THE HISTORY OF THE LAWRENCE BERKELEY NATIONAL LABORATORY INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS PROGRAMME FOR ARCHAEOLOGICAL AND GEOLOGICAL MATERIALS

The Lawrence Berkeley National Laboratory pottery provenance group developed standards and instrumental neutron activation analysis (INAA) methods that are used at many archaeometry laboratories around the world. The background and development of ‘Standard Pottery’ and of methods for INAA are described. Early pottery provenance studies are described, and other research programmes, involving obsidian and magmatic mixing, the origin of the stone used for the Colossi of Memnon, and the ‘Plate of Brass’, are mentioned. Research work by the Laboratory included the discovery of the world‐wide iridium anomaly and extensive subsequent research on what has come to be known as the ‘Asteroid Impact Theory’. Characteristics of the analytical programme for pottery provenance work, including overall aims, precision and accuracy, intercalibration, and irradiation and measurement protocols, are discussed. New research areas developed in the past 15 years, to broaden the usefulness of chemical compositional data for archaeological investigation, and examples of recent work, are described. This research, which makes use of high‐precision X‐ray fluorescence analysis in addition to INAA measurements on sample splits, includes distinguishing the products of different workshops located at the same production site, studies on the significance of the distribution of silver in archaeological pottery and the use of high‐precision chemical compositional data as an aid for making chronological distinctions.     

THE CHARACTERIZATION OF PAINTS AND WATERPROOFING MATERIALS FROM THE SHIPWRECKS FOUND AT THE ARCHAEOLOGICAL SITE OF THE ETRUSCAN AND ROMAN HARBOUR OF PISA (ITALY)*

This work presents the results of a diagnostic survey on the shipwrecks from the archaeological site of the ancient harbour of San Rossore (Pisa, Italy). The original waterproofing, caulking and painting materials were characterized by Fourier transform infrared spectroscopy (FTIR), gas chromatography – mass spectrometry (GC–MS), energy‐dispersive X‐ray microanalysis (EDX) and X‐ray diffraction (XRD). The major constituents of the waterproofing and caulking materials detected on the planks were tricyclic abietanes showing a high degree of aromatization. These compounds are indicative of a pitch obtained from the wood of trees of the Pinaceae family. The analysis of the organic components of the paint samples revealed diterpenoid acids characteristic of Pinaceae resins together with linear long‐chain alcohols and fatty acids, highlighting the presence of beeswax. Noticeably, the characteristic odd carbon number alkanes that are normally present in beeswax were not detected. The EDX and XRD analyses showed that hematite, calcite, cerussite and kaolinite were employed as pigments to paint the ships’ hulls.     

MATCHING PAST AND PRESENT CERAMIC PRODUCTION IN THE BANDA AREA (GHANA): IMPROVING THE ANALYTICAL PERFORMANCE OF NEUTRON ACTIVATION ANALYSIS IN ARCHAEOLOGY USING MULTIVARIATE ANALYSIS TECHNIQUES*

The transfer of advances in chemometrics into archaeometric research opens up a wide range of new application possibilities in this rapidly developing field. Neutron activation analysis (NAA) of ceramic samples from the Banda Traditional Area (west‐central Ghana) combined with chemometrics allowed us to establish a link between current and ancient systems of ceramics production in the historic settlements of Kuulo Kataa and Makala Kataa. Principal component analysis (PCA) and the soft independent modelling of class analogy (SIMCA) method were applied to the Das Dores Cruz data set in order to unequivocally determine the geographical origin of the diverse archaeological samples. After global autoscaling pretreatment, PCA analysis showed a clear difference between samples from different locations. The classification models obtained by SIMCA showed a classification ability of 100% and a prediction ability of 97.7%, with a mean sensitivity of 84% and a specificity of 100% for the three categories. The application of SIMCA showed that some NAA variables (elements) were more important than others in terms of geographical classification. With the class models that we obtained, we were able to determine the origin of the ancient remains. SIMCA has proved to be a powerful technique for the class modelling of archaeological data.     

PINE RESINS AND POTTERY SEALING: ANALYSIS OF ABSORBED AND VISIBLE POTTERY RESIDUES FROM CENTRAL NEW YORK STATE*

Analysis was performed on absorbed and visible residues from 21 New York State prehistoric pottery sherds dating from 2905 ± 35 bp (Intcal04) (1256–998 cal bc ) to 425 ± 40 bp (Intcal04) (1417–1626 cal ad ). The use of pine resin was detected in 10 of 12 absorbed residue samples and 11 of 17 sherds subjected to visible residue analysis. It seems likely that the pots were resin‐sealed to make them more impermeable, constituting the first chemical evidence of extensive resin‐sealing in North America. A comparison of the results of absorbed and visible residues from eight of the sherds indicates that the two kinds of residue provide complementary evidence of vessel use.     

