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.     

MINERALOGICAL AND PETROLOGICAL INVESTIGATIONS OF EARLY BRONZE AGE COPPER‐SMELTING REMAINS FROM THE KIECHLBERG (TYROL,AUSTRIA)

The prehistoric settlement on the Kiechlberg hilltop is located a few kilometres to the north‐east of Innsbruck, in the Tyrolean Inn Valley. Despite its rather isolated location, a multiphase settlement between the fifth and the second millennium bc was confirmed by archaeological investigations in 2007 and 2008. Metallurgical artefacts, such as copper ore fragments, copper slag and raw copper, as well as finished copper and bronze artefacts, are concentrated mainly in Late Copper Age to Middle Bronze Age layers. The chemical compositions of the slag and raw metals confirm Fe—Zn tetrahedrite–tennantite (fahlore) smelting. The ore was most probably imported from the 30–50 km distant copper ore deposits (mainly fahlore) of Schwaz–Brixlegg, in the Lower Inn Valley. The small amount of slag and the presence of slagged and thermally altered ceramic fragments suggest copper production in small‐scale workshops. Most probably, sulphide‐rich ores were smelted in crucibles in a hearth fire. The process was relatively reducing below the 2Sb + 1.5O₂ → Sb₂O₃ reaction (?8.5 log fO₂ at 1100°C), producing Sb‐rich (>10 wt% Sb in metal) raw copper. Inhomogeneous slag remains containing high amounts of sulphide and metal inclusions suggest a poor separation of the metal, matte (copper sulphide) and silicate/oxide melt during the smelting process.     

Lead isotope and chemical signature of copper from Oman and its occurrence in Mesopotamia and sites on the Arabian Gulf coast

Lead isotope data, together with an evaluation of previously published results for the chemical composition of Omani ores and copper‐base artefacts are used to define a material signature of Omani copper. Absent from our group of Bronze Age metal (Umm an Nar and Wadi Suq periods) are the signature of ores from Masirah Island and also from the vast deposits in north Oman inland from Suhar. Contemporaneous copper from Bahrain and from Tell Abraq on the Gulf coast is consistent in its material signature with Omani copper; a derivation from Omani ores of this copper is highly likely. A few exceptions at Tell Abraq point to Faynan/Timna in the southern Levant as a possible source region. Among Mesopotamian artefacts the signature of Omani copper is encountered during all cultural periods from Uruk at the end of the fourth millennium BC to Akkadian 1000 years later. Oman/Magan appears to have been particularly important during Early Dynastic III and Akkadian when about half of the copper in circulation bears the Omani signature.     

The mineral wealth of ancient Arabia and its use I: Copper mining and smelting at Feinan and Timna – comparison and evaluation of techniques, production, and strategies

Near Eastern fieldwork in mining archaeology and archaeometallurgy began at Timna (Israel) in the 1960s and 1970s and continued in Feinan (Jordan) in the 1980s and 1990s. For the first time, Bronze Age copper mines were excavated and cleared and importance was given to the slag recovered. At both sites copper was produced for over 5000 years, from the Chalcolithic to the Mamluk periods. Although the broad outlines of technical development can be traced, much remains to be learned in future studies.     

The potential of stable Cu isotopes for the identification of Bronze Age ore mineral sources from Cyprus and Faynan: results from Uluburun and Khirbat Hamra Ifdan

