2,428 research outputs found
Metallurgical knowledge and networks of supply in the 5th millennium BC Balkans: Belovode and Pločnik in their regional context
The recent set of excavations (campaigns 2012 and 2013) at the sites of Belovode and Pločnik (see Chapters 11 and 26) have shown the use of copper minerals and metallurgical activities to be highly consistent with results from previous analytical research (Radivojević 2007, 2012, 2013, 2015; Radivojević et al. 2010a; Radivojević and Rehren 2016). Specific aspects to emerge so far include: persistent selection of black and green manganese-rich copper ores for metal extraction; similar engineering parameters involved in the early copper smelting technology; field evidence from Belovode supporting the presence of pottery- lined hole-in-the-ground installations; consistent metal making and working technology remains at both sites; and direct absolute dating evidence that leaves no doubt for c. 5000 BC as the beginning of copper metallurgy in the Balkans. In this chapter we will synthesise the evidence for this c. 7,000 years old copper production technology within the Vinča culture, in its local and regional perspective, including data and debates on the provenance of copper ores
Copper processing in the oases of northwest Arabia: technology, alloys and provenance
Very little is known about early metallurgical activity in the north-western part of the Arabian Peninsula, despite the region’s cultural importance. To begin to address this research lacuna, metallurgical remains including crucible fragments, metal dross and a copper artefact were sampled from two oases in northwest Arabia, Qurayyah and Tayma. The metallurgical activity in Qurayyah is dated to the Late Bronze Age, and in Tayma to the Roman/Late Roman period. At both sites we identified evidence for copper alloying and refining. Small scale copper smelting might also have been practiced in Qurayyah. Arsenical copper was processed at both sites, but in Tayma tin bronze and leaded tin bronze dominated. The chemical analysis of metal prills in crucible linings showed that fresh copper and tin instead of scrap metal were employed in these processes. Lead isotope analysis indicates that at least some of the Tayma metal was imported. Access to raw materials from remote areas is consistent with the importance of Tayma in the trading network of northwest Arabia
Qingzhen and Yamato-691: A tentative alphabet for the EH chondrites
Petrological investigations of unequilibrated EH chondrites revealed the presence of three subgroups. They are identified based on the presence of different concentrations of MnS in niningerite. These differences were produced by partitioning of Mn between niningerite and enstatite as a result of different f_S2 and f_O2 during their formation. In order of increasing MnS-contents and hence increasing f_S2 and decreasing f_O2 these groups are : (A) Yamato (Y)-691 and Abee, (B) Indarch, and (C) Yamato-74370,South Oman, Qingzhen, Kota Kota, Kaidun III, and St. Marks. In the third subgroup the meteorites follow an equilibration and evolution sequence; Y-74370 the most primitive and St. Marks the most equilibrated. Y-691 is the most primitive in its subgroup. Differences in the chemical compositions of minerals in Y-691 and Qingzhen reveal a dichotomy in the compositions of niningerite, djerfisherite, kamacite, and perryite. Niningerites in Y-691 contain the least MnS (3.6-6.7 mole%) and counterparts in Qingzhen the most (12-14 mole%). K/Na ratios in djerfisherite are lower in Qingzhen than in Y-691. The Si concentration in kamacite in Qingzhen is higher than in Y-691. Ni in perryite in Qingzhen is higher than in Y-691. Na and K are highly fractionated between two sulfide lithologies. Na resides mainly in chondrules in caswellsilverite, in a Cl-bearing glass in the chondrules, and in Cr-rich sulfides in the matrix. In contrast, K is confined to djerfisherite, which occurs only in sulfide-rich objects in the matrix, and is highly depleted in chondrules. Two new layer structure minerals were discovered in Y-691 : (a) Na-Cu-Cr-sulfide with the general formula (NaCu) CrS_2,and (b) a Na-Cu-Zn-Cr-sulfide. An evolution scheme was constructed for the EH chondrites in the solar nebula and in their parent bodies. Niningerite and oldhamite condensed first and probably acted as nucleation sites for condensing sulfides, metals and silicates. Both minerals are abundant in chondrules, indicating that chondrule formation preceded all other sulfide- and metal-rich objects. For the first time, planetary metamorphic events were recognized. The Qingzhen Reaction, a breakdown of djerfisherite to troilite, covellite, idaite, bornite, and other unidentified phases, was discovered in Qingzhen and Y-691. Thermal episodes took place in the parent bodies at 1.4 Ba (Qingzhen), and 800 Ma (Y-691). Reverse zoning in niningerite indicates that Fe diffused from troilite to niningerite during the thermal event. In Y-691 sphalerite also formed during the metamorphic episode due to mobilization of Zn (and other volatiles). EH chondrites condensed in a chemically inhomogeneous region of the solar nebula where considerable variations in sulfur and oxygen fugacities existed
Early copper metallurgy in Northern Chile
The Central Andean region of South America has a long tradition of mining and metallurgy. Such activities were fundamental to the economic, socio-political and ideological dynamics of the pre-Columbian cultures that inhabited this area. In spite of their importance, few archaeological investigations of metallurgy have been carried out in the Central Andes in general, and in current Chilean territory in particular. The present project investigates archaeometallurgical sites in northern Chile using scientific analysis, as a first step towards a large-scale map of prehistoric copper production and exchange across South America. This research involves documentation and sampling of already excavated archaeological materials from a number of copper-producing sites located in the Atacama District. Preliminary results of XRF analysis of artefacts from the collection of the R. P. Gustavo Le Paige Archaeological Museum, San Pedro de Atacama, have been obtained and enabled us to characterise the different elements present in the metal objects. These results might provide information on the nature of the raw materials used
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
The Metallic Finds from Çatalhöyük: A Review and Preliminary New Work
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 Çatalhöyük
suggests an occupation phase from c.7400–6200 cal
BC, which was further reined by a programme of AMS radiocarbon
dating to the range c.7400–5600 BC (Bronk Ramsey
et al. 2009; Cessford 2001; 2005c; Mellaart 1964). The
concentration of metallic inds from Levels South M-O has
been dated to c.6600–6450 BC. Despite receiving a great deal
of attention, very little research has been conducted on these
inds (Neuninger et al. 1964; Sperl 1990).
