Sabine Klein

The lead and copper isotopic composition of copper ores from the Sierra Morena (Spain)

The paper presents lead and copper isotope analyses of 51 copper ore samples from the Sierra Morena, South of Spain. They are from ancient mines of the Iberian Peninsula collected by Claude Domergue during various field campaigns in the central Sierra Morena from 1965 to 1975. Most samples consist of copper oxide minerals such as malachite, azurite and chrysocolla and stem from the surficial sections of the ore deposits. The aim of the study was to supplement the existing reference data bank on lead isotopic compositions of ancient copper mines from the Iberian Peninsula. This is particularly important for the Sierra Morena for which data exist mostly for lead-zinc but not for copper ores. The lead isotope ratios range from 18.165 to 19.712 (206Pb/204Pb), 0.797 to 0.859 (207Pb/206Pb) and 1.955 to 2.108 (208Pb/206Pb). Two separate fields can be distinguished with a major field intermediate between the ore deposits from SW and SE Spain and a second at higher 208Pb/206Pb values. Copper isotopes were analysed additionally to provide further constraints for provenance studies. The copper isotope ratios δ65Cu of the copper oxide samples are mostly positive and higher on average than those of sulphide minerals. They are a potential tool to distinguish between either sulphide ore or oxide ore deposit derived artefacts.

Lead isotope analyses on Late Republican sling bullets

Forty-two lead objects (mainly sling bullets) from archaeological sites in Spain and Italy, dating into the late Roman Republican period, two ore samples from Portman (Cartagena region) and one further ore sample from a deposit on Ibiza were analysed for their lead isotope ratios by multicollector inductively coupled plasma mass spectrometry (MC ICP-MS). The objective of the present study was to answer questions, which cannot be solved by conventional archaeological methods alone but require further information on the materials composition. For this, MC ICP-MS as a modern and fast analytical method to obtain both chemical and isotopic information paired with very low material consumption is a helpful analytical tool to answer archaeological and technological considerations and questions like (a) on the origin of the raw metals used for the objects, (b) if individual production sites used more than one metal source and (c) if certain metal mining areas were preferred during particular periods in time. The results of this study, which were obtained by combining lead isotope analysis with common archaeological methods, clearly demonstrate that Late Republican sling bullets and some other lead objects of other usage from Menorca originate from ore minerals that were predominantly mined on the Iberian mainland. Mixing relationships also show that a number of them were manufactured from reprocessed material. This is also true for single Italian lead sling bullets. Additionally, some of the objects have lead isotope signatures interpreted as mixing relationships, which point towards a manufacturing from reprocessed material.

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 Dor C shipwreck, Israel: metallurgical analysis and its contribution to the ship characterization

The Dor C shipwreck is the remains of a 60-t schooner that plied the Mediterranean during the last decades of the nineteenth century. The various building materials and ceramic ware found inside the shipwreck suggest an established commercial route between southern France and the Holy Land. Three metal objects were found in the bow area of the shipwreck: a lead pipe, an iron rigging hoop, and a brass wick housing. This study aims to understand their manufacturing processes, to propose possible dating and manufacturing locations, and to verify their use. The metallurgical investigation suggests that the objects were designated for marine use and manufactured using processes developed during the second half of the nineteenth century, probably post-1885, which supports the dating of the ship. The tonnage of the ship, the origin of her cargo, the provenance of some of the metal parts, and the location of the shipwreck, all suggest that her last voyage was a delivery of cargo from Marseilles to Dor.

Dem Euro der Römer auf der Spur — Bleiisotopenanalysen zur Bestimmung der Metallherkunft römischer Münzen

Die Bleiisotopenanalyse ist heute von groser Bedeutung fur die Herkunftsbestimmung der Metalle in archaologischen Objekten. Die Bleiisotopenverhaltnisse von Erzen dienen dabei als Fingerabdruck einer Lagerstatte, und durch einen Vergleich der Bleiisotopendaten von Objekten und Erzen konnen die Metalle ihren Lagerstatten zugeordnet werden. Diese Moglichkeit liefert den archaologischen Wissenschaften neue Denkanstose: Woher die Rohstoffe stammten, ob unterschiedliche Produkte absichtlich oder zufallig mit Rohstoffen unterschiedlicher Herkunft hergestellt wurden, welche Handelsbeziehungen es gab, welche Produktionsstatten bedeutend waren und welche nur geringfugig ausgebeutet wurden, wie sich Handelsbeziehungen im Verlauf einer Zeitspanne anderten (eventuell unter politischen Veranderungen), wann eine Rohstoffquelle versiegte und wo nach alternativen Rohstoffquellen gesucht wurde?

