Metallurgy and specialisation in Prepalatial Mesara, Crete

The purpose of this paper is to examine the technological knowledge and the technological level of copper metallurgy in the Mesara plain in Crete, during the Prepalatial period. In order to investigate this issue, objects from several (12) sites in the area were chosen for examination. In this way, the technological level of the area and each site could be safely ascertained. From the 55 objects that were examined, a very small sample was taken, which was the subject of metallographic and chemical analyses. By using these methods, the manufacturing processes for the production of each object, as well as the alloy that was used in each case, were identified. The combination of these two methods, along with typology of the objects and the number of objects produced at each site, provided safe conclusions as to the technological knowledge and the possible specialisation of metal production in each site and period. In the end, a lack of homogeneity in the Mesara plain was noticed as concerns the production of copper objects. Some sites seem to have a dominant position, with larger production and trading of metal artefacts, while other sites fail to provide any indication of metal production, and it is very possible that the metal objects were obtained from the neighbouring sites. Finally, the existence of specialised production is obvious in some sites in the Mesara plain, especially in the case of two groups of objects (triangular and long daggers), while the lack of organised and standardised production is obvious in the case of some other sites in the same area.     

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.     

Andean Ores,Bronze Artifacts,and Lead Isotopes: Constraints on Metal Sources in Their Geological Context

With a focus on bronze production in the south-central Andes during the Middle Horizon, this study reports the first archaeological use of lead isotope analysis to investigate metallic ores and metal artifacts in the Andean zone of South America. Because the vast majority of metal deposits in the Andean cordillera formed in a convergent plate boundary setting, lead isotope compositions of most Andean ore sources are not unique. Lead isotope ratios of central and south-central Andean ores define four geographically distinct ore lead isotope provinces, oriented and elongated parallel or sub-parallel to the trend of the Andean cordilleras. Consequently, ore lead isotope ratios vary strongly from west to east along transects through the coast, highlands, and altiplano, but they exhibit much less variation from north to south. The strong west-to-east variation in ore lead isotope signatures allows discrimination between ore bodies, and ultimately between metal artifacts, as a function of macro-ecozone location: coast, junga-qiswa, puna, and altiplano. We present the most up-to-date database of ore lead isotope signatures for the south-central Andes including those determined for ores we sampled over an approximate 250,000-km² region within Bolivia, northern Chile, and northwest Argentina. Lead isotope signatures of Cu-As-Ni bronze artifacts from Tiwanaku (altiplano capital) and San Pedro de Atacama (desert oasis entrepôt) establish that altiplano and high sierra ore bodies provided the metal for both assemblages. Conchopata (Wari) arsenic bronze artifacts exhibit lead isotope ratios compatible with the Julcani (Huancavelica) copper sulfarsenide deposit.     

Electrochemical Characterization and Dating of Archaeological Leaded Bronze Objects Using the Voltammetry of Immobilized Particles

The application of solid state electrochemistry techniques for the characterization and dating of leaded bronze objects is described. Characteristic voltammetric signatures of copper and lead corrosion products were used as markers of more or less prolonged corrosion periods. The proposed methodology was applied to samples from the Roman archaeological sites of Valeria (Spain) and Gadara (Jordan), Roman and medieval sites in Xàtiva (Spain), and modern statuary exhibited outdoors, on the campus of the Universitat Politècnica of Valencia, Spain, covering a time interval between the fourth to second century bc and the 20th century ad . For such samples, the ratio between the signals for copper and lead corrosion products decreased monotonically with the corrosion time. This variation was modelled on the basis of thermochemical and kinetic considerations, the experimental data being consistent with a potential rate law for the corrosion process.     

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.     

Production and Consumption of Copper-base Metals in the Indus Civilization

We review the existing data sets for the production and consumption of copper-base objects at Indus sites, outline a working typology for metal objects, and provide new data from on-going analytical work on the copper assemblage from Harappa. The role of metals in the economic and social networks of the Indus tradition is examined in terms of patterns of use and technological style. We note that Indus metalsmiths apparently relied more on procurement of metal ingots or scrap than on primary ingot production through smelting, which would have affected other aspects of Indus metallurgy. Object production did not involve elaborate forms, but may have involved complex alloying. Finally, we conclude that there is no evidence for elite control of metal production, and that access to metals was relatively widespread.     

The use of oxygen,strontium and lead isotopes to provenance ancient glasses in the Middle East

It is sometimes possible to discriminate between glasses made at different factory sites by using chemical analysis. However, this is not necessarily a means of provenancing them unambiguously because glass of slightly different compositions may have been fused using different proportions of the same raw materials. The determination of oxygen, strontium and lead isotopes can provide the possibility of linking the geological sources of the glass raw materials to the production sites on which the glass was fused. Here we consider the possible isotope contributions made to the raw materials thought to have been used in the manufacture of plant ash and natron glasses found at 8th–9th century al-Raqqa, Syria. The isotopic data from al-Raqqa are compared with published results from other Middle Eastern and German glasses. We show that strontium isotopes, in particular, provide a reliable means of distinguishing between the sources of plant ash glass raw materials and that oxygen and lead isotope signatures are less discriminatory.     

