ARCHAEOLOGICAL AMBERS FROM NORTHERN ITALY: AN FTIR–DRIFT STUDY OF PROVENANCE BY COMPARISON WITH THE GEOLOGICAL AMBER DATABASE*

European geological ambers of five different localities and types, and Italian geological ambers from seven different deposits have been studied with Fourier transform infrared spectroscopy (FTIR) and diffuse‐reflectance infrared Fourier transform (DRIFT). Ambers from several localities have been characterized for the first time. The research aims to create a database of European ambers, containing both FTIR and DRIFT data. The FTIR spectra are easily comparable with the data commonly available in the literature, whereas DRIFT analyses are shown to be more useful to characterize the archaeological finds. The provenance of several archaeological ambers from northern and southern Italy, dating from the Middle Bronze Age to the Iron Age, is assessed on the basis of the developed database. Of the 35 analysed archaeological objects, all but five are composed of Baltic succinite amber.     

BRONZE AGE CHILDHOOD MIGRATION OF INDIVIDUALS NEAR STONEHENGE,REVEALED BY STRONTIUM AND OXYGEN ISOTOPE TOOTH ENAMEL ANALYSIS*

Contrasting lifestyles are recorded by the isotope composition of Bronze Age Beaker people (c. 2500–2000 bc ) from three burial sites (Boscombe Down, Normanton Down and the ditch around Stonehenge) at or near to the Stonehenge monument in Wiltshire, southern England. Seven individuals (three adults, a sub‐adult, two juveniles and an infant) were recovered from a single grave at Boscombe Down. Strontium and oxygen isotope analysis of tooth enamel from two teeth (a premolar and third molar) from each of three of the adults in this grave (referred to as Boscombe Bowmen) show that they had all shared a pattern of mobility and migration during their lives. The three adult males spent their early childhood (as represented by data from the premolar teeth) in an area with a radiogenic ⁸⁷Sr/⁸⁶Sr isotope signature of around 0.7135. They each then moved, during early adolescence (as represented by the third molar results), to a less radiogenic area, where they acquired an ⁸⁷Sr/⁸⁶Sr signature of around 0.7112. This implies that they must then have travelled to the Stonehenge area of Wiltshire at a later time in their lives. Wales provides the closest area with rocks that supply suitable ⁸⁷Sr/⁸⁶Sr ratios and δ¹⁸O isotope compositions for these individuals, although other areas of Palaeozoic rock, such as Scotland and parts of Europe, cannot be ruled out. Enamel from the two juveniles from the Boscombe Down burial yields ⁸⁷Sr/⁸⁶Sr ratios of 0.7098 and 0.7099, and strontium concentrations for both of 55 ppm. The very close match of the data for the two juveniles supports the possibility that they were raised in the same environment. The difference in strontium isotope data between the juveniles and three adult males described above shows that the children did not come from the same homeland as the adults with whom they share a grave. The two adult males from the single burials at Normanton Down, and from Stonehenge itself, had static lifestyles and show no evidence of migration, in contrast to the Boscombe Bowmen. Their oxygen and strontium data are consistent with a childhood in the Stonehenge area.     

TL DATING OF BURNT LITHICS FROM BLOMBOS CAVE (SOUTH AFRICA): FURTHER EVIDENCE FOR THE ANTIQUITY OF MODERN HUMAN BEHAVIOUR*

This paper presents the first TL dates for burnt quartzites and silcretes from the Still Bay layers of Blombos Cave (South Africa). These layers contained engraved ochres and marine shell beads that could be an early manifestation of symbolic and thus ‘modern’ behaviour by the Middle Stone Age humans. The procedure devised to calculate the ages is presented in detail, particularly with regard to internal microdosimetry, because the problems faced in estimating the dose rates require an approach different from the one usually used on flints and sediments. A mean age of 74 ± 5 ka was obtained for five burnt lithics unearthed in the BBC M1 member of the Still Bay layers. This result is in good agreement with both ESR dates on teeth and OSL dates on sediment, and demonstrates the great antiquity of the archaeological remains discovered at Blombos Cave.     

THE PROVENANCE OF IRON ARTEFACTS FROM MANCHING: A MULTI‐TECHNIQUE APPROACH*

Iron finds from the Celtic oppidum of Manching in southern Bavaria (Germany) are analysed in view of their possible provenance. The exceptional size and the location of Manching are usually attributed to the presence of abundant iron ores in its vicinity. After a review of previous approaches for source determination of iron artefacts, we introduce lead isotope analysis as a new approach. However, only by combining the trace element patterns of slag inclusions and iron metal with lead isotope ratios in the metal is it possible to distinguish various iron ore formations near Manching. As a result, it turns out that, indeed, the most obvious ones—namely, bog ores near the Danube—constituted the main resources for iron production at Manching. It was even possible to select one occurrence as the most likely ore source.     

