MODELLING CHANGES IN MOLLUSC SHELL INTERNAL MICROSTRUCTURE DURING FIRING: IMPLICATIONS FOR TEMPERATURE ESTIMATION IN SHELL‐BEARING POTTERY*

Firing experiments have been carried out on a clay containing naturally occurring fragments of mollusc shell. The transformation and/or decomposition of mineral phases with temperature was monitored by thermal analysis on the starting material and compared with X‐ray diffraction data on the fired specimens. Scanning electron microscopy revealed systematic changes in the internal microstructure of the shell fragments. Micrometer‐sized intra‐ and inter‐layer pores formed in the shells before the complete decomposition of calcite. The shape, dimension and location of the pores within the shell microstructure were found to be directly related to the firing temperature. The analysis of these microstructural features in archaeometric studies offers a good constraint on the estimation of the firing temperature in shell‐bearing pottery.     

GEOCHEMICAL ANALYSIS OF THE SEDIMENTS IN AND AROUND AN EARLY NEOLITHIC WELL NEAR BRODAU,GERMANY*

The discovery of wells of the linear pottery culture since 1990 has led to new insights on the ability and needs of humans at this time. The still small number of about 20 wells in Europe, compared to the much greater number of known settlements of this period, led to the assumption that they were built for special purposes, other than the water supply for the whole village. Investigations on the origin of archaeosediments of a more than 7000‐year‐old and 4.2 m deep well from the linear pottery culture in north‐west Saxony, Germany were carried out by geochemical analysis to improve our knowledge of the building, the usage and the decay of this wooden construction. Special emphasis was put on the material around two 10‐week‐old piglets that were intentionally deposited in the construction pit. Three major units—the sediment in the well, the infilling of the construction pit and the surrounding gravels—influenced by lateral transport of fine clay could be identified and described.     

GAUSSIAN CURVES FOR VISUALIZING CHRONOLOGICAL PATTERNS OF CERAMIC FINDS AND RESIDUALITY*

This paper describes a particular statistical approach to chronological data from assemblages of archaeological finds (namely pottery) using Gaussian curves: the method enables us to obtain a graphic representation of chronological patterns that avoids an excessive flattening of data, adding an extra dimension to the usual linear temporal concepts. This enables us to arrive at more likely absolute dating and also visualize residuality. The method has been built during the study of a stratigraphic context from the Site of Ancient Ships of Pisa – San Rossore, Italy, and applied to its pottery. Archaeologists may find in the model a useful tool that is easy to apply.     

STUDYING TECHNOLOGICAL PRACTICES AT A LOCAL LEVEL: NEUTRON ACTIVATION AND PETROGRAPHIC ANALYSES OF EARLY CERAMIC PERIOD POTTERY IN CENTRAL CHILE*

We discuss neutron activation and petrographic analyses of domestic ceramics and some raw materials from five archaeological sites in the Valdivia de Paine locality, in Central Chile. During the time period studied, the area was occupied by small‐scale horticultural groups with disperse and sedentary or semi‐sedentary settlement patterns. The analyses indicate that diverse local raw material sources were used in pottery production, and shared by members of different co‐residential units and between different cultural groups. The data indicate as many similarities as differences among the technological practices of pottery‐producing groups who lived in spatial proximity. The results have implications for the understanding of pottery‐producing communities at a local level, as well as small‐scale groups in general.     

Trude Dothan (1922–2016): In Memoriam

Abstract

This paper sheds new light on the most common type of pottery associated with advanced phases of Early Bronze I (EB I) in the southern Jordan valley: the distinctive family or group known as Um Hammad Ware, or Proto-Urban D (PUD) Ware. To date, this kind of pottery was thought to be concentrated mostly around the site of Tell Um Hammad. This study presents new evidence suggesting that this ware was dispersed over a region considerably wider than previously understood, and that the centre of its manufacture was probably in the region of western Wadi Far'ah. This paper also explores the possibility that the origins of this family are to be found in the pottery traditions of the Golan region during the Chalcolithic period.     

