ARCHAEOMAGNETIC DATING OF COPPER SMELTING SITE F2 IN THE TIMNA VALLEY (ISRAEL) AND ITS IMPLICATIONS FOR THE MODELLING OF ANCIENT TECHNOLOGICAL DEVELOPMENTS

Site F2 in the Timna Valley, Israel, is a small copper smelting site of ‘primitive’ technology, dated by its excavator to the Pottery Neolithic (sixth to fifth millennium bce ). This early date challenges the common view of the beginning of smelting technology in the Levant and has been contested by various scholars since its publication. In this study, we present results of archaeointensity experiments conducted on slag fragments from the site. The slag yielded an excellent ancient geomagnetic value (64.1 ± 1.1 μT) that, when compared to the Levantine master curve, suggests an age not older than the second millennium and most probably between the 13th and 11th centuries bce . In addition to demonstrating the applicability of geomagnetic archaeointensity experiments to independent dating of slag, we discuss the implications of the current results for the socio‐historical picture of the Timna Valley, and in particular for the way in which technological developments were previously modelled in the archaeometallurgical research on the region.     

Did China Import Metals from Africa in the Bronze Age?

The origins of the copper, tin and lead for China's rich Bronze Age cultures are a major topic in archaeological research, with significant contributions being made by archaeological fieldwork, archaeometallurgical investigations and geochemical considerations. Here, we investigate a recent claim that the greater part of the Shang‐period metalwork was made using metals from Africa, imported together with the necessary know‐how to produce tin bronze. A brief review of the current status of lead isotopic study on Shang‐period bronze artefacts is provided first, clarifying a few key issues involved in this discussion. It is then shown that there is no archaeological or isotopic basis for bulk metal transfer between Africa and China during the Shang period, and that the copper and lead in Shang bronze with a strongly radiogenic signature is not likely to be from Africa. We call for collaborative interdisciplinary research to address the vexing question of the Shang period's metal sources, focusing on smelting sites in geologically defined potential source regions and casting workshops identified at a number of Shang settlements.     

LEAD ISOTOPE ANALYSES OF BRONZE AGE COPPER‐BASE ARTEFACTS FROM AL‐MIDAMMAN,YEMEN: TOWARDS THE IDENTIFICATION OF AN INDIGENOUS METAL PRODUCTION AND EXCHANGE SYSTEM IN THE SOUTHERN RED SEA REGION*

The results of the lead isotope analysis (LIA) of 15 copper‐base artefacts from the Bronze Age site of al‐Midamman, Yemen, are reported. The LIA data suggest the existence of an indigenous Bronze Age metal production and exchange system centred on the southern Red Sea region, distinct from those in neighbouring regions of Arabia and the Levant. These preliminary results are highly significant for the archaeology of the region, suggesting that local prehistoric copper extraction sites have thus far gone unrecorded, and highlighting the need for systematic archaeometallurgical fieldwork programmes in the countries surrounding the southern Red Sea.     

Metallurgical traditions and metal exchange networks in late prehistoric central Myanmar,c. 1000 BC to c. AD 500

Myanmar has been notably underrepresented in recent studies of archaeometallurgy in Southeast Asia, despite its richness in both mineral and cultural resources and its potentially central role in long-distance exchange networks linking India, China and peninsular neighbours. Here, we present original analytical data on copper-base artefacts from several Bronze Age and Iron Age sites in Myanmar. Observed microstructures range from as-cast, worked, to fully annealed; compositions include leaded copper, low-tin to high-tin bronzes, and arsenical copper/bronze. Lead isotope analyses indicate that the metal originates from different geological sources, including several that match the lead isotope signatures of known prehistoric copper mines in Thailand and Laos. These archaeometallurgical data, including evidence for secondary copper-base production, more than double those currently available for Myanmar and document the presence of multiple local alloying and working traditions, perhaps chronologically differentiated, as well as identifying possible links to primary mineral sources across the region. Overall, this adds significant new information to the emerging picture of Southeast Asian prehistoric metallurgy at the crossroads of several major ancient cultures.     