Starting a new approach, three Neolithic copper-based
artifacts from recent excavations were selected for further
investigation. Before introducing the study of these artifacts,
a brief overview will be presented of evidence for early metallurgy
in Anatolia in order to contextualize the inds from
Çatalhöyük. The inds from Mellaart’s excavations will be
reviewed before introducing those resulting from recent excavations.
Finally, the preliminary investigation into the three
copper-based artifacts will be presented with a discussion of
the results
Copper for the Pharaoh: Identifying multiple metal sources for Ramesses' workshops from bronze and crucible remains
The origin of copper used in Late Bronze Age (LBA) Egypt is very poorly understood despite its cultural and economic importance attested in archaeological and historical sources. Extensive literature discusses major LBA copper sources such as Cyprus (oxhide ingots), Oman (bun ingots) and Egyptian-controlled sites in the Sinai. This paper presents new chemical and lead isotope data for Egyptian copper alloys excavated in several bronze production workshops from the New Kingdom capital Pi-Ramesse, expanding on earlier data from Amarna. Supporting data is obtained from the analysis of crucible remains from the same context, for which the potential contribution of lead isotope analysis is critically evaluated. Diachronic changes in the provisioning of these Egyptian workshops are discussed, incorporating an extensive overview of currently known Egyptian mining and metallurgy. The results have major implications for our understanding of LBA copper circulation in the wider region, for the first time analysing a major Egyptian ‘consumer’ assemblage. The analytical results reveal a complex picture of variable copper supply to the Ramesside workshops, which involved both the recycling of existing bronzes and the use of freshly smelted copper from various origins to produce fresh alloys. Importantly, this includes crucial new evidence for the melting of (Cypriot) oxhide ingot fragments in crucibles for alloying. The royal, internationally connected nature of these workshops makes Pi-Ramesse an exceptional case study of LBA metal trade, and hypotheses raised in this paper highlight the need for more extensive analysis of ancient Egyptian copper artefacts to grasp metal circulation throughout Egypt's long history. More refined frameworks, incorporating the variety of private as well as royal contexts, will improve understanding of Egypt's ancient economic organisation. This paper offers new perspectives onto LBA metal supply and consumption networks, with broader archaeological interpretative models of economic and political interactions across the wider ancient Near East
Repealing the Çatalhöyük extractive metallurgy: The green, the fire and the ‘slag’
The scholarly quest for the origins of metallurgy has focused on a broad region from the Balkans to Central Asia, with different scholars advocating a single origin and multiple origins, respectively. One particular find has been controversially discussed as the potentially earliest known example of copper smelting in western Eurasia, a copper ‘slag’ piece from the Late Neolithic to Chalcolithic site of Çatalhöyük in central Turkey. Here we present a new assessment of metal making at Çatalhöyük based on the re-analysis of minerals, mineral artefacts and high-temperature materials excavated in the 1960s by J. Mellaart and first analysed by Neuninger, Pittioni and Siegl in 1964. This paper focuses on copper-based minerals, the alleged piece of metallurgical slag, and copper metal beads, and their contextual relationship to each other. It is based on new microstructural, compositional and isotopic analyses, and a careful re-examination of the fieldwork documentation and analytical data related to the c. 8500 years old high-temperature debris at Çatalhöyük. We re-interpret the sample identified earlier as metallurgical slag as incidentally fired green pigment, which was originally deposited in a burial and later affected by a destructive fire that also charred the bones of the interred body. We also re-confirm the contemporary metal beads as made from native metal. Our results provide a new and conclusive explanation of the previously contentious find, and reposition Çatalhöyük in a new narrative of the multiple origins of metallurgy in the Old World.Qatar Foundation enabled the new study of this material through its generous funding of UCL Qatar as a joint centre of excellence for Museology, Conservation and Archaeolog
Calibration of dosemeters used in mammography with different X ray qualities: Euromet Project No. 526
The effect of different X ray radiation qualities on the calibration of mammographic dosemeters was investigated within the framework of a EUROMET (European Collaboration in Measurement Standards) project. The calibration coefficients for two ionization chambers and two semiconductor detectors were established in 13 dosimetry calibration laboratories for radiation qualities used in mammography. They were compared with coefficients for other radiation qualities, including those defined in ISO 4037-1, with first half value layers in the mammographic range. The results indicate that the choice of the radiation quality is not crucial for instruments with a small energy dependence of the response. However, the radiation quality has to be chosen carefully if instruments with a marked dependence of their response to the radiation energy are calibrate
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