Iridium to provenance ancient silver

© 2017 Elsevier Ltd Trace levels of iridium in ancient silver artefacts can provide information on the sources of silver-bearing ores as well as the technologies used to extract silver. A geographically and chronologically disparate legacy dataset, comprised of Near Eastern objects from the Sasanian and Byzantine Empires (1st Millennium AD) and coins circulating around the Mediterranean in the mid-1st Millennium BC, shows that Ag-Au-Ir log-ratio plots can help identify silver derived from the same mining areas, as well as broadly differentiating between the ore types exploited. Combining trace element and lead isotope analyses through the Pb crustal age of the ore, further delimits interpretations on the compositions and locations of silver ore sources. Furthermore, it is shown that silver artefacts of Near Eastern origin have exceptionally high iridium levels, suggesting a unique silver-bearing ore source, potentially in the Taurus mountain range of southern Anatolia. The wide range of crustal ages identified for ancient Greek coins and Near Eastern objects suggest that the addition of exogenous lead as a silver collector during smelting was common practice in the Near East as early as 475BCE. The practice of mixing silver from different sources has also been identified by triangulating the log-ratio subcomposition plots, Pb crustal ages of the ore from which the silver derived and absolute values of trace levels of gold and iridium in silver artefacts

New objects in old structures: The Iron Age hoard of the Palacio III megalithic funerary complex (Almadén de la Plata, Seville, Spain)

Cultural contact, exchange and interaction feature high in the list of challenging topics of current research on European Prehistory. Not far off is the issue of the changing role of monuments in the making and maintaining of key cultural devices such as memory and identity. Addressing both these highly-debated issues from a science-based perspective, in this paper we look at an unusual case study set in southern Iberia and illustrate how these archaeological questions can benefit from robust materials-science approaches.We present the contextual, morphological and analytical study of an exceptional Early Iron Age hoard composed of a number of different (and mostly exotic) materials such as amber, quartz, silver and ceramic. This hoard, found under the fallen orthostat of a megalithic structure built at least 2000 years earlier, throws new light on long-distance exchange networks and the effect they could have had on the cultural identities and social relations of local Iberian Early Iron Age communities. Moreover, the archaeometric study reveals how diverse and distant the sources of these item are (Northern Europe to Eastern and Western Mediterranean raw materials, as well as local and eastern technologies), therefore raising questions concerning the social mechanisms used to establish change and resistance in contexts of colonial encounter

Producción y distribución de plata en la sociedad argárica y en los primeros asentamientos orientalizantes. Una aproximación desde el análisis de los isótopos de plomo

Dado el papel que pudo jugar la plata en los procesos de estratificación social tanto en la sociedad argárica del Sureste como en las sociedades del Bronce Final/Hierro I, especialmente del Suroeste de la Península Ibérica, en este artículo tratamos de aproximarnos a la organización de la producción de plata en ambas sociedades mediante el estudio de los isótopos de plomo. Se presenta una primera aproximación a los análisis isotópicos realizados sobre objetos de plata argáricos y orientalizantes, así como una revisión de los análisis publicados (Hunt Ortiz, 2003; Stos Gale 2001; Kassianidou, 1992) sobre los restos de producción de plata a la luz de los nuevos datos disponibles. Se evidencia la llegada de plomo exógeno, necesario para la extracción de la plata de los minerales complejos del Suroeste, desde otras zonas de la Península Ibérica como Gádor o Cartagena/Mazarrón, con las implicaciones socio-económicas que pudiera tener el control no tanto de los recursos argentíferos del Suroeste, como de la distribución del plomo del Sureste

Difusión o innovación tecnológica: los inicios de la metalurgia en la Península Ibérica

Se propone, a partir de datos tecnológicos, la posibilidad de que en la Península Ibérica se hubiera producido un fenómeno de innovación metalúrgica independiente. Se contrastan los datos con la información disponible en otras áreas europeas que hubieran permitido una difusión de ese conocimiento. A las cuestiones tecnológicas se añaden, en apoyo a esta hipótesis, datos arqueológicos y contextuales del registro material durante el Neolítico y Calcolítico. La propuesta de los autores es que en la primera mitad del V milenio cal AC se inicia la metalurgia en la Península Ibérica de manera independiente, sin uso previo de cobre nativo

Approaching the distribution of funerary space in El Argar (Antas, Almería)

El Argar (Antas, Almería) is the main reference site for the study of the Bronze Age in the Iberian Peninsula. The burial assemblages of more than 1000 excavated tombs show the social diversity of the interred. This article analyses the spatial distribution of the burials, considering the multiple variables of the funerary ritual in relation to their location. The aim is to try to understand whether socioeconomic patterns can explain their location. For this, based on the documentation from the Siret Archive, we have been able to situate a considerable number of graves on the plateau that forms the site and we have considered the variability of funerary containers, the burial assemblages and the physical characteristics of the interred. Statistical significance tests do not show a relation between sex, age and location, but they indicate one between rich grave assemblages and spatial distribution, which cluster in a particular area of the site

Gold parting, iridium and provenance of ancient silver: A reply to Pernicka

We present a detailed response to Professor Pernicka's critique of our paper entitled “Iridium to provenance ancient silver”. We have concluded that Pernicka's hypothesis, which suggests that elevated levels of iridium in ancient silver artefacts is a consequence of silver deriving from the cementation (parting) process, does not account for the available evidence and that his critiques of the analyses we presented seem misplaced. We offer a simpler solution and show that the structure of our transformed data is founded on logical reasoning which is borne out by the empirical results. Essentially, this response supports our view reported in the original paper that the variation in iridium in ancient silver is largely geological rather than a consequence of de-silvering gold