Early Metal in South India: Copper and Iron in Megalithic Contexts

In South India early metal artifacts, usually associated with megalithic sites, include both copper and iron. Although in some cases copper artifacts predate those made of iron, there is no evidence of an extensive metallurgical tradition based on copper and its alloys. Typological studies have had limited success in explaining the megalithic sites and the production and consumption of metal, while other approaches have not explicitly addressed the social contexts of metal production. While there emerge some suggestive patterns from the archaeometallurgical evidence to date, understanding the role of metal production and consumption in megalithic contexts means reevaluating traditional paradigms about the nature of these sites and about how metal technologies develop.     

Early copper smelting at Itziparátzico,Mexico

Archaeological fieldwork and archaeometallurgical analysis have identified a Late Postclassic regional centre of copper production in western Mexico. The total output from a single unit of production at the site of Itziparátzico is an estimated ten tons of copper and nearly forty tons of slag over the lifetime of the installation. It is argued that this smelting was based on slag-tapping furnaces, a technology previously unknown from Mesoamerican archaeological sites. The smelting site is in dense woodland with ample fuel supply, some 125 km from the next mining area with documented contemporary ore extraction; the copper produced would have been passed on to the capital, another 60 km away, for further distribution and working. The scale of production at Itziparátzico indicates that copper smelting was done by part-time specialists embedded in a predominantly agricultural economy, and formed part of a centrally organized network of mining, smelting and processing of copper to supply the Tarascan state.     

Variability in single smelting episodes – a pilot study using iron slag from Uganda

Most archaeometallurgical studies of iron smelting are based on the analyses of slag fragments randomly selected from slag deposits, and assume that these samples are representative of the typical smelting conditions of the given context. However, little archaeometallurgical research has been published to explore the variability in slag composition within a single smelt, or between individual smelts at the same production site. The material used in this pilot study originates from two iron smelting sites identified in the Buganda Kingdom, Uganda, dated to the 18th and 19th centuries AD. The remains represent evidence of the industrial scale iron production that supported the growth and power of the kingdom. The slag survives in large clusters of complete blocks, in some cases weighing over 100 kg, each resulting from a single smelting episode in a pit furnace. A multi-sample analytical approach has allowed an insight into the compositional diversity within the slag from single smelting events, reflecting changing parameters in the smelting systems. The internal variation of the slag blocks is subsequently compared within and between sites, to address issues of standardisation and to differentiate two technological traditions that would appear very similar at the macroscopic level. On this basis, some sampling recommendations are made for future slag block studies.     

Reassessment and new data on the diachronic relationship of Thassos Island with its indigenous metal resources: a review

The extraction of mineral ores and its associated metal production has been a persistent element of the economy on Thassos Island since prehistoric times. As early as the Upper Palaeolithic, around 20,000 years ago, ochre had been mined and used for painting, while early silver extraction is attested during the Final Neolithic (early fourth millennium BC). Copper production and alloying becomes an important activity in the coastal settlements of the island during the third and second millennia. The inception of iron metallurgy has been seen in association with copper smelting as confirmed by analyses on slag found in Early Iron Age upland cemeteries. With the arrival of the Greek colonists around 650 BC, intensification in silver and gold extraction became paramount for further economic expansion. This deep history in the use of Thassian metals is being reviewed based on archaeological findings and archaeometallurgical research of the last three decades, while new analytical data on Early Bronze Age copper smelting at Aghios Antonios are being presented.     

Metalworking and Recycling in Late Bronze Age Cyprus – the Evidence from Kition

Excavations at the sacred precinct of the Late Bronze Age city of Kition uncovered the remains of metalworking workshops which were clearly associated with the temples. The results of the excavation as well as a number of specialist reports of the archaeometallurgical finds have already been published. Since their publication, however, archaeological research has progressed and new evidence has come to light regarding the Late Bronze Age in general and metalworking in particular. The object of this paper is to present the finds from these workshops and reconsider some of the issues that their discovery has raised. The results of the previous studies of the archaeometallurgical studies are critically assessed and the evidence reinterpreted based on what is available today. One of the issues addressed is that of metal recycling during the Late Bronze Age. This communication was presented at a research workshop organized by the Israel Science Foundation and the University of Haifa on 'Recycling, Hoarding and Trade in Bronze, 13th–11th centuries BCE' (Haifa 26–28 April, 1998). The first part of the paper was written by Karageorghis, the second part by Kassianidou.     

