天然氧化铜矿与铜制品腐蚀产物区别的探讨

在一些新石器时代的遗址中经常会出现一些铜渣、小块孔雀石等与炼铜有关的遗物。为探究这些孔雀石到底是天然的氧化铜矿还是铜制品的腐蚀产物,本工作对天然氧化铜矿和青铜器腐蚀产物进行岩相分析和元素成分分析。结果表明,天然氧化铜矿大都具有一些特殊的结构构造,而在铜制品的腐蚀产物中却很难发现这些结构构造;同时,二者在元素成分上也有显著不同,Bi、Sb、As、Fe、Mo、Co、Mn等微量元素可以作为区分天然氧化铜矿和青铜器腐蚀产物的一个判别标志。结合岩相分析和成分分析,可以确定一个遗址出土的孔雀石或蓝铜矿是天然氧化铜矿还是铜制品的腐蚀产物;同时,可进一步判断是红铜的腐蚀产物还是青铜的。这一结论对探讨铜冶金的起源有重要意义。     

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.     

The early roman imperial AES coinage II: Tracing the copper sources by analysis of lead and copper isotopes—copper coins of Augustus and Tiberius*

Lead and copper isotopes of Roman Imperial copper coins (denominations as and quadrans) were analysed by MC–ICP–MS. We concentrated on well‐dated coins minted at the official mint of Rome under the Emperors Augustus and Tiberius (between 16 bc and ad 37). The lead isotope results were compared with published lead isotope data of ore bodies from the Aegaean, Cyprus, Italy and Spain, in order to fingerprint the sources of Roman copper. During the Augustan period the main copper supply, as judged from the copper coins, is from Sardinia and south‐east Spain, with minor contributions from Tuscany. Except for Tuscany, this continued into the Tiberian period, when Cypriot copper also appears. Augustan quadrantes and late Tiberian asses came solely from the Rio Tinto area in south‐west Spain. Copper isotopes were applied here for the first time to systematic archaeometric studies. They are supplementary to lead isotopes and allow further grouping and classification of the copper coins.     

LEAD ISOTOPIC ANALYSIS OF COPPER ORES FROM THE SIERRA EL ARAMO (ASTURIAS,SPAIN)*

This study presents the first ever lead isotope ratio data for copper ore samples (malachite and azurite) from the Sierra El Aramo (Asturias, northwestern Spain). The aim of this study was to supplement information in the existing reference database on the lead isotopic composition of Spanish ores. The Sierra El Aramo is particularly important because, while no data for the Asturian ores have been published so far, this northern province of Spain has played a significant role in terms of copper exploitation and metallurgy since the Copper Age.     

Evaluating copper isotope fractionation in the metallurgical operational chain: An experimental approach

Until today, raw material information of copper (Cu) objects is mostly gained from impurities and trace elements and not from the Cu itself. This might be obtained using its stable isotopes. However, isotopic fingerprinting requires the absence of fractionation during the smelting process. The Cu isotope evolution during outdoor smelting experiments with Cu sulphide ore was investigated. It is shown that external materials, in particular furnace lining, clay, manure and sand, alter the isotopic composition of the smelting products. Cu isotopes are fractionated within low viscosity slag derived from matte smelting. The produced metallic Cu has a Cu isotope signature close to the ore.     

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。     

The history of the United States cent revealed through copper isotope fractionation

Copper isotope fractionation in United States cents traces changes in the source of copper and identifies historical events. Application of copper isotopes as a geochemical tracer requires consistent isotopic signatures of the ores and refined metals. Overlapping isotopic signatures of crushed ores, chalcocite and refined metal extracted from Morenci, Arizona indicate modern mining processes that produce distinguishable single ore deposit geochemical signatures. The coincidence of copper isotope ratios in metals and ore deposits also exists within the United States cents analyzed here. Specifically, historical records confirm two different sources for copper in cents from 1800 through 1867. The copper isotope composition of the 1828, 1830, 1836, 1838 and 1843 cents coincides with the Cornwall ores of England, and cents post 1850 (1859, 1862) correspond with the Michigan ores of the United States. Three of the thirty-six post 1867 cents measured possess fractionated copper isotope ratios and indicate the change in source of copper for the United States cent.     

