MEASURING CHRONOLOGICAL UNCERTAINTY IN INTENSIVE SURVEY FINDS: A CASE STUDY FROM ANTIKYTHERA,GREECE*

This paper considers how to make the most out of the rather imprecise chronological knowledge that we often have about the past. We focus here on the relative dating of artefacts during archaeological fieldwork, with particular emphasis on new ways to express and analyse chronological uncertainty. A probabilistic method for assigning artefacts to particular chronological periods is advocated and implemented for a large pottery data set from an intensive survey of the Greek island of Antikythera. We also highlight several statistical methods for exploring how uncertainty is shared amongst different periods in this data set and how these observed associations can prompt more sensitive interpretations of landscape‐scale patterns. The concluding discussion re‐emphasizes why these issues are relevant to wider methodological debates in archaeological field practice.     

LUSTRE-DECORATED CERAMICS FROM A 15TH TO 16TH CENTURY PRODUCTION IN SEVILLE*

A set of 17 fragments of ceramics have been uncovered on the occasion of excavations of a workshop in Triana near Seville. These ceramics are typical of objects that are not commonly encountered in present collections in spite of intensive production during the 15th–16th centuries. Chemical and mineralogical analyses have been performed using various techniques (X-ray fluorescence and diffraction, SEM, ion beam analyses). The majority of the ceramic sherds represent the diversity of the Seville production; three fragments recovered in the same archaeological context were not locally produced and belong to the production of eastern Spain (Valence area). The ceramic bodies of the Seville sherds are compatible with the use of clays from the Guadalquivir valley. The glaze and the lustre decoration are comparable to those produced in eastern Spain. These conclusions are based on data that represent the production of a single workshop in Seville; the scatter of the data is due to variations in the processing and/or to alterations during the five centuries of burial of the ceramic fragments.     

A NEW SETTING FOR THE NORTHERN BORDER OF THE VENETI: METALLIC FINDS FROM THE VENETIC SITE OF MONTE CALVARIO,AURONZO DI CADORE*

In 2000 several bronze and lead objects were discovered at the Venetic‐Roman site (200 bc –ad 200) of Monte Calvario di Auronzo, in the Italian eastern Alps. They were mostly finished artefacts plus semi‐worked products. Analysis included SEM–EDS, EMPA, XRPD, TMS and AMS spectrometry. The compositional results of the finished artefacts suggest that the choice of the alloy had been made according to the decorative techniques to be used. A semi‐worked high‐leaded bronze object indicates the existence of a metallurgical production of cast artefacts at the site. TMS analyses of a lead ingot exclude local provenance, proving the existence of important trade routes.     

TECHNOLOGY AND PROVENANCE OF A COLLECTION OF ISLAMIC COPPER‐BASED OBJECTS AS FOUND BY CHEMICAL AND LEAD ISOTOPE ANALYSIS*

Chemical and lead isotope analyses were utilized to determine the composition, technology and origin of a collection of Islamic copper‐based objects found in Jordan. The atomic absorption spectrometry results show that the objects were made of different types of copper‐base alloys that contain various amounts of zinc, tin and lead. The use of brass, highly leaded brass and quaternary alloys of Cu‐Zn‐Sn‐Pb in the manufacture of everyday, household objects strongly points to Islamic traditions. The lead isotope compositions of the objects match very well that of the copper ore mined from the Dolomite‐Limestone‐Shale unit of the Arabah copper mines.     

THE ESTABLISHMENT OF A DATA BASE OF NEUTRON ACTIVATION ANALYSES OF WHITE MARBLE*

The establishment of a data base of trace element analysis results obtained by neutron activation analysis of 183 marble samples, each weighing about 200 mg, from eight different quarrying localities for use in provenance studies is described and a summary of the results presented. The problems of sampling museum artefacts are discussed, and details of tests of the reproducibility of the technique are given together with those obtained from multiple-samples from single museum objects. Replicate analyses of a marble standard are also discussed. Thus these data are a measure of the accuracy and precision of the technique, as well as allowing an assessment of the variation in trace element composition within quarry sources and single blocks of marble, as used for artefacts.     

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.     

THE CHEMICAL ANALYSIS OF ORIENTAL CERAMIC BODY COMPOSITIONS: PART 1: WARES FROM NORTH CHINA*

This paper presents the body analyses of 70 sherds of ceramics made in north China during the Late Tang and Northern Song dynasties (c. AD 80–1200). The major types represented are Ding, Xing and Cizhou-type wares. The analyses were obtained by atomic absorption spectrometry, giving information on nine major and minor constituents. These have been used to differentiate chemically between the major kiln sites in the north, with the aid of multivariate computer analysis. This has demonstrated that there are differing chemical characteristics associated with these kilns, but the study is hampered by the lack of authentic material from controlled excavations of the kiln sites.     