Pastoralist iron production on the Laikipia Plateau, Kenya: wider implications for archaeometallurgical studies

Recent research conducted on the Laikipia Plateau in Kenya highlighted several shortfalls in the existing models for understanding and interpreting past iron production technologies. The research was undertaken in order to assess variability in past pastoralist iron production techniques – the first such archaeometallurgical exploration in the region. In all, seven furnaces and one iron production refuse area were excavated across two discrete sites separated by only 3 km: Mili Sita and Cattle Dip, both dating to the second half of the second millennium AD. The recovered archaeometallurgical materials – slag, furnace wall, and tuyères – were analysed using a combination of optical microscopy, SEM-EDS and ED-XRF.The results revealed that the technologies in question were complex and sophisticated, and their reconstruction and interpretation required some special considerations. The exploitation of titania-rich black sand was observed to bear a major influence on the resulting slag compositions at both sites, and use of these specific materials resulted in consistently efficient smelting episodes, demonstrating the technical competence and skill of the past smelters. However, although the slag compositions and microstructures of all the samples were markedly similar between the two sites, striking stylistic variation was apparent in the furnace design. This raised questions not only about the organisation and identity of the smelters who were working in this area at this time, but also of the reliability of assuming that similar slag compositions – peculiar as these might be – reflect similar technological (or sociotechnical) systems (cf. Pfaffenberger, 1992). A further problem encountered was that the consequently ulvite-rich slag was comprised of five, not three, major constituents – titania and lime in addition to iron oxide, alumina and silica. This meant that the operating parameters of these smelting episodes could not be easily interpreted using the usual models, which tend to be based around the assumption of fayalitic slag.As such, this paper will discuss to what extent consistency in technological style, in a broad, sociocultural sense, can be inferred through slag analysis, as well as the need for the formulation of wider reaching models that encompass the full scope of technical variation in iron production.     

An Archaeomagnetic Study of a Roman Bath in Southern France

Absolute Thellier–Thellier archaeointensity determinations were conducted on 137 tiles and sedimentary blocks from five different structures from the ‘Site de la Molère’, southern France, to constrain the archaeological interpretation of a relative age difference between structures and add new data to the French secular variation database. We present 89 new archaeointensity and 20 new directional results, with averages of 57 (±8) μT in the second century ad and 68 (±7) μT in the third century ad . The overall data trend is consistent with the limited available data, indicating rapidly increasing field intensity from the second to the third century ad .     

The Phenomenon of the Influence of Gold Melt on Microinclusions of Platinum Group Minerals in Ancient Gold Objects

This study focuses on microinclusions of platinum group minerals (PGMs) in gold objects from the South Urals and North Black Sea archaeological sites. We demonstrate for the first time that melting of gold during archaeometallurgical work affects PGM microinclusions. Desquamation of primary PGM microinclusions with 28–55 wt% Os in the melt and their oxidation by hot air microbubbles results in the formation of secondary particles with 1–20 wt% Os around the primary inclusions. We conclude that the composition only of primary PGM microinclusions in ancient gold products is comparable to the composition of those from natural sources.     