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.     

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.     

Microanalytical study of copper ores from the Chalcolithic settlement of São Pedro (Portugal): Copper production in the south-western Iberian Peninsula

Copper ores recovered at the third millennium bce settlement of São Pedro, Portugal, were characterized by micro-Raman spectroscopy, micro-energy dispersive X-ray spectrometry (micro-EDXRF) and micro-particle-induced X-ray emission spectrometry (micro-PIXE). The collection shows the common presence of secondary copper minerals (malachite, pseudomalachite and libethenite) combined with iron oxyhydroxides (hematite and goethite), while arsenic-rich minerals are absent and, therefore, can be excluded as the source of arsenical copper. Overall, these copper ores suggest a primitive technology involving the exploitation of the superficial zone of ore bodies and reliant on the fortuitous finding of arsenic-rich sources to produce the arsenical copper alloy frequently present among metallic collections of the Iberian Peninsula.     

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.     

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.     

虢国墓地出土部分青铜器微量元素的分析

将微量元素示踪法与铅同位素比值法结合起来对青铜器矿料的溯源会起到相得益彰的效果。先前对虢国墓地青铜器的铅同位素比值测定表明,其青铜器铅同位素与山西中条山和长江中下游地区都有重合。本次微量元素分析结果显示,虢国墓地青铜器与山西中条山古矿冶遗址微量元素特征不同,而与长江中下游地区的湖北铜绿山古矿冶遗址铜锭的微量元素特征相似,推测长江中下游地区可能为虢国墓地青铜器提供了大量的铜料。此外,微量元素与铅同位素都表明虢国墓地不同墓葬的青铜器基本具有一致的矿料来源。     

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.     

A Provenance Study of Early Bronze Age Artefacts Found in Asturias (Spain) by Means of Metal Impurities and Lead,Copper and Antimony Isotopic Compositions

We describe here the first combined isotopic and impurities study on 27 copper artefacts found in the north‐west of Spain. This study follows previous studies on the lead isotopic composition of copper ores in three local mines that were exploited during the Bronze Age. The levels of impurities found were clearly different from ingots and axes, with ingots having much higher levels of impurities. It was not possible to differentiate the origin of the artefacts only by the impurities present. On the other hand, the lead isotopic composition indicated that all artefacts were prepared from local ores, the ‘La Profunda’ mine being the most probable source for most artefacts that carried out a clear radiogenic lead signature. The copper isotopic composition seemed to be able to differentiate artefacts from the ‘El Aramo’ mine from those from the ‘El Milagro’ and ‘La Profunda’ mines. On the other hand, the antimony isotopic signature was not useful for source allocation.     

UNIQUE PRE‐ROMANESQUE MURALS IN KOSTOĽANY POD TRÍBEČOM,SLOVAKIA: THE PAINTING TECHNIQUE AND CAUSES OF DAMAGE

Pre‐Romanesque murals at Kosto?any pod Tríbe?om, Slovakia, have been investigated by portable X‐ray fluorescence and by microanalytical methods to identify painting materials (pigments and binders), and to explain the degradation of colours. Today, missing green and blue shades have been reconstructed according to residual concentrations of Cu, which correspond to copper chlorides—products of salt corrosion of the copper carbonates azurite and/or malachite, accelerated by micro‐organisms. As confirmed by powder X‐ray microdiffraction, original minium (Pb₃O₄) has been transformed to brown–black plattnerite (PbO₂). In increased humidity, even insoluble pigments are washing down from the walls and the intensity of colours further diminishes.     

