The insular nature of the Maltese archipelago provides a unique opportunity to explore trade and cultural change from the Neolithic to the Bronze Ages in the central Mediterranean. I hypothesize that, during the period in which the Maltese islands were experiencing a form of isolation—owing either to their distance from Sicily and other populated regions, to the collective formation of an inwardly-focused culture, or to a combination of these factors—it is unlikely that pottery played a significant role as either an import or export in the archipelago’s exchange relationships with other communities in the central Mediterranean. I accordingly propose that ceramics were only significant in the interaction networks between Malta and its neighbors during periods when the archipelago was culturally connected to Sicily. Except for a limited number of archaeometric studies (Barone et al. 2015; Molitor 1988; Mommsen et al. 2006), analysis of similarities among ceramic wares produced in Malta and elsewhere that allow archaeologists to draw conclusions about the nature of Malta’s connectivity to other communities has been based on macroscopic observation. The present study builds on the few archaeometric studies by determining the provenance of ceramic samples based on their trace elemental composition. Included in this study were both clay samples and ceramic artifacts representing each of Malta’s chronological phases from the Neolithic to the Bronze Ages. Specifically, in order to address the question of the role that pottery played in the prehistoric trade of the Maltese islands, 392 Maltese ceramic sherds were analyzed using a Bruker III-V handheld portable X-ray fluorescence device, which revealed the relative abundance of six trace elements, namely thorium, rubidium, strontium, yttrium, zirconium, and niobium. The trace elemental composition of the Maltese pottery was compared with that of 18 Sicilian ceramic sherds and clay samples from both Malta and Sicily. The results of this research support my hypothesis in part, suggesting that neither ceramics nor raw clay materials played a significant role in overseas trade during Malta’s period of cultural isolation, which extended from the Ġgantija phase to the end of the Tarxien phase. On the other hand, ceramics played a more active role in Malta’s interaction networks during periods of connectivity with Sicily, for instance in the Neolithic Age. This study also provides the first chemical evidence that Malta exported pottery to Sicily during the Bronze Age and that Malta’s contact with Mycenaeans was indirect in nature. The findings presented here thus contribute to understanding Malta’s role in trade and interaction networks from the Neolithic to the Bronze Ages and point to new approaches to exploring the cultural change that becomes apparent in the Maltese Temple Period.

No description available.