Trace elements and lead isotopic composition of copper deposits from the eastern part of the Internal Zone of the Betic Cordillera (SE Iberia): application to provenance of archaeological materials

This paper presents trace element compositions and lead isotope analyses by MC-ICP-MS of 34 copper ore samples from the Internal Zone of the Betic Range, Southeast Spain. Samples were collected during a fieldwork campaign in the mines of Cerro Minado, Pinar de Bédar, Sierra Cabrera and Sierra Almagrera/Herrerías. Most samples are copper oxide minerals from the near surface alteration of the sulfide ore deposits. The aim of the study is to supplement the existing reference data bank on lead isotopic compositions of ancient copper mines from the Iberian Peninsula, complementing this data with trace element compositions. The latter can be useful for discriminating when isotopic overlaps occur. This characterisation will be of great usefulness for provenancing further archaeological materials. Lead isotope ratios range from 18.603 to 20.327 (206Pb/204Pb); from 15.685 to 15.779 (207Pb/204Pb) and from 38.728 to 39.702 (208Pb/204Pb). Data from the literature analysed by TIMS have been also considered for comparison although the larger analytical error is highlighted, especially for isotope 204Pb. The lead isotopic signature of the analysed samples shows three separate isotopic fields. These fields are also consistent with differences in compositions evidenced by principal component analyses

El ámbar de la Cueva de los Cuarenta (Priego de Córdoba, Córdoba)

The presence of exotic objects in archaeological contexts and the long-distance exchanges that they implied are one of the most interesting topics in archaeological discussions. In this paper we present the study of a bead or pendant found in Neolithic contexts in Cueva de los Cuarenta (Priego de Córdoba). This is the only ornament found in the cave, where a minimum number of 41 inhumations dating in the course of the 4th millennium cal BC were documented. Archaeological context of the finding is described as well as its archaeometric characterization by Infrared Fourier Transform Spectroscopy (FTIR). Analytical results show that it is an amber bead made from foreign material, similar to the one used in later amber production such as those found at Valencina de la Concepción (Sevilla). Similar to these, an exogenous provenance is proposed, Sicilian origin being the most likely up to date, which will contribute to the discussion on the implications these foreign materials might have had on Iberian prehistoric societies.La presencia de objetos exóticos en contextos arqueológicos y los intercambios a larga distancia que estos implican es uno de los temas que despierta más interés en la discusión arqueológica. En este artículo presentamos el estudio de una cuenta o colgante hallado en contextos neolíticos de la Cueva de los Cuarenta (Priego de Córdoba). Se trata del único elemento de adorno presente en la cueva, en la que se ha documentado un número mínimo de 41 inhumaciones datadas a lo largo del IV milenio cal ANE. Se presenta la información contextual del hallazgo así como su caracterización arqueométrica mediante Espectroscopía de Infrarrojos por Transformada de Fourier (FTIR). El análisis de la pieza muestra que se trata de una cuenta de ámbar realizada con material foráneo, similar al empleado en las producciones de ámbar posteriores como las de Valencina de la Concepción (Sevilla). Al igual que en estos casos, se propone la procedencia exógena de la materia prima empleada, siendo Sicilia el origen más plausible a día de hoy, lo cual contribuirá al debate sobre las implicaciones que estos materiales foráneos pudieron tener en las sociedades prehistóricas peninsulares

Early metallurgy in SE Iberia. The workshop of Las Pilas (Mojacar, Almeria, Spain)

Big narratives on the role of metallurgy in social change and technological innovations are common in archaeology. However, informed discussion of these issues requires a contextualised characterisation of metallurgical technology at the local level in its specific social and technological context. This paper approaches early metallurgy in Iberia from a technological perspective. We focus on the site of Las Pilas in the Vera Basin (Mojácar, Almería, Spain), where the whole metallurgical chaîne opératoire has been documented in situ through archaeological excavation of a 3rd Millennium BC context. The study includes microstructural, mineralogical and chemical analyses of ores, slag, technical ceramics and finished artefacts, as well as domestic pottery used for comparative purposes. These results are discussed with reference to the archaeological context and evidence for other domestic activities and crafts. Our aim is to contribute to better characterise the early metallurgical tradition of Southeast Iberia, paying particular attention to specific technological tools, knowledge and recipes that may allow future comparative approaches to knowledge transmission or independent innovation debates. For this particular case, we demonstrate the direct production of arsenical copper in a low-scale, low-specialisation, low-efficiency set up that involved the crucible smelting of complex oxidic ores in a context that suggests associations with cereal roasting and, indirectly, with basket and pottery making

Macro-regional scale of silver production in Iberia during the 1st millennium BC in the context of Mediterranean contacts.

The extraction of silver has been traditionally considered one of the main incentives for the Phoenician expansion through the Mediterranean and their settlement in Iberia. In this paper we approach the organization of silver production in Iberia during the Early Iron Age through the study of productive evidence currently available and the development of Lead Isotope Analysis (LIA). Previous results (Hunt, 2003; Stos Gale 2001; Kassianidou, 1992) are considered in the light of new data. The extraction of silver from complex minerals is conspicuously intensified in Southwest Iberia. Imports of exogenous lead, needed for the extraction of silver from these complex minerals, stand out. Flows of lead come in from other Iberian regions such as Gádor, Cartagena/Mazarrón, Linares or even the mining district of Molar-Belmunt-Falset (MBF) in Catalonia. This picture reveals an organization of silver production much more complex than initially thought, with the needed articulation of an exchange network of raw materials at a macro-territorial scale embracing almost all Iberia. Socioeconomic implications that control of these distributions networks of lead could have had are also discussed