Copper isotope ratios differ between hypogene sulfidic, supergene sulfidic and oxidized ore sources. Traditional lead isotope signatures of ancient metals are specific to deposits, while Cu isotope signatures are specific to the types of ore minerals used for metal production in ancient times. Two methodological case studies are presented: First, the mining district of Faynan (Jordan) was investigated. Here, mainly oxidized copper ores occur in the deposits. The production of copper from Fayan’s ore sources is confirmed by the measurement of the Cu isotope signature of ingots from the Early Bronze Age metal workshop from Khirbat Hamra Ifdan. Based on our results illustrating differences in the Cu isotope composition between the ore mineralizations from Timna (Israel) and Faynan, it is now possible to determine these prehistoric mining districts from which copper artifacts originated by combining trace elements and Pb isotopes with Cu isotopes. The second case study presents data on Late Bronze Age copper production in Cyprus. Oxhide ingots from the shipwreck of Uluburun (Turkey) were tested for their lead isotope signatures and assigned to Cypriot deposits in the recent decades. The oxhide ingots from Uluburun show a Cu isotope signature which we also found for oxidized copper ores from Cyprus, while younger oxhide ingots as well as metallurgical slag from the Cypriot settlements Kition and Enkomi show a different signature which might be due to the use of sulfidic ore sources from a greater depth of deposits. We assert that there could be a chronological shift from oxidized to sulfidic ore sources for the copper production in Cyprus, requiring different technologies. Therefore, Cu isotopes can be used as a proxy to reconstruct mining and induced smelting activities in ancient times.     

Iron and bronze production in Iron Age IIA Philistia: new evidence from Tell es-Safi/Gath, Israel

A metallurgically-oriented excavation in Area A at Tell es-Safi/Gath yielded evidence for iron and bronze production dating to the early Iron Age IIA. Two pit-like features, which differed considerably from one another in colour, texture and content, were excavated. Evidence shows that each feature represents a different in situ activity related to iron production, inferred by the presence of hammerscales, slag prills and slag. An upturned crucible was found on top of one of the features. Analysis of the crucible slag showed that it was used for bronze metallurgy. Tuyères, both round and square in cross-section, were found in and around the two features. The presence of the two industries together presents a unique opportunity to explore the relationship between copper and iron working. This is especially important against the background of the scarcity of evidence for iron production in the Levant during the early phases of the Iron Age.     

Prehistoric copper production and technological reproduction in the Khao Wong Prachan Valley of Central Thailand

This paper concerns the identification and explanation of change in prehistoric extractive metallurgical behaviour in the Iron Age Khao Wong Prachan Valley of central Thailand. This metallurgical complex is amongst the largest in Eurasia and constitutes Southeast Asia's only documented pre-modern copper-smelting evidence. The two Iron Age smelting sites investigated, Non Pa Wai (NPW) and Nil Kham Haeng (NKH), provide a sequence of metallurgical consumption and production evidence from c. 500 BCE to c. 500 CE. The enormous quantity of industrial waste at these sites suggests they were probably major copper supply nodes within ancient Southeast Asian metal exchange networks. Seventy-six excavated samples of mineral, technical ceramic and slag from NPW and NKH were analysed in hand specimen, microstructurally by reflected-light microscopy and scanning electron microscopy and chemically by polarising energy-dispersive X-ray fluorescence spectrometry and scanning electron microscopy with energy-dispersive X-ray fluorescence spectrometry. The analytical data were used to generate detailed technological reconstructions of copper-smelting behaviour at the two sites, which were refined by a programme of field experimentation. Results indicate an approximately 1,000-year trend of Valley copper smelters' improving technical proficiency from what may be an experimental phase of production in the mid-first millennium BCE. This amelioration in production was accompanied by a substantial increase in the human effort of copper extraction. This shift in local ‘metallurgical ethos’ is interpreted as a response to rising regional demand for copper in late prehistory.     

REGIONAL VARIATIONS IN BLOOMERY SMELTING SLAG OF THE IRON AGE AND ROMANO‐BRITISH PERIODS*

This study highlights regional variation in the composition of iron‐smelting slag produced in England prior to the medieval period and attempts to link slag composition to the type of ore smelted. For many sites, the slag compositions were consistent with the use of limonite ore, but there is evidence that siderite ore was smelted at sites in Sussex in the late Iron Age/Romano‐British periods. A compositional comparison of smelting slags and slag inclusions in Iron Age currency bars, using data from Hedges and Salter (1979 ), illustrates the potential of smelting slag compositional data in provenance studies of early iron objects.     

