Sourcing of sanukite implements by X-ray fluorescence analysis II

Non-destructive analysis of sanukite stones of known source and sanukite implements was carried out by means of energy-dispersive X-ray fluorescence spectrometry. Attention was focussed on areas in middle-western Japan. Stone taken from four source districts was classified into nine different groups. More than a hundred implements obtained from thirty-six archaeological sites were allocated to their sources by means of Hotelling's T² test.     

X-ray fluorescence analysis of late Roman and Sassanian silver plate

About 200 analyses have been made on late Roman and Sassanian silver objects using energy-dispersive X-ray fluorescence. This has shown that the main feature of the composition of the silver throughout the period and across the geographical area studied was towards high fineness (average silver percentage about 95%). Compositional differences are found between Roman and Sassanian silversmiths' products for the elements copper and lead. Much of the material analysed came from hoards, and using a statistical technique on the analytical data (Discriminant Analysis) broad compositional differences between hoards were found to emerge. The use of different compositions of silver for different joined parts of a single object are discussed.     

Precision in the X-ray fluorescence analysis of sixty-one Augustan quadrantes

Sixty-one Augustan quadrantes were analysed for calcium, iron, nickel, copper, silver, tin, antimony, and lead by X-ray fluorescence. Most coins contained about 99·7% copper with the other seven elements present as trace impurities. Significant differences in composition were found for the three different issues of quadrantes minted in c. 9 BC indicating that these issues were not minted exactly contemporaneously. Quadrantes minted in c. 4 BC have trace element concentrations in ranges that differ from those of the 9 BC quadrantes. The precision is very good for all trace elements (the precision of calcium was not calculated): average standard deviations are 0·0021% for Fe, 0·0026% for Ni, 0·0038% for Ag, 0·0014% for Sn, 0·0031% for Sb, and 0·015 for Pb.     

Energy dispersive X-ray fluorescence analysis of 1st millennium ad glass from Britain

A series of energy dispersive X-ray fluorescence analyses has been undertaken in response to archaeological problems relating to 1st millennium AD glass excavated in Britain. The aim of the work was to furnish a set of comparable analytical results to be used in assessing hypotheses concerning the general state and development of glass technology through this period. Within this framework, however, it has also been possible to attempt answers to specific archaeological questions relating to material from particular sites. The paper discusses the background to, and the interpretation of such results, particulars of the analytical technique used, a general overview of approximately 200 analyses and three examples of the use of this data in relation to specific archaeological problems.     

X-ray and neutron-based non-invasive analysis of prehistoric stone artefacts: a contribution to understand mobility and interaction networks

Carbonate-rich archaeological artefacts are difficult to identify and correlate between them and with raw materials of such heterogeneous geological sources, especially when only non-invasive analysis is possible. A novel combination of X-ray and neutron-based non-invasive analysis is implemented and used for the first time to study prehistoric stone idols and vessels, contributing to culture identity, mobility and interaction in the recent Prehistory of Southern Iberia. Elemental composition was obtained by prompt gamma activation analysis (PGAA) and external beam particle-induced x-ray emission (PIXE); homogeneity of the stone artefacts and the presence/absence of internal fractures were obtained by neutron radiography (NR). These atomic and nuclear techniques, simultaneously used for complementary chemical information, have been demonstrated to be of great value as they provide non-destructive compositional information avoiding sample preparation, crucial in so singular and rare objects. The obtained results, especially of PGAA, are very promising and useful in general assessments of provenance. The stone artefacts show signs of both nearby and long-distance procurement, as well as of unknown attribution.     

Potentialities of X-ray fluorescence analysis in numismatics: the case study of pre-Roman coins from Cisalpine Gaul

X-ray fluorescence (XRF) is a well-known technique for the analysis of ancient metals. Thanks to the availability of portable instruments (p-XRF), it is extensively used for the chemical characterization of coins directly in museums. In this work, the potentialities of the technique have been investigated, through its application to a case study concerning the Cisalpine Gaul coinage. More than 200 drachmas have been analysed to discriminate different productions on the base of minor elements. Major elements, on the other hand, have been used to trace alloy changes through the centuries. As concerns the quantification of the silver content (fineness), XRF and neutron diffraction results have been compared, in order to check the presence of surface-enriched layers.     

