Abstract: A thermoluminescent (TL) glow-curve peak occurs around 110°C for the mineral quartz. Its sensitivity may be changed by application of a radiation dose (termed the pre-dose) followed by a heating of the quartz to 500°C: heating alone causes no sensitivity change. The enhancement observed (measured relative to the sensitivity of the peak prior to heating) is a measure of the magnitude of the pre-dose. For quartz extracted from pottery the sensitivity enhancement induced by laboratory heating records a natural pre-dose, i.e. the accumulated dose experienced during archaeological burial. The latter quantity is used in TL age-determination and a test programme is reported on the application of the pre-dose dating method to sites covering the Roman era in Britain forward to modern times.

Abstract: A statistical approach to the display of sets of 14C dates is suggested. All available dates of any particular culture are used to calculate the two quartiles and the median dates for it. The ‘dispersion’of the dates is then displayed as a bar showing the extreme dates, the quartiles and the median; thus neither individual dates nor their standard deviations are shown. This ‘dispersion diagram’saves much space when the dates of several cultures are to be displayed. The argument is developed that the inter-quartile range, which does not change very much when new dates become available and are added to the set, is a good index of the time span during which a culture flourished, and this range should normally be quoted rather than the mean, median or extreme dates of the culture. With samples of nine or more it can be shown by the Hypergeometric Distribution that there is a 97% chance of two cultures being different if their inter-quartile ranges just fail to overlap, so that this method of display is useful in assessing the overlap of cultures. The fact that the dispersion diagram contains within it a measure of the statistical uncertainties of the individual estimates and therefore can replace the standard deviation of each individual 14C date is discussed.

Abstract: An obsidian source can exhibit considerable variations in chemical composition. One such flow at Borax Lake in Lake County, California has been carefully investigated by neutron activation analysis of specimens from a number of different loci. Composition variations were found to exist but the six elements discussed are linearly correlated with the total iron concentration. Artifacts can be compared to the obsidian source compositions by observing the fit of the data points for the artifacts on the chemical variation diagram obtained for the obsidian source.

Abstract: 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.

Abstract: Soil samples were collected from a deep sounding through the centre of a tell, 11 m in height, at Sitagroi in north-eastern Greece. These samples were analysed for particle size and total phosphate in order to elucidate the formation of the tell. The phosphate results, though very varied, indicated that the tell evolved entirely as a result of occupation of the site. It is proposed that the main process of accumulation was from house collapse and that local alluvium was used for house construction. A similarity is shown between local alluvium, a remnant of a house wall and most of the samples from the deep sounding. Pearson type 1 curves are fitted to the particle size data and this permits a grouping of soil samples. Some of the divisions between the groups coincide not only with occupation phase changes but also with localized lower phosphate contents. Two periods of site abandonment are suggested.

Abstract: Combination of the routine approaches of thermoluminescence dating, the fine-grain and inclusion methods, allows an age to be determined that is independent of knowledge of the environmental dose-rate. This socalled subtraction technique is exampled by several terracottas of museum origin and some pottery collected from archaeological contexts without associated burial media. Age determination is estimated to have an accuracy of around ± 12%, in favourable conditions.

Abstract: X-ray fluorescence analysis of 30 pieces of Anglo Saxon jewellery, from the Ashmolean Museum, Oxford, is followed by a comparison with similar results obtained from contemporary coinage. The standards of fineness for the coinage are applied to the jewellery and used to date its manufacture. An appendix describes repeatanalyses of some coins which, at first, had widely differing results from XRF and specific gravity methods.

Abstract: Measurements of the remanent direction in forty-eight fired structures are reported, spanning 500 b.c. to the present. From the third to the fourteenth centuries a.d. there is continuous coverage and the composite Declination and Inclination curve shows counterclockwise motion.

Abstract: Archaeomagnetic intensity measurements are reported for 200 leaked clay samples taken from bricks, pottery kilns, furnaces and hearths, etc.

Abstract: A technique is described by which the spatial distribution of uranium as well as of thermoluminescent minerals can be examined in the same archaeological sample. The uranium distribution is replicated on an aluminized plastic film with the help of a ‘spark counter’following reactor-irradiation of the sample, while the TL pattern is photographed directly from a γ-irradiated sample. Implications for dating from such a comparative examination are discussed for certain pottery and flint samples.

Abstract: The forms of inhomogeneity in metals and their origins are discussed in relation to the significance of analysis in an archaeological context. Particular consideration is given to the inhomogeneity that can arise from the redistribution of solutes during the solidification of an alloy casting.

Abstract: The glazes and bodies of fifteen Persian ceramic objects datable to c. A.D. 1300 were analysed by X-ray fluorescent and optical emission spectroscopyin order to test the veracity of parts of Abū'l-Qāsim's treatise on pottery manufacture. The results showed that the bodies of these pots were closely akin to so-called Egyptian faience, and it is suggested on the basis of textual evidence that this body was used in Persia before the Seljuq period to imitate Chinese pottery, and may have been developed either from beads or glass.

Abstract: Previous work on iron-arsenic alloys has shown that considerable superficial arsenic enrichment occurs during oxidation at high temperatures. This process is very likely to be the explanation for the layers of high arsenic concentration that have been observed in the microstructure of early iron artifacts by many workers. Experiments have been made to determine how far the alternative theory of the use of Fe-As alloys as joining media could be responsible. It has been shown that Fe-As alloys can in some cases facilitate joining but that when they do the resulting joint is embrittled. When the arsenic concentration is reduced sufficiently to avoid this there is then no advantage over the normal hammer welding without an arsenic interlayer. Similar experiments have been carried out with phosphorus and similar conclusions have been drawn.

