Abstract: This twenty-fourth list of accelerator dates consists mainly of material dated since the beginning of 1994, but includes a number of measurements made earlier in the dating programme. I t also includes, for the first time, a list of samples measured incollaboration with the Centre de Datation par le Radiocarbone de Lyon: Lyon samples both pretreated and measured at Oxford have been assigned Oxford laboratory numbers in the usual way, in addition to Lyon numbers, whereas those pretreated at Lyon and measured at Oxford have only a Lyon laboratory number and the suffix '(OxA)'. All dates have been achieved by the methods described in Law and Hedges (1989), Hedges rt ul. (1989 and 1992). Determinations with OxA numbers greater than 2095 were measured on the CO, gas ion-source (Bronk and Hedges 1989) rather than on the previous iron-graphite system. In accordance with international radiocarbon convention all dates are expressed in radiocarbon years before AD 1950 (years BP) using the half-life of 5568 years. Errors are quoted as one standard deviation and are based on an assessment of all the contributions to the error in the laboratory isotope ratio measurement. Natural fractionation of carbon isotopes is accounted for by measuring the 6 ' T values relative to PDB (with errors of approximately 0.3!%0). All combining procedures and significance tests are based on Ward and Wilson (1978). Comments composed by the Laboratory on the basis of information supplied by submitters are given without attribution. Previous Archueometry datelists are referred to in the form: Arch. List 23.

Abstract: Liste des resultats d'analyses des isotopes de plomb realisees sur des echantillons de minerais metalliferes preleves sur des gisements bulgares, publiee dans la cinquieme edition de la base de donnees d'Archaeometry

Abstract: In this paper optical dating results for a range of British archaeological sediments are presented to illustrate the potential this method offers for archaeologists. The optical dating is shown to offer an absolute method for directly dating the deposition of sediments for an age range of approximately 1-300ka. Problems have been found with recuperation of the optically stimulated luminescence signal and insufficient bleaching at deposition of the sediment. A suitable correction method for the recuperation has been found and a method of identifying insufficient bleaching is suggested.

Abstract: Lead-glazed pottery from the medieval workshop of Les Olleries Majors (Paterna, Spain) has been studied by Mossbauer spectroscopy, X-ray difraction, X-ray Jluorescence and optical spectroscopy. Yellow, brown and honey-coloured glazes occur on pots glazed on only one surjace. They have virtually identical compositions and transmittance spectra, their apparent differences in colour are due to the colours of the underlying pastes. Yellow glazes occur on cream-coloured calcareous bodies, h0ne.y-coloured glazes occur on less calcareous bodies with some development of hematite, while brown glazes occur on red siliceous cooking-pots. Green glazes arejound on pots glazed on both surfaces; the glazes trapped C02 evolved by decomposing carbonates, resulting in an internal reducing environment. This caused the reduction of iron to the ferrous state which coloured the glaze green by diffusion.

Abstract: Amino acid racemization (AAR) in fossil biominerals has been used over the last 30 years to develop reliable chronologies and thermal histories in archaeological settings from all over the world. It is a biochemical reaction which progresses with time and temperature, and has the potential to be used in any material capable of sequestering amino acids (e.g., avian eggshell, molluscs, teeth, and bones). AAR is not a numerical dating method, per se; however, it can be used for a variety of chronological and palaeotemperature applications. Provided there is some independent age control, AIR can be used to extend or to improve upon the chronology, or to reconstruct the temperature history at a site. The use of AAR as a dating/ palaeothermometry tool has been somewhat underutilized by the archaeological community, presumably due to a series of errors made on studies of human bone shortly after the technique was first discovered. Since these early studies, continued exploration of AAR has demonstrated the growing power of the technique for chronological and palaeothermometry research in certain sample types, as well as some novel applications pertinent to archaeologists and anthropologists. For example, relevant information on human behaviour, including burial practices, the use of fire, and the degree of mixing at a site, can be determined using AAR. This paper presents the basic principles behind AAR and a review of the technique as it has been applied to the archaeological record. AAR in some of the biominerals commonly associated with archaeological sites is reviewed, and guidelines for sample collection presented. Finally, a brief description of some of the chromatography techniques used for amino acid analysis is given.

