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.     

LEAD ISOTOPE AND TRACE ELEMENT ANALYSIS IN THE STUDY OF OVER A HUNDRED SOUTH INDIAN METAL ICONS*

Technical investigations were made on 130 South Indian statuary images and a few miscellaneous artefacts mostly sampled from the Government Museum, Madras, India, and from the Victoria and Albert Museum and the British Museum, UK. Lead isotope investigations were attempted on 60 of these, and compositional analysis for 18 elements on 115, using inductively coupled plasma optical emission spectroscopy; thus, for 40 objects both lead isotope and trace element analysis was done. From the isotopic and elemental framework, insights are obtained into some art-historical problems of images and artefacts of the Pre-Pallava, Pallava, Chola (i.e., Vijayalaya Chola), Later Chola (i.e., Chalukya-Chola and Later Pandya), Vijayanagara (and Early Nayaka) and Later Nayaka (and Maratha) dynasties, spanning the Early Christian era to the nineteenth century, along with a few other regional styles. Inferences are also made regarding provenance of the lead and the early use of zinc and brass in the early historic period (c. fourth century BC—fourth century AD).     

Geological constraints on the use of lead isotopes for provenance in archaeometallurgy

The first part of this paper is a brief critical history of the use of Pb isotopes for inferring the geological provenance of archaeological materials, with an emphasis on non-ferrous metals. The second part examines variation in the Pb isotopic ratios of oxide and sulphide ore minerals in selected regions of the world, and relates these to the geological histories of ore formation in each region. This exercise shows that in regions where most ore deposits are of similar geological age—as in the Andes, Europe and the circum-Mediterranean—provenance analysis with Pb isotopes is inherently difficult because geographically distant sources often exhibit similar isotopic ratios. Conversely, regions with many periods of ore formation—such as southern Africa—appear to be very promising regions for future studies of provenance with Pb isotopes. The wider implication of this exploratory survey is that archaeologists should carefully consider the range and clustering of geological Pb isotopic ratios in their regions of interest before investing large sums of money into Pb isotopic analysis of artefacts.     

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.     

ON THE COMPOSITION AND PROVENANCE OF METAL ARTEFACTS FROM POLIOCHNI ON LEMNOS

Summary. The majority of the well-stratified Early Bronze Age metal objects from Poliochni, with the exclusion of one hoard find, was analyzed for their chemical and lead isotope composition. The results show that a major change occurred in the metal used at Poliochni during periods contemporary with Troy I and Troy II. Unalloyed or arsenical copper with relatively high lead contents during the earliest two periods 'azzurro' and 'verde' is gradually replaced and supplemented by tin bronze which, during period 'giallo', i.e., by the end of Troy II, becomes the dominant metal type. Lead isotope abundance ratios in the earlier artefacts are consistent with a derivation of the metal from regional ore sources but the trace element abundance pattern is not. Concurrent with the appearance of tin bronzes is an increase in the diversity of ore deposits exploited; for about one third of the artefacts from period 'giallo' there is as yet no matching ore source in all Anatolia and the Eastern Mediterranean. It is argued that the tin bronzes have been imported as such but that the lead isotope signature does not provide any direct clues to the origin of the tin.     

Local mining or lead importation in the Roman province of Africa Proconsularis? Lead isotope analysis of curse tablets from Roman Carthage,Tunisia

This study attempts to determine if there was Roman lead mining in Africa Proconsularis, approximately the area of modern day Tunisia, using lead isotope analysis. Another important aspect of the study is the innovative use of electron microprobe analysis (EMPA) as a screening tool to greatly reduce the number of expensive lead isotope analyses needed for the study. The EMPA X-ray mapping for arsenic, antimony, copper, and silver narrowed the sample of curse tablets to those most likely produced from Tunisian ores; these tablets were then tested using thermal ionization mass spectrometry (TIMS) analysis. A total of 96 Roman lead curse tablets from Carthage, Tunisia were screened with EMPA and twenty selected for TIMS to determine the ore sources of the lead used to manufacture the tablets. Comparing the lead isotope ratios of twelve of the sixteen tablets most likely to be made of Tunisian lead to samples of Tunisian ores suggests that the Romans were mining lead in Africa Proconsularis and were not relying solely on imports.     

