESULTS OF CHEMICAL ANALYSES*

Five sherds of green glazed pottery excavated at Canosa (Apulia) in Italy have been analysed by scanning electron microscopy. The aim of the investigation was to determine the chemical composition of the glazes and thus obtain information on the methods used in their production. The glazes were all of the high‐lead type, coloured green by the addition of copper. Intermediate layers, observed at the interface between the glaze and body and giving the appearance of an applied white slip, were the result of the crystallization of lead feldspar from the molten glaze. Non‐calcareous clays were used in the production of the pottery bodies. Concentration profiles from the glaze exterior to the body suggested that the glazes were produced by applying a suspension consisting of lead oxide plus silica to the bodies. On the basis of the glaze and body compositions, it is suggested that the Canosa glazed pottery was produced locally.     

BYZANTINE CERAMIC PRODUCTION FROM CUMA (CAMPI FLEGREI,NAPOLI)*

Samples of table and cooking ware, dating back to the Byzantine period of the ancient Greek colony of Cuma, were analysed by optical microscopy, X‐ray diffraction, X‐ray fluorescence and scanning electron microscopy, in order to reconstruct the main technological properties of these manufactures. The comparison of minero‐petrographical data from these samples with those of some kiln wastes allowed us to hypothesize a local manufacture for most of the investigated specimens and to confirm the relative reference groups. A restricted number of samples did not link with the main groups, indicating a regional (or maybe extra‐regional) production, in agreement with the widespread circulation of this high‐medieval ceramic production in southern Italy.     

CHEMICAL AND MINERALOGICAL CHARACTERIZATION OF SASANIAN AND EARLY ISLAMIC GLAZED CERAMICS FROM THE DEH LURAN PLAIN,SOUTHWESTERN IRAN*

One hundred and seventy‐five glazed ceramics from Sasanian and Early Islamic period sites located on the Deh Luran Plain in southwestern Iran were examined by instrumental neutron activation analysis for characterizing differences in ceramic pastes and by laser‐ablation inductively coupled plasma mass‐spectrometry for identifying the constituents of the ceramic glazes. The results of the analysis reveal that alkaline‐based glazed ceramics have paste compositions that are distinct from contemporary and later ceramics decorated with alkaline–low‐lead and lead‐based glazes.     

MINERALOGICAL ANALYSIS OF SUDANESE NEOLITHIC CERAMICS

The archaeologist must often determine if ceramics having similar designs and forms but from widely separated locations were locally made or are the result of diffusion. This paper describes a methodology of technological analysis of ceramics utilised to solve such a problem. Results of a mineralogical analysis of ceramics and a discussion of the cultural implications of the results is presented. It is concluded that this methodology is an essential tool in distinguishing sites and elucidating relationships within the Sudanese Neolithic.     

THE ANALYSIS OF SECOND MILLENNIUM GLASS FROM EGYPT AND MESOPOTAMIA,PART 1: NEW WDS ANALYSES*

A recent analytical study by SEM–WDS was carried out on 226 glasses from the Late Bronze Age, analysing each of the glasses for a total of at least 22 elements, the largest such analytical study conducted on these glasses. The aim of the analysis was first to identify which elements were brought in with each of the raw materials and, second, to accurately characterize those raw materials. Since different glassmaking sites in Egypt and the Near East would probably use at least some local raw materials and these raw materials will vary slightly from site to site, this has potential for provenancing the glass. Analysis showed new patterns in the compositions of glass from the various sites and led to new conclusions about the supply of raw materials and personnel for the glass workshops. This forms the basis for further work by LA–ICPMS to be presented in part 2 of this paper.     

RAW MATERIALS OF GLASS FROM AMARNA AND IMPLICATIONS FOR THE ORIGINS OF EGYPTIAN GLASS*

Analysis has been conducted on 19 blue glasses from Amarna in Middle Egypt dated to around 1350 BC. The results suggest that these glasses fall into two distinct types: cobalt coloured glasses with a natron based alkali made from local Egyptian materials, and copper coloured glasses with a plant ash alkali, which follow a Mesopotamian tradition of glass making. It is suggested that at least some of this copper/plant ash glass is imported into Egypt during the Amarna period despite extensive local production of cobalt/natron glass. Existing analyses (Lilyquist and Brill 1995) of the earliest glass from the reign of Tuthmosis III (c. 1450 BC) suggest that during this period the same two types of glass are present. Local Egyptian cobalt and natron in these early glasses implies that, despite the lack of archaeological evidence for production sites, glass was produced from its raw materials in Egypt as early as the reign of Tuthmosis III.     

NEW ARCHAEOINTENSITY RESULTS FROM GREEK MATERIALS*

This paper reports palaeointensity results from Greek materials from EC and AD periods, recently obtained in the Sofia palaeomagnetic laboratory. The classical Thellier method was applied and of 26 specimens studied 20 gave acceptable results. The paper aims to compare the newly obtained results with previously published ones from Greece and neighbouring territories relating to the same period of time. The trend of palaeointensity obtained for the period 2900–1700 BC coincides well with the Bulgarian intensity variation curve, while the younger period, 1900–1200 BC, needs further investigation because of the contradictory results obtained by different authors. It is also established that the bricks from the church of Agios Ioannis are earlier than the date of the building's construction and are reused.