ASSESSING NATURAL CLAY COMPOSITION IN THE VALLEY OF OAXACA AS A BASIS FOR CERAMIC PROVENANCE STUDIES

The Oaxaca Clay Survey was initiated to provide baseline data on clay composition within the Valley of Oaxaca, Mexico, to assist in provenance determination of prehistoric ceramics. Natural clays were sampled from 135 locations throughout the valley, and analysed using INAA in combination with ceramic petrography. Observed geographical trends in trace‐element and mineralogical composition confirm that while parent material (surficial geology) strongly affects clay composition, a continuum of variation exists within the valley. The study develops and tests a continuous spatial model of clay composition that provides greater resolution in ceramic sourcing than bedrock alone. By establishing a regional framework for Oaxaca Valley clays, the survey will support significant advances in our understanding of pottery production and exchange within the valley, and provide a more robust means for monitoring exchange between the valley and neighbouring regions.     

X-RAY MICROANALYSIS OF ANCIENT GLASSY MATERIALS: A COMPARATIVE STUDY OF WAVELENGTH DISPERSIVE AND ENERGY DISPERSIVE TECHNIQUES*

Sensitivity, precision and accuracy of quantitative microanalysis of major, minor and trace elements present in ancient glasses by energy dispersive spectrometry (EDS) is compared to that by wavelength dispersive spectrometry (WDS). Although there are certain problems with EDS due to peak overlaps and background noise, the precision and minimum detection limits of EDS for most of the important elements in ancient glasses were found to compare favourably to those of WDS. Both EDS and WDS, when quantified by comparison to glass standards, can produce reliable results which are adequate for most technological questions.     

PLAIN POTTERY AND SOCIAL LANDSCAPES: REINTERPRETING THE SIGNIFICANCE OF CERAMIC PROVENANCE IN THE NEOLITHIC

This paper focuses on plain, stylistically unvaried pottery from three Late Neolithic sites from the Mondego Plateau, Portugal, and investigates ceramic production and exchange among small‐scale prehistoric societies by means of thin‐section petrography and chemical analysis (INAA). The results show that the majority of the pottery was made with widely available, granite‐derived sedimentary clays, but petrographic differences between fabrics indicate collection at multiple locations within these deposits. Variation in chemical composition is consistent with site‐specific sourcing areas, while comparison with data from earlier sites in the Mondego and surrounding mountains suggests that such sources were geographically restricted within the plateau. In contrast, the small percentage of vessels produced with residual clays of metamorphic and intermediate igneous origin, which outcrop over 10 km and 30 km from the archaeological sites, demonstrates that plain pottery did circulate during the Neolithic beyond the funerary sphere. This is the product of the routines of mobility and social networks of Neolithic groups across the wider landscape, which involved the exchange of ‘mundane’ vessels. Finally, the study demonstrates that micro‐regional provenance studies can provide significant insights into prehistoric social landscapes if the data are interrogated beyond simplistic classifications of local and non‐local.     

IN‐SITU ELEMENTAL AND Sr ISOTOPE INVESTIGATION OF HUMAN TOOTH ENAMEL BY LASER ABLATION‐(MC)‐ICP‐MS: SUCCESSES AND PITFALLS*

Trace element and Sr isotope data were obtained by laser ablation‐ and solution mode‐(MC)‐ICP‐MS analysis for tooth enamel from remains excavated at the New Kingdom period Egyptian colonial and Nubian cemetery site of Tombos (Sudan). Elemental abundances determined by both methods of ICP‐MS analysis yielded comparable values; however, ⁸⁷Sr/⁸⁶Sr values obtained by laser ablation were higher compared to their solution mode counterparts. This discrepancy is related to the production of a molecular interference—Ca + P + O (overlaps ⁸⁷Sr); hence the higher ⁸⁷Sr/⁸⁶Sr values recorded during ablation analyses. Laser ablation studies of enamel may provide relatively precise ⁸⁷Sr/⁸⁶Sr values rather quickly but cannot be used for accurately deciphering historical population migrations.     

MOLECULAR AND ISOTOPIC DEMONSTRATION OF THE PROCESSING OF AQUATIC PRODUCTS IN NORTHERN EUROPEAN PREHISTORIC POTTERY*

A number of charred surface residues, adhering to ceramic containers, were obtained from various coastal and inland sites in north‐west Europe dating from the sixth to the fourth millennium cal bc . In order to investigate the use of these vessels and in particular to identify any marine products, the residues were subjected to carbon and nitrogen stable isotope analysis. Variation in carbon isotope ratios between different samples indicated that some vessels may have been used to process marine products. This analysis was corroborated by specific identification of aquatic products following structural and isotopic characterization of lipids extracted from selected samples.     

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.     

