Thilo Rehren

Corrigendum to: Thilo Rehren, Sam Nixon, Bokbot, Y., Brunella Santarelli, Biyang Wang, & Desai, M. (2026). Multiple metallurgies in Medieval Tamdult, a mining, smelting and caravan town in southern Morocco. Historical Metallurgy, 56(1), 3-19. https://doi.org/10.54841/hm.686 The corrigendum is also included on the last page of the article.

The early Islamic settlement of Tamdult in southern Morocco is at the centre of an archaeological mining-metallurgical landscape with strong evidence for the production and working of lead, silver, copper and brass. Here, we provide an overview of the various metallurgies identified, and discuss their likely common origin from a sulfidic complex lead-zinc-copper ore mineralisation, leading to two distinct primary products: silver pellets and brass ingots. The presence of ancient mining traces, multiple locales of copper and lead smelting, fragments of litharge, numerous coin moulds with silver traces, and various types of ore, slag, crucibles and moulds linked to brass making, constitutes the most comprehensive inter-connected set of chaînes opératoires for copper, brass, lead and silver production in northwestern Africa. The initial results presented here allow key aspects of the raw material procurement and processing to be reconstructed, and to identify remaining gaps in our understanding and documentation of early medieval metal production on the western fringes of the Sahara.

Metallographic and compositional analyses of several ferrous and non-ferrous objects from recent Megalithic excavations in south- central India provide new albeit limited insights into regional metalworking practices. A heavily worked but functionally enigmatic lead object containing minor tin, points to the recycling of available lead sources. In contrast, a low-tin bronze wire, marked by sulphide and lead inclusions, reflects the use of freshly smelted metal. All the iron implements were made from bloomery steel of medium carbon content, with slag inclusions characteristic of the bloomery process, and their preserved microstructures documenting Megalithic craftsmanship. Taken together, these results reveal a community proficient in working a variety of metals, from recycled lead to freshly smelted bronze and bloomery steel. At present, the broader cultural interpretation remains constrained by the scarcity of comparative material from the wider region, especially for the non-ferrous objects. More studies are necessary to provide a basis on which future isotopic studies can be built, for tracing the geological origins of these metals and placing Megalithic south-central India more firmly within broader technological and exchange networks.

Copper-related metal artefacts and ingots are prominent metal objects of the Trans-Saharan trade route, providing a nexus between producers and consumers often separated by vast distances. The role of Gao in southern Mali as a major transit point of this trade is archaeologically and historically well established, within the framework of other Medieval trade towns. However, the study of Gao’s metallurgical heritage is not fully explored and is full of potential. Of particular interest are the hundreds of crescent-shaped metal objects found across the different parts of Gao, but not encountered elsewhere. We present a pilot study on five crescent fragments and one brass ring from Medieval Gao, offering new compositional and isotopic data. It is unlikely that these objects were re-melted or recycled, given the frequent presence of sulphide inclusions in them. The results show that the crescent-shaped objects are heavily leaded copper and retain their as-cast texture, making a functional use unlikely. Their composition is either due to a possible mixing of lead and copper metal, or the smelting of multi-metallic ores where different batch compositions result in different concentrations in lead, antimony and arsenic within the dominant copper metal. The lead isotope data, presented here for the first time, confirm general statements made earlier for a similar set of artefacts from Gao, arguing that the metal is isotopically consistent with lead ores from Tunisia as well as being similar to several artefacts from Nigeria, in particular Igbo Ukwu. In the absence of a comprehensive database of regional copper ore data and the long-distance trade of lead across the Sahara, a firm assignment of geological origin of the metal from Gao’s crescent-shaped objects remains elusive.

Copper was central to the Late Roman Cypriot economy, represented by large-scale production sites. This study examines often-overlooked small-scale mining by focusing on Pyrga in the Pouzis Valley, Southeast Cyprus. Surveys by the Hala Sultan Tekke Hinterland Survey Project (2021–ongoing) revealed dispersed slag heaps near potential church remains. Metal slag analysis reveals a consistent manganese-rich composition and low residual copper, suggesting controlled and efficient smelting. Viewed alongside the Codex Theodosianus and Codex Justinianus, regulating mining, taxation and landownership, and the proximity of churches to production sites, this raises the possibility that Pyrga’s production was part of a centrally organised network. This research examines how ecclesiastical institutions may have steered local economy, administration and taxation, and technological practices. This dual exploration of administration and technology deepens our understanding of the relationship between ecclesiastical power and the copper economy of Late Roman Cyprus.

Despite an early surge in copper-ore mining during the sixth and fifth millennia BC (the ‘boom’), evidence for metal production in the Balkans dwindles in the fourth millennium (the ‘bust’). Here, the authors present new evidence for copper mining at Curak in south-west Serbia, c . 3800 cal BC, during this apparent downturn. By integrating field surveys, excavations and provenance analyses, they explore activity at the site, challenging the visibility bias in the archaeological record of this region for this key period. Rather than a societal collapse, the authors argue, fewer artefacts may instead reflect a widening Balkan sphere of influence.

The composition of early 19th century platinum coins reflects the advances of platinum metallurgy from laboratory-scale refining to industrial-scale processing. An array of neutron methods was used to determine for the first time the bulk phase and elemental composition of two coins, dated 1837 and 1838. Neutron imaging confirmed the homogenous internal structure of the metal at the micrometer scale, with further support from small-angle neutron scattering at the nanometre scale. Prompt gamma activation analysis showed the coins to consist of technically pure platinum, appropriate for the time of their production with iridium and iron between 1 and 2 weight percent. Lower amounts of copper, rhodium, manganese and gold were also detected in the range of tens to thousands of g/g. Overall, the investigation demonstrated the suitability of neutron methods as noninvasive and reliable bulk means to determine the composition of early industrial platinum to track the development of refining processes and metallurgical processing.