CHEMICAL CHARACTERIZATION AND STATISTICAL MULTIVARIATE ANALYSIS OF ANCIENT POTTERY FROM MESSINA,CATANIA, LENTINI AND SIRACUSA (SICILY)*

This paper presents the chemical characterization of 79 fragments of Archaic and Hellenistic fine‐grained pottery from archaeological sites in Messina, Catania, Lentini and Siracusa (Sicily). The sherds were classified as ‘calcidian’, ‘banded’, ‘unvarnished’ and ‘black varnished’ pottery. The major and trace elements identified by X‐ray fluorescence (XRF) were statistically elaborated using the method proposed by J. Aitchinson in 1986 for the analysis of compositional data. From cluster analyses using element/SiO₂ log‐ratios, it was possible to group the pottery found in Catania, Lentini and Siracusa into highly linked clusters. Conversely, the Messina pottery was divided into two clearly distinct groups. With the aim of identifying any possible mineralogical differences between the two Messina groups, Fourier transform infrared (FT–IR) absorption measurements were made, showing only quantitative differences in plagioclase and muscovite. The specific groups of pottery with restricted chemical compositions are considered to be of local production, also on the basis of archaeological and petrographic evidence.     

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.     

广东博罗先秦硬陶的XRF和INAA研究

为揭示广东博罗梅花墩、银岗、横岭山三地古陶器的产源、烧造工艺、技术传播和化交流等方面情况,用波长色散X射线荧光分析(WDXRF)、仪器中子活化分析(INAA)同时测量了广东博罗梅花墩、银岗、横岭山等三地点所出38片西周至春秋、战国硬陶中Al、Ba等元素的含量。并用主成分分析分别处理了测量数据。两套数据的分析结果均表明,梅花墩、银岗和横岭山的硬陶原料互不相同,各地点硬陶可能主要是“自烧自用”。数据分析还表明在南方各省区中,广东硬陶具有Al2O3含量偏高这一明显的地区特征。     

Roman lava quarries in the Eifel region (Germany): geochemical data for millstone provenance studies

Roman millstones of assumed Eifel origin were produced and exported in huge quantities to many parts of Roman Europe and can be used as tracers for trade patterns in Roman times. This study presents for the first time a raw-material centred geochemical definition of the 13 well-known Roman basaltic lava quarries in the Quaternary East and West Eifel volcanic fields. The aim is to find a way to characterize the individual exploitation sites precisely by means of their geochemical composition and to recommend a standard procedure for further millstone provenance analysis. Based on major and trace element composition analyses by XRF, a differentiation of each quarry is achieved by using a combination of geochemical discrimination and cluster and discriminant analysis. Therefore, for provenance analysis of a unknown millstone sample the following procedure is recommended: (1) geochemical discrimination to check if it actually belongs to the volcanic Eifel quarries; (2) cluster analysis to check to which quarry or cluster of quarries the millstone can be affiliated; and (3) discriminant analysis to assign the sample to its quarry of origin with a certain confidence.     

ARAMAIC BASALT STATUES FROM TELL HALAF,SYRIA: LOCATING THE ANCIENT QUARRIES

Tell Halaf is the locality of the ancient Aramaic city of Guzāna (c. 1000–800 bc ) in Syria. The statues of Tell Halaf were made from monolithic basalt blocks, comprising massive as well as amygdaloidal types. However, the exact location of the original quarries was as yet unknown. Reconnaissance mapping and sampling concentrated on the four basaltic centres in the vicinity of Tell Halaf, covering both south‐eastern Turkey and north‐eastern Syria. In addition, basaltic artefacts from the two archaeological sites of Tell Beydar (c. 2700–2300 bc ) and Djebelet el Beda (c. 2600–2350 bc ) were investigated. All basalt samples were analysed for their bulk rock major and trace element compositions by X‐ray fluorescence, ICP–MS analysis and the mineral chemistry of individual minerals by combined electron microprobe analysis and laser‐ablation ICP–MS. The data show that basalt works of art from all three archaeological sites were derived from the Syrian basalt plateau of Ard esh‐Sheikh, approximately 57 km south of Tell Halaf. Accordingly, this basalt quarry was actively exploited over a considerable time span of c. 1900 years. This study demonstrates that petrographic and geochemical investigations of basalt, combined with electron microprobe and laser‐ablation ICP–MS analysis of minerals, are powerful tools to discriminate between possible sources of raw materials, especially if isotopic data yield unsatisfying results.     

Post‐Depositional Elemental Alterations in Pottery: Neutron Activation Analyses of Surface and Core Samples*

From 38 sherds with ‘corroded’ surfaces, two samples per sherd were examined using Neutron Activation Analysis, one from the surface and one from the core of each sherd, in order to analyse post‐depositional alterations of minor and trace elements. The most striking effect was that a leaching of Ca could be found at the surface. Another group of elements that is severely affected are the alkali metals, with Cs and Rb showing the strongest changes. A third conspicuous group of elements are the Rare Earth Elements. Finally, the effect of such alterations on a statistical data evaluation to classify pottery according to provenance is investigated.     