CAMPANIAN POTTERY FROM ANCIENT BRUTTIUM (SOUTHERN ITALY): SCIENTIFIC ANALYSIS OF LOCAL AND IMPORTED PRODUCTS*

One hundred and fifty-seven sherds of Campanian pottery were analysed by inductively coupled plasma optical emission spectroscopy (ICP-OES) and flame emission spectroscopy (FES). The sherds were found in the course of archaeological excavations carried out at the sites of Sibari, Cosenza, Crotone, Locri, Reggio and Oppido Mamertina in southern Italy (ancient Bruttium, today Calabria). Analyses were carried out on dissolved samples, determining 15 elements per sample (Al, Fe, Ca, Mg, Ti, Mn, Sr, Ba, Cr, Cu, Y, La and Sc by ICP-OES, and Na and K by FES). Analytical data were subject to multivariate statistical treatment by hierarchical cluster analysis and principal components analysis. Results indicated different compositional groups, allowing one to separate suspected imports from Campania, Etruria and Sicily from each other and from likely local products. The latter could be further classified into different groups, comprising imitations of foreign forms as well as original local products.     

THE PETROGRAPHY AND CHEMISTRY OF THIN‐WALLED WARE FROM AN HELLENISTIC– ROMAN SITE AT SEGESTA (SICILY)*

Samples of Roman thin‐walled ware from Segesta (northwestern Sicily), dating back to the early Imperial period, were studied by optical microscopy (OM) and Neutron Activation Analysis (NAA). Up to now, this class of Roman fine tableware has only occasionally been evaluated archaeometrically. Nevertheless, numerous production centres are believed to have been simultaneously active in the western Mediterranean area. Petrographic and chemical data seem to be in agreement with the archaeological hypothesis of local manufacture in Segesta for most of the analysed samples, through a comparison with kiln wasters and local raw materials. The effectiveness of thin‐section petrography for determining the provenance of such a tiny tempered class of pottery and the integrated use of two different grouping procedures (petrography and chemistry) were also tested.     

EXPERIMENTAL EVIDENCE FOR THE PROCESSING OF MARINE ANIMAL PRODUCTS AND OTHER COMMODITIES CONTAINING POLYUNSATURATED FATTY ACIDS IN POTTERY VESSELS*

ω‐(o‐Alkylphenyl)alkanoic acids are known to form in vitro from triunsaturated fatty acids following protracted heating. These compounds have recently been identified in absorbed lipid extracts obtained from archaeological pottery vessels, providing a potentially valuable new class of indicator for the processing of commodities, such as marine oils, which contain high abundances of polyunsaturated fatty acids. Experiments were conducted to assess whether ω‐(o‐alkylphenyl)alkanoic acids form when pure compounds and complex triacylglycerol mixtures are heated with a fired clay. The results demonstrate that ω‐(o‐alkylphenyl)alkanoic acids are only produced following heating of unsaturated fatty acids (tri‐, di‐ and monounsaturated species) or complex unsaturated fatty acyl lipids at around 270°C. Heating saturated fatty acyl lipids does not yield ω‐(o‐alkylphenyl)alkanoic acids. Thus, when searching for evidence for the processing of marine derived animal fats in archaeological pottery vessels, it is essential that: ω‐(o‐alkylphenyl)alkanoic acids of carbon length C₁₈ and C₂₀ should be present, ideally with C₂₂ also detectable (if only in trace abundances), together with at least one of the three isoprenoid fatty acids (phytanic, pristanic or 4,8,12‐tetramethyltridecanoic acid).     

SAND FOR ROMAN GLASS PRODUCTION: AN EXPERIMENTAL AND PHILOLOGICAL STUDY ON SOURCE OF SUPPLY*

This paper reports the results of an experimental study performed on Campanian littoral sand, together with a careful philological analysis of Pliny's text concerning the production of glass using the above sand in order to verify its suitability. Accurate chemical and mineralogical characterization of sand samples and experimental glasses was carried out, proving the unsuitability of sand for glass production in its original state. Taking into account both the results of the philological analysis of Pliny's text and the mineralogical assemblage of the sand, a new hypothesis regarding Roman glass‐making technology is proposed and tested here. The technology implies the production of ‘quartz‐enriched’ sand by means of selective grindings according to the different degrees of hardness and cleavage of the mineralogical phases. Melting experiments, carried out on treated sand and in the temperature range compatible with Roman technology, yielded a glass with composition similar to those of typical Roman glasses. Therefore, new perspectives on the sources of supply of raw materials, hitherto debated, are opened up.     

A STUDY OF CHINESE PORCELAIN RAW MATERIALS FOR DING,XING, GONGXIAN AND DEHUA WARES*

The raw material used largely determines the type and quality of porcelain produced. Twenty-three raw materials used for making Ding, Xing, Gongxian and Dehua porcelain bodies were studied using principal component analysis. Results show that for Dehua wares, only one raw material was used. For Ding wares, although there were many possible raw materials, the use of one alone is unlikely. Lingshan clay was the main raw material but it has to be mixed with other raw materials: Pinjiawa clay, quartz, feldspar and dolomite. The Xing pieces can be divided into three groups and Gongxian wares into two groups, which are discussed in detail.     