Types of Gold, Types of Silver: The Composition of Precious Metal Artifacts Found in the Royal Tombs of Ur, Mesopotamia

Abstract The many gold and silver artifacts from the Early Dynastic Royal Tombs of Ur in Mesopotamia are among the greatest metal finds of Ancient Mesopotamia in the third millennium BC. Within the framework of a research project, 32 of these artifacts were analyzed for their composition using a portable X-ray fluorescence spectrometer and a scanning electron microscope. Predominantly gold-silver alloys rather than pure gold were identified, containing up to 50 wt.% of silver and often with additional copper content well above 10 wt.%. This spectrum of composition ranges from alloys that could be of natural origin to alloys that were intentionally produced. Some gold artifacts were deliberately blended to gold-silver-copper alloys for color gradation. In addition, Sumerian written sources from the end of the third millennium BC can be compared to the results of the analyses of this study and offer more information on the processing of these metals at that time. In the present study, it is shown that gold originating from placer deposits was brought to Ur. Direct association of gold artifacts with lapis lazuli in many precious objects from the Royal Tombs and the particular composition of inclusions of platinum group minerals in the worked gold both point to a possible provenance in northern Afghanistan. One significant result was the confirmation of the use of depletion gilding for the removal of copper from surfaces; the technique of refining silver-bearing gold, known as parting, is not thought to have been known at this time. A previous version of this paper has been presented as a talk at the 62e Rencontre Assyriologique Internationale of Philadelphia 11th–15th July 2016 by A. Hauptmann, S. Klein and R. Zettler under the title: “A. Hauptmann, S. Klein, and R. Zettler, Sorts of Gold, Sorts of Silver from the Royal Tombs of Ur, Mesopotamia”. “For the late Hans-Gert Bachmann, the pioneer of ancient gold metallurgy. (Andreas Hauptmann)”

Copper Alloy Coins from the Byzantine-Period Ma‘agan Mikhael B Shipwreck, Israel: Metallurgical Characterization

After three excavation seasons the Ma‘agan Mikhael B shipwreck has revealed, among other objects, seven coins. The coins were found covered with a black concretion layer, which was carefully removed from five of them. Metallurgical methods were used in order to reveal the composition, microstructure, and manufacturing process of the coins and to determine their date and the origin of the raw material. The coins were made of cast copper-lead alloy and were heated before being stamped. Based on the portrait of the House of Constantine I found on coins 120.1 and 120.2, and the figure on coin 120.5, combined with the composition of the coins, they were dated to the fourth century AD, when high concentrations of lead were added to alloys, most probably due to economic constraints. The study of the coins does not identify the ship’s origin or her ports-of-call, since coins were essentially mobile.

Metallkundliche und analytische Untersuchungen an den im Deposito Archeologico der Soprintendenza Archeologica di Pompei aufbewahrten Metallgefäßen

