Abstract: Mechanical testing of lithologies used for stone tool manufacture has shown that fracture toughness is the most objective measure of the quality of raw materials shaped by either flaking or pecking/grinding. Materials amenable to pressure flaking and blade manufacture have low values of fracture toughness, whereas those shaped by pecking/grinding have high values. The fracture toughness test is also the most definitive for quantifying the improvement in flaking properties of materials subjected to intentional heat treatment. Cryptocrystalline and macrocrystalline siliceous lithologies demonstrate a well-defined, gradual reduction in fracture toughness with increased temperature. When heated to optimum temperatures, their fracture toughness approaches that of obsidian, the lithology generally regarded as having the best flaking properties.

Abstract: RQ-mode principal components analysis (PCA) is a means for calculating variable and object loadings on the same axes, so that elements can be displayed along with data points on a single diagram. The biplots resulting from RQ-mode PCA preserve both Euclidean relations among the objects and variance-covariance structure. When used with data on the chemical composition of archaeological pottery, such biplots facilitate recognizing compositional subgroups and determining the chemical basis of group separation. RQ-mode PCA is illustrated in this paper with neutron activation data on Mesoamerican Plumbate pottery.

Abstract: A multidisciplinary programme of research on Islamic pottery has been focused on questions of the dating, provenance and technology of Islamic pottery. One particular question has been the development of stonepaste, a material made primarily of crushed quartz with added frit-glass and clay. The combination of the different approaches of this study has revealed early foundations for the technology in ninth-century AD Iraq, apparently originating in the clay ceramic rather than the ‘Egyptian faience’ tradition. Subsequent and final practice developed in tenth- and eleventh-century AD Egypt. This technology becomes the primary body for all fine Islamic ceramics.

Abstract: (Res.d'A.) La sensitivite et la precision des microanalyses quantitative d'elements majeurs, mineures ou de traces d'anciennes pieces de verre par spectrometrie emetrice d'energie (EDS) est comparee a l'analyse par spectrometrie emetrice d'ondes (WDS). Bien qu'il existe certains problemes avec EDS, dus aux bruit de fond et aux chevauchements de charges maximum, la precision et les limites de detetection minimum d'EDS des elements de verre les plus importants ont ete favorablement compares a ceux de WDS. En ce qui concerne l'evaluation par comparaison de standards, EDS et WDS peuvent produire des resultats efficaces, adequats a la plupart des questions technologiques

Abstract: Sixteenrlt- ancl seventeentbcentury Europeart blue glass tracle beadsfrom aborigirtal sites irt the easteru Great Lakes area of North Anterica have been attalysed nort-clestructivellt using low nentron dose instruntental neutron activation analy.vs, so rltat rhe beads coulcl be returned to their keepers. Dark blue (cobalt-coloured) beads are readily separable front Iurquoise (copper-coloured) beads. Dffirences in the chentistries of tie rurquoise blue beads appear to be useful in separating glass beadsfront tlte two ceituries. Lor+,calciurrt, sixleentlr-centur)' lurquoise beads tend to distintegt'ate by a leaching of tlte alkali ntetals.

Abstract: 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.

Abstract: Description des resultats d'une prospection geophysique sur le centre urbain precolombien de Teotihuacan (Mexique), dans les environs de la Pyramide du Soleil. Le but de la prospection etait de localiser un systeme de tunnels souterrains. L'hypothese proposee dans cet article est la suivante : ce systeme de passages souterrains a ete creuse, a l'origine, dans le but de fournir la ville en materiaux de construction, puis a ete utilise a des fins ideologiques (rituels, culte, astronomie, etc.)

Abstract: This paper presents the body analyses of 70 sherds of ceramics made in north China during the Late Tang and Northern Song dynasties (c. AD 80–1200). The major types represented are Ding, Xing and Cizhou-type wares. The analyses were obtained by atomic absorption spectrometry, giving information on nine major and minor constituents. These have been used to differentiate chemically between the major kiln sites in the north, with the aid of multivariate computer analysis. This has demonstrated that there are differing chemical characteristics associated with these kilns, but the study is hampered by the lack of authentic material from controlled excavations of the kiln sites.

Abstract: Statistical methods in conservation science are reviewed, with an emphasis on deterioration and treatment studies. A survey of all articles published in two major conservation journals during the period 1981–1992 shows that less than one-third of the papers reported any statistical analysis; most that did included only simple descriptive statistics. Basic components of experimental design that impact subsequent data analysis and interpretation are discussed in the context of conservation research. An overview is given of statistical methods particularly useful to conservation scientists. Some of the most important are correlation analysis, regression analysis, t-tests, analysis of variance, and the Kruskal-Wallis test.

Abstract: The simultaneous measurement of different physical properties of the soil with a single apparatus can be of value in archaeological prospecting. This paper establishes, from theoretical calculation, that the use of the medium frequency range allows the determination of the soil permittivity as well as of the soil conductivity with a Slingram electromagnetic device.

Abstract: The black inlay decoration with superb marine, hunting and other scenes on Mycenaean bronze daggers and silver cups has often been referred to in the literature as niello—a mixture of sulphides of copper, silver or lead—despite the absence of any systematic analysis of these precious metal artefacts. This paper presents semi-quantitative surface analyses of an example of black inlay on a Mycenaean dagger, now in the Archaeological Museum at Patras in Greece. Using non-destructive X-ray fluorescence spectrometry, it has been established that, contrary to the traditionally-held view, the black inlay is a copper-gold alloy with some silver and possibly small amounts of tin.

