PROVENANCE STUDIES OF ROMAN AFRICAN RED SLIP WARE USING NEUTRON ACTIVATION ANALYSIS

African Red Slip ware (ARS) from Carthage and San Sisto Vecchio (Rome) was analysed by neutron activation analysis. The Carthage tableware was linked with Oudna and the type 1 lamps were probably from a northern ARS/lamp factory other than the sources currently investigated. Two samples were central Tunisian, probably manufactured at El Ala. The San Sisto samples divided into three groups and three outliers of undetermined provenance. Group 1 was central Tunisian, probably from El Ala, and was composed entirely of terra sigillata chiara C forms. Group 2 was of unknown origin within northern Tunisia. Group 3 was the largest subset and most of its constituent samples were associated with El Mahrine. Additionally, four samples were linked with Oudna.     

NEUTRON ACTIVATION ANALYSIS OF ROMAN AFRICAN RED SLIP WARE KILNS

Roman African Red Slip ware (ARS) sherds from four ARS kiln sites in modern-day Tunisia (El Mahrine, El Ala, Oudna and Pheradi Maius) have been analysed using instrumental neutron activation analysis. Multivariate statistical methods (including cluster analysis and Manhattan City Block distances), with a dilution correction applied to the data, were used to interpret the concentration data. Reference groups for each of the four kiln sites were established. Both El Mahrine and Oudna were described by two dilution-related groups. These kiln groups were all shown to be compositionally distinct from each other and suitable for use in provenance studies.     

CHEMICAL CHARACTERIZATION OF TIN‐LEAD GLAZED POTTERY FROM THE IBERIAN PENINSULA AND THE CANARY ISLANDS: INITIAL STEPS TOWARD A BETTER UNDERSTANDING OF SPANISH COLONIAL POTTERY IN THE AMERICAS*

Majolica pottery was the most characteristic tableware produced in Europe during the Medieval and Renaissance periods. Because of the prestige and importance attributed to this ware, Spanish majolica was imported in vast quantities into the Americas during the Spanish Colonial period. A study of Spanish majolica was conducted on a set of 186 samples from the 10 primary majolica production centres on the Iberian Peninsula and 22 sherds from two early colonial archaeological sites on the Canary Islands. The samples were analysed by neutron activation analysis (NAA), and the resulting data were interpreted using an array of multivariate statistical approaches. Our results show a clear discrimination between different production centres, allowing a reliable provenance attribution of the sherds from the Canary Islands.     

A CHARACTERIZATION OF THE COMPOSITIONAL VARIATIONS OF ROMAN SAMIAN POTTERY MANUFACTURED AT THE LEZOUX PRODUCTION CENTRE

The study addresses the chemical variations for Roman Samian wares manufactured during various periods at different workshops within the Lezoux production centre. Instrumental neutron activation analysis and inductively coupled plasma spectrometry were used to determine the chemical constituents of the pottery. The two techniques were evaluated based on the capacity of each to identify the same compositional groups for Lezoux Samian with the use of multivariate statistics. The compositional analysis redefines and clarifies how potters used the clay sources at the site to produce fine wares. The results indicate that the majority of potters from different workshops at Lezoux shared the same clay source during the second century AD.     

DETERMINING POTTERY PROVENANCE: APPLICATION OF A NEW HIGH-PRECISION X-RAY FLUORESCENCE METHOD AND COMPARISON WITH INSTRUMENTAL NEUTRON ACTIVATION ANALYSIS*

A recently developed high-precision X-ray fluorescence (XRF) method, applied for the first time to the study of archaeological pottery, determines the abundances of 13 trace and four major elements from one X-ray spectrum acquired over a 1000 second counting interval. For replicate archaeological samples, the short-term and long-term measurement precisions were close to 1% for the ten elements measured with highest precision. These are comparable to the best results achieved on replicates of clay and pottery standards, and obsidian, using instrumental neutron activation analysis (INAA). High-precision XRF analysis, however, does not require a nuclear facility, and is markedly preferable to INAA in terms of the ease of both sample preparation and analytical procedure. Consequently, element abundance data can usually be provided by a single analyst within a few hours after the start of sample preparation. The accuracy of the method, determined by comparison with data of other workers on eight standard reference materials, averaged 2.4% for the ten best-agreeing elements. The effectiveness of the method for determining pottery provenance is demonstrated for a difficult problem, in which high-precision XRF analysis successfully distinguished the products of two nearby pottery manufacturers in Roman Galilee (Shikhin and Nahif) that had not been clearly differentiated by INAA. The greater effectiveness of high-precision XRF than INAA in this provenance study is a result of the different array of elements measured, and the higher precision obtained for certain elements, by XRF. These results suggest that high precision XRF has potential broad applicability for pottery provenance studies.     

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.     

THE DISCOVERY OF ANOMALOUSLY HIGH SILVER ABUNDANCES IN POTTERY FROM EARLY ROMAN EXCAVATION CONTEXTS IN JERUSALEM*

This is the first study on the differential distribution and concentrations of silver in ceramics recovered from archaeological excavations. The chemical compositions of 1174 pottery vessels from 38 Roman‐period sites in Israel have been determined. Unusually high and variable abundances of silver were discovered in pottery samples of all vessel types and chemical compositions from four distinct archaeological contexts dating to late first century bce to 70 ce Jerusalem. The large majority of the Jerusalem vessels could be distinguished by their silver abundances from all analysed pottery pieces recovered at rural sites outside Jerusalem, even when the pottery types and chemical compositions, except for silver, of pottery found within and outside Jerusalem were indistinguishable. The evidence is suggestive of a human origin for the high and variable silver abundances, and dispersion of the silver by aqueous transport. The differential silver concentrations found in excavated pottery from Jerusalem and other urban and rural sites suggest that attention to the distribution of silver in pottery from excavated contexts may be helpful for evaluating the nature and function of archaeological remains and patterns of urban contamination.     

