Το Μεταπόντιο (Μπαζιλικάτα, Ν. Ιταλία) αποτελεί μια από τις πρώτες και σημαντικότερες ελληνικές αποικίες της Αχαΐας, ενώ ταυτόχρονα θεωρείται ως η πρώτη επιτυχημένη προσπάθεια αποικιακού κινήματος σε παγκόσμια κλίμακα. Οι ανασκαφές που έχουν πραγματοποιηθεί στην ευρύτερη περιοχή από τη δεκαετία του 1970 έχουν επιτρέψει την ανάπτυξη μιας ενδελεχούς διεπιστημονικής προσέγγισης σε μια πληθώρα θεματολογιών που αφορούν την ανθρωπολογία, την γεωργία, την αστική γεωγραφία, τις διατροφικές συνήθειες, τις πολιτικές σχέσεις μητρόπολης-αποικίας κ.α. Οι ανασκαφές που έχουν διεξαχθεί στους αρχαιολογικούς χώρους των περιοχών Sant’ Angelo Vecchio, Pantanello και Kerameikos στην περιοχή του Μεταπόντιου έχουν αποκαλύψει εργαστηριακούς χώρους παραγωγής, αρχαίων κεραμικών υλικών αρχαϊκής, ελληνιστικής και ρωμαϊκής περιόδου αναδεικνύοντας την περιοχή ως ένα από τα πλέον σημαντικά κέντρα παραγωγής κεραμικής των περιόδων αυτών. Έχοντας ως απώτερο στόχο να αποτελέσει τη βάση της αρχαιομετρικής μελέτης της κεραμικής ειδωλίων και πήλινων πλακών τύπου Terracotta που αποτελεί σήμα κατατεθέν της συγκεκριμένης περιοχής, η παρούσα διπλωματική εργασία έχει ως σκοπό να προσφέρει τις απαραίτητες εκείνες πληροφορίες που απαιτούνται για τις πρώτες ύλες που είναι διαθέσιμες στην περιοχή, τον πετρογραφικό και γεωχημικό χαρακτηρισμό της τοπικής κεραμικής αλλά και για την τεχνολογία και την παραγωγική διαδικασία που ακολούθησαν οι αρχαίοι κεραμείς. Για την απόληψη πρώτων υλών πραγματοποιήθηκαν διατρήσεις βάθους έως 2 μέτρων εντός των αρχαιολογικών χώρων του Sant’ Angelo Vecchio και του Pantanello. Ως κεραμικό υλικό επιλέχθηκε να μελετηθούν κεραμικά δομικά υλικά, κυρίως κέραμοι αλλά και πλάκες κάλυψης ταφικών δομών και πήλινοι αγωγοί αποστράγγισης. Συνολικά επιλέχθηκαν 37 δείγματα αρχαίων κεράμων, 2 κονιάματα, 6 δείγματα αργιλικών πρώτων υλών και 2 δείγματα άμμων. Ο κύριος σκοπός της μελέτης αυτής ήταν ο προσδιορισμός των ιστολογικών και συστασιακών τους χαρακτηριστικών ώστε να καθοριστεί η προέλευση των δειγμάτων αυτών με τη χρήση ορυκτολογικών, πετρογραφικών και γεωχημικών αναλύσεων. Τα συμπεράσματα που προέκυψαν, επέτρεψαν το σχηματισμό και χαρακτηρισμό συστασιακών ομάδων βάσει της ορυκτολογικής, πετρογραφικής και χημικής τους σύστασης, καθώς και την εξαγωγή συμπερασμάτων για τις συνθήκες όπτησης του αρχαιολογικού υλικού. Στα παραπάνω αποτελέσματα στηρίχθηκε και ο σχεδιασμός του πειραματικού σταδίου, που συμπεριέλαβε την παρασκευή κεραμικών δοκιμίων (briquettes) από τα επιλεγμένα δείγματα αργιλικών πρώτων υλών και εν συνεχεία την πειραματική τους έψηση. Η σύγκριση των πετρογραφικών και χημικών δεδομένων μεταξύ των κεράμων και των αργιλικών πρώτων υλών οδήγησε στην ταυτοποίηση των αργίλων από την περιοχή Sant’ Angelo Vecchio ως πηγή της πρώτης ύλης που χρησιμοποιήθηκε σε μέγιστο βαθμό για την κεραμική ύλη στην περιοχή αυτή. Στην περιοχή του Pantanello, αντίθετα δεν κατέστη δυνατή η άμεση συσχέτιση των πρώτων υλών που αναλύθηκαν με τις αρχαίες κεράμους που μελετήθηκαν από την περιοχή, ωστόσο τα αποτελέσματα έδωσαν σημαντικά στοιχεία που υποδεικνύουν μια περισσότερο πολύπλοκη διαδικασία παραγωγής. / The colonization of the Metaponto area (Basilicata, Southern Italy) is considered as the first successful colonial movement worldwide. The strong relationship of the colonies established therein with the area of Achaia (Greece) has indicated the latter as the possible Metropolis. The archaeological excavations carried out in the area since the 1970s, have triggered the interest of the archaeologists and led them to apply several multi-disciplinary research projects in a variety of themes relating to anthropology, agriculture, urban geography, eating habits, social-economic relations between metropolis-colony etc. The excavations that carried out at the archaeological sites of Sant' Angelo Vecchio, Pantanello and Kerameikos in Metaponto, have revealed ancient ceramics of Archaic, Hellenistic and Roman periods at ceramic workshops and indicated this