L'arsenic est un metalloïde toxique et cancérigène. Ubiquiste dans la pedosphere, il est très sensibleaux fluctuations des conditions redox du sol, ce qui influe significativement sa toxicité et mobilité. Nousétudions le cycle biogéochimique global de l'arsenic, en tenant compte de l'usage croissant des ressources, etpassons en revue l'importance respective de l’arsenic geogénique et anthropogénique dans l’environnement.La contamination à l’arsenic est souvent diffuse dans les bassins sédimentaires de l'Europe. Cependant, desconcentrations dans l'eau interstitielle du sol peuvent être élevées lors de périodes de saturation du solcausées par la monté des eaux souterraines ou les inondations, prévues d'augmenter dû aux changementsclimatiques. La spectrométrie de fluorescence X quantitative et sans standard a été utilisée pour analyserl'arsenic dans des sols relativement contaminés de la plaine alluviale de la Saône au moyen de protocoles depréparation d'échantillons conçus pour optimiser la précision d'analyse et l'exactitude in situ aux bassesconcentrations d'arsenic. L'arsenic dans ces sols est associe aux (hydr)oxydes du fer et de manganèse de lataille d'argile colloïdale. Ceux-ci subissent une dissolution réductrice par les microorganismes lors desinondations, libérant une importante concentration d'arsenic dans la phase aqueuse. Si, par la suite, l'arsenicdégagé n'est pas éliminé avec l'eau de crue évacuée, il est ré-immobilisé pendant l'oxydation du sol et lareprécipitation des oxydes métalliques. Grâce à une combinaison novatrice d'analyses chimiques par voiehumide, d’écologie microbienne, de spectroscopie ainsi que de modélisation thermodynamique et cinétique,nous démontrons que les cycles d'oxydo-réduction séquentiels entraînent une atténuation d'arsenic aqueuxdans des conditions réductrices dû à la coprécipitation croissante, et a une diminution de l'activitémicrobienne causée par l’appauvrissement en matière organique labile. Des processus d'atténuationsimilaires sont observés en l'absence d'activité microbienne pour Cr et As dans des argiles pyriteuses lorsquecelles-ci sont exposés aux oscillations redox provoquées par l'ajout de substances humiques réduites. Ainsi,nous montrons que les effets cumulatifs de cycles redox successifs sont extrêmement importants pour lamobilité de divers contaminants dans l'environnement. / Arsenic is a toxic and carcinogenic metalloid, ubiquitous in the pedosphere and highly sensitive tofluctuations in soil redox conditions which dramatically influence both its toxicity and mobility. We reviewthe global biogeochemical cycle of arsenic in light of increasing resource usage and re-evaluate theimportance of anthropogenic and geogenic arsenic inputs to the exogenic cycle. Arsenic contamination isoften diffuse in European sedimentary basins. Despite this, concentrations in soil pore-water may be highduring periods of soil saturation caused by rising groundwater or surface flooding which is predicted toincrease due to climatic change. Standardless quantitative X-ray fluorescence spectrometry is used toanalyse for arsenic in moderately contaminated soils on the alluvial plain of the Saône River with samplepreparation protocols designed to optimize analytical precision and accuracy in-situ at trace arsenicconcentrations. Arsenic in these soils is shown to be associated with colloidal and clay sized iron andmanganese (hydr)oxides which undergo microbially mediated reductive dissolution during flooding, releasingsubstantial arsenic to the aqueous phase. If released arsenic is not subsequently removed with recedingflood water it is re-immobilized during soil oxidation and re-precipitation of metal oxides. We demonstratethrough a novel combination of wet chemistry, microbial ecology, spectroscopy and thermodynamic andkinetic modelling that sequential reduction-oxidation cycles result in aqueous arsenic attenuation duringreducing conditions due to increased co-precipitation and decreases in microbial activity due to depletion oflabile organic matter. Similar attenuation processes are observed in the absence of microbial activity for Crand As in pyrite-bearing clays when subjected to redox oscillations induced by addition of reduced humicsubstances. We demonstrate that the cumulative effects of successive redox cycling are therefore of greatimportance to contaminant mobility in a variety of environments. / El arsénico es un metaloide tóxico y cancerígeno, ubicuo en la pedosfera y altamente sensible a lasfluctuaciones de las condiciones redox del suelo, las cuales controlan tanto su toxicidad como su movilidad.La presente tesis doctoral tiene como objeto de estudio el ciclo biogeoquímico global del arsénico y examinala importancia de los aportes del arsénico antropogénicos y geogénicos al ciclo exógeno tomando en cuentael uso creciente de recursos.La contaminación con arsénico es generalmente difusa en las cuencas sedimentarias europeas. No obstante,las concentraciones en las aguas intersticiales del suelo pueden ser elevadas durante los periodos desaturación causados por el aumento de aguas subterráneas o inundaciones, cuyo incremento se prevédebido a los cambios climáticos. La espectrometría de fluorescencia de Rayos-X cuantitativa y sin estándar esutilizada para analizar el arsénico en suelos relativamente contaminados en la llanura aluvial del río Saône,mediante protocolos de preparación de muestras diseñados para mejorar la precisión analítica y la exactitudin-situ a bajas concentraciones de arsénico. La presencia de arsénico en estos suelos demuestra estarasociada a los (hidr)óxidos de hierro y de manganeso de tamaño de arcilla coloidal, los cuales experimentanuna disolución reductora por acción microbiana durante las inundaciones, liberando así una importanteconcentración de arsénico en la fase acuosa. Si, posteriormente, el arsénico despedido no se elimina con elagua saliente, éste se vuelve a inmovilizar durante la oxidación del suelo y la re-precipitación de óxidosmetálicos. Gracias a una combinación innovadora de análisis químicos por vía húmeda, ecología microbiana,espectroscopia, así como modelado termodinámico y cinético, demostramos que los ciclos de oxidoreducciónsecuenciales provocan una atenuación de arsénico acuoso durante condiciones de reduccióndebido al aumento de coprecipitacion y disminución de la actividad microbiana causada por el agotamientode materia orgánica lábil. Se observan procesos de atenuación similares en caso de ausencia de actividadmicrobiana para Cr y As en arcillas piritas cuando son sometidos a oscilaciones de redox inducidas mediantela adición de sustancias húmicas reducidas. Es así como demostramos que los efectos acumulativos de ciclossucesivos de redox son muy importantes para la movilidad contaminante en una variedad de ambientes.

No description available.

Imitation of archeological artifacts or replacing the authentic ones with fake replicates is a universal problem / it is particularly important in Turkey for historical metal objects. Traditionally used visual inspection methods alone are not sufficient for the solution of contemporary problems. In this study, chemical characterization has been used to determine the differences between the authentic and fake objects. The non-destructive analyses were carried out by Portable X-ray Fluorescence Spectrometry (P-XRF). Silver Roman Coins (27 B.C. to 244 A.D.) were the objects handled in this research. In particular the concentrations of Zr, Pt, Pb and Bi were used for differentiation / it has been observed that the concentrations have different trends in the authentic and fake silver coins. In authentic coins the average Pb concentration was found to be 0.77%, while this value was 0.055% for the fake ones. Bi could be determined in 86% of the authentic coins while it could not be detected in any fake coin. It has been generally observed that the silver and copper concentrations could not be utilized in authenticity tests. Another approach was the use of Line Scanning Electron Microscopy-Energy Dispersive X-Ray Fluorescence Spectrometry (LSEM-EDX). Using LSEM-EDX technique, it was observed that the concentration changes near the interface between the matrix and the copper-rich locations exhibits difference behaviors for the authentic and fake objects. This difference is originated by the fact that a newly formed copper amalgam contains copper-rich phases while with extended time concentration changes at interfaces become more gradual or not detectable. Pearson correlation was used in order to elucidate the relations between the element concentrations determined by P-XRF. In order to see whether the authentic and silver fake coins can form separate groups, dendograms have been constructed utilizing SPSS 16.0 software and Euclidian Square Distance method. It has been observed that the authentic and fake coins can be successfully grouped when the proper statistical choices are used. It has been observed that these groups have significant differences using t-test. The selected and used technology is proposed for use by museums and entities keeping archaeological collections in order to prevent forgeries.

