The Mineralogy of Bronze Age Copper Ores from the British Isles: Implications for the Composition of Early Metalwork

Numerous analytical studies during the latter half of this century have contributed to the compilation of a large compositional database of Early to Middle Bronze Age copper-based artefacts revealing distinctive impurity patterns which appear to change over time. However, attempts to relate these data to copper ore sources proved problematic in the absence of firm evidence for the location of prehistoric copper mines. Over the last fifteen years this situation has changed dramatically with the discovery of numerous Early and Middle Bronze Age copper mines in England and Wales. This study is the first attempt at a comprehensive mineralogical survey of the principal mines investigated to date in order to define the likely composition of the copper ores as mined in antiquity for comparison with the artefact database. The study suggests that the majority of these mines can only have produced essentially pure copper. Only one mine, Ross Island, is likely to have produced copper with a significant level of impurities. The relative purity of the known ore sources is contrasted with significant levels of various metallic impurities among the analysed artefacts, leading to the conclusion that metal circulation and mixing may have been more extensive than previously thought even during the earliest part of the Bronze Age.     

TECHNOLOGY AND PROVENANCE OF A COLLECTION OF ISLAMIC COPPER‐BASED OBJECTS AS FOUND BY CHEMICAL AND LEAD ISOTOPE ANALYSIS*

Chemical and lead isotope analyses were utilized to determine the composition, technology and origin of a collection of Islamic copper‐based objects found in Jordan. The atomic absorption spectrometry results show that the objects were made of different types of copper‐base alloys that contain various amounts of zinc, tin and lead. The use of brass, highly leaded brass and quaternary alloys of Cu‐Zn‐Sn‐Pb in the manufacture of everyday, household objects strongly points to Islamic traditions. The lead isotope compositions of the objects match very well that of the copper ore mined from the Dolomite‐Limestone‐Shale unit of the Arabah copper mines.     

LEAD ISOTOPE CHARACTERISTICS OF THE CYPRUS COPPER ORE DEPOSITS APPLIED TO PROVENANCE STUDIES OF COPPER OXHIDE INGOTS

Nearly 200 new lead isotope analyses of sulphidic and oxidized ores from 26 copper mines on Cyprus show that the mines from different geological regions group in five distinctive isotopic groups, each with a substructure, related to the geological history of the ore formation. Comparison of lead isotope compositions of Bronze Age artefacts with these data can in many cases reveal the actual mines from which the copper for particular artefacts was obtained. The particular case of the provenance of the copper for 78 Late Bronze Age copper ‘oxhide ingots’found in Cyprus, Crete, Greece, Sardinia, Turkey and Bulgaria is discussed. The data show that all oxhide ingots so far analysed, dating to the fourteenth century BC and later, were made of copper consistent isotopically with only one mining region in the geographical north of Cyprus, and especially the Apliki mine. The study provides further evidence which supports the validity of the conventional approach to the use of lead isotope analysis for provenancing metals; this evidence is antithetical to recent suggestions of a model for the production of copper oxhide ingots which involved widespread mixing of copper from a number of ore sources throughout the Mediterranean.     

Worker Housing in the Vermont Copper Belt: Improving Life and Industry Through Paternalism and Resistance

During the mid-nineteenth century, east-central Vermont supported two major copper mines and their associated villages. In order to wrest thousands of tons of copper from the earth these mines, the Elizabeth and Ely mines, hired and housed thousands of miners, laborers, and their families. Both mines pursued the same resource in the same environment during the same period, but the Ely Mine developed a centralized village, while the Elizabeth Mine housed its workers in isolated housing clusters. The causes of these differences in worker housing can be traced to differences in scale, setting, and managerial philosophy, and can be analyzed within the larger historical context of Improvement and the larger ethnographic context of paternalism in mining communities.     