area as one of the most important pottery production centers throughout time. Coroplastic figurines and Terracotta plates as well as table ware and cooking ware constitute some of the most important expressions of the ceramic artisans in this area. Aiming to build a scientific foundation for the detailed archaeometric study of likewise material, the effort of the present study was to establish the means and the tools towards such an approach. In order to achieve this, the local ceramic production should have been characterized by means of compositional and textural parameters aiming to play the role of local reference groups. In this respect, clayey raw materials and ceramic tiles have been selected from the study area and studied by employing minero-petrographic and geochemical techniques. Sampling of the raw materials was performed in the archaeological sites of Sant' Angelo Vecchio and Pantanello by perforations to a depth of 2 meters. The ceramic materials selected comprise roof tiles, tomb tiles and drainage pipes. The selected material included 37 samples of ceramic tiles, 2 samples of mortars, 6 samples of Pliocene clayey sediments and 2 sand samples. The main purpose of the study was to establish local ceramic reference groups and draw conclusions about the conditions of firing of the ancient tiles. The laboratory work included the preparation of briquettes from the selected samples of clay sediments and their experimental firing in a high temperature kiln. The analyses performed in both the ceramic samples and the experimental briquettes comprised their macroscopic observation, mineralogical and petrographic examination and geochemical analysis. The comparison between them has permitted to identify the clays source employed for the manufacture of the tiles from Sant’ Angelo Vecchio. On the other hand, in Pantanello a similarly straightforward correlation between the tiles and the locally available clayey raw material was not easy to be highlighted. The results revealed important evidence suggesting a more complex production chain in that area

But du travail : Apporter une description pétrographique détaillée de ces massifs ophiolitiques, tel est le but essentiel que nous avons voulu atteindre. Une telle description est doublement interessante; elle aidera en effet à : - déterminer la nature originelle de ces roches vertes et, la même, à préciser leur mode de formation; - mettre en évidence les modifications ultérieures subies par ces roches et ainsi à améliorer nos connaissances sur la nature du métamorphisme qui a affecté cette région.

With the end of Western Roman rule and the emergence of new polities in the medieval world, it has been assumed that the technology of mortar reverted to a weak and friable building material. However, this period brought about the implementation of large-scale construction projects that still remain as a testament to their high quality construction techniques and materials. In order to meet the needs of its growing populace, the infrastructure of the new capital city of Constantinople was bolstered by these projects, many rivaling the scale and intricacy of Imperial Rome. A prime example of this is the extensive channel networks of the fourth and fifth centuries, built in the hinterland of Constantinople to supply fresh water from springs hundreds of kilometres away. In addition, the sixth century Long Wall of Thrace was built from the Black Sea to the Sea of Marmara as a first line of defense against increased aggression. This project examines the tradition of monumental construction in the Late Antique and early Byzantine world through laboratory analysis of mortars and valuations of the structural makeup of the Water Supply of Constantinople and Anastasian Wall. By investigating the material technology, scale, and labour requirements of these systems, a better understanding can be gained of two of the largest building project of the early medieval period.

