Freezing and melting behaviors of H2O‐NaCl‐CaCl2 solutions in fused silica capillaries and glass‐sandwiched films: implications for fluid inclusion studies

Fluid inclusions of the H₂O‐NaCl‐CaCl₂ system are notorious for their metastable behavior during cooling and heating processes, which can render microthermometric measurement impossible or difficult and interpretation of the results ambiguous. This study addresses these problems through detailed microscopic examination of synthetic solutions during cooling and warming runs, development of methods to enhance nucleation of hydrates, and comparison of microthermometric results with different degrees of metastability with values predicted for stable conditions. Synthetic H₂O‐NaCl‐CaCl₂ solutions with different NaCl/(NaCl + CaCl₂) ratios were prepared and loaded in fused silica capillaries and glass‐sandwiched films for microthermometric studies; pure solutions were used with the capillaries to simulate fluid inclusions, whereas alumina powder was added in the solutions to facilitate ice and hydrate crystallization in the sandwiched samples. The phase changes observed and the microthermometric data obtained in this study have led to the following conclusions that have important implications for fluid inclusion studies: (i) most H₂O‐NaCl‐CaCl₂ inclusions that appear to be completely frozen in the first cooling run to ?185°C actually contain large amounts of residual solution, as also reported in some previous studies; (ii) inability of H₂O‐NaCl‐CaCl₂ inclusions to freeze completely may be related to their composition (low NaCl/(NaCl + CaCl₂) ratios) and lack of solid particles; (iii) crystallization of hydrates, which is important for cryogenic Raman spectroscopic studies of fluid inclusion composition, can be greatly enhanced by finding an optimum combination of cooling and warming rates and temperatures; and (iv) even if an inclusion is not completely frozen, the melting temperatures of hydrohalite and ice are still valid for estimating the fluid composition.     

Analysis and interpretation of flint toolmarks found on bones from West Tump long barrow,Gloucestershire

West Tump is a Neolithic chambered tomb originally excavated in 1880. The mound was found to contain a mixed skeletal assemblage, the majority of which was disarticulated. Between 2000 and 2001 material from the site including human bone was re‐examined with a portion of this project focused on taphonomic evidence observed on the human skeletal material. Amongst the factors selected for investigation were deliberate toolmarks. Three specimens were identified as exhibiting toolmarks. Analysis demonstrated that the observed features were cutmarks, consistent with the use of flint tools. However those on two of the specimens were found to be both post‐mortem and recent. The cutmarks observed on the remaining specimen, a right clavicle, were identified as having been inflicted during the peri‐mortem period and consistent with decapitation. British Neolithic mortuary practice has been the subject of ongoing debate since the earliest excavations of relevant sites, but until very recently few assemblages from such contexts have been re‐examined and much of the data in use has derived from sources of considerable age and questionable reliability. The selective removal of specific skeletal elements (particularly skulls) has repeatedly been described in the literature regarding the collective funerary monuments of this period. It has often been assumed that such practices took place after the soft tissues had decayed. One of the examples discussed, suggests this may not always have been the case and the potential significance of this finding is discussed in addition to a possible interpretation of the cutmarks seen on the remaining specimens. Copyright © 2004 John Wiley & Sons, Ltd.     

Pottery Production, Distribution, and Consumption—The Contribution of the Physical Sciences

The study of the life cycle of pottery, from the selection of raw materials and the production stage through distribution and use to ultimate discard, can make a valuable contribution to archaeological research. The aim of the present paper is to provide a summary and critical assessment of the particular contribution of the physical sciences to the reconstruction and interpretation of this life cycle, in large part through the presentation of selected case studies. The topics covered include the reconstruction of the technology used in pottery production, through a combination of microscopy, radiography, and chemical analysis; the investigation of the extent of craft specialization and the organization of pottery production; the reconstruction of pottery distribution from its production center, using thin-section petrography and chemical analysis, and the interpretation of these data in terms of exchange and trade; the reconstruction of the consumption stage or uses to which pottery was put, from the study of surface wear, organic residues, and performance characteristics; and a discussion of the reasons for the introduction of pottery and for the different technological choices made in pottery production. Throughout, the importance of considering the overall environmental, technological, economic, sociopolitical, cultural–ideological and historical context in which the pottery was produced, distributed, and consumed is emphasized. The paper is concerned, almost-exclusively, with unglazed earthenware spanning prehistory through to circa 1500 AD.     

OPTICAL DATING OF SINGLE AND MULTIPLE GRAINS OF QUARTZ FROM JINMIUM ROCK SHELTER,NORTHERN AUSTRALIA: PART I,EXPERIMENTAL DESIGN AND STATISTICAL MODELS*

Jinmium rock shelter is famous for the claims made by Fullagar et al. (1996) for the early human colonization and ancient rock art of northern Australia. These claims were based on thermo-luminescence ages obtained for the artefact-bearing quartz sediments that form the floor deposit at the site. In this paper, we outline the background to the optical dating programme at Jinmium, and describe the experimental design and statistical methods used to obtain optical ages from single grains of quartz sand. The results, interpretations, and implications of this dating programme are reported in a companion paper (Roberts et al. 7999, this volume).     

Insecurity and Pastoral Development in the Sahel

In this article it is argued that conventional agro-ecological and organizational concepts used in pastoral development are strongly biased towards the formulation and enforcement of norms. This leads development experts to attempts to control pastoralists and their herds. The policies and development interventions based on these assumptions have been largely unsuccessful. As a consequence attention for dryland areas and pastoral development has declined among researchers and development agencies. An important reason for this failure is the fundamental misfit between these normative concepts and the reality of dryland ecosystems and pastoral society. In order to show this, an alternative view on rangeland ecology and pastoral society is presented, supported by a case study of Fulbe pastoral society in dryland Central Mali. The authors argue that approaches to pastoral development must be revised in the direction of the dynamics inherent in the pastoral way of life.     

A Synthesis of Aggregation Methods for Multifacility Location Problems: Strategies for Containing Error

When solving a location problem using aggregated units to represent demand, it is well known that the process of aggregation introduces error. Research has focussed on individual components of error, with little work on identifying and controlling total error. We provide a focussed review of some of this literature and suggest a strategy for controlling total error. Consideration of alternative criteria for evaluating aggregation schemes shows that the method selected should be compatible with the objectives of the analyses in which it is used. Experiments are described that show that two different measures of error are related in a nonlinear way to the number of aggregate demand points (q), for any value of the number of facilities (p). We focus on the parameter q/p and show that it is critical for determining the expected severity of the error. Many practical implementations of location algorithms operate within the range of q/p where the rate of change of error with respect to q/p is highest.     

The Intellectual Internment of a Conflict: The Forgotten War in Northern Ireland

One of the most enduring ideas about the Northern Ireland conflict is that it has been rigorously studied. This is a myth. The stark absence of analysis of its military and international dimensions makes the conflict one of the least understood of modern times. Scholarly studies of Northern Ireland have been insulated from influences in the wider academic world by the dominance of hitherto unchallenged images about the crisis. These images support a dominant orthodoxy that has confined intellectual investigation of the 'Troubles' to Northern Ireland itself, sustaining a view that little of value can be gained from studying the military nature of the conflict. This orthodoxy is one to which, depressingly, the international relations community has been only too willing to contribute to justify its fear and neglect. Not only does this reflect poorly on academic practice but it has also helped to engender a dangerously distorted image of the conflict that bodes ill for the future.