THE ELEMENTAL COMPOSITION OF BENIN MEMORIAL HEADS*

Among the Nigerian cast copper‐alloy artefacts, the chronology of the Benin memorial heads has been the most fully worked out. Therefore, a study focused upon their elemental compositions is particularly likely to be interpretable in terms of development of the alloys used in their making. The elemental analyses, both published and unpublished, of 66 Benin heads, supplemented with seven analyses of some artefacts excavated from a well‐dated, very early Benin site, have been collected, analysed statistically and computed to the elemental analyses of 11 heads and figures from Udo. All but a very few of the Benin heads and artefacts separate into five compositional groups, indicating a chronological sequence of different alloying traditions. All but one of the Udo objects fall into a distinctly separate compositional group, together with two Medicine heads. The compositional groups correlate remarkably well with the stylistic types proposed by Dark.     

PROVENANCE STUDY OF MARBLE ARTEFACTS FROM THE ROMAN BURIAL AREA OF FASCHENDORF (CARINTHIA,AUSTRIA)*

Numerous marble artefacts were among the extraordinary findings excavated at the Roman burial area of Faschendorf (Carinthia, Austria). The provenance of marble objects, particularly in the Roman provinces, is mostly unclear. Predominantly Mediterranean marbles have been used, but there are also some marble occurrences in the eastern Alpine regions that were exploited in those times. Besides a mineralogical–petrographic analysis, grain‐size evaluation in particular, and the determination of carbon and oxygen isotopes allow an effective characterization of the Faschendorf materials. Their provenance from the Gummern Marble complex in Carinthia is very likely.     

OFFSHORE FINDS FROM THE BRONZE AGE IN NORTH-WESTERN EUROPE: THE SHIPWRECK SCENARIO REVISITED

Summary.   This article challenges received thinking relating to the interpretation of Bronze Age finds from the seabed in the waters of north-western Europe, especially the North Sea and Channel area. Metal objects recovered from the sea are traditionally presumed to be the result of shipwrecks. As such, their interpretation as casual, if unfortunate loss is unquestioned. However, abandoning the shipwreck scenario as a remnant of the 'sacred vs profane' heuristic, it is suggested that offshore finds could provide insight into deliberate Bronze Age maritime practice, rather than misadventure. Certain patterning in the data of offshore finds, including affinities with hoards on terra firma , urges another interpretive framework – that of considering the sea as a place for deposition. This appeared to be the case particularly in regions which experienced an intensity of maritime interaction, such as the Channel area during the later Bronze Age. From this it is hypothesized that rather than being considered outside the Bronze Age social realm, the sea, especially in the MBA to earlier LBA in the Channel area, was incorporated into Bronze Age cosmology in similar ways to other zones in the landscape.     

PROVENANCE STUDIES OF KOREAN CELADONS OF THE KORYǑ PERIOD BY NEUTRON ACTIVATION ANALYSIS*

Neutron activation analyses of the body fabric of celadons from the main production sites of the Koryǒ period have shown differences in composition between kilns. Comparison of over 50 celadon objects in the collections of the British Museum with this data base from the production sites has permitted the assignment of over 40 of the pieces to their kiln of origin The majority show the trace element pattern of the Sadangri kilns, a smaller proportion are assigned to Yuchǒnri, while others are assigned to the kilns at Chinsanri (underglaze iron) and Kyǒngsǒ-dong (unglazed). A representative group of Chinese Yue wares arc clearly different from Koryǒ celadons in trace element composition.     

MARBLE PROVENANCE INVESTIGATION OF ROMAN SARCOPHAGI FROM THESSALONIKI*

The provenance question of the marbles used for making the sarcophagi of local production of Thessaloniki in the Roman period had been posed by archaeologists in the past. The hypothesis was that the material came mainly from the quarries of Thassos Island. This paper presents the scientific analysis of 23 characteristic samples from selected sarcophagi at the Museum of Thessaloniki, using three different techniques: electron paramagnetic resonance (EPR) spectroscopy, stable isotope analysis and maximum grain size measurements, plus in-situ examination. New combinations of parameters were used in order to resolve fully the provenance of all samples. The results showed that the vast majority of the objects were indeed made in Thassian marble but from three different quarries, namely Vathy/Saliara (dolomitic marble), Aliki (calcitic marble) and Acropolis/Phanari (calcitic marble). The calcitic marbles from Aliki and to a lesser degree from Acropolis/Phanari are met in all the basic types of sarcophagi (framed type, plain type, garland sarcophagi). The use of the better quality and snow-white dolomitic marble from Vathy/Saliara quarries is relatively restricted and is often found in works that are above the average regarding the quality of their workmanship. In addition, two sarcophagi were made in Pentlelic marble and one in Proconnesian. The scientific analysis results provide a good confirmation of the archaeological estimates and, furthermore, the conclusions constitute henceforth a secure basis for the study of the entire sculptured works of Thessaloniki.     

MICROCHEMICAL CHARACTERIZATION OF BUILDING STONE FROM SEVILLE CATHEDRAL,SPAIN

Enrichment diagrams for trace elements have been proposed as a useful and straightforward procedure to identify ores and stones. The identification of the diverse stone of the exterior of the Cathedral of Seville has been achieved by this means. Fourteen trace elements have been analysed, from both quarry and building material samples, using atomic absorption and flame emission spectrometry in order to apply enrichment diagrams for identification purposes.     