Les modifications cristallines et les stigmates présents à la surface des artéfacts préhistoriques résultent de phénomènes physico-chimiques et mécaniques interdépendants. Une fois décryptés et leurs évolutions comprises, ils permettent d’assigner à l’objet une position stratigraphique génétique, un emplacement paléogéographique et une histoire post-génétique relative aux lieux de résidence successifs. Cette démarche pétroarchéologique dynamique, fondée sur une optimisation des techniques d’observation de la pétrographie, de la minéralogie, de la micropaléontologie et de la morphoscopie aux différentes échelles, est un outil simple de détermination des matériaux et de leurs origines, dont les limites ne sont que celles de l’expérience et des référentiels. L’altération des matériaux est utilisée pour dépasser la simple gîtologie de la formation géologique d’origine et ainsi aboutir à une gîtologie des formations superficielles relatives, au sein de laquelle l’espace et le temps différencient les silex. Un silex est dès lors inscrit dans un itinéraire qui lui est propre et qui permet de mieux appréhender les lieux et les modalités de prélèvement par les hommes. Le domaine géographique utilisé pour cette recherche est vaste et comprend une bonne partie de la moitié sud de la France ainsi que certaines régions du Maroc. Cette variété régionale renforce la fiabilité des méthodes de diagnose utilisées. Ce mémoire se veut outil de caractérisation, établi sur les propriétés d’enregistrement des changements paléoenvironnementaux lisibles sur et dans les silex. Cet effort participe à la mise en place d’un protocole commun de recherche sur les matières premières, dans le but d’impulser une véritable dynamique collective au sein de la communauté des préhistoriens. Nous participons ce faisant à la résolution de deux problèmes archéologiques essentiels :- en reconstituant l’itinéraire parcouru par le silex avant sa collecte par l’homme préhistorique, nous précisons grandement la provenance du mobilier lithique présent dans une unité archéologique ;- en décryptant l’intensité et la chronologie des mécanismes susceptibles d’avoir pris part à la sédimentogenèse et à la diagenèse des dépôts, nous participons à l’évaluation du degré d’intégrité de la zone fouillée.À l’issue de ce travail, nous disposons donc d’un outil de diagnose robuste, assorti de données cartographiques à une échelle suprarégionale et de fiches détaillées de caractérisation d’un très grand nombre de types de silex, tant pour le sud de la France que pour le centre-ouest du Maroc. / The characteristics of their initial crystallization and the evidence for subsequent alterations present on the surfaces of prehistoric flint artifacts are the result of a range of interdependent physical, chemical and mechanical phenomenas. Once decoded, the information retrieved allows us to assign a genetical/stratigraphical position to the flint as well as a post-genetic paleo-geographical location. Both data sets reveal the story ofan objects successive residential contexts. This petro-archaeological analytical methodology, is based on anoptimization of the optical techniques commonly used in petrography, mineralogy, micro-palaeontology and morphoscopy using a range of magnifications is a simple tool for classifying objects and identifying the source of lithic raw materials. The limitations of the methodology are determined by the experience of the operatorand the geographical spread of available reference collections. A study of the various alterations to which lithic raw materials were subjected and which are recorded within their surface characteristics allows connections to be made between the lithic objects and the surface exposures where these characteristics manifest in the lithics rather than just seeing the objects from a perspective that does not connect them with landscapes and specific resource localities. Thus, the methodology used here allows the comparison of flint objects within the context of time and space, and within which the genesis of each object can be followed, thus resulting in a greater understanding of where, why and how, it was collected during prehistory. The geographical extent in which this research has been undertaken is wide and includes parts of Moroccoand the southern part of France and has taken place within broad investigations into lithic raw materials being conducted by a number of members of a research team. A trial of the methodology over such a broad spectrum of site locations has allowed an improvement to be made in the reliability of the analytical techniques that are required. This work aims to aid in the characterization of the lithic tools as they describe and catalogue the properties of palaeo-environmental changes that can be read on the surface of the flint. The outcome of this work is that it produces a greater understanding of the many physical, geological and environmental processes to which lithic objects have been subjected both before gathering by humans and after discard in the archaeological site. This helps for a more precise location of gathering areas and a better evaluation of the archaeological layers integrity. These results are expressed on large scale maps and stored in an indexing system which catalogues the varied characteristics of a large number of types of flint found in the South of France and the west central region of Morocco.