甘肃新石器时代与青铜代陶器研究的内容和科学意义

综述了现代分析测试方法和数学方法在古代陶器成分分析、年代测定、制作工艺、产地判断、形态分析方面的应用以及甘肃新石器与青铜时代陶器研究的意义。     

Pottery Styles during the Early Jomon Period: Geochemical Perspectives on the Moroiso and Ukishima Pottery Styles

Energy‐dispersive X‐ray fluorescence (EDXRF) was used to determine the minor and trace element chemistry of 92 Early Jomon pottery sherds. The sherds came from four contemporary sites in the Kanto region and belong to either the Moroiso or Ukishima style of pottery. Principal components analysis (PCA) and discriminant analysis indicate that there are four major groups in the data set, which correspond to site location. Furthermore, for sites having both Moroiso and Ukishima pottery, the statistical tests indicate that both styles of pottery were made from the same or geochemically similar raw materials. This suggests that both styles were probably made at the same site, and indicates that if the different pottery styles are reflecting ethnic identity, then intermarriage between ethnic groups is occurring. Alternatively, the pottery styles could be reflecting some sort of social interaction between groups.     

LEAD ISOTOPIC ANALYSIS FOR THE IDENTIFICATION OF LATE BRONZE AGE POTTERY FROM HALA SULTAN TEKKE (CYPRUS)

Lead isotopic compositions were measured for 65 sherds from five pottery wares (Plain White, Coarse, Canaanite, White Slip and Base‐ring) excavated from the Late Bronze Age site of Hala Sultan Tekke (Cyprus). The elemental composition and isotopic signature of the sherds were compared with those of 65 clay samples collected in south‐east Cyprus, mainly in the surroundings (<20 km) of Hala Sultan Tekke. This work shows the effectiveness of using lead isotopic analysis in provenance studies, along with other analytical techniques, such as X‐ray diffraction (XRD) and a scanning electron microscope (SEM) equipped with an energy dispersive X‐ray detection (EDX) facility, to identify the composition of pottery wares and the clay sources used for pottery ware production.     

THE UTILIZATION OF TRACE CHEMICAL COMPOSITION TO CORRELATE BRITISH POST-MEDIEVAL POTTERY WITH EUROPEAN KILN SITE MATERIALS

This study uses X-ray fluorescent analysis to compare the trace chemical composition of seventeen pottery sherds excavated from sites in Britain with the trace analyses of twenty four sherds from continental sources. Results indicate that certain elements, notably zirconium, titanium, rubidium, and strontium show little variation within a particular sherd and are consistent among samples from the same source. Certain other elements appear to show wide variation which is possibly attributable to firing conditions, burial or is connected with the glaze. The comparisons of analyses indicate that nine of the seventeen British sherds can be closely correlated with particular continental sources. Tentative correlation is suggested for five sherds. The remaining three sherds clearly do not come from any of the sources investigated.     

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.     

MODIFIED MAHALANOBIS FILTERS FOR GROUPING POTTERY BY CHEMICAL COMPOSITION*

A statistical procedure for grouping pottery in provenance studies by chemical data is presented, which now is routinely in use in our laboratory. It is based on the Mahalanobis filter method and X² -statistics, and can be used for both establishing groups and assigning single sherds to already known groups, thus replacing principal components analysis or cluster analysis and avoiding their problems in grouping pottery. The new method is able to consider correlations, uncertainties of measurement and constant shifts of the data in case of dilution. In particular, considering dilution effects results in both a better assignment to and separation of reference groups and is also equivalent to the compositional data approach, if log-transformed data are used. Other distortions of data (e.g., mixing of clays) can also be considered.     

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 forest or the trees? Behavioral and methodological considerations for geochemical characterization of heavily-tempered ceramic pastes using NAA and LA-ICP-MS

In this paper, the utility of LA-ICP-MS for instrumentally separating clay and temper within pottery samples is examined through a well-known case study that has been previously characterized through NAA and petrography. Coarse Orange pottery is composed of kaolinitic clays heavily tempered within volcanic ash from the basalt-rich Tuxtla Mountains of southern Veracruz, Mexico. We attempt to address the following topics with analyses on this pottery: 1) can LA-ICP-MS replicate the same groups previously identified by NAA and petrography; 2) can instrumental isolation of the clay fraction within the pottery replicate known patterns in raw clay source geochemistry in the Tuxtla Mountains; 3) can data for both the clay and volcanic ash fractions of each pottery sherd be combined to simulate the bulk INAA data? The results demonstrate that the clay fraction of the pottery sherds can be isolated. Furthermore, the LA-ICP-MS data for the clay fractions display nearly identical chemistry to available NAA data for raw clay samples collected from geological contexts in the region. Instrumentally isolating the clay fraction in this case eliminates the homogenizing effects of adding a common temper and increases the chemical separation among groups making it easier to identify clay procurement strategies for each specimen. However, focusing only on the clay fraction ignores significant tempering variation. Attempts to simulate the bulk NAA by combining LA-ICP-MS data for clays and temper was reasonably successful in reestablishing the tempering variation lost by exclusive focus on clays, but such an approach could not replace the more precise data generated from NAA and petrography.     