First comprehensive peat depositional records for tin,lead and copper associated with the antiquity of Europe's largest cassiterite deposits

Tin, as a constituent of bronze, was central to the technological development of early societies, but cassiterite (SnO₂) deposits were scarce and located distantly from the centres of Mediterranean civilizations. As Britain had the largest workable ore deposits in the ancient Western world, this has led to much historical speculation and myth regarding the long-distance trading of tin from the Bronze Age onwards. Here we establish the first detailed chronology for tin, along with lead and copper deposition, into undisturbed ombrotrophic (rain-fed) peat bogs located at Bodmin Moor and Dartmoor in the centre of the British tin ore fields. Sustained elevated tin deposition is demonstrated clearly, with peaks occurring at 100–400 and 700–1000 calendar years AD – contemporaneous with the Roman and Anglo-Saxon periods respectively. While pre-Roman Iron Age tin exploitation undoubtedly took place, it was on a scale that did not result in convincingly enhanced deposition of the metal. The deposition of lead in the peat record provides evidence of a pre-Roman metal-based economy in southwest Britain. Emerging in the 4th century BC, this was centred on copper and lead ore processing that expanded exponentially and then collapsed upon Roman colonization during the 1st century AD.     

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.     

Dating environmental change using magnetic bacteria in archaeological soils from the upper Thames Valley,UK

An archaeomagnetic date has been recovered from an organic rich sediment at the base of an alluviated ditch section found during archaeological excavations near the village of Yarnton, Oxford, UK. The magnetic minerals carrying this remanence include greigite and biogenic magnetite, derived from magnetotactic bacteria, that both indicate the presence of a micro-aerobic environment. It is proposed that the archaeomagnetic date from this material indicates the onset of floodplain conditions at the site due to increased population pressure and intensification of land clearance in the late British Iron Age.     

A new approach for geomagnetic archaeointensity research: insights on ancient metallurgy in the Southern Levant

We present results from an archaeointensity investigation based on a relatively unexploited recording medium, copper slag deposits. Together with a recently improved experimental design for the archaeointensity experiment, we demonstrate the applicability of this medium, as well as other archaeometallurgical artifacts, for the study of the ancient geomagnetic field intensity. In addition to archaeointensity data from well-dated archaeological contexts, we obtained reliable archaeointensity results from poorly dated or contentious archaeometallurgical sites in the Southern Levant. These results shed new light on the dating of these sites, among them the copper smelting installation of Timna 39b – a site that has important implications for the beginning of metallurgy during the fifth millennium BCE. The paper also aims to introduce archaeointensity research to the archaeologist scholar, and to encourage further collaboration between the disciplines in future research.     

Post-Roman crop production and processing: Archaeological evidence from Goldthorpe,South Yorkshire

The remains of a ditched field system dating from the late Iron Age to the early post-Roman period, and two associated corn drying ovens (dating to the 5th–6th centuries AD) were revealed during archaeological excavations at Goldthorpe, South Yorkshire. The site was excavated during 2012 and 2013, during which bulk environmental samples were taken in order to retrieve any surviving botanical remains from deposits associated with the corn drying ovens, and other features across the excavated area. Early post-Roman occupation is under-represented in the archaeological record, especially in northern England, as such human activity and subsistence during this period are currently not well understood. This paper combines evidence for the field system, the physical remains of the corn drying ovens and their associated botanical remains to further understand early post-Roman change and continuity in landscape use and crop production and processing practices.     

The Potential for Dating the Old Scatness Site,Shetland, By Optically Stimulated Luminescence

A series of deposits from the agricultural infield of the multiperiod settlement mound, Old Scatness, were investigated for their potential to yield optically stimulated luminescence dates. Luminescence properties of quartz grains were found to vary through the sequence, but dates were successfully obtained from five deposits, including anthropogenic soils, windblown sands and sands within midden deposits. Single‐aliquot equivalent dose measurement was found to be the most appropriate method for dating the deposits. The OSL dates obtained accorded well with the dates provided by archaeological evidence and included the post‐medieval, Iron Age, Bronze Age and Neolithic periods of Shetland, while a substantial midden was dated to the Bronze/Iron Age transition.     

