Thomas Birch

• PhD
• Arkæometallurg | Archaeometallurgist at Moesgaard Museum

A few years ago, an article on Roman folding knives in Denmark would have been unfeasible, as this small and distinct group of artifacts had not yet been identified. However, the increasing use of metal detectors in Denmark has led to the discovery of numerous new artifact types, some readily identifiable and others less so. The identification proc...

Metallographic and chemical analysis of iron and slag remains from Ribe with a discussion on iron provenancing.

This study presents results from the analytical investigation of the polymetallic, non-ferrous metallurgical cycle at early Viking Age Ribe, Denmark, in the 8th and 9th centuries CE. We combine extensive surface analyses of crucibles and moulds (handheld XRF) with targeted micro-destructive examination (micro XRF, electron microprobe spectroscopy—E...

Metallographic, chemical and lead isotopic analyses of copper-based artefacts recovered from the Northwest Quarter in Jerash (ancient Gerasa) in Jordan provide new information on the civic life and material culture from a key urban site in the Roman Empire’s eastern provinces. The samples span the city’s occupation from its flourishing under Roman...

A common issue in non-destructive surface analysis of historical silver coins is depletion of Cu from the near-surface areas, which in turn results in higher Ag content at a coin’s surface. This paper reports a non-destructive analytical strategy using µXRF for identification of Ag and Cu surface enrichments and depletions by comparing peak intensi...

The conventional approach to ore provenance studies of ancient silver coins and artifacts has been to first analyze and then try to match them to published data about mining districts, a difficult task given our incomplete knowledge of these. While literary sources are useful to identify possible provenances, they potentially bias interpretations p...

This paper introduces the large-scale coin sampling project, Coinage and the dynamics of power: the Western Mediterranean 500-100 BC, along with the results of the archaic coins analysed. The results demonstrate that multiple silver sources were accessible for minting archaic coinage, mostly consigned to the Aegean. In formulating a research design...

We present the results of geochemical analysis of silver coinage issued by Rome and dated between the 4th and 2nd century BCE, which are complemented by data of coinage issued by Carthage, the Brettii and the Greek colony of Emporion. Each of these minting authorities represents one of the major parties involved in the struggle for hegemony in the...

Provenance studies on archaeological iron

This study presents the results of compositional and lead isotopic analysis of coinage issued by the Greek colonies of Syracuse, Metapontum, Taras and Thurium in the fifth to third centuries bce. The data suggest that each colony in Magna Graecia, regardless of its motherland roots and despite ongoing conflicts between the cities, had access to the...

New compositional and metallographic data are presented for the fourth to eighth century CE copper coins from the Northwest Quarter of Gerasa/Jerash, Jordan. The majority of the coins are small copper and copper alloy nummi minimi from the Late Roman and Byzantine periods. Also represented are pre-reform and post-reform fulūs minted under the Umayy...

An exciting £1million project funded by the Arts and Humanities Research Council (UK) and led by Lancaster University will set out to recover the 'lost' history of Sardinia from 1,000 years ago. The four-year project on ‘Power, society, and (dis)connectivity in medieval Sardinia’ will be led by Dr Alex Metcalfe from Lancaster University’s History D...

Traditionally, standardisation of manufacture has been investigated using metrics (e.g. length and width) and compared in terms of the coefficient of variation (CV). This paper argues that standardisation should not only be investigated via metrics, but also in terms of shape. An Iron Age lance head type ('Havor'), known from three main weapon depo...

This chapter examines a single weapon type classified as the ‘Havor’ lance, recovered from the famous war booty sacrifices of southern Scandinavia during the Late Roman and Early Germanic Iron Age. A metallographic analysis of 13 samples reveals that the Havor lance was produced using a fairly uniform construction technique, labelled here as the ‘s...

In 2009, part of a ‘slave shackle’ was recovered from archaeological investigations at Trianon, an indentured labourer site on Mauritius dated from the beginning of the nineteenth century. This paper presents the results of a metallurgical assessment of the artefact, thought to represent colonial ironwork, a category that has hitherto remained unde...

Full reference: Birch, T. (2017). "Abandoned or unused? Ultra-high carbon steel and cast iron lumps from Semlach/Eisner", in: Cech, B. (ed.), Die Produktion von Ferrum Noricum am Hüttenberger Erzberg: Die Ergebnisse der interdisziplinären Forschungen auf der Fundstelle Semlach/Eisner in der Jahren 2006-2009 / The Production of Ferrum Noricum at the...

Full reference: Birch, T. (2017). "A Roman mining tool: the investigation and identification of an iron object", in: Cech, B. (ed.), Die Produktion von Ferrum Noricum am Hüttenberger Erzberg: Die Ergebnisse der interdisziplinären Forschungen auf der Fundstelle Semlach/Eisner in der Jahren 2006-2009 / The Production of Ferrum Noricum at the Hüttenbe...

Few critical evaluations of fieldwork methods applied to iron production and ironworking remains exist. This paper demonstrates how an experimental smelt can be a proxy for testing and evaluating methods used to detect, record and excavate a bloomery furnace and smithing hearth. In this investigation, a series of smelting and smithing experiments w...

The metallic artifacts from Çatalhöyük are of particular importance as they constitute some of the earliest examples known. Metal inds have been recovered from as early as Level IX (South K), spanning to Level II, with VII and VI (South M-O) being the most productive (Mellaart 1964, 111). Radiocarbon dating of the archaeological sequence at Çatal-h...

The purpose of pattern-welding, used for the construction of some Anglo-Saxon swords, has yet to be fully resolved. One suggestion is that the technique enhanced the mechanical properties of a blade. Another explanation is that pattern-welding created a desired aesthetic appearance. In order to assess whether the technique afects mechanical propert...

The production of iron in Anglo-Saxon England is little understood due to the lack of evidence. There are less than a dozen iron smelting sites known. This is a distinct contrast to the wealth of evidence of iron smelting during the Roman period. Should we believe that the Anglo-Saxon world was relying on recycled Roman iron? The absence of evidenc...