X-ray fluorescence analysis and intra-island exchange in the Society Island archipelago (Central Eastern Polynesia)

We apply X-ray fluorescence (XRF) geochemical analysis to a collection of 'Opunohu Valley lithic artifacts from Mo'orea island to investigate the local scale of raw material procurement, adze production, use, and exchange within the Society Island archipelago. We use these data to document the distribution of non-local versus local volcanic artifacts in 'Opunohu Valley house sites, ritual sites, and specialized sites, as a means for establishing intra-site production and consumption patterns, and access to exotic, possibly superior, stone resources, and how these two themes correlate with site function or household wealth and status. Overall, 30% of the artifacts analyzed via WDXRF derive from non-local sources, notably two other islands in the archipelago outside of the political boundaries of Moorean chiefdoms. Our case study thus provides the first direct material evidence of intra-archipelago trade and exchange in the Society Islands. Intra-archipelago trade in adzes was certainly in place by as early as A.D. 1350, if not earlier, and continued up until the time of European contact. In addition, our analyses have identified a local adze production locale in the Afareaitu district of Mo'orea island. The patterns of local versus non-local adze production and exchange strongly suggest that dual interaction spheres were involved. The correlation between adzes and adze-related debris produced from off-island sources and sites with specialized use, which were often reserved for the social, ritual, and political elites in Ma'ohi society suggests that some of the exotic adzes derived from gift exchange between Mo'orea and ruling elites in Tahiti and the Leeward Islands. These adzes from afar would have solidified socio-political and ideological alliances between elites in the Windward and Leeward sectors of the archipelago.     

Provenance of prehistoric obsidian artefacts from Kul Tepe,northwestern Iran using X-ray fluorescence (XRF) analysis

Analysis by X-ray fluorescence of 53 obsidian artifacts the main source of obsidian for the workshops in Kul Tepe was Syunik but obsidian sources as far as west as the Lake Van region (Nemrut Da? and Meydan Da?) and as far north as Gutansar were also utilized. These new results indicate a broad network of trade and exchange.     

Application of X-ray fluorescence imaging to ceramics from the American Southwest

We have used synchrotron-based X-ray fluorescence imaging (XRFI) to examine sherds of painted ceramics from prehistoric cultures of the American Southwest. These sherds are very well suited to XRFI analysis. Paints can generally be detected and distinguished by the fluorescence intensities of their constituent elements. Spatial maps of element distributions yield the spatial distribution of pigments. Pigments can be distinguished that are (or have become) visually similar; layers that have been obscured by overpainting can be examined; and pigment residues can be distinguished from surface contaminants deposited after painting and firing. As a result, XRFI allows the painted motifs to be clarified and hidden features to be revealed. Furthermore, the very rapid scanning and high sensitivity elemental detection possible with synchrotron-based XRFI facilitate measurements on large collections of sherds, allowing an integrative rather than anecdotal analysis.     

Non-destructive provenance study of cuneiform tablets using portable X-ray fluorescence (pXRF)

Portable X-Ray Fluorescence (pXRF) apparatus of the last generation was tested to determine its potential for routine provenance determination of clay cuneiform tablets, which cannot be analyzed by “classical” intrusive methods. A group of tablets from Hattuša (Bo?azköy) and from el Amarna, which were previously provenanced using optical mineralogy (OM) and instrumental neutron activation analysis (INAA), was analyzed by pXRF and the results were used to establish the grouping according to their elemental concentrations. These groups were compared with the previous results retrieved by OM and INAA in order to confirm their validity. The results corroborate the high potential of the pXRF for non-destructive study of well-defined, ‘closed’ assemblages of clay-derived, delicate artifacts, such as cuneiform tablets, bullae, and fine-ware pottery. Consequently, a group of previously unexamined tablets from Hattuša was analyzed by pXRF and the results are discussed with implications on future research.     