The local and global dimensions of metalliferous pollution derived from a reconstruction of an eight thousand year record of copper smelting and mining at a desert-mountain frontier in southern Jordan

This paper establishes an eight thousand year history of anthropogenic metal pollution at one of the oldest, most important and longest sustained sites of the extraction and smelting of copper ores in the Old World: the Faynan Orefield in Jordan, which is located between the hyper-arid southern desert and the front of the wetter Mountains of Edom. The modern land surface is shown, in significant part, to be a complex palimpsest of archaeological sites, metal pollution of various ages and ore processing deposits. Quantitative and qualitative observations of the storage and cycling of heavy metals through the local natural and domestic systems have produced a body of information on processes with which the past has been interpreted. Heavy metal concentrations in semi-continuous sedimentary bodies indicate that over the last 1500 years, metals were removed by natural processes at a comparatively slow rate given the scale of the original anthropogenic metal burden: the proportions of lead with respect to copper have increased as the overall metal burden has been lowered. Distinctive anthropogenic metal-pollution signatures have been detected in ash- and charcoal-rich deposits that were discarded onto the banks of a perennial stream in the late Neolithic. At present, the nature of the human activities that might have produced these pollution signatures is unknown. Substantial metal pollution from industrial-scale smelting activity was present from the Early Bronze Age. The intensity of heavy metal pollution produced in Classical Times locally exceeded that recorded at major European copper smelting centres in the nineteenth century A.D. The pollution evidence indicates that intensive copper smelting at the immediate area took place until approximately the end of the Byzantine period; with the exception of one further minor episode of smelting radiocarbon dated to cal. BP 530–330. An observed partial, but perhaps significant, parallelism is also noted between this local record and the records of the metal burdens of the northern hemisphere determined at mire or ice-sheet sites at high-altitudes or high-latitudes.The paper discusses the extent to which this parallelism might be a geochemical indicator of the actual existence of “economic systems” of a geographical scope and scale to have both exercised substantial “pull” upon the resources of such isolated and difficult locations at the Wadi Faynan, and to have generated sufficient overall metal pollution to have materially altered the chemistry of the global atmosphere. The comparative absence of quantitative information upon the nature, spatial scale and impacts of human, industrial and natural processes affecting metal-pollution in other metal-rich arid lands provides a significant impediment to such approaches that seek to research “locally and think globally”.     

Paint It Black: The Rise of Metallurgy in the Balkans

This paper integrates archaeological, material, microstructural and compositional data of c. 7,000 years old metallurgical production evidence with the aim to address the knowledge of the world’s earliest metalworkers. The main focus is placed on copper minerals, ores, slags, slagged sherds and metal droplets coming from four Vin?a culture settlements in Serbia and Bosnia and Herzegovina: Belovode, Plo?nik, Vin?a and Gornja Tuzla, all dated between c. 5400 and 4400 BC. Chemical study of copper minerals throughout all sites points at striking uniformity in selecting black and green minerals from the early days of the settlements’ occupation, some of which predate the metal smelting events. Microstructural examination of metal production debris showed convincing technological similarity throughout c. six centuries of copper making in the studied sites, as well as a consistent choice of black and green ores for metal extraction. We argue that black and green ores were intentionally selected as ingredients for the metal smelting ‘recipe’ in the early stages of Balkan metallurgy based on the knowledge related to their characteristic visual aspects. This finding demonstrates how important the adequate combination of colours was for the early copper metalworkers and suggests a unique technological trajectory for the evolution of metallurgy in this part of the world. It also illustrates the capacity that micro-research carries in addressing the how and why of the emergence of metallurgy, and outlines a methodology for future studies of early metallurgies worldwide.     

汉代铸造铸钱金属范之陶范的分析研究

汉代的铸钱遗址中出土了大量铸造铸钱金属范的阳文陶范,阳文陶范既反映出了铸造金属范时的铸型,又可看出所铸造的铸钱金属范的铸型.为揭示铸钱金属范的铸造工艺及变迁,本工作从铸造工艺角度对阳文陶范进行分析,通过对汉代阳文陶范出土概况的统计,了解了阳文陶范铸型的变迁.以西安相家巷和窝头寨铸钱遗址采集的阳文陶范为基础,对陶范的面层与背层进行了X射线荧光成分分析,在电子探针下对型腔面进行了形貌和成分分析.分析结果表明,阳文陶范分层制作的原因是为了将模上的钱币铭文和形状清晰地复印到陶范上,型腔面的检测不能表明是否使用了表面涂料.     

