A ‘match–no match‘ numerical and graphical kernel density approach to interpreting lead isotope signatures of ancient artefacts

A new method for interpreting lead isotope ratios of artefacts is presented: a numerical and graphical ‘match–no match‘ with possible raw materials. By calculating the definite integral under the kernel density estimate plot of different mining districts, using open-access software and legacy data, the relative probability that an object is made of an ore is indicated. A match with the reference data set may indicate the true origin, while no match indicates an unknown origin, that is, not present in the data set of mineral resources. Likewise, the composite or recycled nature of artefacts can be investigated in a probabilistic manner.     

Roman Rigging Material from the Red Sea Port of Myos Hormos

Excavation of the Roman port of Myos Hormos on the Egyptian Red Sea coast has revealed both the extent of the Roman harbour and a significant corpus of maritime artefacts. These include a relatively large quantity of rigging material such as brail-rings and sailcloth dating from the late-1st century BC to the middle of the 3rd century AD. These finds are important for our understanding of ancient shipping in the Mediterranean, Red Sea and Indian Ocean regions.
© 2007 The Author     

Post-flood assessment of emergency evacuation policies in the Red River basin, Southern Manitoba

A discrete choice experiment (DCE) was used as a part of a post‐flood survey among the residents of four small urban communities on the Red River ‐ Emerson, Morris, Ste. Agathe, and St. Adolphe ‐ to assess their preferences for emergency evacuation policies. The respondents were asked to choose repeatedly among three hypothetical evacuation policies described in terms of (a) the type of evacuation (mandatory, voluntary, no evacuation), (b) notification time for evacuation (1, 2, 4 days), (c) post‐evacuation flood relief (75%, 80% current, 90%), and (d) an overall evaluation of the risk of hazardous flooding, i.e. chances of over‐dike flooding or breaching through dikes (99%, 75%, and 50%). The survey results indicated that, despite significant differences between Ste. Agathe and other communities in the magnitude of impact of the 1997 flood, overall, a voluntary evacuation seemed to be preferred at the 50 percent risk of hazardous flooding; whereas the preference for a mandatory evacuation was related to a 99 percent risk. A notification time of 2 days for evacuation was preferred over that of 1 day but the preference for 2 days was not statistically different from that of 4 days. In both types of evacuation a 10 percent increase in the amount of flood relief was preferred over the current amount of 80 percent and the marginal utility of a 5 percent decrease was nearly equivalent to the suggested 10 percent increase. Because of such ability of the DCE to assess tradeoffs of alternative choices/policies, the paper suggests further applications of the model for eliciting floodplain residents' preferences for various flood management issues. Dans le cadre d'une enquête effectuée auprès des résidents de quatre petites communautés urbaines ‐ Emerson, Morris, Ste‐Agathe et St‐Adolphe ‐ à la suite des inondations de la rivière Rouge, les préférences du public quant à la politique à suivre en cas d'évacuation ont étéétudiées. L'évaluation a été menée à partir d'un modèle à choix discret. Les personnes interrogées devaient choisir entre trois hypothèses d'évacuation, hypothèses établies sur les bases suivantes: a) le type d'évacuation (obligatoire; volontaire; non‐évacuation); b) le délai accordé avant l'évacuation (1, 2 ou 4 jours); c) les secours procurés à la suite de l'évacuation (75%, les 80% actuels, 90%); et, d) une évaluation d'ensemble des dangers d'inondation, par exemple, les possibilités qu'une digue soit submergée, ou que les digues rompent par endroits (99%, 75% et 50%). Les résultats de l'enquête montrent que, dans l'ensemble, malgré une différence significative dans l'importance de l'impact de l'inondation de 1997 à Sainte‐Agathe et dans les autres communautés, le choix d'une évacuation volontaire était préféré quand ne se présentait qu'une possibilité d'inondation de 50 pour cent; la préférence pour une évacuation obligatoire n'étant indiquée que dans le cas de 99 pour cent de risques d'inondation. Un avertissement avant évacuation de 2 plutôt qu'l jour était préféré par les personnes interrogées, mais, statistiquement parlant, il n'y avait pas de différence notable entre un choix de 2 ou de 4 jours. Dans les deux types d'évacuation proposés, on préférait une augmentation de 10 pour cent des secours par rapport aux 80 pour cent actuels, l'utilité marginale d'une baisse de 5 pour cent étant presque équivalente aux 10 pour cent d'augmentation suggérés. En raison des possibilités qu'offre un modèle à choix discret pour évaluer les compromis possibles entre les différents choix et politiques d'évacuation proposés, cet article suggère que d'autres études à partir d'un tel modèle soient menées afin d'établir les préférences de ceux qui résident dans des plaines susceptibles d'inondation quant à la prévention et à la gestion de ces inondations.     

On the post-mortem accumulation of lead by skeletal tissues

Lead concentrations in a number of bones and soil samples taken from the same graves at the site of Bordesley Abbey were significantly correlated. Statistical analysis of the results indicated that 59% of the variation in the bone lead concentrations was due to contamination from the soil.A study of the distribution of lead in a tooth from the Romano-British site at Cirencester by fast particle activation analysis indicated that virtually all the lead was on the external surface, indicating post-mortem absorption.These results strongly suggest that lead is absorbed by skeletal tissue after death even in soils which have an alkaline pH. In the light of these findings, suggestions are made for the strategies which might be adopted for further research in this area.     

二里头文化研究的新视角——从青铜器的铅同位素比值看二里头四期的文化性质

对于二里头文化的性质问题,学术界已进行了数十年的讨论,然而直到目前,共识却仍未能达成。本文首次从青铜器铅同位素比值分析入手,对二里头文化的性质问题予以探讨。经过对偃师二里头、郑州二里岗、黄陂盘龙城、安阳殷墟等遗址出土青铜器的铅同位素比值数据的分析与讨论,我们支持二里头文化一至三期属夏文化、第四期遗存则已进入了商代纪年的观点。     

A further example of long-bone damage due to chewing by deer

A central diaphyseal fragment of a red deer metacarpus of recent origin is described, showing signs of bone chewing by deer, the most prominent being fork formation at either end of the specimen. Compared with a red deer metacarpus from the same region described previously, the present one was in a much more advanced stage of bone destruction as a result of osteophagia. Additionally, alterations resulting from gnawing by small rodents and from root etching were present in the specimen. Detailed knowledge of the full spectrum of bone changes originating from chewing by ruminants may prevent the erroneous interpretation of such altered bones as human artefacts.     

The behaviour of lead as a corrosion resistant medium undersea and in soils

Lead is a highly corrosion resistant metal in some environments and an attempt has been made to show its strength and weakness under long-term corrosion in land and marine conditions by means of examples taken from archaeological contexts. Some analyses and thicknesses are given of the corrosion films found on them. The importance of fine grain size and the role of certain impurities in obtaining this may be one reason why the older leads are often more resistant than modern leads.     

Micro-invasive method for studying lead isotopes in paintings*

A micro-invasive technique is presented that enables pigment sampling from individual layers of a painting cross-section by obtaining a furrow 10–50 μm wide of chosen length. Combined with increased sensitivity of lead (Pb) isotope analysis using multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) equipped with a 10¹³ Ω resistor or a Pb double-spike technique, the amount of Pb needed for isotopic analysis is drastically reduced, while maintaining a relative 2 SD precision for ²⁰⁶Pb/²⁰⁴Pb of < 0.02%. The methodology proved able to characterize Pb isotope differences within paint layers.