Abstract: This paper examines the limitations and deficiencies of the current archaeomagnetic calibration curve in use in Britain and explores a different approach to its construction, drawing on recent advances in this subject, in particular the use of a weighted moving window method of averaging. The main advantage of this method is shown to be its ability to take into account uncertainties in both the magnetic direction and the archaeological date of data used in the calibration curve, leading to a secular variation curve with an associated error estimate. Hence, when dating a magnetic direction, the uncertainties in the calibration curve can be taken into account, as well as the uncertainties in the magnetic direction to be dated.

Abstract: The preparation of glass in New Kingdom Egypt heavily involved the use of crucibles. Shape, mode of operation and function of these vessels have been reconstructed on the basis of new, stratified material from the excavation at Qantir, eastern Nile Delta. The crucible fabric, the internal layer protecting the vessel from the charge, and the glass melted in the crucibles are characterized by chemical and petrographic studies. The crucibles were apparently employed mainly to add the colourants to the glass. The broader archaeological context strongly suggests that glass production in the Late Bronze Age has been a highly developed, specialized and organized craft, with different factories for glass production, for colouring, and for working, connected by a wide-ranging trade network.

Abstract: 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.

Abstract: A recent suggestion that some ancient metallurgical processes might give rise to large changes (> 0.5%) in the isotopic composition of tin gave hope that it might be possible to identify ancient bronze samples which had undergone recycling and mixing processes. This paper describes a method for the analysis of the isotopic composition of tin by thermal ionization mass spectrometry and applies it to analyse a number of ancient bronzes and tin metal objects from the Bronze Age Mediterranean. No observable isotopic fractionation of tin was found above ±0.1% in the ratio 122 Sn/ 116 Sn. Consequently, either recycling of bronze in the Late Bronze Age Mediterranean was not so common as supposed, or the isotopic composition of tin is not fractionated by anthropogenic metallurgical processes to the extent predicted by the Bradford group.

Abstract: Publication des dates radiocarbone obtenues par acceleration de spectrometrie de masse. Ces dates concernent le paleolithique et le mesolithique de Grande Bretagne, d'Irlande, d'Allemagne ; la protohistoire de Grande Bretagne, la mediterranee orientale et du Proche Orient (Egypte, Bahrain, Oman, Israel) ; l'Afrique (Madagascar) ; l'Asie centrale et du Sud Est (le Pakistan, la Thailand, Hong Kong) et des donnees environnementales pour le Chili

Abstract: Ancient mortars from northern Italy, dating from the fifth to the seventeenth century AD, were examined in order to formulate an hypothesis regarding the origin of the white lumps often observed in these mortars and in other samples of the same geographical provenance. Various characterization techniques were employed, including scanning electron microscopy, X-ray powder diffraction and Fourier transform infrared (FTIR) and micro-FTIR spectroscopy.

Abstract: 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.

Abstract: The characterization of various samples of white marble from the archaeological site of Tharros (Sardinia) is the starting point for the reexamination of the capabilities of electron spin resonance (ESR) spectroscopy as a tool for identifying the quarries of origin of ancient marble artefacts. Existing methods and data bases are employed for the assignment of our samples, but also reviewed to see if a more extensive use of the technique is feasible. It turns out that ESR spectroscopy, coupled with other available methods, may readily provide valuable information, often yielding the final answer to the problem of marble provenance. However, it is also clear that much work has still to be done to standardize the data collection and analysis procedures and to expand the available data base.