Non-invasive characterization through X-ray fluorescence and neutron radiography of an ancient Japanese lacquer

Oriental lacquer artefacts represent very interesting objects of investigation, involving a huge variety of materials and manufacturing techniques. Lacquers are very attractive not only for their stylistic features but also for understanding the variety of production processes, time evolution, use and artistic applications involved in their manufacturing. Till recently, the research activity on these materials has been mainly based on standard, more or less invasive, analytical methods. With the aim to characterise a nineteenth century Japanese lacquer in a totally non-invasive and non-destructive way, in situ X-ray fluorescence (XRF) and neutron radiography (NR) have been employed. While XRF suggested an identification of the pigments embedded into superficial layers, NR allowed revealing, in a single measurement, the average bulk properties of the sample.     

Patterning in procurement of obsidian in Chaco Canyon and in Chaco-era communities in New Mexico as revealed by X-ray fluorescence

X-ray fluorescence analysis of obsidian artifacts from sites located in Chaco Canyon and from three Chaco-era communities in New Mexico permits determination of their geological origin. These source data are used to describe patterning in obsidian procurement in sites located in Chaco Canyon dating from A.D. 500–1150, and in a three non-Canyon communities occupied during the period of Chaco Canyon's regional prominence (ca. A.D. 875–1150). These data demonstrate that the most proximate sources generally dominate the sourced obsidian assemblages from sites of all periods, but also suggest differences in procurement patterning both over time and across space. Within Chaco Canyon, there is a notable shift from Mount Taylor obsidian to use of Jemez Mountains sources over time. These data also suggest that earlier analyses of obsidian from sites in Chaco Canyon misidentified some obsidian artifact sources; these new data indicate the central areas of disagreement and provide a revision of procurement patterning. In the Chaco-era communities located outside Chaco Canyon, procurement patterning diverges. The Blue J community shows an increase in use of the nearby Mount Taylor source over time. Two communities located toward the southern extent of the Chaco great house distribution reveal a markedly distinct procurement pattern, obtaining nearly all of their obsidian from southern sources largely unrepresented at Chaco Canyon. Combined, these data provide new insights into raw material procurement and artifact production at sites in Chaco Canyon, and in communities occupied during the Chaco Phenomenon, the period of the Canyon's greatest regional influence.     

Comparison of celadon from the Yaozhou and Xicun kilns in the Northern Song Dynasty of China by X-ray fluorescence and microscopy

The Xicun kiln is a typical kiln for firing porcelains for export, including celadon, which imitates the products of the Yaozhou kilns. In this paper, 10 pieces of celadon from the Xicun kiln and 8 celadon samples from the Yaozhou kiln were analysed in situ non-destructively by energy dispersive X-ray fluorescence microprobe and optical microscopy. The results indicated that the body of the Xicun celadon contained less TFe₂O₃, Cr, Sr and Zr, and more K₂O and Rb than that of the Yaozhou celadon. Also, the glaze of the Xicun celadon contained lower quantities of Sr and higher Rb; thus, these elements could be employed as relevant markers for the non-destructive discrimination of the provenance of Xicun celadon. In addition, the thicker glaze, the numerous bubbles, and the existence of the middle layer could be used as auxiliary indicators for a micro-structural distinction between samples from the Yaozhou kiln and those originating from Xicun.     

Element localization in archaeological bone using synchrotron radiation X-ray fluorescence: identification of biogenic uptake

Trace element analysis related to archaeological bone is viewed as one way to determine levels of element exposure in past populations. This area of research is complex because there is the potential for the incorporation of trace elements from the burial environment into archaeological bone. We tested the hypothesis that matching the spatial distribution of trace elements within cortical bone with the biological structures would provide evidence of biogenic uptake. We examined samples from a non-segregated Royal British Naval cemetery (1793–1822) in Antigua, West Indies. A key historical question related to this population was the extent of exposure to lead and the resulting health effects. Images from conventional light microscopy (histological) analysis of the bone samples were matched with elemental maps of calcium, strontium, and lead that were created through the use of synchrotron radiation X-ray fluorescence (SR-XRF). Biogenic uptake of both strontium and lead was indicated based on the localization of these trace elements within discreet microstructural elements. The successful integration of histological information with XRF data is a powerful technique for the interpretation of past biological events through trace elements.     