Abstract: A method of evaluating the pore-size distribution of pottery is described and results obtained from a number of samples ranging from Neolithic to modern pottery shown graphically. The method may serve to distinguish between similar-looking sherds if no other means of identification exists, but further work is needed before a series of determining curves can be established.

Abstract: Two samples of obsidian projectile points from northwestern Nevada, one surface collected and the other excavated, were subjected to obsidian hydration measurement. The temporal ordering of the three projectile-point types in each of the two samples was demonstrated to be the same on the basis of their hydration measurements. The validity of this temporal ordering of the projectile-point types in the two samples was confirmed by the stratigraphic sequence of the types in the excavated sample. We have found that surface-collected obsidian artifacts can be relatively dated by hydration measurement. In northwestern Nevada they hydrate at a rate almost double that of their excavated typological counterparts, but their relative ordering remains the same.

Abstract: A comparative study is made of the thermoluminescence (TL) of terracottas of the Renaissance era and some known limitations of such ware dating to the middle of the last century. The data shows that conclusions on authenticity of an unknown work can be reliably obtained using this scientific method. Also examples are presented of accurate dating of genuine terracottas despite a lack of knowledge about the environmental circumstances of each piece's archaeological past.

Abstract: This paper describes the application of some further statistical methods for the calibration of floating treering chronologies to data pertaining to the Neolithic settlement at Auvernier. The more general statistical approach utilizes the information contained in the successive time-derivatives as well as the absolute values of the bristlecone pine calibration curve, by fitting polynomial or piecewise polynomial curves, thereby producing better estimates, in general, of the absolute dates of the floating chronologies. Presentation of results in terms of joint confidence regions enables the relevant stratigraphic evidence to be included in the analysis by simple graphical means. In addition, the paper offers a new approach, using only floating tree-ring chronologies, to the testing of Libby's principle of simultaneity.

Abstract: The application of the recently developed thermoluminescent method of pre-dose dating to thirty-seven glazed ceramics, purporting to have been manufactured during the T'ang Dynasty in China (a.d. 618–906), is reported. The modern origin of eight of these pieces is established. The remaining twenty-nine authentic pieces are discussed with respect to the accuracy of dating possible for such wares. The criterion for authenticity judgement commonly used for this material, that of glaze crackleur, is discussed critically and shown to be of only limited reliability.

Abstract: The use of Mossbauer effect spectrometry as a tool to study iron-bearing materials in works of art is introduced. A large range of pigments containing iron has now been surveyed. In addition, some interesting conclusions concerning the distinction between two types of terracotta is presented. The method, which can be applied completely non-destructively, has great potential for purposes of identification and authentication.

Abstract: In the neutron activation analysis of museum specimens, for which sampling is not permitted, corrections must be applied to measured activities to take into account the sample shape and its position relative to the detector. Correction factors are derived for samples of cylindrical shape such as segmented faience beads and a model technique is suggested for those of irregular shape such as flint and obsidian implements. These techniques used in gamma-ray spectrometry with lithium-drifted germanium detectors enable elemental concentrations to be determined from the measured count rates.

Abstract: Fired bricks are used in archaeomagnetic work to determine the Inclination I of the earth's magnetic field at the time of firing. However, in addition to the usual mean error of between ± 1/2° and ± 2° due mainly to inexact levelling of the bricks during the firing, there is a systematic error in the measured mean value of the Inclination that may amount to 2° or 3° at high magnetic latitudes (I˜ 80°), while at lower magnetic latitudes (I< 60°) it is usually less than 1/2°. A method of correction based on the measured statistical spread of the bricks is suggested.

Abstract: Non-destructive methods of chemical analysis always involve uncertainties, and in some circumstances they can be quite unsuitable for a true analysis. The greater value of a completely destructive chemical analysis and a comprehensive metallographic study for revealing the intentions of the moneyers and the entire metallurgical history of an ancient coin is demonstrated for the case of a rare silver-coated debased silver issue of the early fourth century A.D.

Abstract: Neutron activation analysis has been employed for the characterization of Samian ware sherds. The analysed samples were classified in ten groups, seven of which belonged to the Arretine production, according to archaeological evidence. By means of high resolution gamma-ray spectroscopy, 22 elements have been identified and analysed. Compositional characterization was looked for by taking counting rate ratios of different nuclides in the samples. The compositional pattern of the sherds was found to be fairly uniform both for each pot and for each group so that, at least in the examined cases, it can be assumed to be characteristic of a given workshop.

Abstract: A new X-ray fluorescent analyser is described which uses a miniature X-ray tube or radioisotope source as alternative means of primary excitation. The advantages of this approach as compared to previous methods, particularly where elements low in the periodic table are concerned, is discussed. The second part of the paper describes an application of the technique. The non-destructive analysis of valuable ceramics, where elements low in the periodic table are important for differentiation purposes, has previously presented a problem. By using the ‘Isoprobe’such measurements are possible. In this instance the separation of early Chinese porcelains into Northern and Southern production groups is shown to be possible. Although samples have been ground from the wares for comparison with optical emission spectrometry, it is shown that analysis of the unglazed portions of the pots themselves gave similar results.