Spartan dependence on Laurion lead

This article presents contextual evidence for the interpretation of lead isotope analysis (LIA) of artefacts from the Archaic Greek Mediterranean. In particular, I make a response to Wood’s suggestion in Archaeometry (2022, first view, ‘Other ways to examine the finances behind the birth of Classical Greece’) that the end of the production of lead votive figurines in Sparta might have been caused by Athenian restrictions to Laurion lead exports, drawing on new LIA of the Spartan lead votives and wider considerations concerning the trade, cost and volume of lead in the 7th to 5th century bce Mediterranean.     

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.     

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.     

Other ways to examine the finances behind the birth of Classical Greece

Although the birth of Classical Greece is often attributed to the constitutional reforms of Cleisthenes (508/507 BCE), the achievement of an economically minded government under the Peisistratid tyrant Hippias (527–510 BCE) potentially paved the way by advancing Athenian silver for exportation in international trade. It is proposed here that new silver technology, which initiated the transition from acquiring silver from ‘dry’ silver ores to silver-bearing lead ores, was introduced to Greece during the time of the Peisistratids (561–510 BCE). Massive exploitation of silver-bearing lead ores at Laurion in Attica, which later financed the construction of a war navy, appears evident in the lead pollution records of Greenland ice, lead isotopic analyses of sixth-century BCE Attic silver coins and late Iron Age Levantine hacksilver, and is reflected in the numbers of lead votive figurines at sanctuaries in Sparta. Against the backdrop of the threat of war with Persia and an imminent Spartan invasion which resulted in the overthrow of Hippias (510 BCE), it is considered that a political transition occurred because Greece was both geologically and politically disposed to adopt this labour-intensive silver technology which helped to initiate, fund and protect the radical social experiment that became known as Classical Greece.     

The Provenance of Red Figure Vases From Locri Epizephiri (Southern Italy): New Evidence by Chemical Analysis

Thirty‐nine samples of red figure pottery found at Locri Epizephiri were analysed for 18 chemical elements by inductively coupled plasma emission spectroscopy. The finds, dated from the end of the sixth to the fourth century bc , were assigned to Attic, Sicilian and Locrian workshops due to their style of execution. Prior to facing the archaeological questions, possible biases on sample classification due to variable firing conditions, or to alteration during burial, were investigated: the results supported the opportunity of a refiring pre‐treatment. Multivariate statistical treatment of the analytical data confirms the separation between Attic and non‐Attic samples; comparison with the composition of black gloss pottery suggests that all the non‐Attic red figure vases could be the output of Locrian workshops.     

IDENTIFICATION OF LEAD SOURCES BY STABLE ISOTOPE RATIOS IN BONES AND LEAD FROM POUNDBURY CAMP, DORSET

Summary. Skeletal material from the Romano-British cemetery at Poundbury Camp on the outskirts of Dorchester is remarkable for the high concentration of lead detected in the bones. In an attempt to discover whether this lead was local in origin or had been introduced in imported commodities lead isotope ratios were determined for a selection of bones. The isotope ratios indicated at least two sources for the lead. Three of the individuals tested appear to have acquired lead derived from local, British, ores while the bone from the fourth individual, a child, had a lead isotope ratio identical to ore from Laurion in Greece. The isotope ratios are so close as to indicate immigration of the child rather than importation of lead in food or wine.     

How Mineralogy and Geochemistry Can Improve the Significance of Pb Isotopes in Metal Provenance Studies

Lead isotopes combined with trace element data represent a powerful tool for non‐ferrous metal provenance studies. Nevertheless, unconsidered geological factors and archaeological data, as well as ignored analytical procedures, may substantially modify the interpretation of the isotopic and trace element signature obtained as a potential ore candidate. Three archaeological examples, accompanied by high‐resolution lead isotopic measurements (MC–ICP–MS), are presented here to discuss the above‐mentioned criticisms and to propose some solutions. The first example deals with prehistoric/historical gold/silver‐mining activity from Romania (the Baia Bor?a and Ro?ia Montan? ore deposits). The second one regards the lead/silver metallurgical activity from the Mont‐Lozère massif (France) during medieval times. The third example focuses on the comparison between two batches of lead isotope data gathered on Roman lead ingots from Saintes‐Maries‐de‐la‐Mer, using different SRM 981 Pb values.     