Unserer Forschungsgruppe bot sich in den Jahren 1996−1998 die Gelegenheit, eine Auswahl von Metallgefasen aus dem antiken Pompei makroskopisch zu untersuchen und Materialproben zu entnehmen. Allgemein bekannt ist, dass die Stadt am 24. August und in den darauffolgenden Tagen des Jahres 79 n. Chr. infolge eines verheerenden Ausbruchs des Vulkans Vesuv untergegangen und nahezu vollkommen verschuttet worden war. Damit ist fur die gesamte materielle Hinterlassenschaft ein bedeutender chronologischer Fixpunkt gegeben. In den Magazinen der Soprintendenza Archaeologica di Pompei werden heute 1 678 Gefase und Gefasfragmente aus Kupfer und Kupferlegierungen aufbewahrt, daneben auch mehrere Kisten mit deformierten Gefasfragmenten, die Folge eines Bombardements der Royal Air Force im Jahre 1943, bei dem etliche Gebaude beschadigt wurden und das Antiquarium zerstort worden war. Fur den uberwiegenden Teil des Inventars lasst sich noch der ursprungliche Fundort innerhalb der Wohnbebauung (Tassinari 1993, 122−193) ermitteln. Im Unterschied zu anderen archaometrischen Projekten, bei denen die in Frage kommenden Objekte unterschiedlicher Zeitstellung und Herkunft aus verschiedenen Aufbewahrungsorten zusammengetragen werden mussen, bestand hier somit der grose Vorteil einer transparenten zeitlichen und lokalen Zuordnung des Materials. Wir stellen mit dieser Studie ein gemeinschaftliches Projekt vor, deren Ziel es ist, die archaologische mit der naturwissenschaftlich-analytischen Fragestellung eng zu verbinden. Dabei sollen die Darstellung der naturwissenschaftlichen Untersuchungsmethoden und die Diskussion der sich daraus ergebenden Resultate eindeutig im Vordergrund stehen. Der archaologische Teil beschrankt sich dagegen nur auf eine allgemein gehaltene Einfuhrung in die besondere Problematik der Metallgefasfunde in den Vesuvsiedlungen. Eine Modifizierung und Vereinfachung der von Suzanne Tassinari erstellten Typologie (Tassinari 1993: Tavole sinottiche A−X), die sicherlich sinnvoll waren, war ebenso wenig geplant wie die Erarbeitung einer Feinchronologie des Materials, die uber den allgemein verbindlichen terminus ante quem von 79 n. Chr. hinausgeht und vor allem durch die Analyse der Fundvergesellschaftungen auserhalb der Vesuvregion zu erreichen ware, der wiederum Untersuchungen zur Gesamtverbreitung der kampanischen Produkte in der hellenistisch-romischen Welt zu folgen hatten. Fur die einschlagigen gestempelten Gefastypen hat Richard Petrovszky (1993) ja bereits eine chronologische Studie vorgelegt und methodisch den Weg gewiesen. Insgesamt gesehen wurden aber derartige Fragestellungen den Rahmen dieser Untersuchung sprengen. Vorrangig sollte herausgearbeitet werden, welche Unterschiede in den physikalisch-chemischen Eigenschaften zu erkennen sind und welche Folgen sich daraus fur den Herstellungsprozess der Gefase ergaben. Dabei ist zwischen den einzelnen Gefaskorpern und den angefugten separat gearbeiteten Gefasteilen zu unterscheiden. Es stellte sich heraus, dass die kupferbasierenden Legierungen fur die Gefase aus Zinnbronzen bestehen, die eine nur geringe Variationsbreite in der Zusammensetzung besitzen. Lediglich in Zinnlegierungen mit Bleizusatz, wie sie haufig fur Griffe, Henkel, Attaschen und andere Zierelemente verwendet wurden, war der nachgewiesene Bleigehalt stark schwankend. Offenbar verfugten die verschiedenen Werkstatten uber genaue, empirisch gewonnene Kenntnisse, in welchem Verhaltnis zueinander die beiden wesentlichen Bestandteile der Bronze, Kupfer und Zinn, gemischt werden mussten, um gebrauchstaugliche und belastbare Gefaskorper herzustellen. Dieses Wissen war ganz offensichtlich eine Art von Allgemeingut und in der Alten Welt weit verbreitet, so dass man nicht unbedingt von werkstattspezifischen Betriebsgeheimnissen sprechen sollte (Furger / Riederer 1995, 166 ff.; Voss / Hammer / Lutz 1999, 159 ff.; 277 f.). Uberraschenderweise gelang der Nachweis von Messing in der Gefasproduktion Kampaniens, ging man doch bislang von dem Gegenteil aus. Bekanntlich wurde diese Legierung in Italien in der romischen Reichspragung seit der augusteischen Munzreform verwendet. Ein weiteres Anliegen der vorliegenden Studie bestand darin, die Herkunft der Metalle zu ermitteln. Dies geschah mittels Bleiisotopenanalysen. Mit Hilfe metallographischer Untersuchungen an etlichen Fragmenten schlieslich liesen sich Einblicke in die Herstellungsprozesse gewinnen.

Les lingots de cuivre de l'épave romaine Plage de la Corniche 6 à Sète et le commerce du cuivre hispanique en Méditerranée occidentale

L’article presente onze lingots de cuivre romains decouverts en mer a la fin de l’ete 2009 au large de Sete (Herault). L’etude typologique et epigraphique ainsi que les analyses isotopiques du plomb effectuees sur ces lingots permettent de les attribuer aux mines du Sud-Ouest de la peninsule Iberique. Le site de Plage de la Corniche 6 vient s’ajouter a la dizaine d’epaves et de gisements sous-marins ayant livre des lingots de cuivre romains au large des cotes de Languedoc-Roussillon. L’ensemble de ces lingots, qui sont eux aussi d’origine hispanique et proviennent de diverses regions minieres du sud de la Peninsule, est presente a la fin de l’article.