Bitumen in Early Ceramic Art: Bitumen‐Painted Ceramics From Late Neolithic Tell Sabi Abyad (Syria)*

The paper presents the results of a chemical analysis of black pigment used to decorate pottery from Late Neolithic Tell Sabi Abyad, northern Syria (c. 6100 cal bc ). The pigment appears to be bitumen. A comparison with known reference samples from modern locations of bituminous sources in the Near East suggests that the bitumen used to paint ceramics at Tell Sabi Abyad came from at least two different source areas in northern Iraq. The bitumen‐painted ceramics at Tell Sabi Abyad represent the earliest evidence attested so far of bitumen used as a pigment for pottery decoration.     

The Preservation and Identification of Piñon Resins by GC‐MS in Pottery from the Western Great Basin

Gas chromatography — mass spectrometry analysis of a sherd from the Nevada Test Site revealed a high quantity of terpenes, including sesquiterpenoids and diterpenoids, demonstrating that piñon resins were prepared in the pot in prehistoric times. The presence of these biomarkers allowed for a very specific identification of the products prepared in the pot, a level of detail not often achieved in lipid residue analysis. That the terpenes are relatively unoxidized demonstrates that they are quite stable over long periods of time. The study also shows that sherds on the surface of archaeological sites can preserve lipids and terpenes and are amenable to organic residue analysis.     

AN ARCHAEOMAGNETIC STUDY OF POTTERY KILNS FROM BRÜHL-PINGSDORF (GERMANY)*

Four pottery kilns from Brühl-Pingsdorf (Germany) were dated by comparing their characteristic remanent magnetization with a curve of the palaeo-secular variation of the geomagnetic field. Archaeomagnetic results suggest last heating events between AD 775 and 1020. The archaeological evidence generally supports the relative temporal succession and the duration of use, but indicates that the kilns are about 150 years younger on average. Hence, a systematic offset between these independently developed chronologies must be considered. Rock magnetic parameters display radial variations through the kiln walls. These variations are controlled by the maximum temperature the rock was exposed to. These parameters were used to identify specimen which acquired a thermoremanent magnetization.     

CHEMISTRY VERSUS DATA DISPERSION: IS THERE A BETTER WAY TO ASSESS AND INTERPRET ARCHAEOMETRIC DATA?

Given the common use of chemical concentration data to define ceramic groups that aid in the exploration of ancient technology, trade and provenance, it is important to reflect on how we collectively establish and define both chemical groups and outliers. In this paper, we argue that commonly used data analysis procedures, such as principal component analysis and centred log‐ratio principal component analysis favoured in the examination of ceramic chemical data, although rapid and easy, may overlook existing chemical groups and outliers, especially when the ratio of non‐diagnostic to diagnostic elements is high. To evaluate whether geochemistry is more important than data dispersion in data assessment, we re‐examine chemical concentration data from previously published ceramic, clay and daub samples from the lower Ohio River Valley. We begin by briefly discussing steps we took to ensure that the data set reflects geochemical differences, rather than analytical or data transfer errors. Next, we use bivariate plots, as well as PCA and CLR–PCA, to examine different versions of our altered data, using varying numbers of element combinations. We propose that the careful examination of bivariate plots is critical in establishing the elements that should be included in PCA and other multivariate analyses.     

PROVENANCE DETERMINATION OF MYCENAEAN IIIC VESSELS FROM THE 1934–1939 EXCAVATIONS AT TARSUS‐GÖZLÜKULE BY NEUTRON ACTIVATION ANALYSIS

Neutron Activation Analysis (NAA) has been carried out in order to determine the provenance of a selected set of 30 sherds of Mycenaean style excavated at Tarsus‐Gözlükule. The provenance could be established or made feasible in 80% of the samples. The results confirm the current status of research, namely that in the LH IIIC phase trade patterns changed and Mycenaean wares, which used to be exported to the Near East, were now produced locally. At Tarsus, the LH IIIC imports came from Cyprus and the eastern Aegean.