Potentially stylistic differences between backed artefacts from two nearby sites occupied 60,000 years before present in South Africa

Archaeologists are commonly interested in material signatures that can be used to identify past population groups. In the Palaeolithic such population groups are often identified at large spatial scales, yet the material expressions of smaller groups comparable to those documented ethnographically have proved more difficult to isolate. The present paper considers differences in silcrete backed artefacts recovered from two nearby sites. These sites, both of which were occupied during the Howiesons Poort period, are situated in different ecological contexts with variable access to stone resources. Site context does not, however, explain observed differences in technology, nor do potential differences in tool function. Variation is instead inferred to be stylistic, or at least to be adaptively neutral. The results imply occupation of the study area by two different groups maintaining different technological traditions some time around 60,000 years before present.     

Lead isotope and metal source of Shang bronzes: a response to Sun et al.’s comments

In this brief response to Sun et al.’s ( 2018 ) comments on our paper, we re‐emphasize that archaeological, chemical and isotopic evidence are all relevant to the discussion about the metal source of the Shang period with highly radiogenic lead isotope ratios. The southern African bronzes have much lower lead contents and quite different lead isotopic signatures than the Shang bronzes. More importantly, there was no metallurgy of any kind in southern Africa before c.200 ce , so southern Africa cannot possibly be the source of Shang bronze, which date to about 1500 to 1000 bce .     

Copper quality and provenance in Middle Bronze Age I Byblos and Tell Arqa (Lebanon)

Forty-four Middle Bronze Age I weapons discovered at the sites of Byblos and Tell Arqa in Lebanon were investigated in order to study their copper quality and provenance. The evaluation of copper qualities is based on quantifying permanent inclusions such as copper sulfide and lead globules. The provenance of copper was studied using lead isotope analyses. For further discrimination between copper groups and sources elemental analyses by PIXE were performed on some of the weapons investigated. The results revealed two copper groups that could be qualified as “dirty” copper and “clean” copper. The former was used in most of the weapon types whereas the latter was reserved for items made of high-tin bronzes (>11 wt%) which underwent heavy hammering during the manufacturing process. Even though several potential copper sources were identified, the data point to Iran and Oman as the most probable areas of origin for the metal used in these weapons. These results contribute to the study of inter-regional exchange networks in the ancient Near East.     

Lead isotope analysis as a new method for identifying material culture belonging to the Vázquez de Coronado expedition

Archaeological evidence has become an increasingly important component of efforts to identify the route of the Francisco Vázquez de Coronado expedition through northern Mexico and the southwestern United States (1540-1542). Here, we report the first high-precision lead isotopic measurements of artifacts from two archaeological sites with strong material evidence for the expedition’s presence: Piedras Marcadas Pueblo in New Mexico and the Jimmy Owens Site in Texas. The analysis of lead and copper armaments from both sites reveals that many artifacts have overlapping or extremely similar isotopic ratios. We propose that the narrow range of lead isotopic ratios measured on these artifacts can be interpreted as a geochemical fingerprint for some of the Coronado expedition’s surviving material culture, and provides evidence that we interpret to suggest the expedition derived lead and copper metal from Mexican sources. Such a geochemical fingerprint presents an empirical method for discriminating between artifacts that belonged to the Coronado expedition and those related to subsequent Spanish, historical, or modern activity in the Southwest U.S. Thus, this method could significantly impact the search for and identification of archaeological sites associated with the Coronado expedition.     

The Hogeye Clovis cache,Texas: quantifying lithic reduction signatures

The Hogeye Clovis cache is comprised of 52 late-stage bifaces, finished points, and knife/cores cached in central Texas. Because these artifacts were all likely made and cached approximately 13,000 years ago by one or a handful of knappers belonging to a single band with a shared Clovis cultural template, Hogeye provides a rare opportunity to investigate Clovis lithic reduction signatures. This paper builds on previous analyses and presents new methods for quantifying Clovis biface production signatures, including serial flaking and the timing of last overshot flaking. The results show that the Hogeye cache bifaces technologically and morphologically differ from other regional Clovis biface reduction signatures. Additional data is needed to determine whether these differences reflect individual knapping preferences or regional cultural signatures. The methods used and developed here are not Clovis-specific and could be modified and combined with other analytical techniques to identify reduction signatures in biface assemblages from other times and places.     