Abstract: Inductively coupled plasma-mass spectrometry (ICP-MS) is a relatively new analytical technique, growing in popularity, that offers many advantages over previously available instrumentation for the measurement of both the elemental and isotopic composition of metallic antiquities The application of this method of analysis to archaeological metalwork is discussed and the technique compared with other methods of analysis commonly used in archaeometallurgy Particular attention is drawn to the potential pitfalls and difficulties associated with ICP-MS and the need for extremely careful sample preparation and instrument operation

Abstract: Glow discharge optical emission spectrometry (GDOES) has been used for obtaining calibration curves for copper, tin, lead, silver, antimony, arsenic, zinc and iron from standards including copper-base alloys (Cu 6133-9995%) and from bronze Punic coins The GDOES results were calibrated using atomic absorption spectroscopy with inductively coupled plasma atomization (ICPAAS) to analyse the standards and coins For all these materials, the results show that via GDOES it is possible to obtain reliable and reproducible calibration curves for copper, tin, lead, zinc and iron with a linear behaviour as a function of the content The quantitative GDOES and ICPAAS data for the coins have been also compared with those obtained via X-ray fluorescence (XRF) and it is shown that GDOES, ICPAAS and XRF agree well with one another considering that the bronze coins are inhomogeneous to some degree As an example of GDOES analytical features, a depth concentration profile through a thin bronze patina is shown and briefly discussed

Abstract: There has been a long but sporadic history of research on stone axes in Ireland, leading to the formation of the Irish Stone Axe Project (ISAP) in 1990. The purpose of this paper is to outline the research strategy of the project and to indicate the petrological techniques that are being applied in parallel with archaeological and archival studies to classify and identify potential sources for Irish stone axes. These include macroscopic studies, transmitted and reflected light microscopy on polished thin sections and X-ray fluorescence analyses. The results of the macroscopic examination of 15916 axes indicate that one rock type, porcellanite, was the dominant source, but that a wide range of other lithologies was also exploited. Several avenues for more detailed research are highlighted. A case study of gabbro axes demonstrates the value of this systematic approach to stone axe studies, and the results of this study suggest that some of these axes are petrographically consistent with British Group I, presumed to originate from sources in Cornwall, south-west England.

Abstract: Eighty-six Roman amphora sherds from the Plemmirio B shipwreck, off Sicily, have been analysed by neutron activation analysis. A large group representative of the amphora cargo, mainly of forms Africana 1 and Africana 2A (from the area of modern Tunisia), was subsequently defined. No differences between Africana 1 and Africana 2A samples were observed, thus implying a similar origin for both forms. The provenance of this cargo group was then investigated by comparison with a Roman amphora kiln data base. After elimination of the more mobile elements it was shown that the cargo amphorae were more likely to have been manufactured at kilns around Sullecthum rather than Leptis Minor. The analytical conclusions are thoroughly consistent with the known archaeological information.

Abstract: Some 630 Roman silver coins excavated at Augusta Raurica (Switzerland) have been analysed by non-destructive X-ray fluorescence and X-ray diffraction. Furthermore, the density and the weight have been determined. The measured average density of plated and massive depletion-silvered coins is lower than the density calculated from the chemical composition, whereas massive coins display equal values for both of the densities. Based on experimental X-ray investigations of modern silver (tempering, acid treatment, production of corrosion layers), the nature of corrosion products on silver, their impact on surface analysis, and aspects of wearing-off by circulation are briefly discussed.

Abstract: Archaeological artefacts identified as jet are often assumed to have originated from the principal British source, which is at Whitby in Yorkshire. Geological samples of jet have also been found within the Kimmeridge Blackstone in Dorset—a seam of oil shale which has been worked since prehistoric times to produce artefacts similar to those made from jet. This paper discusses the geology and geochemistry of jet samples from both Whitby and Kimmeridge, and shows that the geological samples can be discriminated by differences in their organic components, as elucidated by Fourier transform infrared spectroscopy and pyrolysis-gas chromatography/mass spectrometry.

Abstract: A new method for soil phosphate analysis has been developed for field measurement which will increase the applicability of phosphate mapping in archaeological prospection.

Abstract: Archaeomagnetic dating in the American south-west is progressing rapidly in terms of both method and application. Of particular importance has been the creation of a master curve of geomagnetic direction change for the region. However, confirmation, extension and refinement of this curve are always welcome contributions to the technique. So, efforts are under way to accumulate a large body of well-dated virtual geomagnetic pole positions and document these through publication so that the basis for dating samples of unknown age can be evaluated. This article adds 23 new dated pole positions to the list discussed in Eighmy (1991) and reports the results of our experiments with refining the south-west USA master curve, especially the creation of a new south-west master curve, SWCV595.

