Bulk element composition versus trace element composition in the reconstruction of an obsidian source system

It has become possible, through compositional analysis, to differentiate among discrete obsidian quarry and collecting localities within a single source area. The analytical potential of such information is considerable yet studies are seldom undertaken owing to the difficulties associated with trace element analysis.This study is intended to explore the feasibility of using bulk element data instead of trace element data in such compositional analyses. Techniques of bulk element analysis are far more accessible to archaeologists. The results of an experiment utilizing carefully controlled samples from the El Chayal obsidian source, Guatemala, are reported and discussed.     

FINGERPRINTING ANCIENT EGYPTIAN QUARRIES: PRELIMINARY RESULTS USING LASER ABLATION MICROPROBE-INDUCTIVELY COUPLED PLASMA-MASS SPECTROMETRY*

Microchemical analysis of minerals present in pottery and stone artefacts may help determine their provenance. Electron microprobe major element analyses of augite suggest that minor elements (Ti0₂,MnO, Aa₂O) are important in fingerprinting basalts. This points to the potential usefulness of trace elements. Augite present in six basalt samples (representing all known/suspected Pharaonic basalt quarries in northern and middle Egypt) and basaltic temper fragments in two New Kingdom pottery sherds was analysed for 28 trace elements (Sr, Ba, Th, U, Zr, Hf, Nb, Ta, Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu. Sc, V, Cr, Ni, Ga) by laser ablation microprobe-inductively coupled plasma-mass spectrometry (LAM-ICP-MS, laserprobe). Cluster and discriminant analysis indicate that (1) laserprobe trace element data are more effective at fingerprinting basalts than conventional electron-microprobe data and (2) basaltic temper in the two sherds does not match any of the quarries. Microbeam techniques providing trace element data may represent the future for mineral-based provenance studies.     

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.     

Quantitative EDXRF Studies of Obsidian Sources in Northern Hokkaido

Quantitative trace element data from six obsidian sources on the Japanese island of Hokkaido is presented. Previous work by Japanese scholars has utilized neutron activation analysis (NAA) focusing on the rare earth elements, or qualitative energy dispersive X-ray fluorescence (EDXRF). In this study, non-destructive EDXRF is used to generate trace element data for 9 elements. Bivariate plots of the incompatible trace elements (Ba, Rb, Sr, Y, and Zr) can be used to separate the obsidian sources in this study. Source separation was confirmed by using linear discriminant analysis. Stepwise discriminant analysis indicates that Ba, Sr, Rb, Ti, Y, and Zr are the most discriminating elements.     

Geochemical sourcing of rock specimens and stone artifacts from Nihoa and Necker Islands,Hawai'i

We report geochemical analysis of seven rock specimens and six stone artifacts from Nihoa and Necker Islands, Hawai'i. The analyzed rock specimens exhibit chemistry consistent with published data sets and establish a major element distinction between Nihoa and Necker. Their trace element data indicate that the analyzed rocks and artifacts are local in origin and they reliably discriminate from sources on Kaua'i. These preliminary results support Emory's thesis that early (archaic) Hawaiian colonists on Nihoa and Necker relied on their local basaltic stone to manufacture stone tools, containers, and other portable objects.     

The Last Domicile of the Iceman from Hauslabjoch: A Geochemical Approach Using Sr,C and O Isotopes and Trace Element Signatures

We present Sr, C and O isotope ratios and quantitative ratios of trace element ratios in the rib and the femur of the Tyrolean Iceman “Ötzi”. The results from the rib and the femur are compared with those obtained from pre-industrial historic human skull bone fragments collected in the late 19th century from charnel houses located on different geological backgrounds throughout North and South Tyrol. Comparison of strontium isotope data from the bone fragments locates the Iceman's domicile, during the last 5 to 10 years of his life, to the crystalline part of the Central Alps. Statistical analysis of the trace element ratios, together with oxygen isotope results, suggests that the Iceman probably spent most of his last years in southern elevated part of the Ötztal. However, the results from Iceman only represent those from a single individual and are not a representative average of a group. It cannot therefore be established with absolute certainty that the original trace element signatures were conserved, especially during the first stage of mummification. Our conclusions should therefore be regarded as tentative, but nevertheless the best possible indication his domicile, and a stimulus for further research.     

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.     

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.     

THE DESIGN OF EVALUATION OF ASSAYS OF TRACE ELEMENTS IN A FOSSIL BONE*

The flame atomic absorption spectroscopy method of analysis of trace elements (Mn, Sr, and Cu) in a mammoth's bone and the method of estimation of the data using regression analysis are described. The concentration fields of the single elements in a cross-section through the bone are well described by a fourth degree polynomial. The minimum values and their coordinates have been determined. A method of determination of the original concentrations of trace elements in fossil bones is described further. The approximating features of the regression exponential equations and of the diffusion functions of various shapes were determined and a method for calculating the concentrations and diffusion properties of the bones once deposited in the soil is suggested. The original trace element concentration can be estimated by extrapolation of a suitable exponential or diffusion function.     