A PRELIMINARY PETROGRAPHIC ANALYSIS OF CYPRIOT WHITE SLIP II WARE*

Samples of Late Bronze Age White Slip II ware from Cyprus were analysed using optical and scanning electron microscopy in conjunction with energy and wavelength dispersive analyse The slip has a novel granular nature and the coarser aggregates are impressed into the outer surface of the body, indicating that it was applied to a moist surface before the vessels were fired. It has a consistent mineral assemblage (Mg‐chlorite + illite‐smectite + sphene + anatase/rutile ± albite) which is very similar to that of hydrothermally altered zones associated with copper orebodies in the Troodos Massif which were mined in antiquity Our analysis suggests that the raw material for the slip was not found at the ground surface, because the alteration assemblage is unaffected by oxidation and copper carbonate or iron staining. It may, therefore, be a by‐product of sub‐surface ore extraction     

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.     

THE FORMATION OF THE INDUSTRIAL COMPLEX OF THE KURSK MAGNETIC ANOMALY

The industrial complex in the area of the vast iron-ore bearing province known as the Kursk Magnetic Anomaly (Central Russia) has been shaped in the past by an advantageous economic-geographic situation in the heart of the European USSR, by the availability of labor resources and by the presence of a wide range of agricultural raw materials for industry (sugar beets, sunflower, hemp). Further development will hinge on the massive use of mineral resources, both iron ore for the iron and steel industry, and cement materials in the overburden of open-pit iron mines. In 1975 the KMA will supply one-sixth of all the iron ore mined in the Soviet Union. About 60 percent of the ore (direct-shipping ore and concentrates derived from low grade-quartzites) moves to nearby plants at Lipetsk and Tula, and 25 percent moves to the Urals. If plans for a 12-million-ton integrated iron and steel plant for the Comecon countries materialize, 40 percent of the ore will be consumed locally, still leaving 60 percent for shipment to other steel plants. See also Soviet Geography, November 1974, pp. 593–94.     

Large scale smelting of speiss and arsenical copper at Early Bronze Age Arisman,Iran

We report analyses of different slag types found at the Early Bronze Age site of Arisman in North-West Iran. Here, an estimated 20 tons of slag provide evidence of sustained and large-scale production of metal, using both furnaces and crucibles. The results show that both speiss, an iron-arsenic alloy, and arsenical copper were produced, apparently side-by-side at the same site but using different ores and processes. We offer a tentative outline of the metallurgical processes involved in the production of these arsenic alloys and an explanation why speiss needed to be produced from arsenopyrite in a separate step, instead of using the mineral in its native form as a source for arsenic. We suggest that the speiss was then added either to secondary copper ore or to separately smelted copper metal, in order finally to produce arsenical copper in a regular and well-controlled process.     

商周时期南北方铜矿开采技术比较研究--以鄂赣交界地带和辽西地区为例

本文选取了鄂赣交界地带和辽西地区的4座晚商至西周早中期的古铜矿遗址,分别从探矿技术、开采技术、开采工具、相关配套设施和选矿技术等方面对南北两区域古铜矿的开采技术进行全面比较,并试图从两地的自然环境、矿物品质以及生产组织方式等不同方面来解释出现这种差异的原因。     

An Alakul funeral and ritual site in the Eastern Orenburg region

An unusual funeral and ritual site of the Alakul culture is described. It is situated in the northern periphery of a Late Bronze Age mining and metallurgical center in the Ural–Mugodzhary region, and is associated with the Ishkinovka group of ancient copper mines, which began to be exploited in the Early Bronze Age. A stone statue and votive objects suggest that the kurgan was a sanctuary marking a tribal area and a ritual center of a population engaged in copper mining and copper metallurgy     

EARLY BRONZE AGE TIN PROCESSING AT KESTEL/GÖLTEPE,ANATOLIA

Chemical analysis of statistically significant numbers of samples including minerals, sediments, soil, host rock as well as powdered materials, crucible accretions and metal artefacts revealed information about the distribution of cassiterite at Kestel and the tin smelting processes that took place at Göltepe c. 2600 BC. Using the ancient technique of vanning for the isolation of tin ore (cassiterite), followed by assaying by blowpipe/charcoal block, as well as crucible smelting with a blowpipe, good tin metal suitable for alloying with copper to make bronze was obtained. There is every indication that tin was mined and smelted in the Early Bronze Age at the Kestel/Göltepe sites.     