Abstract: 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.

Abstract: The raw material used largely determines the type and quality of porcelain produced. Twenty-three raw materials used for making Ding, Xing, Gongxian and Dehua porcelain bodies were studied using principal component analysis. Results show that for Dehua wares, only one raw material was used. For Ding wares, although there were many possible raw materials, the use of one alone is unlikely. Lingshan clay was the main raw material but it has to be mixed with other raw materials: Pinjiawa clay, quartz, feldspar and dolomite. The Xing pieces can be divided into three groups and Gongxian wares into two groups, which are discussed in detail.

Abstract: A ground-penetrating radar study of medieval kiln sites located near Suzu city, on the Noto peninsula, was conducted prior to excavation. Archaeological site plans estimated from time slices of the closely-spaced parallel radar profiles are compared with excavations and a proton magnetometer survey. The results indicate that non-destructive remote sensing with radar can help to determine effectively the presence and general structural features of intact kiln floors.

Abstract: Microprobe and digitized electron-backscatter image data reveal that eighteenth-century Bow porcelain consists of a silica polymorph(s) (25–43 vol. %), a calcium phosphate phase (42–55%) with homogeneous and stippled textural variants, and a silicon-, aluminium-, and calcium-rich, former melt phase represented by discrete domains (14–20%) and micron-scale blebs that occupy 20–70% of the stippled calcium phosphate. Bulk compositions calculated from these data are deficient in calcium phosphate components and more siliceous than those determined by microprobe analysis of fused powders of the same samples. This reflects difficulties in determining representative values for the composition and volume of the melt phase, and underscores the limitations of the method where applied to media containing compositionally- or texturally-heterogeneous phases.

Abstract: Limestone from quarries known to medieval craftsmen and from the monuments they built and embellished, as well as from carvings now in museum collections, has been characterized by neutron activation analysis. Specimens from 38 quarries in the Lutetian and Jurassic limestone formations of France and from sculptures in American and French museums have been tested, and the results have been compiled in a data base to which art historians may refer when attempting to determine provenance for sculptures. Multivariate statistical analysis of concentration data shows stone from a particular quarry in the Paris basin to be compositionally homogeneous and distinguishable from other quarries in the same formation. The same approach to data related to quarries near the Burgundian abbey of Cluny finds general agreement between classifications based on compositional and on petrographic data, but the number of samples available for analysis at the time of writing was insufficient to achieve the finer distinctions reported for the Paris basin.

Abstract: 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.

Abstract: The vallum is a major earthwork along the south side of Hadrian's Wall. All surface traces of it have been obliterated over a 500-m-long stretch past the fort of Vindobala at Rudchester, Northumberland. To the west of the fort, the vallum's course had previously been delineated by running shear-wave seismic refraction lines to obtain depth profiles of rockhead. We have now run more seismic refraction lines, using both shear waves and compressional waves, to the south-west and south of the fort, and thereby located the complete course of the vallum at Vindobala. The seismic refraction technique is successful at this site because the glacial drift cover is thin, so the vallum ditch was cut down into bedrock. During the second phase of seismic work, compressional waves gave better results than shear waves. Previously, test profiles using compressional waves had failed to locate the vallum ditch west of the fort where the surface elevation is lower; we now interpret that failure as being due to a shallow water table within the drift, which would have eliminated the compressional-wave velocity anomaly. Although the vallum does not pre-date the fort at Vindobala, its asymmetrical course around the fort suggests that it may already have been under construction to the west when the decision to build the fort was taken.

Abstract: The recently-developed laser microprobe 40argon-39 argon technique has been used to give a geological date for a rhyolitic tuff stone axe fragment from the Stonehenge environs. The method requires only milligramme-sized samples and gives dates of sufficient accuracy to aid in provenancing artefacts to sources, as well as information on the heating history of samples. The axe sample is of Lower Carboniferous date (341 ± 5 Ma) and this limits possible sources to outcrops within the Scottish Midland Valley and small altered exposures in Dartmoor. X-ray fluorescence analysis of the axe suggests the Scottish Midland Valley as the more likely source. The laser argon analysis also shows that the implement had not been heated in antiquity. Laser argon-argon dating can, therefore, be a useful tool in artefact study.

Abstract: The walls and floors of the Minoan settlement of Gournia (Crete) have retained a perpendicular relationship since their construction between 3650 and 2025 BC. Their present orientation indicates that they were tilted in unison in an east-south-east direction. This was established by the reconstruction of a representative block, of which the side planes and the base plane were defined by the present orientation of the wall and floor remnants respectively. Stereographic projection methods, derived from geological practice, were used to determine the geometric elements and the orientation of the representative block.

Abstract: Discriminant analyses of distances and angles obtained from 25 coins struck by P. Crepusius in 82 BC permitted the correct chronology for five groups of closely-related dies to be obtained by the method of Carter and Frurip. Twenty distances and 15 angles were measured on 10 x projections of the coins which represented five groups of dies separated in time from each other. The use of all or many variables gave poorer results than the use of five to ten variables having a high ‘figure of merit’, defined as the maximum range of mean values for a given variable in the five groups of dies divided by the mean standard deviation of the variable in the five groups. It is recommended that chronologies of ancient coins be determined from Mahalanobis distances by using only variables of relatively high figure of merit.

Abstract: We have developed a simple field kit for identifying C4 plants, the use of which requires little technical training The system has proven very useful for surveying plants in areas for which carbon isotopic dating and dietary studies are to be undertaken

Abstract: 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.