Making sense out of cents: compositional variations in European coins as a control model for archaeometallurgy

Archaeometallurgy frequently seeks to correlate between the temporal and spatial distribution of ancient metal objects and their chemical composition. In this study, we examined whether and to what extent local or temporal deviations in the content of modern artifacts can be identified as a proxy for archaeological material that is typically less controlled and therefore more difficult to cluster. For this purpose, Euro coins of 10, 20 and 50 cents from Germany, France, Spain, Italy and Belgium, which are made of copper (Cu) with 5% aluminum (Al), 5% zinc (Zn) and 1% tin (Sn), were analyzed using a simple XRF analyzer. The mass ratios Sn/Cu and Zn/Cu were measured with a relative precision c.a. of 5%. The mean content of the coins from each country was then determined for 20–39 of them. The difference of the mass ratio Sn/Cu observed – from 0.0101 to 0.0111. One coin from Luxemburg shows differences in various areas of its surface of up to a factor of 1.5. Thus, the results of this small pilot research show that even in modern metal artifacts we can detect differences in metal content, which can be correlated to their production and utilization places. Therefore, this study can serve as a model for evaluating compositional variations noted in archaeometallurgical studies where the standard deviations are greater and the differences can be linked more readily to spatial and temporal differences.     

ARCHAEOMETALLURGICAL CHARACTERIZATION OF HELLENISTIC METAL OBJECTS: THE CONTRIBUTION OF THE BRONZE OBJECTS FROM RISHON LE‐ZION (ISRAEL)*

An archaeometallurgical analysis is presented of 14 bronze artefacts retrieved from an Early Hellenistic–period farmstead in controlled archaeological excavations at Rishon Le‐Zion, Israel, and dated to the first quarter of the third century bce according to coins and pottery vessels. The bronze assemblage includes a needle, pins, spatulas and fibulas. The aims of the research are to determine the composition, microstructure and manufacturing process of these artefacts, and to discover their place of production. This will provide a better understanding of Hellenistic technological abilities and material culture. The examination included optical microscopy, microhardness, SEM including EDS, and XRD. The results show that the collection consists of Cu–Sn binary alloys, with evidence for a controlled alloying process and the absence of recycling. Furthermore, the microstructure of the objects indicates that all artefacts were produced by a cold‐working process. Moreover, the manufacturing process of the rectangular cross‐section fibulas included sophisticated joining techniques of copper and iron.     

Recent archaeological research at Saruq al‐Hadid,Dubai, UAE

In September 2014, the University of New England (UNE), Australia, began a three‐year programme of archaeological fieldwork and post‐excavation analyses focused on the site of Saruq al‐Hadid. In this paper, we present the initial results of our current field and laboratory research particularly related to site stratigraphy and formation processes, relative and absolute chronology, and the preliminary results of various programmes of post‐excavation analyses including archaeobotanical, zooarchaeological, ceramic and archaeometallurgical studies. These studies provide new data to build into the archaeological understanding of Saruq al‐Hadid that has, to date, focused largely on intensive excavation.     

On Pins and Needles: Tracing the Evolution of Copper-base Alloying at Tepe Yahya, Iran, via ICP-MS Analysis of Common-place Items

From 1967 to 1975 a team of archaeologists excavated the site of Tepe Yahya in southeastern Iran under the direction of C. C. Lamberg-Karlovsky. Although there are two forthcoming “final reports” (Hiebert (in progress), and Magee (in press); see also Lamberg-Karlovsky & Potts, 2001), analysis of the materials continues as opportunities allow. Metal artefacts, most especially those made of copper and its alloys, are found at this site from the late Neolithic through the Iron Age. Archaeometallurgical analysis, radiocarbon chronologies, and archaeological interpretation allow one to state when and how a type of metal or a style of object was invented, its use as a trade item, and its function and value to an ancient community. In the hopes of establishing a framework for future archaeometallurgical studies, most of the metal artefacts from Tepe Yahya, Iran, stored in the Peabody Museum of Harvard University, were analysed for elemental composition to complement stylistic and metallographic data.     

Silver production at al‐Radrad: archaeometallurgical analysis of ore,slag and technical ceramics from early medieval Yemen

The zinc‐lead‐silver deposit of al‐Jabali, about 65 km north‐east of Sana'a in Yemen, has been identified as the location of the late antique/Islamic period silver mine al‐Radrad. Exploitation of the mine is known from the account of al‐Hamdani, an Arab geographer of the tenth century AD. The al‐Jabali area has been the focus of geological and archaeometallurgical surveys, and extensive metallurgical remains have been discovered. Samples of ore, slag and technical ceramics were collected for archaeometallurgical analysis. The technology of silver production is discussed in relation to the historical record, and elemental and lead isotope characterisation of ore and slag provides a basis for future provenance studies.     

