Luminescence characteristics and dose distributions for quartz and feldspar grains from Mumba rockshelter,Tanzania

Mumba rockshelter is a key archaeological site for the Middle and Later Stone Age occupation of East Africa, but its chronology has remained unresolved. We report the results of a dating study, focussing on the characterisation of the optically stimulated luminescence (OSL) and infrared stimulated luminescence (IRSL) properties of quartz- and potassium-rich feldspar grains. Quartz has previously proven troublesome for dating in East Africa. We identified five general types of quartz grain behaviour, based on the shapes of their OSL decay and dose–response curves. Dose recovery experiments and measurement of the natural samples revealed particular problems with quartz grains that had hyperbolic dose–response curves, low characteristic saturation doses and anomalously large changes in sensitivity between regenerative-dose cycles. The use of pulsed irradiation during measurement and standard and additional quality-assurance criteria during data analysis reduced the number of grains that suffered from these problems. We applied these procedures to individual grains of quartz from eight samples and, using appropriate statistical models, identified post-depositional mixing in three samples. The remaining samples had scattered equivalent-dose distributions typical of quartz grains that had received variable beta dose rates during burial. Stratigraphically consistent OSL ages were obtained for all but the deepest sample. Feldspar ages were estimated for the latter sample and three other samples, using the elevated temperature IRSL signal that exhibited low rates of anomalous fading. Fading-corrected feldspar ages for the latter three samples are consistent with their single-grain quartz ages, but single-grain dating is needed to address problems of post-depositional mixing.     

Diet,social differentiation and cultural change in Roman Britain: new isotopic evidence from Gloucestershire

This study uses stable isotope analyses (δ¹³C and δ¹⁵N) of human bone collagen to reconstruct the diet of three Romano-British (first to early fifth century AD) populations from Gloucestershire in South West England. Gloucestershire was an important part of Roman Britain with two major administrative centres at Gloucester (Glevum) and Cirencester (Corinium) and numerous smaller settlements and farmsteads. To investigate potential dietary differences between the rural and urban populations of Roman Gloucestershire, we compared human bone collagen stable isotope values from 32 individuals from urban Gloucester with those of 46 individuals from two rural cemeteries at Horcott Quarry and Cotswold Community, respectively. Seven individuals from urban Gloucester were buried in a mass grave; all others were buried in single inhumations. Results show small but significant differences in stable isotope ratios between the urban and rural populations which indicate that the urban population might have consumed slightly more marine and/or freshwater resources than the people living in the rural communities. We interpret this difference as a direct reflection of Rome’s influence on Gloucester’s population and the town’s economic status. Subtle differences in stable isotope ratios were also observed at the site level, as burial practice does correlate with diet in some cases. Overall, the results from this study demonstrate that diet, as reconstructed through stable isotope analysis, is a very sensitive, if settlement-specific, indicator of social differentiation and culture change.     

Le Métier de Juriste Entre Règle de Droit et Expérience de l’Histoire

The activities of jurists, they may be judges, lawyers or university teachers, occupy a central role in the maintenance of the political and social order of modern societies. In Germany the confrontation of the recent past provoked in the early 1960’s a large debate about the real foundations of the modern state and his role in the crisis of the modernity which have been pursuit in the course of the eighties issuing in the beginning of the century in the discussions about integration and a general order of values to be recognized by everybody.     

Jack of Two Trades,Master of Both: Smelting and Healing in Ufipa,Southwestern Tanzania

Pre-colonial African ironworking was much more than just a technology; it encompassed economic, social, political, symbolic, and even healing components. It is only unfortunate that archaeometallurgical research has not availed equal weight to each aspect, hence the apparent obscurity of some of them. Revealing the multiple facets of healing as manifested in ironworking technology, this paper attempts to rectify this imbalance. Essentially, the paper examines pros and cons of combining ironworking with healing of humans, a phenomenon common among ironworking communities in pre-colonial Africa. It is revealed that by combining the two, iron smelters ensured themselves of gains beyond technology and economy; they also became socially and politically influential. In addition, the paper notes that there existed a very close connection between healing and ritualism not only among smelter–healers but also conventional healers. After a thorough examination, it is found that the connection between the two was also pragmatic and deliberately instituted by the practitioners in order to enhance monopoly of their trade and protect their inventions against interlopers.     

Schematic Rock Art,Rain-Making and Islam in the Ethio-Sudanese Borderlands

Two sites with schematic rock paintings in Western Ethiopia, where Islamic ceremonies connected with rain-making are performed and miraculous events are said to occur regularly, are interpreted in the light of such factors as the beliefs of local informants, the Islamic appropriation of prehistoric rituals in Northern Africa, the characteristics of similar sites linked to rain-making rituals throughout Eastern Africa and the apotropaic meaning of schematic marks in many traditional cultures. Probably painted by the ancestors of the current Koman language speakers during the Later Stone Age or shortly afterwards, the rock art contextual analysis reveals the complexity of interregional relationships and processes affecting the multi-ethnic frontier regions in pre-colonial times and shows how the local groups have recombined prehistoric and historic religions and ideologies into an original mix that bears witness to the region’s multifaceted history.     

Stimulated Variation and Cascades: Two Processes in the Evolution of Complex Technological Systems

Michael Schiffer’s theoretical and methodological contributions to archaeology are substantial. For the last two decades, Schiffer has become increasingly interested in the history of electrical technology, including portable radios, electric automobiles, eighteenth-century electrostatic technology, and, most recently, nineteenth-century electric light and power systems. Schiffer has long held a behavioral view, which focuses analytical attention on interactions between humans and material things, including complex technological systems (CTSs). For Schiffer, two key aspects of the evolution of CTSs are stimulated variation, defined as an increase in invention resulting from changing selective conditions, and cascading, defined as sequential spurts of invention that occur through the recognition of emergent performance problems in a CTS. To attain maximum usefulness, these concepts should be placed in a modern evolutionary framework that correctly identifies, and does not oversell, the role played by cultural selection. Research on individual and social learning provides the critical link between Schiffer’s stimulated variation and cascade models and the diffusion of CTSs.     

High Dynamic Range Imaging for Archaeological Recording

This paper notes the adoption of digital photography as a primary recording means within archaeology, and reviews some issues and problems that this presents. Particular attention is given to the problems of recording high-contrast scenes in archaeology and high dynamic range imaging using multiple exposures is suggested as a means of providing an archive of high-contrast scenes that can later be tone-mapped to provide a variety of visualisations. Exposure fusion is also considered, although it is noted that this has some disadvantages. Three case studies are then presented: (1) a very high-contrast photograph taken from within a rock-cut tomb at Cala Morell, Menorca, (2) an archaeological test pitting exercise requiring rapid acquisition of photographic records in challenging circumstances and (3) legacy material consisting of three differently exposed colour positive (slide) photographs of the same scene. In each case, high dynamic range (HDR) methods are shown to significantly aid the generation of a high-quality illustrative record photograph, and it is concluded that HDR imaging could serve an effective role in archaeological photographic recording, although there remain problems of archiving and distributing HDR radiance map data.