The Determinants of Regional Sourcing by Multinational Manufacturing Firms: Evidence from Yorkshire and Humberside,UK

An examination of the factors influencing the extent of regional sourcing by multinational manufacturing firms using data collected by interview from 50 foreign- and UK-owned plants in Yorkshire and Humberside. The evidence shows that higher levels of regional sourcing are observed where certain demand characteristics coincide with strengths in the supply potential of the region. A 'corporate filter' reduces regional sourcing. There were no differences in regional sourcing between foreign- and UK-owned multinationals. The findings identify barriers to policy aspirations of increased regional sourcing and emphasize that any policy initiatives should target the plants of domestic, as well as foreign, multinational enterprises (MNE).     

Guilty by Association: A Cross-industrial Approach to Sourcing Complementary Knowledge in the Uppsala Biotechnology Cluster

A wide range of industrial studies recognize the tendency of similar and related economic activities to co-locate in so-called industrial systems or clusters. While a cluster is defined by its cross-industrial relations the supporting and complementary role of cluster actors is seldom fully explored. This study will focus on the dynamics of cluster relations and give an account for the complementary nature of clusters by analysing anchor firms and complementary agents (such as specialized service providers and institutions for collaboration) in the Uppsala biotechnology cluster in Sweden. The empirical data used involves a triangulation of interview, survey and individual-based register data based upon a mapping of cluster actors active in 2002 and 2003. It is shown that both the formerly dominant pharmaceutical company and the local university have actively taken the role as anchor firms/organizations creating a local and dynamic milieu for biotechnology activities. Furthermore, it is shown that the local cluster consists of a variety of complementary agents contributing to knowledge spillovers and cluster competitiveness.     

Assessing the applicability of portable X-ray fluorescence spectrometry for obsidian provenance research in the Maya lowlands

Recent innovations in portable energy-dispersive X-ray fluorescence (PXRF) spectrometry have increased its utility for the geochemical characterization of obsidian artifacts for archaeological provenance research. However, concerns over the utility of PXRF instrumental analyses have been raised, focused on the validity and reliability of the geochemical data produced. Here we adopt the framework of Richard Hughes (On Reliability, Validity, and Scale in Obsidian Sourcing Research, 1998), whereby reliability addresses instrument stability and issues of measurement while validity pertains to an instrument’s ability to discern geochemical source provenance. This is done in order to test the utility of PXRF instruments for archaeological provenance research. k-Means cluster analysis was used to test the accuracy of PXRF through statistical comparison of data acquired via laboratory and portable energy-dispersive XRF instruments. Multivariate analysis was employed to demonstrate obsidian source representation at two Classic Maya archaeological sites in southern Belize – Uxbenká and Ek Xux – and to test the validity of data obtained from a PXRF instrument in answering archaeological research questions pertaining to regional interactions between lowland Maya polities. Results suggest that portable XRF instruments produce internally consistent results. However, data acquired from a PXRF instrument are not statistically equivalent to other XRF instruments. This is to say that while PXRF is not a reliable technique, it is valid for questions pertaining to geochemical source representation.     

X-ray powder diffraction analysis of Late Holocene reservoir sediments

X-ray powder diffraction (XRD) analysis of clays from anthropogenic Late Holocene reservoir sediments can provide a paleoclimatic proxy. Illite and smectite are climate sensitive clay minerals and their relative amounts correlate with climatic episodes. Relative percent composition of clays in Late Holocene reservoir sediment is diagnostic of different mineral source areas and their hydraulic transport processes, which are climate controlled. Climosequences of clay minerals from Late Holocene reservoir sediments are correlative with magnetic susceptibility records and provide a relatively simple and cost-effective tool for gaining insight into paleoclimate.