The objective of this thesis is to determine the mineralogy and petrography of 13 'opuka' stone samples taken out from different construction phases of the Church of the Beheading of St. John the Baptist in Dolní Chabry. The analysis of a mineralogical composition and structural properties of the extracted samples alongside with a comparison of their physical characteristics provided a basis for estimation of the samples' origin within the construction phase. Methodology used for the samples analysis has been inspired by the methods described in project NAKI (no. DF13P01OVV008 ) also known as "Materiálový rozbor přírodního kamene - opuky - exaktními laboratorními metodami jako nástroj ke stanovení zdrojové oblasti". These methods includes besides macro and microscopic analysis also X-ray powder diffraction and high pressure mercury porosimetry which together provided a complete set of data about the samples. For the purpose of obtaining the general characteristic of the rock and the initial estimate of the content of mineral phases within it the optical microscopy was used. The results made it possible to classify the samples into four groups depending on content of a silica matrix. This in turn allowed to link some of the samples conclusively with some of the older construction phases of the site....

IDans la région de Dabakala située au Nord-Est de la Côte d’Ivoire, la croûte birimienne de l’Afrique de l’Ouest comporte trois séries volcano-Sédimentaires, toutes orientées NNE-SSW: celle de la Haute Comoé à l’est, celles du Haut-N’Zi et de Fettêkro à l’ouest. Elles constituent l’encaissant d’importants massifs granitiques datés à 2,1 Ga, l'ensemble formant une ride granitique bordée par deux sillons volcano-Sédimentaires.Les données pétrographiques et géochimiques montrent que les volcanites présentent des variations de composition continues de basalte à rhyolite. Les métabasites, subalcalins à alcalins montrent une source de type lherzolite à spinelle, avec une possible contamination crustale. Leur environnement de mise en place serait un contexte de subduction. Les andésites montrent une affinité avec les arcs insulaires continentaux matures, suggérant un modèle de subduction avec délamination crustale. Les volcanites acides, également mises en place dans un contexte d’arc volcanique, terminent la lignée calco-Alcaline.Les plutonites de la région de Dabakala, comprenant des massifs de pegmatite, granite, granodiorite, diorite, tonalite et trondhjémite, sont liées à des arcs volcaniques et caractérisent un magmatisme calco-Alcalin de marge active. Les métasédiments se reportent quant à eux dans le champ des arcs insulaires continentaux.Au plan structural, la région de Dabakala présente des directions de fractures majeures orientées N-S à NNE-SSW senestres pour la plupart (les plus anciennes), N90° à N100° dextres (les plus récentes), NW-SE dextres ou senestres. Une structure significative, de direction N075° à N080° est identifiée pour la première fois: la faille de Sarala (FSr). La carte structurale du prospect aurifère de Bobosso indique globalement un fort développement des linéaments NNE-SSW recoupés par des linéaments NW-SE. Les premiers dessinent une mégastructure de premier ordre dénommée Zone Tectonique de Bobosso (ZTB), abritant plusieurs structures secondaires avec des lentilles minéralisées.Concernant la minéralisation aurifère, le prospect de Bobosso dans la série de la Haute-Comoé présente une déformation polyphasée avec une déformation cassante à l’origine de la formation de plusieurs générations de veines de quartz. La minéralisation aurifère présente un contrôle structural principalement marqué par les filons de quartz liés à la mise en place d’intrusions dans les basaltes et les andésites. Il existe deux types de minéralisations: une disséminée et l’autre filonienne. Cette distribution bimodale de l’or a été également mise en évidence dans les gisements de la ceinture Ashanti au Ghana et dans plusieurs gisements aurifères mondialement connus.La minéralisation disséminée serait syngénétique, d'après l’existence de teneurs élevées dans les sections de sondages sans aucun filon de quartz. La minéralisation filonienne est évidemment épigénétique. Les teneurs les plus élevées ont été obtenues dans les zones de sondages montrant la présence de lentilles, veines et filons de quartz, calcite ± tourmaline ± sulfures. La paragenèse métallifère est essentiellement constituée de pyrite, mais également de pyrrhotite, chalcopyrite et d’arsénopyrite, avec présence de magnétite et d’hématite. L'or n’est jamais visible à l’oeil nu, même dans les sections de forage présentant les plus fortes teneurs.Nous pouvons retenir une principale phase de minéralisation dans le prospect aurifère. Elle est de type hydrothermal et liée à la mise en place de granitoïdes dans les métasédiments et les volcanites lors de la fermeture des bassins à la fin de l’orogenèse éburnéenne. La minéralisation filonienne montre de plus fortes teneurs en Or. / In Dabakala region located in the northeastern part of Côte d'Ivoire, the birimian crust of West Africa displays three volcano-Sedimentary series: the Upper Comoé serie to the east, and the Upper N'Zi and Fettêkro series to the west. These three volcano-Sedimentary series are NNE-SSW oriented and enclose an important granitic mass dated to 2.1 Ga; thus constituting a granitic ridge bordered by two volcano-Sedimentary trenches.Petrographic and geochemical data show that these pyroclastic rocks have basalts, andesites, andesite basalts, dacites, rhyolites and rhyodacites compositions. Metabasites are generally subalkaline to peralkaline and show their source composition between those of N- MORB and E- MORB. Fettêkro serie basalts, with La / Yb values between 1.43 to 1.83 and La values between 2.21 to 5.6, are close to average of Nauru basalts and belts’ mafic. Their magmatic source would be spinel lherzolite type, with probably possible crustal contamination in an environment of implementing intra -Oceanic environment with building oceanic plateaus. Andesites show an affinity to continental and mature island arcs basalts, corresponding to a subduction model with crustal delamination. Acid volcanics are implemented in a volcanic arcs context and follow a calc-Alkaline suite.The plutonic rocks of the Dabakala region are composed to pegmatite, alkali and natural granite, granodiorite, diorite and gabbro. These rocks correspond to syn-Collisional volcanic arc plutonites, and are probably related to a calc-Alkaline magmatism of active margins. Metasediments generally defer in the field of continental island arcs.Structurally, the Dabakala region has major fractures directions oriented NS to NNE-SSW sinistral for most (older), N90° to N100° dextral (latest), NW-SE to NNW-SSE dextral or sinistral. A significant structure, oriented N075° to N080° is identified for the first time: the Sarala fault (FSr). The structural map of the Bobosso gold prospect generally indicates a strong development of NNE-SSW lineaments cut by NW-SE lineaments. The first ones draw a first order megastructure called Bobosso Tectonic Zone (ZTB), containing multiple secondary structures or mineralized lenses.Concerning gold mineralization, the Bobosso prospect (Upper-Comoé serie) has a polyphase deformation with brittle deformation as manifested in several ways. The latter is the cause of the formation of several generations of quartz veins. Gold mineralization presents mainly a structural control by quartz veins, related to the development of intrusions in basalts and andesites.. Two types of mineralization may be mentioned: disseminated and vein. This bimodal distribution of gold has also been highlighted in the Ashanti belt deposits in Ghana and several gold deposits known worldwide.Disseminated mineralization is syngenetic and relies on the existence of high grade in sections of surveys without quartz vein. The vein mineralization is evidently epigenetic. The highest grades were obtained in sections showing the presence of lenses, veins and quartz veins, tourmaline ± calcite ± sulfides. The metalliferous paragenesis consists essentially of pyrite, but pyrrhotite, chalcopyrite and arsenopyrite with presence of magnetite and hematite. Gold is not visible, even in the drill sections with the highest grades.We retain two main phases of mineralization in the Bobosso gold prospect: 1) a first phase (SEDEX type) occurred while opening rear arc basins. It occurs mainly in the metasediments and 2) a second phase (hydrothermal) related to the implementation of various granitoids in the metasediments and volcanics when closing pools at the end of the eburnean orogeny. Vein mineralization shows higher grades of gold.