Assessing mussel shell diagenesis in the modern vadose zone at Lyon's Bluff (22OK520), Northeast Mississippi

This study considers the chemical alteration of archaeological freshwater shell above the water table at the Lyon's Bluff site (22OK520), a single-mound and village complex located in east-central Mississippi, and the changes in trace element concentrations between unfired and fired shell. Thin-section petrography, X-ray diffraction, cathodoluminescence, and scanning electron microscopy analyses were conducted on archaeological shell from four natural layers from Unit 20N20W, over a depth of 80 cm and spanning 450 years. ICP–MS analysis also was conducted on a modern freshwater shell subjected to kiln firing. Microscopy results indicate a pristine aragonite crystal structure in the archaeological samples. ICP–MS data show that certain trace elements within the modern shell maintain their concentration after firing at 500 °C. The broader implications are: 1) that diagenetic alteration does not hinder chemical sourcing of shell at Lyon's Bluff, and 2) that certain trace elements are more reliable than others, namely Sr²⁺, Al²⁺, Ba²⁺, and Mn²⁺, when conducting trace element provenance studies on fired-shell temper.     

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.     

Pottery production on Rishiri Island,Japan: perspectives from X‐ray fluorescence studies

Energy‐dispersive X‐ray fluorescence (EDXRF) was used to determine the minor and trace element composition of 54 sherds of pottery dating from the Final Jomon to Okhotsk periods. The majority of the sherds came from Rishiri Island, Japan. Principal component (PC) scores were calculated using the log transformed concentration values, and groups were sought in the PC scores using kernel density estimates (KDEs). Two main groups were found in the data; linear and quadratic discriminant analysis classified both groups successfully. Significant differences in the concentrations of Cu, Fe, K, Nb, Pb, Rb, Th and Zr were found to exist between the two groups. The lack of correspondence between chronological ware types and geochemical groups implies that the same raw materials and paste recipes were in use during the Epi‐Jomon and Okhotsk eras on Rishiri Island. One possiblity is that the Epi‐Jomon and Okhotsk potters used the same clays and tempers, since no other alternatives were available. Alternatively, the Okhotsk potters could have adopted the same paste recipes as the Epi‐Jomon potters, or the Okhotsk pottery tradition could be descended from the Epi‐Jomon pottery tradition.     

Ceramics Technology at Late Classic K’axob,Belize

Abstract

Excavation of a Late Classic Maya platform at K’axob, Belize, has revealed a suite of pit features and associated artifacts that are strongly suggestive of pottery production. Interpretation of the features as remnants of pit kilns used to fire pottery is bolstered by comparanda from the Andean region. Archaeometric and experimental replication studies also support the interpretation of this locale as one of pottery fabrication. Findings discussed include features identified as kilns, raw material suitable for temper, lumps of fired clay, ground stone, and expedient clay-working tools made of recycled pottery sherds. This research contributes to knowledge of the organization of Maya pottery production by providing the most comprehensive information presented to date on the technology of ancient Maya pottery fabrication and firing.     

NON-DESTRUCTIVE SURFACE ANALYSIS OF ROMAN TERRA SIGILLATA: A POSSIBLE TOOL IN PROVENANCE STUDIES?

In the past, studies on the average chemical composition of a sherd vs its origin have successfully been carried out, but attempts failed to reach the same goal with spot analysis (electron microprobe) on the high gloss surface of terra sigillata. When chemical data on the average composition of the surface is used for provenance determinations, significant results are obtainable on the basis of non-destructive energy dispersive X-ray fluorescence analysis (EDS-XFA). Terra sigillata from Arezzo, Lezoux, La Graufesenque and Lyon (± 20 B.C. to ± 150 A.D.) were analysed in order to determine the statistically distinctive chemical elements. It is clearly possible under favourable conditions to allocate archaeologically unknown sherds to specific pottery centres.     

CORRESPONDENCE AND DISCRIMINANT ANALYSES OF SAND AND SAND TEMPER COMPOSITIONS,TONTO BASIN,ARIZONA*

Geologists use petrographic modal analysis to relate fluvial sand composition to source rock composition, thus establishing provenance. Archaeologists seeking to establish provenance of sand temper in pottery can use similar petrographic methods, but their finer scale of investigation requires more precise statistical tools than those employed by geologists. A quantitative method for performing that task is presented. It utilizes correspondence analysis and discriminant analysis of logratio transformed point‐count data to define petrofacies, or sand temper resource procurement zones. The procedure is illustrated with sand and sand‐tempered sherd samples collected from the Tonto Basin, central Arizona; temporal trends in utilitarian ceramic production c. AD 100–1350 are reviewed.