Archaeometry 16

Panels of certain 16th-century paintings have provided a tree-ring sequence which could be tied, by region-to-region bridging, to the Munich master chronology. The work has shown the feasibility of dendrochronology for oaks of slow and regular growth in late medieval times in a region stretching from Oxford to SE England and to Flanders and parts of France. Au(abr) See also first-named author on Tree-ring dates for some panel paintings in Enaland, Burlington Mag, 116, 1974, 250-8.

The paper argues the importance of the contribution that multivariate statistical techniques can make to the analysis of data from trace element characterisation of sources of raw material and of artefacts. A three-phase analysis is outlined and a model is developed using New Zealand obsidian. Au(abr)

Two possible sources of error in the measurement and interpretation of the specific gravities of gold coins are investigated. First, the effect of the presence of copper is found more significant than previously thought; secondly, the importance of cleaning the coins before measuring the specific gravity is also demonstrated. Au(abr)

Because of differences in their physical properties, bone, tooth dentine and tooth enamel react very differently during the course of fossilisation; care must be used in applying fluorine content methods even among bones from the same deposit. Au(abr)

It has been suggested that utilisation of the bristlecone pine calibration for 14C age correction can result in dates which are up to several hundred years too early in comparison with archaeological evidence. Among other possible causes, in situ production of 14C due to the high altitude growth region of the bristlecone pine has been proposed to explain this effect. Although theoretical evaluation indicates that a significant amount of 14C could be produced by this mechanism, irradiation of bristlecone pine wood with a neutron dose equivalent to the calculated cosmic ray maximum received by a 6000-year-old tree did not produce any detectable effect. Other geochemical considerations related to the growth environment of these trees may offer a possible explanation for enhanced 14C levels. These inherent uncertainties in the 14C record of the bristlecone pine emphasise the need for an alternative source of tree-rings for comparative correlation with the 14C time-scale. Au

The silver content within the body and at the surface of 22 Roman "bronze" coins dating to AD 274-305 was determined by X-ray fluorescence; results indicate that antoniniani and fractional coins of the period 274-294 were probably both silver-dipped and minted in an argentiferous alloy. Radiate and laureate fractions issued after 295 do not seem to have had an argentiferous alloy, nor does this analysis provide any evidence that they were silver-dipped. Au(abr)

Employing cluster analysis, patterns and relationships have been looked for within the trace and alloying elements of about 80 bronze daggers of the Wessex Culture and contemporary cultures in Brittany, together with a group of flat riveted daggers (Late Beaker type). Some Irish EBA daggers were added for comparison. The results showed that only one of the four types of daggers could be linked with a particular metal cluster, that various types of daggers were used parallel to one another over considerable periods, and that the more advanced metal clusters have an almost entirely British distribution. The Irish daggers, though they form a very homogeneous group, show no strong relationship with either the British or the French groups. Au(amp)

Presents a method for dealing with unpaired skeletal elements in order to approach the questions of (1) how many animals are represented in an assemblage; and (2) how large these individuals were. The method is designed for use with fish remains and can easily be extended to paired elements. It is shown how the interplay between the data appropriate to the solution of both problems may be compared in order to provide a method of verification of the results arrived at by standard methods of assessment of the minimum number of individuals. Au