Mining Archaeology and Micro‐Raman Analysis Associated with ESEM‐EDX: Toward a Chrono‐Spatial Definition of Ore Consumption in a Pyrenean Medieval Workshop, 14th–16th Centuries

The rapid expansion of non‐ferrous metallurgy in the late Middle Ages (14th–15th centuries) enhanced ore demand, which was supported by mining intensification. Metallurgical workshops developed various supply strategies based on geological, political and economic constraints. This is particularly true for the Pyrenean multi‐metals workshop of Castel‐Minier (Ariège, France), where recent excavations unearthed an exceptional corpus of non‐ferrous ores. A specific analytical methodology combining micro‐Raman spectroscopy and environmental scanning electron microscopy with energy dispersive X‐ray (ESEM‐EDX) was set up to study these artefacts. This composite methodology permitted the fast characterization of both mineral and gangue as well as a discussion of their economic potential. Ores identified were compared with ancient mines in neighbouring mining districts in order to sketch a geography of the mineral resources available to medieval metallurgists. Moreover, a chrono‐stratigraphic study of ore distribution in Castel‐Minier revealed the supply strategies, technological choices as well as spatializing of copper and lead metallurgies.     

Sourcing copper ores for production of bronzes excavated at Shuangyantang,a Western Zhou (1046–771 <Emphasis Type="SmallCaps">bc</Emphasis>) site in Chongqing (Southwest China): evidence from lead isotope analysis

Energy-dispersive X-ray fluorescence (EDXRF) and lead isotope analyses were applied to 12 Western Zhou (1046–771 bc) bronzes unearthed from the Shuangyantang site in Wushan County, Chongqing (southwest China), to investigate their chemical compositions and possible mineral source(s). The results showed that (1) the investigated bronzes were mostly bronzes with low, common lead and (2) their lead isotopic values almost all fall into a relatively narrow range, suggesting possibly the use of raw materials from a common copper mine. The comparison between lead isotopic values for Shuangyantang bronzes and those already published for copper mines and other bronzes produced and used about at the same times leads us to believe that the Shuangyantang bronzes probably used the same copper ores as used in bronzes from the Peng and Jin states in Shanxi Province. However, it would not be possible at this point to come up with a clear idea of where exactly these copper ores may come from. Candidate copper mines might be the Tonglvshan mines in Hubei Province, the Zhongtiaoshan mines in Shanxi Province, or the Dajing copper mines in Inner Mongolia.     

Copper Mines,Chromite Copper Ores and Slags of the Ishkinino Bronze Age Archaeological Microregion,The Southern Urals

The study addresses copper mines structure and composition of copper ores and slags at the Ishkinino archaeological microregion, Orenburg Province. Both ores and slags contain chromites derived from the host ultrabasite rock. Chromites were subdivided into three categories in terms of Cr2O3 content: 45–50%, 50–55%, and 55–61%. The proportions are similar to those observed in chromites of the malachite ores of the Ishkinino cobalt-copper-pyrite deposit. The reguli found in the slag contain copper sul?des and iron phosphides with a high content of nickel. Our results evidence the exploitation of local copper mines in the Late Bronze Age. Finds of chromite ores and slag at the archaeological sites of the Southern Urals are listed, and goals for future research are outlined.     

秦始皇帝陵园出土彩绘青铜水禽铜矿料来源探索

关于秦始皇帝陵出土彩绘青铜水禽铜矿料来源的研究,对进一步研究秦代的物质文化、青铜器冶铸工艺、装饰工艺以及铜矿来源均具有重要意义。本研究对部分秦始皇帝陵园出土彩绘青铜水禽基体进行了铅同位素分析及微量元素分析。并在此基础之上,与甘肃东部及关中西部出土的部分早期秦文化铜器、国墓地出土的部分铜器、周原李家铸铜作坊出土的部分铜器、山西中条山、江西瑞昌、江西铜岭、安徽铜陵以及湖北大冶铜绿山古铜矿以及秦岭山区的部分现代铜矿的相关数据进行了对比研究。结果发现,秦始皇帝陵园出土的青铜水禽使用了相同的矿料,且与绝大多数早期秦文化铜器所使用的矿料基本相同,但与国墓地以及李家铸铜作坊出土西周铜器的矿料明显有别。秦人使用的铜矿与秦岭山区现代铜矿较为接近,表明秦人的铜矿来源可能与秦岭山区有关。     

何郢遗址出土青铜器铜矿料来源的初步研究

本文利用地球化学示踪的方法对何郢遗址出土青铜器的铜矿料来源进行了初步研究.采用ICP-AES测试了样品的微量元素,根据元素的地球化学亲和性,探索其在冶炼过程中的化学行为和再分配规律,从而选出对铜绿山和皖南的铜陵、南陵铜矿具有指示意义的特征元素,作为判断其铜料输出路线的综合判别标志.结合文献和地质资料,可初步认为何郢遗址青铜器的铜矿料来自滁县.     