A região de São Félix do Xingu, localizada no centro-sul do estado do Pará e, geologicamente, no contexto da Província Amazônia Central do Cráton Amazônico. Apresenta em seus arredores um registro extremamente preservado das atividades vulcâno-plutônicas ocorridas durante o final do Paleoproterozóico (1870 - 1880 Ma), agrupadas no Grupo Uatumã, que é dividido na região nas formações Sobreiro e Santa Rosa. Estas rochas foram depositadas sobre o embasamento arqueano, representado pelo Terreno Granito-Greenstone do Sul do Pará e pelo Cinturão de Cisalhamento Itacaiúnas, e unidades paleoproterozóicas, tal como o Granito Parauari. Por fim, estas rochas foram invadidas em ~1860 Ma pelos granitos do tipo A da Suíte Intrusiva Velho Guilherme e recobertas pelas rochas sedimentares da Formação Triunfo. A Formação Sobreiro é a unidade basal. Suas rochas tem filiação cálcio-alcalina e são representadas por vulcânicas e piroclásticas predominantemente intermediárias, com componentes ácidos no topo da sequência. Em estudos de campo são reconhecidas ao menos duas sequências de derrames vulcânicos que variam de andesitos basálticos com fenocristais de augita e magnésio-hastingsita nos derrames basais, para andesito e latito com fenocristais de magnésio-hastingsita e de andesina a labradorita e, por fim, quartzo-latito e riolito com fenocristais de plagioclásio sódico e de feldspato potássio, além de quartzo ocasional. Intercalados nestes derames de lava ocorrem corpos de rochas piroclásticas representadas principalmente por tufos máficos de cristais, lapilli-tufo máfico e tufos máficos laminados de cristais. De modo geral essas, são rochas hipocristalinas, maciças, formadas por cristais e fragmentos de cristais líticos e vítreos. Os tufos de cristais máficos laminados apresentam melhor seleção granulométrica, estrutura laminada e arcabouço constituído porcristais e fragmentos de cristais e líticos. A Formação Santa Rosa, como descrita atualmente na literatura, é a unidade superior e representa um vulcanismo intraplaca do tipo A. É composta por rochas vulcânicas, subvulcânicas e piroclásticas com alto teor de \'SiO IND.2\' (> 70% na maioria das amostras). Ao menos três fácies são reconhecidas: a) pórfiros graníticos e riolitos com megacristais de anfibólio, plagioclásio sódico, feldspato potássico e quartzo; riolitos com fenocristais de feldspato potássico e plagioclásio sódico com eventuais megacristais de quartzo; b) álcaliriolitos e pórfiros álcali-riolíticos com fenocristais de feldspato potássico (ortoclásio) e quartzo; c) tufo félsico de cristais hiprocristalino, tufo félsico de cristais levemente soldado com fiamme, tufo soldado laminado, lapilli-tufo acrescionário e tufo vítreo com glass shards. A assembleia de alteração hidrotermal da Formação Sobreiro é composta por epídoto + clorita + clinozoisíta + pirita + quartzo + carbonato + albita + sericita na alteração propilítica; sericita + clorita + quartzo \'+OU-\' pirita \'+OU-\' fluorita \'+OU-\' barita \'+OU-\' alloclasita \'+OU-\' esfalerita na alteração sericítica; e sericita + hematita + quartzo + argilo-minerais \'+OU-\' galena \'+OU-\' ouro na alteração argílica. Indícios de alunita sugerem que a Formação Sobreiro pode hospedar em suas rochas sistemas epitermais do tipo low-e high-sulfidation. Já na Formação Santa Rosa, a assembleia mineral de alteração hidrotermal é composta por feldspato potássico + biotita + quartzo + sericita na alteração potássica; e sericita + quartzo + pirita + clorita \'+OU-\' fluorita \'+OU-\' carbonato na alteração sericítica. Tais assembleias podem hospedar nas rochas da Formação Santa Rosa mineralizações do tipo Intrusion Related Gold Systems. Estudos litoquímicos revelam a naturezacálcio-alcalina de alto potássio da Formação Sobreiro, com enriquecimento em elementos litófilos como K, Ba, Sr, Rb, e baixa concentração de elementos de alto potencial iônico como Nb e Ta. Esta unidade mostra rochas enriquecidas em elementos terras raras leves em relação a terras raras pesados, indicada pela razão \'(La/Yb) IND.N\' ~ 12, sem anomalias de Eu nas rochas menos evoluídas e com anomalias levemente negativas nas rochas mais evoluídas. Tais características são típicas de andesitos orogênicos e estudos comparativos revelam que as rochas da Formação Sobreiro são bastante semelhantes às de alguns arcos magmáticos mais jovens, como o Arco Eólio na região da Sicília. Isto corrobora a hipótese de que a Formação Sobreiro é relacionada a um vulcanismo associado a um evento de subducção. A Formação Santa