Abstract: A combination of analytical techniques, including thin-section observations, scanning electron microscopy, X-ray diffraction and X-ray fluorescence analysis, was applied to study the nature and origin of an adhesive used for mounting flint sickle blades to a wooden handle, recovered from early Eighteenth Dynasty culture layers of the multi-layer settlement at Tell el Dab'a, Lower Eygpt. The results obtained from these investigations led to the conclusion that the adhesive is a pure lime plaster, thus providing the oldest evidence for the use of this material as a binding agent so far known in ancient Egypt.

Abstract: We present results of particle size and radioactivity analyses of sediment samples collected from five sites with different burial environments. The uranium, thorium and potassium concentrations in the five sample sets are shown to vary with particle size. The potential effects of the observed size-dependent variations on electron spin resonance (ESR) dating of tooth enamel are assessed using two hypothetical models. Our results show that any bias to relatively fine fractions could result in a significant overestimation of the total environmental dose rate, leading to an underestimation of the calculated ESR age.

Abstract: A non-destructive gamma-ray spectrometry was used for direct dating of fossil animal and human bones taken from an alluvial Quaternary site in northern Italy. The ages were obtained using the U-Pa method: the chronological results are in agreement with palaeofaunal indicators and taphonomic data. The ages of two samples showed concordance with the U-Th method; in a third case good agreement was also found with the radiocarbon date, thus lending credence to our modified gamma spectrometric method.

Abstract: The chemical compositions of 14 glass beads from two Early Sarmatian-period burials were determined. Al, Ca, Fe, Mg, K, Na, and Si were measured by electron probe microbeam analysis, while the Co, Cu, Ga, Mn, Ni, Pb, Rb, Sr, Th, Ti, Y, Zn, and Zr contents were measured using energy dispersive X-ray fluorescence. All the beads can be classed as low-magnesia soda-lime-silica glasses. The blue glass beads examined in this study were coloured with Co and Cu containing minerals. Cluster analysis and principal components analysis suggest that two distinct glass recipes were used to manufacture these beads.

Abstract: A low-background germanium spectrometer was used to measure the gamma-ray spectra of the three parts of the Swanscombe skull. Detailed studies of the method showed that it was possible to make accurate measurements of the content of 226 Ra and 231 Pa but less accurate ones of 238 U and 235 U. Results from the three samples were inconsistent, showing that their exposure to radioactive ground water must have been very different, although they were found close together. The uncertainty in the ratio of 234 U to 238 U in the ground water and the lack of knowledge of the time at which the bones acquired the uranium also prevented the deduction of any reliable dates for these specimens.

Abstract: Ceramic vessels from Later Stone Age sites in the Seacow river valley, South Africa, were heavily tempered with C4 grasses. However, most δ 13 C values of the temper fall between the known δ 13 C ranges for C4 and C3 grasses. Among possible C3 additives that could skew the signal, ground bone, animal dung, alpine grass, Karoo scrub ash, and humic acid contamination are eliminated. The sherd surfaces yield fatty chars with C3-like values. Although these are not enough to account for all the skewing, they represent only the final cooking event. They were preceded by many such events in which fat was absorbed into the C4 grass then charred to soot by later periods in the fire. Thus organic carbon with the isotope composition of the fat built up while the vessel remained in use.

Abstract: The Metropolitan Cathedral of Mexico City has undergone alarmingly large differential settlings. An extensive geotechnical investigation programme was performed in its subsoil, as part of the studies required in an ongoing salvage project. The results of many of the soundings performed can be interpreted from the viewpoint of the archaeologist. This paper shows, based upon the framework provided by previous archaeological research performed in the cathedral, that the geotechnical investigations allow the unique opportunity of establishing hypotheses regarding the extent and distribution of some of the structures that existed in the ritual precinct of Tenochtitlan, as well as of its foundation.