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.     

INSTRUMENTAL NEUTRON ACTIVATION BASED PROVENANCE STUDIES AT THE HEBREW UNIVERSITY OF JERUSALEM,WITH A CASE STUDY ON MYCENAEAN POTTERY FROM CYPRUS

A neutron activation programme aimed at archaeological provenance research operated at The Hebrew University of Jerusalem between the years 1974 and 1997. The history and accomplishments of that laboratory are presented. Endeavours to preserve unpublished results are described. Results on Cypriote pottery are presented.     

THE ORIGIN OF THE PICTORIAL KRATER FROM THE ‘MYCENAEAN’ TOMB AT TEL DAN

A Late Bronze Age Mycenaean pictorial krater, decorated with a chariot procession, from tomb 387 at Tel Dan, Israel, was examined by instrumental neutron activation analysis. The origin of the krater is placed in the Argolid, very likely in the region of Mycenae or Berbati.     

INTERREGIONAL CONTACTS BETWEEN TELL EN-NASBEH AND LITTORAL PHILISTINE CENTRES IN CANAAN DURING EARLY IRON AGE I*

Philistine bichrome ware from Tell en-Nasbeh, an Israelite village in the hill country, has been characterized by instrumental neutron activation analysis. A group of pottery stylistically indistinguishable from wares made in Philistia is shown to be of local origin, while other sherds match kiln wasters found in the littoral Philistine city of Ashdod. These findings attest to complex and reciprocal interregional contacts between the Philistines and the Israelites during the eleventh to twelfth centuries BC.     

NON-DESTRUCTIVE ANALYSIS OF OBSIDIAN ARTEFACTS USING NUCLEAR TECHNIQUES: INVESTIGATION OF PROVENANCE OF NEAR EASTERN ARTEFACTS

A non-destructive analytical method using both instrumental neutron activation and proton-induced gamma ray emission techniques was developed to study the provenance of obsidian artefacts from Turkey, Syria and Iraq.     

THE EFFICIENT COMPUTATION OF UNBIASED MAHALANOBIS DISTANCES AND THEIR INTERPRETATION IN ARCHAEOMETRY*

This paper argues for cross-validation to reduce bias in estimating Mahalanobis distances of individuals to groups, a particular problem with small sample sizes. Formulae for the efficient computation of cross-validated distances, which avoid excessive matrix inversion, are given. The use of Mahalanobis distances as measures of consistency, or as indications of outlying values, is described. The little-known technique of gamma plotting is outlined and discussed as an aid to interpreting distances in these terms. Both cross-validation and gamma plotting are illustrated in an example on marble composition.     

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.     

NEUTRON ACTIVATION ANALYSIS OF ARCHAEOLOGICAL MATERIALS: AN OVERVIEW OF THE ITN NAA LABORATORY,PORTUGAL

Instrumental neutron activation analysis (INAA) has been applied to archaeological samples at the Portuguese Research Reactor (RPI) since 1973, and the number of samples analysed has increased steadily since the mid‐1990s. Archaeometric applications of INAA at RPI include the analysis of archaeological ceramics and the stones used in monumental architecture (menhirs) and other historical monuments. A programme of analysis also exists for measuring the precision of and contributing to the certified values of geochemical reference samples. In addition, the study of interference factors is performed to obtain better accuracy in the determination of concentrations of some elements (e.g., corrections for spectral interferences from uranium fission products in the determination of barium, rare earth elements and zirconium).     

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.     

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.     

A PROVENANCE STUDY OF POTTERY FROM ARCHAEOLOGICAL SITES NEAR CANOSA,PUGLIA (ITALY)*

Studies have been carried out to assess the provenance of selected pottery excavated at archaeological sites near Canosa, Puglia (Italy). Sixty-six sherds, ranging in date from the mid-seventh century BC to the beginning of the third century BC, were analysed by atomic absorption spectroscopy and 16 elements were determined. The analysis data were subjected to multivariate classification procedures. Tests showed that the majority of the examined sherds came from ancient local kilns; a probable Ionian origin was established for some other sherds, while the rest were of unknown origin.     

TRACE ELEMENT GEOCHEMISTRY OF NATIVE COPPER FROM THE WHITE PINE MINE,MICHIGAN (USA): IMPLICATIONS FOR SOURCING ARTEFACTS*

Eighty-five samples of native copper from the White Pine mine in upper Michigan were analysed by neutron activation to document geochemical variability within a single locality. Silver, sodium, antimony and scandium contents vary by two orders of magnitude, whereas arsenic values vary by three orders of magnitude. This variability reinforces the need for provenance studies of artefacts to examine sufficient samples to test for heterogeneity within the source area. The White Pine suite contains some of the most impure native copper that has been analysed to date. Arsenic and silver values of these impure samples overlap with those of European coppers, but consideration of several elements can still distinguish native copper from European copper.