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.     

清代云南铜矿垄断经营利润的考察

清政府对云南铜矿实行高度垄断经营的政策,即以低于商品自由贸易市场数倍的价格收购矿铜,又以相对较高的价格将矿铜批发给各铸钱局,通过统购统销来赚取价差,获得了大量垄断利润"铜息"。低价矿铜用于铸钱,极大地降低了铸钱成本,各铸钱局获得了丰厚的"铸息"。不仅如此,各铸钱局利用商品货币市场铜钱价格的高昂,通过出售铜钱或搭放兵饷等途径,最大限度地扩大"铸息"。"铜息"是清政府对云南铜矿实行垄断经营的直接利润,"铸息"是铜矿垄断经营的间接利润,是铜矿垄断利润向铸钱利润的转移。     

Characterisation of the raw metal sources used for the production of copper and copper-based objects with copper isotopes

Copper isotopes can be successfully used to determine the origin of copper or bronze artefacts from either primary or supergene sulphide or hydrocarbonate ores. In conjunction with lead isotopes, they provide information on the origin and type of the metal ore. We demonstrate this in this paper from the combination of literature and own data on metal ores and artefacts (coins and ingots). Low-temperature hydrocarbonates (esp. malachite and azurite) do not fractionate the copper isotopes amongst each other and have identical lead isotopes. Substantial fractionation of copper isotopes, however, occurs between copper sulphides and hydrocarbonates (malachite, azurite) such that the ⁶⁵Cu isotope is always enriched in the oxidised relative to the sulphide phase with a clear distinction between the two ore types. Expressed in the δ⁶⁵Cu notation, we assigned supergene sulphides to values less than −0.4‰ down to negative values of −2‰ and more, primary sulphides to a range between −0.4 and +0.3‰ and hydrocarbonates to positive values higher than +0.3‰. We have applied these boundaries to copper coins and ingots from the time of the Roman emperors with known ages from Augustus up to 250 AD. The deposit fields of the metal used for the production of the coins were previously identified from the lead isotope ratios to lie in the Southwest and the Central South of Spain. From the combination of the lead and copper isotopes and the exact time constrains, we could develop a picture of the change in mining activities in Spain involving continued mining sulphide ore deposits and, indicated by positive δ⁶⁵Cu values as proxies for malachite and azurite, the opening of new mines in various time slots. This first application shows that copper isotopes will become the most important tool in archaeometallurgy to distinguish between the exploitation of deeper-seated primary and supergene sulphide ores and shallower, secondary hydrocarbonate ores. This will become especially relevant for archaeometric questions regarding the distinction between occasional and intentionally produced alloys.     

Partitioning of trace elements between the ores, fluxes, slags and metal during the smelting of copper

This paper gives the results of smelting seven parcels of copper ores from well-known mining areas. The behaviour of the trace elements introduced from the ore, the fuel, and the fluxes has been investigated by analysis of the main products, metallic copper and the slags. Most of the ores were capable of giving copper of relatively high purity and therefore, in order to represent conditions believed to have existed in the Early Bronze Age, two artificial ores were made up and copper high in arsenic and nickel was obtained.The results show that it is relatively easy to smelt a wide range of copper minerals to give copper of high purity apart from iron. This latter element can be removed by careful refining. The remaining elements are present at the parts/10³ level. Wood fuel is thought to contribute little to the trace element pattern. Even if it did, it would merely reinforce the elements already contributed by the ore and flux as the timber is likely to have been grown in the immediate vicinity of the ore and will probably contain the same trace elements.Useful comparison is made between the trace element pattern resulting from these smelting runs and material from archaeological sites in the vicinity of the mining areas.