How Mineralogy and Geochemistry Can Improve the Significance of Pb Isotopes in Metal Provenance Studies

Lead isotopes combined with trace element data represent a powerful tool for non‐ferrous metal provenance studies. Nevertheless, unconsidered geological factors and archaeological data, as well as ignored analytical procedures, may substantially modify the interpretation of the isotopic and trace element signature obtained as a potential ore candidate. Three archaeological examples, accompanied by high‐resolution lead isotopic measurements (MC–ICP–MS), are presented here to discuss the above‐mentioned criticisms and to propose some solutions. The first example deals with prehistoric/historical gold/silver‐mining activity from Romania (the Baia Bor?a and Ro?ia Montan? ore deposits). The second one regards the lead/silver metallurgical activity from the Mont‐Lozère massif (France) during medieval times. The third example focuses on the comparison between two batches of lead isotope data gathered on Roman lead ingots from Saintes‐Maries‐de‐la‐Mer, using different SRM 981 Pb values.     

Oscillatory zoning and trace element incorporation in hydrothermal minerals: insights from calcite growth experiments

Oscillatory zoning and fine‐scale variations in trace element chemistry are commonly observed in hydrothermal minerals. It has been suggested that fine‐scale chemical variations are caused by extrinsic changes in the parent hydrothermal system, such as varying fluid composition, pressure or temperature, as well as changes in mineral growth rate. In this study, LA–ICP–MS (laser ablation, inductively coupled plasma mass spectrometer) analyses were carried out on calcite crystals grown in Ca–NH₃–Cl solutions doped with rare earth elements (REE). The variety of crystal morphologies observed (euhedral to acicular), likely relate to variations in trace element abundance and calcite supersaturation state. Crystals display oscillatory and sector zoning, with significant variations in REE concentrations among zones. Cyclic variations in REE concentrations (exceeding 10‐fold) occur over distances of <1 mm along the growth direction of acicular calcite crystals. In general, trace element concentrations decrease during progressive crystal growth, implying that the concentration of trace and REEs within crystals reflects the overall composition of the growth solution. However, bulk changes in crystal composition are modulated by fine‐scale (<1 mm) variations, which are inferred to be caused by growth‐rate‐controlled incorporation of trace elements. These results have important implications for using hydrothermal minerals to infer fluctuations in fluid compositions in ancient, exhumed hydrothermal systems.     

TRACE ELEMENT CONTENT OF ROMAN LEAD BY NEUTRON ACTIVATION ANALYSIS

The trace element contents of 13 lead pigs and 20 water pipes, all of Roman origin, were determined by instrumental neutron activation analysis. The contents of Cu, As, Ag, Sn, Sb, and Au were determined with an experimental reproducibility of ±7%; the analytical values are given for all samples. The results are discussed with respect to the homogeneity of samples, the difference between pipes and pigs, the difference between bulk and joint material in pipes, and the possible correlation of the trace element contents with the place of origin.     

Evidence for the trade of Mesopotamian and Egyptian glass to Mycenaean Greece

The origins of raw glass used to fashion Mycenaean beads were explored using trace elements analyzed by laser ablation ICP-TOFMS. The use of this minimally destructive technique for the in-situ analysis of these beads was ideal given that the material is exceedingly rare and thus too sensitive to make use of traditional micro-sampling (e.g., by scalpel). A wide range of trace elements were measured to compare these Greek glasses to other Late Bronze Age glass coming from Egypt and Mesopotamia. Of the eleven beads analyzed, four blue glasses colored with cobalt and two blue/green glasses colored with copper have trace element compositions consistent with an Egyptian origin of manufacture. The other five of the glasses, all colored with copper, were found to conform to the composition of Mesopotamian glass. These data are the first to demonstrate direct and clear evidence for the trade of raw glass to the Mycenaean states.     

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.     

DISCRIMINATING SOURCES OF MEDITERRANEAN MARBLES: A PATTERN RECOGNITION APPROACH

A computer-based pattern recognition procedure has been applied to trace element data obtained from marble samples of different Mediterranean quarries. Nineteen elements, mostly hydromagmatic and rare earth elements were first determined by neutron activation analysis. These elemental concentrations are then used as the data for further multivariate analysis. The results indicate significant differences in chemical patterns of the marble sources.     