A GEOLOGICAL PERSPECTIVE ON THE USE OF Pb ISOTOPES IN ARCHAEOMETRY

Lead isotope ratios in ore bodies and magmatic rocks depend in a complex way on several a priori independent parameters, including the geological age of the tectonic province in which the ores and magmas formed and its U/Pb (μ) and Th/U (κ) ratios, two very sensitive parameters characteristic of metal sources. All these parameters are entangled in hard‐to‐read Pb isotopic ratios. With respect to the commonly used fingerprinting techniques, which rely on the comparison of raw isotope ratios, the main motivation for the present work is to provide a method for making geologically and geochemically educated guesses about metal provenance even in the absence of isotopic data on reference ores. It shows how to unscramble a geological model age and μ and κ information from isotopic measurements. This approach brings to light a new organization of the Pb isotope database and an untapped wealth of information that can be used for provenance studies and other archaeometric purposes. We provide expressions with which to calculate these parameters and, using literature data, demonstrate how Pb isotopes in ores and magmas define clear zones in the silver‐rich provinces of the Central Andes. We further show how the geological model age and μ and κ values fingerprint production areas in 16th–18th century silver coins minted in Mexico and South America. Finally, we use Pb isotopes to illustrate how the Reconquista of the Emirate of Granada (1482–91) and the seizure of the Betic silver mines are reflected in the silver coins of the Catholic Monarchs.     

SERIPHOS SURFACES: A STUDY OF COPPER SLAG HEAPS AND COPPER SOURCES IN THE CONTEXT OF EARLY BRONZE AGE AEGEAN METAL PRODUCTION

Kephala and Phournoi, on the island of Seriphos, add to a growing number of EBA metal production sites identified in the south‐central Aegean. Analytical examination of samples from the two sites addressed the technological parameters of the copper smelting process, indicating the use of mixed oxidic and sulphidic copper–iron ores to produce unalloyed copper with minute copper sulphide inclusions. A preliminary geological reconnaissance of the island identified several small copper mineralizations, one of them close to the site of Kephala. Nevertheless, the ore sources used remain unclear. Comparisons are made with other contemporaneous neighbouring smelting sites.     

TRACING THE RESOURCES OF IRON WORKING AT ANCIENT SAGALASSOS (SOUTH‐WEST TURKEY): A COMBINED LEAD AND STRONTIUM ISOTOPE STUDY ON IRON ARTEFACTS AND ORES*

Lead and strontium isotope analyses were performed by thermal ionization mass spectrometry (TIMS) on Roman to Byzantine iron artefacts and iron ores from the territory of ancient Sagalassos (south‐west Turkey), to evaluate Pb and Sr isotopes for provenance determination of ores for local iron production. It can be demonstrated that for early Roman artefacts and hematite iron ore processed in early Roman times from Sagalassos proper, as well as for magnetite placer sands and early Byzantine raw iron from the territory of the city, Sr isotopes are much less ambiguous than Pb isotopes in providing clearly coherent signatures for ore and related iron objects. Late Roman iron objects were produced from iron ores that as yet remain unidentified. Early Byzantine iron artefacts display more scatter in both their Pb and Sr isotope signatures, indicating that many different ore sources may have been used. Our study demonstrates that iron objects can be precisely analysed for their Sr isotopic composition, which, compared to Pb isotopes, appears to be a much more powerful tool for distinguishing between chronological groups and determining the provenance of raw materials.     

MC‐ICP‐MS analyses of tin isotopes in Roman‐era bronze coins reveal temporal and spatial variation

Tin's small mass fractionation and the lack of accepted reference standards have hindered Sn isotopy in archaeology and conservation science. Because of ore field variation and potential fractionation during ore reduction, attempts to determine artefacts’ ore sources have been limited. After norming the fractionations to NIST 3161a (Lot #070330), significant differences in Sn isotope mass fractionation in Judaean bronze ‘Biblical’ coins minted by different rulers during the first centuries bce and ce were discovered. These variations and those in δ ⁶⁵Cu and ²⁰⁶Pb/²⁰⁴Pb are connected to historical events in the Levant.