ABSTRACT DIFFERENTIATION AND CLASSIFICATION OF COUNTERFEIT AND REAL COINS BY APPLYING STATISTICAL METHODS Tansel, I&ccedil / ten M.Sc, Archaeometry Graduate Program Supervisor : Assist. Prof. Dr. Zeynep Isil Kalaylioglu Co-Supervisor : Prof. Dr. Sahinde Demirci June 2012, 105 pages In this study, forty coins which were obtained from Museum of Anatolian Civilizations (MAC) in Ankara were investigated. Some of those coins were real (twenty two coins) and the remaining ones (eighteen coins) were fake coins. Forty coins were Greek coins which were dated back to middle of the fifth century BCE and reign of Alexander the Great (323 &ndash / 336 BCE). The major aims of this study can be summarized as follow

L'ancienne cité maya d'Ucanal se situe à la frontière des grandes capitales et de leurs influences stylistiques pendant la majeure partie de son histoire. De plus, sa localisation sur la rivière Mopan en fait un lieu décisif pour les réseaux d'échanges puisqu'elle relie la mer des Caraïbes au golfe du Mexique. A ce titre, la ville fut convoitée par les grands centres afin de maîtriser les grands axes de communication. Cependant, ces centres n'ont jamais été assez forts pour contrôler complètement la ville d’Ucanal. Cette étude examine ces relations politiques et sociales et leurs changements du point de vue des céramiques d'Ucanal durant la période du Classique Récent (environ 600-810 DNÈ) au Classique Terminal (environ 810-950/1000 DNÈ). Nous avons établi un nouveau protocole méthodologique pour l'analyse chimique des pâtes céramiques à l'aide d’un instrument portable de Fluorescence par Rayons X (pXRF) et comparé les résultats sur les mêmes échantillons à l'aide de l’Analyse Instrumentale par Activation Neutronique (INAA), une méthode plus conventionnelle et plus précise pour les études de provenance chimique. Les résultats de ces comparaisons révèlent que le pXRF pourrait fournir des désignations de provenance préliminaires pour identifier les céramiques locales et non locales (article 1). Une analyse de la répartition des céramiques décorées et importées sur le site d'Ucanal comparant les maisonnées d'élite, de statut intermédiaire et non élite, a indiqué que les maisonnées de statut intermédiaire ont obtenu un accès croissant aux céramiques fines et importées durant le Classique Récent et le Classique Terminal, et que cette dernière était une période de grande mobilité sociale (article 2). À son tour, une analyse du point de vue des communautés de pratique des céramiques moulées de la période du Classique Terminal a révélé qu'Ucanal et sa région se trouvaient à un noeud important des réseaux de production et d'échange de céramique, ce qui a aidé à créer un paysage politique décentralisé mais fortement interconnecté (article 3). / The ancient Maya city of Ucanal sat at the frontier of larger political capitals and their stylistic influences throughout most of its history. Moreover, its localization alongside the Mopan River placed it in a decisive location for exchange networks between the Caribbean Sea and the Gulf of Mexico. As such, the city was coveted by major centers in their attempted control of this major communication axis. However, these centers were never strong enough to completely control the city of Ucanal. This research project examines these social and political relationships from the perspective of Late Classic (ca. 600-810 CE) and Terminal Classic (ca. 810-950/1000 CE) period ceramics from Ucanal. It establishes a new methodological protocol for the chemical analysis of ceramics using a portable X-ray fluorescence instrument (pXRF) and comparing the same samples with Instrumental Neutron activation Analysis (INAA), a more established and precise chemical analysis method. The results indicate that pXRF analyses can provide preliminary provenience identifications of local and non-local ceramics (article 1). A distribution analysis of decorated and imported ceramics from Ucanal that compares elite, middle-status, and non-elite household contexts reveals that middle-status households had increasing access to decorated and imported ceramics between the Late Classic and Terminal Classic periods, and that the latter was a period of substantial social mobility (article 2). In turn, an analysis of molded Terminal Classic ceramics from the theoretical perspective of communities of practice demonstrates that Ucanal and its surrounding region were situated at an important nexus of ceramic production and exchange and helped forge a decentralized but highly interconnected political landscape (article 3).