THE ORIGIN of METAL OBJECTS FROM the EARLY BRONZE AGE SITE of THERMI ON the ISLAND of LESBOS

Summary: Lead isotope analysis of metal are deposits in the Mediterranean provides an important database for provenance studies of ancient metal artefacts. the Isotrace laboratory at Oxford has accumulated during the past decade well over 2000 lead isotope data on copper and lead ores and these data (in addition to analyses published by other groups) can be used for comparisons with lead isotope compositions of ancient metal objects. In a search for the roots of Early Bronze Age metallurgy in Europe we have analysed 34 copper-based objects from the Early Bronze Age strata of the town of Thermi on the Aegean island of Lesbos. the results of lead isotope analysis show that the metal objects on this site have a quite varied origin. Some of the objects are made of copper consistent with an origin from the mineral deposits of the Troad whilst others might be made of copper from the Cyclades. However, there are also some objects which are not made of copper from any of the Aegean deposits. These imports have later parallels on the site of Kastri on Syros and amongst the objects excavated by Schliemann at Troy.     

The Volterran Urns: Etruscan Painting and Travertine Supply

The artistic evolution of the Volterran cinerary urns is a good representation of Etruscan painting from the fourth to the first century bc . The interest generated by this type of object directed our research towards the study of the Volterran artefacts, including the analysis of the pigments as well as that of the rocks used for the coffers. The entire colour range shown by the painted urns has been sampled and investigated through Raman microscopy and scanning electron microscopy. Rock samples were taken both from the urns and from outcrops in ancient carbonate rock quarries near Volterra, from where they may potentially have been sourced. A set of 30 samples was collected and submitted to stable carbon and oxygen isotope analyses. The results obtained showed that the pigments used for the decoration of the Volterran urns were basically constituted by red ochre, Egyptian blue, carbon black and gypsum. The identification of lead‐based pigments and barium sulphates further informed us about old restorations undergone by several urns. As far as the provenance issue is concerned, the isotopic data indicate that the rocks used for the four urns were favourably comparable to those outcropping at Pignano, while two other urns were more similar to those sampled along the Elsa River at Colle Val d'Elsa.     

The medieval iron market in Ariège (France). Multidisciplinary analytical approach and multivariate analyses

The medieval iron market in Ariège (French Pyrenees) is characterised by its complexity leading to many questions regarding the ore used in relation to the artefacts encountered in archaeological settings. Despite the conclusive study of the treaty that regulated iron vs. coal exchanges from the 14th to the 19th c. by Verna et al., many questions remain unanswered concerning provenance and circulation of ores and products. Based on a combination of trace elemental analysis and multivariate statistical methods (discriminant analysis, hierarchical clustering analysis), we propose to follow an elemental-based signature from ore to artefacts, suited to the direct iron process, to clarify provenance hypotheses. We define the chemical signature of the Ariège area and compare it to that of slag inclusions in artefacts uncovered in several main archaeological sites from the Ariège area but also outside of this region. The results from this study are consistent with prior knowledge from historical sources. In the Ariège region, results highlight the multiple origins of products encountered at Montréal-de-Sos, a site close to known trade routes, whereas the isolated Castel-Minier site primarily contained objects from local ores and most objects retrieved from the Mirabat castle (Couserans) are coming from outside Ariège, possibly an indirect consequence from the exchange treaty. The presence of pins made of Ariegean ores is also demonstrated in the far more distant Capestang collegiate (near Narbonne, outside Ariège). This opens the way to finer studies in the politico-economical control of the iron supply for the building of medieval monuments in Southern France.