ENERGY DISPERSIVE X-RAY FLUORESCENCE ANALYSIS OF ANCIENT COPPER ALLOYS: EMPIRICAL VALUES FOR PRECISION AND ACCURACY

Energy dispersive X-ray fluorescence (EDXRF) analyses are compared with neutron activation as well as atomic absorption analyses of ancient copper-based alloys in order to examine their accuracy and to estimate realistic values for precision and sensitivity of EDXRF. The results show that it is possible to obtain reliable data of the surface composition of objects non-destructively. Better results for bulk composition are usually obtained with drill samples where the sensitivity of the method is at least competitive with atomic absorption spectroscopy with flame atomization.     

STATISTICAL ANALYSIS OF CHEMICAL COMPOSITIONAL DATA AND THE COMPARISON OF ANALYSES

Recent statistical work on approaches to analysing compositional data - where variables sum to a constant for each row of a data matrix - may encounter difficulties when applied to data of the kind typically arising in scientific archaeology. The reason is that results obtained may be unsatisfactory from a substantive viewpoint for identifiable technical reasons. This paper explores and illustrates some possible resolutions of the problem. A feature of the approach used is to analyse subsets of the variables on separate scales. A synthesis of the results obtained from separate analyses is essential and the use of multiple correspondence analysis for this purpose is illustrated.     

METALLOGRAPHIC STUDY OF IRON ARTEFACTS FROM THE EASTERN TRANSVAAL,SOUTH AFRICA

The microstructures of two adzes, two hoes and a spear point from Iron Age settlement sites in the Kruger National Park have been examined. Electron microprobe analyses of the slag inclusions were also made. Some of the objects are made of high carbon steel while others have a highly variable carbon content. All appear to have been forged at relatively low temperature and then annealed at a low temperature near 700°C. None have been hardened by quenching and tempering. Some of the objects contain only traces of included slag while others have large slag inclusions. The slag compositions are quite different from those of medieval bloomery slags and are representative of African iron smelting practice in their high content of CaO, K₂ O and Na₂O. On the basis of the titanium content of the included slag, two of the objects are identified as made of the ore from Rooiwater and one from Phalaborwa ore.     

X-RAY FLUORESCENCE CHARACTERIZATION OF THE CORONA FERREA*

X-ray fluorescence (XRF) analyses of metals, glasses and enamels from the Corona Ferrea, or Iron Crown, of Monza are reported. The method followed to obtain quantitative analysis of metal alloys was based on comparison with standards and it is framed on the more general problem of XRF quantitative analysis of irregularly shaped objects with a portable instrument. Preliminary radiocarbon dating results are also reported.     

NON‐DESTRUCTIVE INVESTIGATION OF BRONZE ARTEFACTS FROM THE MARCHES NATIONAL MUSEUM OF ARCHAEOLOGY USING NEUTRON DIFFRACTION*

Non‐destructive neutron diffraction techniques were applied to determine composition and microstructure data, and hence to derive information on manufacturing techniques of Picenum bronze artefacts. Furthermore, texture analyses were carried out on standards and suitable ancient artefacts to investigate their potential role in archaeometallurgical studies. This is a first step towards an overall characterization of the bronze collection of the Marches National Museum of Archaeology, Italy, and the analytical demonstration of relations with and differences compared to Etruscan metallurgy. The work is also an example application of the powerful non‐destructive archaeometrical approaches provided by time‐of‐flight neutron diffraction.     

Roman Glazed Ceramics in the Western Mediterranean: Chemical Characterization by Inductively Coupled Plasma Atomic Emission Spectrometry of Ceramic Bodies

Several objects of Roman lead-glazed ceramic, found inHispania(Spain), were sampled and analysed in order to characterize them to study the spread of glazed ceramic in the western Mediterranean. Chemical analyses were carried out by Inductively Coupled Plasma Atomic Emission Spectrometry.Studies of the chemical composition of the ceramic bodies indicate that ceramics from two different production centres reachedHispaniaduring the Roman period: a non-calcareous fabric, coming from Lyon workshops, and calcareous bodies with bicoloured glazes from another main production centre, which is suggested to be Italy. Other objects, of central Gaulish or eastern origin, have also been found in the western Mediterranean, but only occasionally.     

PROVENANCE OF MARBLES FROM NAXOS BASED ON MICROSTRUCTURAL AND GEOCHEMICAL CHARACTERIZATION

A detailed quantitative microstructural study coupled with cathodoluminescence and geochemical analyses on marbles from Naxos demonstrates that the analysis of microstructures is the most sensitive method to define the origin of marbles within, and between, different regions. Microstructure examination can only be used as an accurate provenance tool if a correction for the second‐phase content is considered. If second phases are not considered, a large spread of different microstructures occurs within sample sites, making a separation between neighbouring outcrops difficult or impossible. Moreover, this study shows that the origin of a marble is defined more precisely if the microstructural observations are coupled with cathodoluminescence data.