METALLURGY OF BRONZE USED IN TOOLS FROM MACHU PICCHU,PERU*

Although the tin‐bronze artisans’ tools found at Machu Picchu appear to have been cast to their final shape, examination of their microstructures shows that they were forged and annealed. As found, the tools were broken or cracked due to poor ductility of the bronze. Rolling and annealing of samples of bronze formulated with sulphur and iron additions to replicate the metal used at Machu Picchu show that the minimum amount of deformation needed to induce the observed recrystallization is a 12% reduction in thickness. The sulphur and iron impurities retard nucleation of new grains during annealing, but do not inhibit subsequent grain growth. Tensile tests show that while up to 10% porosity in cast bronze has no effect on hardness or initial strain‐hardening rate, it reduces the tensile strength and ductility enough to embrittle the metal. Hardness is an inadequate indicator of the strength properties of cast bronze intended for use in tools or weapons. The results show that when the metalsmiths at Machu Picchu started making bronze tools for use by stone and woodworkers, they had not mastered the art of making metal with adequate strength properties for this service. The forging and annealing procedure they used did not enhance the mechanical properties of their tools, and may reflect an inherited metallurgical tradition.     

INSIGHTS INTO NORTH MESOPOTAMIAN ‘METALLIC WARE’*

With the aim of shedding new light on the still poorly understood North Mesopotamian metallic ware, ceramic and soil samples from Tell Beydar (northeastern Syria, third millennium bc ) were investigated using a range of analytical techniques, including optical microscopy, SR–XRD and SEM–EDX. The objective of this work was to differentiate calcareous metallic ware from non‐calcareous ware without the aid of chemical analyses and to find further validation of the existing hypothesis that the former group is an imitation of the latter. A third group of metallic wares from Tell Beydar is believed to be of non‐local, still regional origin.     

REGIONAL VARIATIONS IN BLOOMERY SMELTING SLAG OF THE IRON AGE AND ROMANO‐BRITISH PERIODS*

This study highlights regional variation in the composition of iron‐smelting slag produced in England prior to the medieval period and attempts to link slag composition to the type of ore smelted. For many sites, the slag compositions were consistent with the use of limonite ore, but there is evidence that siderite ore was smelted at sites in Sussex in the late Iron Age/Romano‐British periods. A compositional comparison of smelting slags and slag inclusions in Iron Age currency bars, using data from Hedges and Salter (1979 ), illustrates the potential of smelting slag compositional data in provenance studies of early iron objects.     

GEOCHEMICAL PROVENANCE OF OBSIDIAN ARTEFACTS FROM THE MSA SITE OF PORC EPIC,ETHIOPIA*

Obsidian geochemical analysis has become an indispensable tool in archaeological research and has wide applications. However, in spite of the abundance of geological and archaeological obsidian, there has been virtually no such investigation in Ethiopia. Recent instrumental characterization of 31 obsidian artefacts from the Middle Stone Age site of Porc Epic and numerous obsidian geological sources show that artefacts were being transported from as far as 250 km away. We believe this has relevance to the understanding of the emergence of modern human behaviour.     

ARCHAEOLOGICAL DATA ANALYSIS AND FUZZY CLUSTERING

Cluster analysis is widely used in archaeological data analysis. Fuzzy clustering is a more modern technique than methods normally used by archaeologists and has not been much exploited. Applications that have been reported are sometimes unsatisfactory and usually do not exploit the ‘fuzziness’ of the procedure. After a brief review of the more common methods of cluster analysis, fuzzy ideas and fuzzy clustering are discussed. The method is applied to three data sets of different sizes and complexity, to illustrate particular aspects of, and problems in, application. Summarizing results is less easy than for more standard methods, but has the potential to reveal features of the data concealed by other methods.     

THE APPLICATION OF TIME‐OF‐FLIGHT SECONDARY ION MASS SPECTROMETRY (ToF‐SIMS) TO THE CHARACTERIZATION OF OPAQUE ANCIENT GLASSES*

Time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) has been used, for the first time, for the characterization of opaque ancient glasses. Isotope‐specific chemical imaging with sub‐micron resolution enabled the separate analysis of opacifiying inclusions and the surrounding glass matrix. Phase identification has been demonstrated and quantification of the matrix composition has been investigated by use of Corning Glass Standard B as a model. Trace element detection limits are typically in the range 0.5–5.0 ppm atomic—in favourable cases down to 0.01 ppm. For the analysis of inclusions in particular, this has the potential to provide new information of use in establishing provenance and trade routes by ‘fingerprinting’ as well as the investigation of manufacturing techniques, as demonstrated by comparisons between glasses and with EDX data from the same samples.