Slag as evidence for early iron production in arctic Norway

Physical, structural and chemical analyses were made on slag remains obtained from three sites in Iron Age arctic Norway. Scanning electron microscopy and x‐ray microanalysis were employed to confirm that the slag can only be a result of iron production. Although a distinction between slag produced by smithing and smelting proved difficult, consideration of the processes and the resources available support the assumption that both were practiced at the sites. The results provide firm evidence of iron production in the region of Norway north of the 69th parallel, by at least the sixth century AD.     

Salt production in pre-Funan Vietnam: archaeomagnetic reorientation of briquetage fragments

Bronze to Iron Age briquetage found in the northern Mekong Delta has an appearance similar to analogous material from Europe and Asia; however, the orientation in which the briquetage was employed during the production of salt is still under debate. As a consequence of the heating and subsequent cooling of the briquetage during the evaporative recovery of salt, the magnetic mineral particles within the ceramic formed a stable thermoremanent magnetization in alignment with the Earth's magnetic field. It thus becomes possible to find the orientation in which the ceramics were last fired by aligning their recorded archaeomagnetic signal with estimates of the Earth's ancient field direction in Vietnam. The archaeomagnetic directions obtained from 22 samples taken from five different briquetage artefacts are somewhat scattered, but they reveal a consistent orientation and thus the mode in which the briquetage was employed can be reconstructed.     

Context for a carnyx: excavation of a long-lived ritual site at Leitchestown,Deskford, Moray,north-east Scotland

Excavations at the findspot of the Deskford carnyx, a major piece of Iron Age decorated metalwork found in a bog in the early nineteenth century, revealed a special location with a long history. Early Neolithic activity on the adjacent ridge consisted of massive postholes and pits, suggesting a ceremonial site. An Early Bronze Age cremation became the focus for a feasting event in the Middle Bronze Age. Around this time, peat began to form in the valley, with vessels of pot and wood smashed and deposited there; these activities on ridge and bog may be connected. Activity in the bog intensified in the later Iron Age, when offerings included quartz pebbles, the dismantled carnyx head, and two unusual animal bone deposits. The ridge was cut off at this period by a complex enclosure system. This Iron Age activity is interpreted as communal rituals at a time of increasing social tension. The site’s significance in this period may stem from its unusual landscape character, with flowing water to one side and a bog to the other. The area saw occasional activity in the Early Medieval period, but its significance had waned.     

Provenance of Early Bronze Age metal artefacts in Western Switzerland using elemental and lead isotopic compositions and their possible relation with copper minerals of the nearby Valais

Ten Early Bronze Age (BzA1, 2200–2000 BC) copper artefacts from the central Valais region from Switzerland were studied for their elemental composition and lead isotope ratios. In order to answer the archaeological question of a local copper supply, a database for copper minerals across the Valais (Switzerland) has been established. This database contains 69 data on lead isotope ratios as well as additional information on the minerals and geochemical associations for copper minerals from 38 locations in the Valais. Comparisons of the artefacts were also made with data pertaining to minerals from various deposits from Europe and Anatolia taken from the literature. The provenance of the materials is very diverse. Some of the data are compatible with the data from the copper mineral deposits of the Valais region. Moreover, three copper lunulae were identified as possibly Tuscan, which suggests contacts between Italy and the Valais region. This pattern also establishes a multiplicity of provenances for the metal and cultural influences in the Alpine environment of the Rhone Valley of Switzerland at the beginning of the Early Bronze Age.     

Iron smelting and smithing in major urban centers in Israel during the Iron Age

By-products of iron production, mainly slag and bloom fragments, unearthed at three Iron Age urban centres in Israel (Hazor, Tel Beer sheba and Rehov), were analysed in order to better understand the organization of iron production during the Iron Age. The production remains studied are all dated not earlier than the Iron Age IIA, and thus shed light on a period of transition from bronze to iron production. Chemical composition and microstructural analyses enable us to determine that both the smelting of iron ores and the refining of the bloom took place within the urban centres of Hazor and Beer-Sheba. We show that slag cakes are the products of smelting, possibly carried out in pit-furnaces. Hammerscales, products of primary and secondary smithing, were attached to slags. From these observations we infer that all stages of iron production were practiced in these urban centres.