Reconstructing site organization in the eastern Aleutian Islands,Alaska using multi-element chemical analysis of soils

This study presents the results of multi-element analysis of weak-acid extractions of 953 soil samples collected by coring on and around pre-historic village sites on two islands, Sanak and Amaknak, in the eastern Aleutians. Concentrations of aluminum (Al), barium (Ba), calcium (Ca), iron (Fe), potassium (K), magnesium (Mg), manganese (Mn), phosphorus (P), strontium (Sr), titanium (Ti), and zinc (Zn) were determined using an inductively coupled plasma-mass spectrometer (ICP-MS). Resultant elemental signatures allow the identification of site features and organization in the absence of large-scale excavation. All the archeological sites showed similar and distinct chemical signatures regardless of the several thousand year date range of the sites or the length of time a site was occupied. However, intensity of occupation does appear to affect concentrations of elements. Site features such as houses, house berms, house floors and middens had distinct anthropogenic signatures and could be distinguished from one another. This approach may be used to identify sites that do not have distinct surface features and to target areas for excavation.     

Bronze technology of the ancient megalithic communities in the Vidarbha region of India

Metallographic examination was carried out on forty-nine copper and bronze objects from five megalithic sites located in Vidarbha, India. The artifact assembly consists of horse ornaments, kitchenware, bangles, rings, small bells and the hilt of an iron dagger. Results show that the technology involved is characterized by the use of bronze alloys containing approximately 10% tin based on weight and the application of forging as a key method of fabrication. No deliberate addition of lead was observed. Arsenic was detected, but very rarely and only as an insignificant minor element. The consistent selection of such specific alloys indicates that the megalithic communities in this particular region had established a fully developed and standardized bronze tradition optimized for the production of forged items. Their advanced technological status was also noted in a special technique applied to two forged high-tin bronze bowls. Such a unique bronze tradition, dedicated to sheet metal technology, was most likely a practical choice made by these people to take advantage of the changing role of bronze. Specifically, with the introduction of iron, bronze seems to have become a more prestigious material that could serve as an indicator of the appearance of a more rigid socio-economic stratification within the megalithic communities of the Vidarbha region.     

Stable Lead Isotope Studies of Black Sea Anatolian Ore Sources and Related Bronze Age and Phrygian Artefacts from Nearby Archaeological Sites. Appendix: New Central Taurus Ore Data

The accumulated published database of stable lead isotope analyses of ore and slag specimens taken from Anatolian mining sites that parallel the Black Sea coast has been augmented with 22 additional analyses of such specimens carried out at the National Institute of Standards and Technology. Multivariate statistical analysis has been used to divide this composite database into five separate ore source groups. Evidence that most of these ore sources were exploited for the production of metal artefacts during the Bronze Age and Phrygian Period has been obtained by statistically comparing to them the isotope ratios of 184 analysed artefacts from nine archaeological sites situated within a few hundred kilometres of these mining sites. Also, Appendix B contains 36 new isotope analyses of ore specimens from Central Taurus mining sites that are compatible with and augment the four Central Taurus Ore Source Groups defined in Yener et al. (1991).     

The Source of Iron‐Oxide Pigments Used in Pecos River Style Rock Paints

The likely sources of iron‐oxide pigments used in prehistoric rock paintings in the Lower Pecos Archaeological Region were identified on the basis of chemical fingerprinting using LA–ICP–MS. The chemical signatures of 13 red rock paint samples collected from two south‐west Texas sites were compared with three potential source materials (ochre, siltstone and rhyolite), and two pigment cakes (crayons) that were excavated near the sampling sites. The significant chemical similarities between the paint and siltstones suggest that siltstone was used as the source of the colour. The overlapping chemical signatures for one of the pigment cakes and siltstone further suggests that some of the prehistoric people inhabiting the area 3000–4000 years ago had acquired the skills to extract iron oxide from siltstone and process it into paint pigments.     

Soil Chemical Analysis Applied as an Interpretive Tool for Ancient Human Activities in Piedras Negras,Guatemala

The applicability of soil chemical analysis to the interpretation of ancient human activity areas in the Maya region was studied for potential implications in anthropogenically modified soils. We studied chemical signatures associated with a horizontally excavated site in Piedras Negras, Guatemala. The focus of this study is on soil phosphate and trace metals as indicators of ancient activity. We compared total phosphate with Mehlich extractable phosphate to see which method was superior. We also compared total (nitric-perchloric) digestion with the DTPA extraction procedure of heavy metal determination to resolve which method most accurately indicates ancient activity areas. We used principal component analysis to compare the metals and give probable locations of ancient activities. Statistical analysis of chemical patterns indicated possible areas of food preparation and craft production as well as sweeping patterns. We found that elevated phosphate, barium and manganese levels indicate areas of organic refuse disposal. Mercury and lead concentrations indicate areas of craft production. These observations are compared with the artifact data. We were also able to determine areas associated with similar activities using chemical analysis. The comparison of the total and extractable element analysis demonstrated that both methods yield important information regarding activity areas. However, because of the resolution obtained, convenience, economy, and safety, we suggest the extractable DTPA and Mehlich methods.