Partitioning of trace elements between the ores, fluxes, slags and metal during the smelting of copper

This paper gives the results of smelting seven parcels of copper ores from well-known mining areas. The behaviour of the trace elements introduced from the ore, the fuel, and the fluxes has been investigated by analysis of the main products, metallic copper and the slags. Most of the ores were capable of giving copper of relatively high purity and therefore, in order to represent conditions believed to have existed in the Early Bronze Age, two artificial ores were made up and copper high in arsenic and nickel was obtained.The results show that it is relatively easy to smelt a wide range of copper minerals to give copper of high purity apart from iron. This latter element can be removed by careful refining. The remaining elements are present at the parts/10³ level. Wood fuel is thought to contribute little to the trace element pattern. Even if it did, it would merely reinforce the elements already contributed by the ore and flux as the timber is likely to have been grown in the immediate vicinity of the ore and will probably contain the same trace elements.Useful comparison is made between the trace element pattern resulting from these smelting runs and material from archaeological sites in the vicinity of the mining areas.     

Does it come from the Pays de Bray? Examination of an origin hypothesis for the ferrous reinforcements used in French medieval churches using major and trace element analyses

A new methodology based on major and trace element analyses of slag inclusions is proposed to determine (or exclude) the provenance of iron artefacts. It is applied to verify if the Pays de Bray, a French area between Rouen and Beauvais, could have been an important supplier for the ferrous reinforcements used in the Middle Ages for the building of churches and cathedrals in these two towns. To this purpose, the behaviour of trace elements during both direct and indirect operating chains is studied combining experimental smelting and different analytical methods, such as SEM–EDS, ICP–MS, LA–ICP–MS and INAA, performed on archaeological samples. The chemical signature of the Pays de Bray iron ore and slag is determined considering MnO and P₂O₅ contents as a first rough filter and seven couples of trace elements. Then, the major and trace elements are analysed using the same methods in the slag inclusions of 32 artefacts from the Beauvais and Rouen churches, made by the bloomery process. The trace element signature of the inclusions from each artefact is compared with the ore from the Pays de Bray area. The iron used in the Rouen and Beauvais churches seems not to come mainly from the Pays de Bray.     

Migration and mobility at the Late Lapita site of Reber–Rakival (SAC), Watom Island using isotope and trace element analysis: a new insight into Lapita interaction in the Bismarck Archipelago

This paper uses strontium isotope (⁸⁷Sr/⁸⁶Sr), oxygen isotope (δ¹⁸O) and Ba/Sr trace element data in archaeological tooth enamel samples to investigate migration and mobility at the Late Lapita site of SAC, Watom Island in the Bismarck Archipelago. Previous archaeological models have identified Lapita mobility at a community level using obsidian distribution patterns and changes in ceramic design, whereas isotope and trace element data can potentially reconstruct prehistoric mobility on an individual level. Human and pig teeth were sampled from SAC and a selection of human teeth were included from the Late–Post Lapita site of Lifafaesing, Tanga Islands as a geographic/geological comparison.The results indicate that there is a large amount of isotopic variation in the Bismarck Archipelago which is useful for identifying non-local individuals and possibly determining their origins. One human individual and several pigs were suggested as coming from elsewhere in the region. Three potentially separate locations were identified for the non-local pigs. It is argued, using the data from SAC, that Late Lapita communities in the Bismarck Archipelago were more mobile than previously assumed. The potential for identifying individual migrants in a Lapita context are discussed in terms of assessing the more subtle aspects of Lapita society in the Southwest Pacific Islands.     

A LOW DILUTION,WAVELENGTH-DISPERSIVE X-RAY FLUORESCENCE PROCEDURE FOR THE ANALYSIS OF ARCHAEOLOGICAL ROCK ARTEFACTS

A method is described for the analysis of archaeological rock artefacts which provides major and trace element data. Wavelength-dispersive X-ray fluorescence (WDXRF) analysis of 2:1 fusion beads permits the accurate and precise measurement of a wide range of elements. Accuracy and precision are nominally 1-5% for elements having concentrations above 3 times the detection limit. The method requires a much smaller sample size than conventional WDXRF procedures and has been successfully used to characterise early millstones; a number of other applications in archaeology are suggested here.     

何郢遗址出土青铜器铜矿料来源的初步研究

本文利用地球化学示踪的方法对何郢遗址出土青铜器的铜矿料来源进行了初步研究.采用ICP-AES测试了样品的微量元素,根据元素的地球化学亲和性,探索其在冶炼过程中的化学行为和再分配规律,从而选出对铜绿山和皖南的铜陵、南陵铜矿具有指示意义的特征元素,作为判断其铜料输出路线的综合判别标志.结合文献和地质资料,可初步认为何郢遗址青铜器的铜矿料来自滁县.