This paper reviews the research into the methodology of lead isotope provenance studies carried out at the University of Oxford between 1975 and 2002, at first in the Department of Geology (Geological Age and Isotope Research Laboratory), later in the Isotrace Laboratory based in the Department of Nuclear Physics, and eventually part of the Research Laboratory of Archaeology and the History of Art. These 27 years of intensive work, funded initially by the Stiftung Volkswagenwerk, and later from numerous UK Government and Charitable funds and finally by the Institute of Aegean Prehistory laid the foundations of the lead isotope provenance methodology and resulted in a large database of analytical isotope and elemental results. In spite of the efforts of the authors, this database is still not comprehensively published or easily accessible in a digital format by all researchers interested in using this method for their projects. The possibilities of advancing this situation are discussed. The authors discuss in detail the basic restrictions and advantages of using the lead isotope compositions of ores in mineral deposits for finding the origin of the raw materials used for making ancient artefacts. Methods for the scientific interpretation of the data are discussed, including attempts to use statistical methods. The methodology of creating the Oxford lead isotope database (OXALID) is outlined and a summary is given of the lead isotope resource provided by OXALID.

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Metal provenancing using isotopes and the Oxford archaeological lead isotope database (OXALID)

This paper gives a synopsis on affine invariant tests of the hypothesis that the unknown distribution of a d-dimensional random vector X is some nondegenerate d-variate normal distribution, on the basis of i.i.d. copies X
 1,...,X
 n of X. Particular emphasis is given to progress that has been achieved during the last decade. Furthermore, we stress the typical diagnostic pitfall connected with purportedly ‘directed’ procedures, such as tests based on measures of multivariate skewness.

Invariant tests for multivariate normality: a critical review

For the last 180 years, scientists have been attempting to determine the ‘provenance’ (geological source) of the copper used in Bronze Age artefacts. However, despite advances in analytical technologies, the theoretical approach has remained virtually unchanged over this period, with the interpretative methodology only changing to accommodate the increasing capacity of computers. This book represents a concerted effort to think about the composition of Bronze Age metal as the product of human intentionality as well as of geology. It considers the trace element composition of the metal, the alloying elements, and the lead isotopic composition, showing how a combination of these aspects, along with archaeological context and typology, can reveal much more about the life history of such artefacts, expanding considerably upon the rather limited ambition of knowing where the ore was extracted. Beyond Provenance serves as a ‘how-to handbook’ for those wishing to look for evidence of human intentionality in the chemical patterning observed in bronzes.

Beyond Provenance : New Approaches to Interpreting the Chemistry of Archaeological Copper Alloys

Archaeologists often seem either sceptical of science-based archaeology or baffled by its results. The underpinnings of science-based archaeology may conflict with social or behavioural factors uns...

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Archaeology, Science-Based Archaeology and the Mediterranean Bronze Age Metals Trade

The accumulated published database of stable lead isotope analyses of ore and slag specimens taken from Anatolian mining sites that parallel the Black Sea coast has been augmented with 22 additional analyses of such specimens carried out at the National Institute of Standards and Technology, Multivariate statistical analysis has been used to divide this composite database into five separate ore source groups. Evidence that most of these ore sources were exploited for the production of metal artefacts during the Bronze Age and Phrygian Period has been obtained by statistically comparing to them the isotope ratios of 184 analysed artefacts from nine archaeological sites situated within a few hundred kilometres of these mining sites. Also, Appendix B contains 36 new isotope analyses of ore specimens from Central Taurus mining sites that are compatible with and augment the four Central Taurus Ore Source Groups defined in Yener et al. (1991).

Stable Lead Isotope Studies of Black Sea Anatolian Ore Sources and Related Bronze Age and Phrygian Artefacts from Nearby Archaeological Sites. Appendix: New Central Taurus Ore Data

Samples from ore bodies, mined for copper in antiquity, can be characterized by measurements on three lead isotope ratios. Given sufficient samples, it is possible to estimate the lead isotope field-a three-dimensional construct-that characterizes the ore body. For the purposes of estimating the extent of a field, or assessing whether bronze artefacts could have been made using copper from a particular field, it is often assumed that fields have a trivariate normal distribution. Using recently published data, for which the sample sizes are larger than usual, this paper casts doubt on this assumption. A variety of tests of univariate normality are applied, both to the original lead isotope ratios and to transformations of them based on principal component analysis; the paper can be read as a case study in the use of tests of univariate normality for assessing multivariate normality. This is not an optimal approach, but is sufficient in the cases considered to suggest that fields are, in fact, 'non-normal'....

N. H. Gale

Papers

Testing for multivariate normality via univariate tests: A case study using lead isotope ratio data