The book is based on the doctoral thesis of Alan Williams, a former mining geologist, completed after an intense career in the mining industry and a long-term interest in prehistoric mining and metallurgy (e.g. Williams 1985).
This 343-page book about the Great Orme Bronze Age copper mine in north Wales is organised in 10 chapters, with an up-to-date bibliography. It also includes appendices with the analytical results of published ore and metal analyses for the following: British and Irish Bronze Age mines (Appendix I); Cornish (Appendix II); and Great Orme copper ores (Appendix III); chemical analyses of Group-1 palstaves (Appendix IV); and a compilation of isotope results of British and Irish Bronze Age copper mines (Appendix V). The book ends with a useful subject/geographical index. Some of the core results contained in this book were previously synthesised (Williams & Le Carlier de Veslud 2019) and incorporated into broader Atlantic research projects such as ‘Moving Metals’ (e.g. Melheim et al. 2018) and ‘Maritime Encounters’ (https://www.gu.se/en/research/maritime-encounters), on which I am a collaborator.
The Introduction (Chapter 1) presents the state of research and the new concept of a ‘mine-based metal group’ to establish the chemical and isotopic relationship between the Great Orme mine and the metal artefacts. Chapter 2, ‘The Bronze Age research context’, deals with metal production in the Bronze Age and its archaeological sequence from the Early to Late Bronze Age; from the initial role of Ross Island in Ireland; and the ‘bronzization’ at the end of the third millennium BC. Based on this an independent western discovery of this alloy is proposed, supported in the existence of alluvial deposits of cassiterite in Cornwall and Devon.
Chapter 3, ‘Bronze Age mining and smelting’, emphasises the importance of the geochemical characterisation of the mineral deposits and its relationship with the metal produced. This includes the lead isotopic composition, with a review of the development of its research and the current situation in Great Britain and continental Europe. ‘The Great Orme mine site and Pentrwyn smelting site’ (Chapter 4) explains the extensive archaeological and dating work that was undertaken in the mine. It estimates the extent of copper production and gives details on the excavation of the limited remains of the rare smelting site of Pentrwyn, with just a hundred grams of Cu smelting residues.
Chapter 5 is a ‘Review of metal characterisation and provenance techniques’ and focuses on trace element chemistry and lead isotopes techniques to characterise and source metals. In Chapter 6, ‘Methodology, materials and analytical methods’, the analytical techniques for the characterisation of ores and artefacts are discussed, in addition to the sampling strategy for the Great Orme—only made possible after decades of excavations—and the inclusion of bits of bronze picks and copper prills from the Pentrwyn site as well as from smelting experiments.
Chapters 7 and 8 reveal the results on ‘Defining the Great Orme mine-based metal group’ and ‘Great Orme ore mineralogy and Pentrwyn slag studies’. The chemical components forming the Great Orme mine-based metal group are specified, which establishes a characteristic range of composition that is consistent with Bronze Age metal assemblages (specifically Acton Park) and metal types from Britain (Group I palstaves) as well as from continental Europe (e.g. the Hönö hoard, Sweden). The ‘unusual’ lead isotopic field (or fields) for the Great Orme mine, with its ‘long radiogenic tail’, is defined and the book explains how it is distinguishable from other copper mineral deposits—with the exception of Alderley Edge, Cheshire—exploited in Irish/British Bronze Age. In Chapter 9, ‘Discussion and interpretation’, the Great Orme is considered to be the major copper source for Britain during a relatively short period of time covering the demand (source for Acton Park metal assemblages, c. 1600–1400 BC). The mine was probably controlled by regional north-east Wales elites, and specific metal types were exported to the continent through exchange/trade networks, with a sudden collapse of production, substituted by foreign sources, of which southern Spain is one.
In ‘Conclusions and future work’ (Chapter 10), the convenience of the use of the new ‘mine-based metal group’ proposal is highlighted, and moreover, the need for further investigation on copper mineralisation (also continental), smelting sites, metal ingots and objects, absolute dating of mining works (which means through archaeological excavations) is pointed out.
To sum up, the book presents a new and solid interpretation of the role of the Great Orme mine and is an inspiring lesson for those of us involved in prehistoric mining and metallurgy research. Based on a doctoral thesis, nothing is taken for granted, everything is explained, and the training and experience of Williams, in addition to the precise study of the Great Orme mine and its regional and European context, allow us to consider this work, with its controversial hypothesis, as a new reference book on prehistoric mining and metallurgy investigation.