HISPANO-MORESQUE POTTERY PRODUCTION OF THE FOURTEENTH-CENTURY WORKSHOP OF TESTAR DEL MOLÍ (PATERNA,SPAIN)

Excavation of Testar del Molí, the only workshop found in the Manises-Paterna area, revealed the existence of a fourteenth-century ceramic workshop covering the remains of the thirteenth-century workshop. This study is concerned with the fourteenth-century production, and forthcoming papers will connect both epochs following the findings of current excavations. The chemical and mineralogical characterization of the ceramic production of this workshop shows the presence of three groups of ceramic pastes which could also be distinguished by, and, thus, related to, their daily use. The raw materials found in the excavation have also been mineralogically and chemically characterized, and a model of possible mixtures of raw materials has also been developed in order to determine their possible use in the manufacture of the pottery previously characterized.     

TECHNOLOGY AND COLOUR DEVELOPMENT OF HISPANO-MORESQUE LEAD-GLAZED POTTERY

Lead-glazed pottery from the medieval workshop of Les Olleries Majors (Paterna, Spain) has been studied by Mössbauer spectroscopy, X-ray diffraction, X-ray fluorescence and optical spectroscopy. Yellow, brown and honey-coloured glazes occur on pots glazed on only one surface. They have virtually identical compositions and transmittance spectra, their apparent differences in colour are due to the colours of the underlying pastes. Yellow glazes occur on cream-coloured calcareous bodies, honey-coloured glazes occur on less calcareous bodies with some development of hematite, while brown glazes occur on red siliceous cooking-pots. Green glazes are found on pots glazed on both surfaces; the glazes trapped CO₂ evolved by decomposing carbonates, resulting in an internal reducing environment. This caused the reduction of iron to the ferrous state which coloured the glaze green by diffusion.     

ANOMALOUS CARBON-13 VALUES FOR FIBRE TEMPER IN CERAMICS*

Ceramic vessels from Later Stone Age sites in the Seacow river valley, South Africa, were heavily tempered with C4 grasses. However, most δ¹³C values of the temper fall between the known δ¹³C ranges for C4 and C3 grasses. Among possible C3 additives that could skew the signal, ground bone, animal dung, alpine grass, Karoo scrub ash, and humic acid contamination are eliminated. The sherd surfaces yield fatty chars with C3-like values. Although these are not enough to account for all the skewing, they represent only the final cooking event. They were preceded by many such events in which fat was absorbed into the C4 grass then charred to soot by later periods in the fire. Thus organic carbon with the isotope composition of the fat built up while the vessel remained in use.     

HOW MANY POTS MAKE FIVE?—AN HISTORICAL REVIEW OF POTTERY QUANTIFICATION

This paper reviews the ways in which assemblages of pottery have been quantified throughout the twentieth century, and the use to which such data have been put. The values of various ways of quantifying pottery are compared, and a theoretical basis for the comparison of assemblages is described. Finally, the practical steps that need to be taken to make best use of the theory are set out.     

ARCHAEOMETRY AT SLOWPOKE‐TORONTO

This paper describes the archaeometric research conducted at the SLOWPOKE Reactor Facility of the University of Toronto (SLOWPOKE‐Toronto) during its existence from 1971 to 1998. The contributions to student teaching and research are described, and the total contribution of the facility to studies of an eclectic assortment of ancient and historic materials is addressed.     

CALCAREOUS MICROFOSSILS IN BRONZE AGE AEGEAN CERAMICS: ILLUMINATING TECHNOLOGY AND PROVENANCE*

The calcareous skeletal remains of various microscopic organisms such as foraminifera and ostracods are a striking feature of thin sections of many archaeological ceramics from the Aegean Bronze Age. While the presence of these calcareous microfossils in pottery has been noted for some time, attempts to utilize them to further the aims of ceramic compositional analysis have been few in number. In the following paper, we take a first detailed look at the occurrence and utility of calcareous microfossils in archaeological ceramics. By presenting selected case studies from the Bronze Age of Crete, we demonstrate the potential of calcareous microfossils, especially the extremely small ‘nannofossils’ and the highly contextual geological information that they contain, in terms of the characterization and grouping of ceramics, the determination of their provenance and the reconstruction of ancient technology.     

THE PROVENANCE AND TECHNOLOGY OF NEAR EASTERN GLASS: OXYGEN ISOTOPES BY LASER FLUORINATION AS A COMPLEMENT TO STRONTIUM*

The ability to make rapid measurements on small samples using laser fluorination enhances the potential of oxygen isotopes in the investigation of early inorganic materials and technologies. δ¹⁸O and ⁸⁷Sr/⁸⁶Sr values are presented for glass from two primary production sites, four secondary production sites and a consumer site in the Near East, dating from Late Antiquity to the medieval period. δ¹⁸O is in general slightly less effective than ⁸⁷Sr/⁸⁶Sr in discriminating between sources, as the spread of measured values from a single source is somewhat broader relative to the available range. However, while ⁸⁷Sr/⁸⁶Sr is derived predominantly from either the lime‐bearing fraction of the glass‐making sand or the plant ash used as a source of alkali, δ¹⁸O derives mainly from the silica. Thus the two measurements can provide complementary information. A comparison of δ¹⁸O for late Roman – Islamic glasses made on the coast of Syria–Palestine with those of previously analysed glasses from Roman Europe suggests that the European glasses are relatively enriched in ¹⁸O. This appears to contradict the view that most Roman glass was made using Levantine sand and possible interpretations are discussed.     

Chemical characterization of ancient pottery from sudan by x‐ray fluorescence spectrometry (xrf), electron microprobe analyses (empa) and inductively coupled plasma mass spectrometry (ICP–MS)*

Sixty‐four sherds and seven natural clays from prehistoric sites in northwestern Sudan have been submitted to petrological and chemical analysis using XRF spectrometry, EMPA and ICP–MS. According to their texture, the sherds form five different groups. The high contents of P₂O₅ (more than 0.5 wt%) discerned in 19 samples and the variation of the P₂O₅ content in two samples of the same vessel can be explained by post‐depositional processes or by the ancient organic contents (e.g., milk) of the vessel. Chemical classification of the pottery bulk suggests that vessels were made locally, as only sherds from the same area show homogeneity of data.     

ON STATISTICAL APPROACHES TO THE STUDY OF CERAMIC ARTEFACTS USING GEOCHEMICAL AND PETROGRAPHIC DATA*

The scientific analysis of ceramics often has the aim of identifying groups of similar artefacts. Much published work focuses on analysis of data derived from geochemical or mineralogical techniques. The former is more likely to be subjected to quantitative statistical analysis. This paper examines some approaches to the statistical analysis of data arising from both kinds of techniques, including ‘mixed‐mode’ methods where both types of data are incorporated into analysis. The approaches are illustrated using data derived from 88 Late Bronze Age transport jars from Kommos, Crete. Results suggest that the mixed‐mode approach can provide additional insight into the data.     

ON THE USE OF COLOUR COORDINATES TO EVALUATE FIRING TEMPERATURES OF ANCIENT POTTERY*

Colour measurement was investigated as a means to evaluate equivalent firing temperatures of ancient pottery. Colour coordinates were determined on samples of six clays previously fired, and then refired, in the temperature range 600–1100°C. Under the adopted conditions, significant variations of colour hue and saturation were normally observed on refired samples only after the original firing temperature had been exceeded; less reliable information was provided by luminosity. Original firing temperatures of clay samples were correctly recognized in most cases by projecting the points representing samples’ colour on to the a*b* plane of the ClEL*a*b* colour space.