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Abstracts 2002-2003

Andrew Millard’s Publication Abstracts 2002-2003

Millard AR (2003) Taking Bayes Beyond Radiocarbon: Bayesian Approaches to Some Other Chronometric Methods. In Buck CE and Millard AR (eds.): Tools for Constructing Chronologies: Crossing Disciplinary Boundaries. London: Springer Verlag.

Building on the models for, and practical applications of, Bayesian chronological analysis on the basis of radiocarbon and archaeomagnetism outlined by Buck (Chapter 1), Bayliss and Bronk Ramsey (Chapter 2) and Lanos (Chapter 3), this chapter looks forward to the potential of Bayesian modelling for other chronometric methods. Suitable mathematical formulations are suggested for dendrochronology, uranium-series, amino-acid racemization and trapped charge (luminescence and ESR) dating methods. Some are only initial suggestions for formulations which may lead to practical implementations. For dendrochronology, uranium-series and ESR dating the chapter offers more detailed models, initial implementations, and for the latter two, illustrative case studies which indicate the nature of inferences we can expect to make if such models are adopted more widely. By suggesting such a broad range of extensions to the Bayesian chronological framework this chapter offers great potential for substantially extending the kinds of problems that can be tackled within it, and provides encouragement to researchers who rely on a wide range of dating methods and would like to integrate them all within one coherent framework.

Millard A, and Gowland R (2002) A Bayesian approach to the estimation of age of humans from toothwear. Archeologia e Calcolatori 13:197-210.

Examination of dental development is considered to be an accurate method of ageing non-adults, but ageing adults from dental wear is much less accurate. Miles’ method is generally accepted to be the best way we have to derive estimates of tooth-wear ages because it takes into account population variability in wear-rates. Here we develop a Bayesian approach to ageing from dental development and tooth-wear, using a latent trait model and logistic regression to estimate the ages of individuals whose tooth development and/or wear has been scored on ordinal scales. In addition to the original methods this: (a) accounts for uncertainties in tooth development; (b) incorporates in a natural fashion individuals with teeth missing post-mortem. Numerical integrations were performed using Markov-Chain Monte-Carlo techniques and WinBUGS software.

Millard A (2002) A Bayesian approach to sapwood estimates and felling dates in dendrochronology. Archaeometry 44:137-143.

An improved methods of generating sapwood estimates for oak is developed. This suggests a revision of the 95% confidence range from 10- 40 to 9-36 rings for trees from southern England. Current methods for estimating felling dates on timbers with incomplete sapwood do not generate true 95% confidence limits, and a Bayesian method for deriving such limits is presented. For timbers with no sapwood, the addition of 12 years to the date of the final ring is shown to give a 95% confidence limit on the terminus post quem for felling. The further application of these methods is illustrated by calculation of the common felling date for timbers from the Great Kitchen as Windsor Castle.

Philip G, Jabour F, Beck A, Bshsesh M, Grove J, Kirk A, and Millard A (2002) Settlement and landscape development in the Homs Region, Syria: research questions, preliminary results 1999-2000 and future potential. Levant 34:1-23.

This report describes the results of the first and second seasons of field work by an interdisciplinary research team studying the landscape history of the upper Orontes Valley near Homs in western Syria. Initial discussions address the value of survey data to Syrian archaeology, the research aims of the project and describe the survey area. The project methodology, which includes a combination of both extensive and intensive survey methods, is outlined, and the use of satellite imagery as a means of site location discussed. Work on geomorphological processes and off-site artefact distributions has facilitated the development of sampling strategies for intensive surface collection planned for 2002 and 2003. A test core has established that pollen is well-preserved in the silts of Lake Qattine, which appear to offer a west Syrian palaeoenvironmental sequence. Preliminary work in the basalt terrain west of Homs has allowed the refinement of methodologies for the mapping and analysis of cairns and field systems which predominate in this area, and has highlighted the threat resulting from current bulldozing. The report concludes with some preliminary observations on the main trends as these are emerging from the data.

Collins MJ, Nielsen-Marsh CM, Hiller J, Smith CI, Roberts JP, Prigodich RV, Weiss TJ, Csapo J, Millard AR, and Turner-Walker G (2002) The survival of organic matter in bone: A review. Archaeometry 44:383-394.

If bone is considered as a composite of collagen (protein) and bioapatite (mineral), then three pathways of diagenesis are identified: (1) chemical deterioration of the organic phase; (2) chemical deterioration of the mineral phase; and (3) (micro)biological attack of the composite. The first of these three pathways is relatively unusual and will only occur in environments that are geochemically stable for bone mineral. However, because rates of biomolecular deterioration in the burial environment are slow, such bones would yield useful biomolecular information. In most environments, bones are not in thermodynamic equilibrium with the soil solution, and undergo chemical deterioration (path 2). Dissolution of the mineral exposes collagen to biodeterioration, and in most cases the initial phase of dissolution will be followed by microbial attack (path 3). Biological attack (3) also proceeds by initial demineralization; therefore paths 2 and 3 are functionally equivalent. However, in a bone that follows path 3 the damage is more localized than in path 2, and regions equivalent to path 1 may therefore exist outside these zones of destruction. Other biomolecules, such as blood proteins, cellular lipids and DNA, exist within the physiological spaces within bone. For these biomolecules, death history may be particularly important for their survival.

Roberts SJ, Smith CI, Millard A, and Collins MJ (2002) The taphonomy of cooked bone: Characterizing boiling and its physico-chemical effects. Archaeometry 44:485-494.

Cooking is perhaps the most common pre-burial taphonomic transformation that occurs to bone, yet it is still one of the least understood. Little progress has been made in determining a method of identifying cooked bone in the archaeological record, despite its import for various branches of archaeology. This paper attempts to describe boiling in terms of its physico-chemical effects on bone, and uses a suite of diagenetic indicators to do this. It is shown that cooking for brief periods of time has little distinguishable effect on bone int he short term, but that increased boiling times can mirror diagenetic effects observed in archaeological bone. The relationship between the loss of collagen and alterations to the bone mineral is explored through heating experiments, and the results compared with archaeological data. The possibility of boiling being used as an analogue for bone diagenesis in future studies is raised, and the key relationship between protein and mineral is once again highlighted as vital to our understanding of bone diagenesis.