PETROGRAPHY AND PROVENANCE INTERPRETATION OF THE STONE MOULDS FOR BRONZE DAGGERS FROM THE GALDONG PREHISTORIC SITE, REPUBLIC OF KOREA*

This paper presents material characteristics and raw material provenance of the stone moulds for bronze slender daggers from Galdong. This type of bronze dagger is uniquely distributed in the Korean Peninsula and these stone moulds were the first to be found by excavation. The stone moulds were made of igneous hornblendite with course-grained holocrystalline textures. Based on petrological, mineralogical and geochemical characteristics, the original rock materials of the moulds were inferred to be derived from the Jangsu or Namwon areas which are about 50 km away from the excavation site. It is a notable achievement that this provenance study confirmed the domestic production of Korean-styled daggers.     

NON‐DESTRUCTIVE SOURCING OF BRONZE AGE NEAR EASTERN OBSIDIAN ARTEFACTS: REDEVELOPING AND REASSESSING ELECTRON MICROPROBE ANALYSIS FOR OBSIDIAN SOURCING*

Despite predictions in the 1980s that electron microprobe analysis (EMPA) would become a popular technique for obsidian sourcing, few studies have used it with this goal, and most of them are now outdated and unrepresentative of modern EMPA. For example, Merrick and Brown (1984 ) recorded their data on punch cards. Furthermore, these studies destructively prepared artefacts for analysis. The research at hand endeavoured: (1) to establish the modern capabilities of EMPA for obsidian sourcing; and (2) to develop and evaluate procedures for non‐destructive artefact analysis. Issues such as diagenetic effects and compatibility with NAA and XRF data were also investigated.     

THE SECTILIA PANELS OF FARAGOLA (ASCOLI SATRIANO,SOUTHERN ITALY): A MULTI‐ANALYTICAL STUDY OF THE RED,ORANGE AND YELLOW GLASS SLABS*

SEM–EDS, EMPA, ICP–MS and ICP–OES were applied to the study of three sectilia panels made of red, orange and yellow glass slabs. In order to determine the chemical state of Cu, XAS was also performed. The results indicate that, with the exception of the red samples, all slabs were made by mixing a siliceous sand with natron. The red slabs show significant compositional differences with respect to K₂O and MgO contents, probably linked to the use of plant ashes as a source of alkali. The red, orange and yellow slabs are coloured by metallic copper, cuprite and Pb antimonates, respectively. The comparison between the chemical composition of the Faragola samples and several glass reference groups did not provide conclusive evidence of provenance.     

AN EVALUATION OF ANALYTICAL AND INTERPRETATIVE METHODOLOGIES FOR THE EXTRACTION AND IDENTIFICATION OF LIPIDS ASSOCIATED WITH POTTERY SHERDS FROM THE SITE OF SAGALASSOS,TURKEY*

Three lipid analysis methods were applied to extracts of archaeological potsherds from the ancient city of Sagalassos, south‐west Turkey. In the fatty acid methyl ester fraction, obtained by selective transesterification of acylglycerols, the ratio of methyl palmitate to methyl stearate was determined. Secondly, by means of gas chromatography– combustion–isotope ratio mass spectrometry (GC–C–IRMS), stable carbon isotope ratios were measured for the same methyl esters. Finally, triglyceride composition was determined via high‐performance liquid chromatography–mass spectrometry (HPLC–MS). All three methods can be used to trace the origin of animal fat. Agreement between them is reasonable, especially in recognizing ruminant adipose fat. One sample was found to be of dairy origin using both GC–C–IRMS and HPLC–MS. The advantages of the various methods are discussed. Variations in lipid composition were observed between samples from different periods and excavated in diverse areas within the city of Sagalassos.     

UNOFFICIAL COINAGE IN THE THIRD CENTURY ad IN THE GALLO‐ROMAN WORLD: CHEMICAL AND PHYSICAL ANALYSES FOR DETERMINING THE LOCALIZATION OF THE WORKSHOP*

The third century ad was a complex period of crisis in the Roman world. In this paper, official and unofficial antoniniani, and double sestercii and sestercii, were analysed by fast neutron activation analysis (FNAA) to determine the alloys used by the craftsmen for producing forgeries. Moreover, at Châteaubleau, archaeologists discovered antoniniani and bronze forgeries from Postumus. Similar materials have been found in other hoards. They are believed to have been produced by a workshop called ‘atelier II’ by numismatists. The question was whether it is possible to differentiate the Châteaubleau production from the atelier II production.