ARCHAEOMAGNETIC FIELD INTENSITY DURING THE ROMAN PERIOD AT SIWA AND BAHRYN OASIS,EGYPT: IMPLICATIONS FOR THE FIDELITY OF EGYPTIAN ARCHAEOMAGNETIC DATA

A preliminary survey was conducted in Siwa and Bahryn Oasis to test the possible influence of various rock magnetic and experimental constraints on the fidelity of the Egyptian archaeomagnetic field record. Five potsherds from the Roman era, which lasted from 1981 bp to 1555 bp , have been investigated. Archaeologists dated the localities to ～1620 bp . Ten ceramic specimens, two of each potsherd, were subjected to archaeointensity determination, including tests for domain state effects, magnetic anisotropy and magnetic cooling rate dependency. Six successful archaeointensity determinations are obtained from three individual cooling units, revealing an average field value of 37.7 μT for the late Roman period in Siwa and Bahryn oasis, which is comparable to the present‐day field strength. The error propagation of the individual uncertainties related to all applied experimental techniques results in a maximum uncertainty estimate of 4.4 μT. The obtained field value is significantly smaller than early results and slightly smaller than some more recent determinations of the field intensity in Egypt. The difference is attributed to a combined effect of alteration, magnetic anisotropy and magnetic cooling rate dependencies. Along with other high‐quality data from the south‐east Mediterranean, our data suggest a field intensity minimum during the Egyptian Roman era.     

COINS,ARTEFACTS AND ISOTOPES—ARCHAEOMETALLURGY AND ARCHAEOMETRY*

Archaeometallurgy is one of the earliest manifestations of archaeometric research, using science‐based approaches to address cultural–historical questions. This review first outlines the extent of the field, defining in some detail the main branches of archaeometallurgy, and their specific methodological approaches. It then looks at some of the early publications pioneering archaeometallurgical research, to set the scene for the publication pattern of archaeometallurgy in general, and the role that Archaeometry played in publishing archaeometallurgical research. The analysis of archaeometallurgy‐themed publications in Archaeometry, their change over time and their relationship to the total range of work done in the field indicates that there is a rather narrowly defined and specific type of archaeometallurgy that gets published in Archaeometry, initially with a strong focus on coin and object analysis, often combined with method developments. The more recent developments in isotope‐based studies in archaeometallurgy find only a limited representation in the journal, despite the leading role that the Isotrace Laboratory played in this discipline, for some considerable length of time. More recently, this Archaeometry‐specific ‘flavour’ of archaeometallurgy seems to weaken, with an increase of papers on iron and on primary production in general, subjects still much under‐represented.     

Metallurgical Characterization of A Coated Roman Iron Coin By Analytical Investigations

A coated Roman iron coin from Villa Loig in Salzburg, Austria was investigated. The coating is a copper alloy consisting of Cu, Pb, Sn, Zn and negligible amounts of Ag, a variant of gunmetal known as ‘leaded red brass’. The numismatic term for such a coin is subferratus (Latin). From an archaeometallurgical point of view, information about the chemical composition, the microstructure and the manufacturing technique are of interest. To achieve these objectives, different analytical techniques and metallographic examinations were applied. Droplet‐shaped iron inclusions were observed in the red brass coating, while at the grain boundaries, inside the iron core, copper and lead were detected (liquid metal embrittlement). The dendritic microstructure of the coating, the spheroidal‐shaped iron inclusions in the coating and the liquid metal embrittlement show that the iron coin was plated by immersing it in a molten copper alloy. The iron core is a low‐carbon steel with slag stringers, both of which are characteristic of a bloomery iron. Deformation twins (Neumann lines) were observed in the microstructure of the iron core and indicate that the coining was performed after the flan was cooled.