Rosa mostra resultados mais heterogêneos. Algumas das amostras analisadas apresentam afinidade cálcio-alcalina metaluminosa, com enriquecimento em Ba, Rb e Sr semelhantes às rochas evoluídas da Formação Sobreiro. Nestas amostras são observadas anomalias negativas de nióbio e tântalo em diagramas normalizados de elementos traços, além de suaves anomalias negativas de Eu em diagramas de elementos terras raras, com enriquecimento em terras raras leves em relação aos pesados similar à Formação Sobreiro. Estas características, junto às razões de Ba/Ta > 450 e Rb/Nb > 7, mostram mais semelhanças com as rochas cálcio-alcalinas da Formação Sobreiro do que com as rochas do tipo A da Formação Santa Rosa. O outro grupo de amostras da Formação Santa Rosa apresenta um comportamento completamente diferente, sendo caracterizado por rochas alcalinas, peraluminosas, com enriquecimento em elementos de alto potencial iônico (principalmente Nb e Ta) e fortes anomalias negativas para elementos litófilos (principalmente Ba e Sr, além de CaO, P e Ti) emdiagramas normalizados de elementos traços. Em relação aos elementos terras raras, este grupo apresenta enriquecimento muito mais discreto em elementos terras raras leves em relação aos pesados, evidenciado pela razão \'(La/Yb) IND.N\' ~ 4, com forte anomalia negativa de Eu. As razões Rb/Nb < 7 indicam que estas amostras atendem a maioria dos critérios classificatórios para rochas subalcalinas do tipo A e, portanto devem ser classificadas como pertencentes à Formação Santa Rosa. Por fim, os resultados sugerem que embora agrupados somente na Formação Santa Rosa nos trabalhos anteriores, ao menos uma parte dos riolitos mostra características que apresentam associação ao vulcanismo cálcio-alcalino da Formação Sobreiro / The São Felix do Xingu region, located in the center-south region of the state of Pará - Brazil, under the Central Amazonian province of theAmazonian Craton context, presents in its surroundings extremely well preserved volcano-plutonic activities occurred during the Paleoproterozoic (1870 - 1880 Ma), where units are grouped into the Uatumã Group which is therefore divided into formations Sobreiro e Santa Rosa. These rocks are intrusive in units of the Archean basement represented by the South Pará Granite-Greenstone Terrain and by the Itacaiúnas Shear-belt; and rocks of Paleoproterozoic such as the Parauari Granite. Thus, these rocks are intruded in ~1860 Ma by A-type granites of the Velho Guilherme Intrusive Suite and covered by sedimentary rocks of the Triunfo Formation. The Sobreiro Formation is the basal unity. It is calc-alkaline, composed of volcanic and pyroclastic rocks of mainly intermediate composition, with acid components on the top of the sequence. In field study, at least two sequences of volcanic flows which vary from andesi-basalts with phenocrysts of augite and magnesium-hastginsite in the basal flows, to andesites and latites with phenocrysts of magnesium-hastginsite and plagioclase (andesine to labradorite) and finally, quartz-latites and rhyolites with phenocrysts of sodic plagioclase and potash feldspar, besides occasional quartz, are recognized. Interspersed with these lava flow rocks, pyroclastic rocks represented by mafic crystal tuffs, mafic crystal lapilli-tuffs and laminated mafic crystal tuffs occur. The Santa Rosa Formation, as described in literature nowadays, is the superior unit and represents an A-type intraplate volcanism. It is composed by volcanic, subvolcanic and pyroclastic rocks with high \'SiO IND.2\' content (>70% in most of the samples). At least three facies are identified, the first consisting of granitic porphyry and rhyolite with megacrysts of amphibole, sodic plagioclase, potash feldspar and quartz; the second of rhyolites with phenocrysts of potash feldspar and sodic plagioclase with occasional quartz; and the last of alkali-rhyolites and alkali-rhyolitic porphyries with phenocrysts of potash feldspar (orthoclase) and quartz. Hipocrystalline felsic crystal tuff, lightly welded crystal tuff with fiamme, laminated welded tuff, accretionary lapilli-tuff and vitreous tuff with glass shards represent the pyroclastic rocks associated with Santa Rosa Formation. The hydrothermal alteration mineral assemblage of the Sobreiro Formation is composed of epidote + chlorite + clinozoisite + pyrite + quartz + carbonate + albite + sericite in the propylitic alteration; sericite + chlorite +quartz + carbonate ± pyrite ± fluorite ± barite ± alloclasite ± sphalerite in the sericitic alteration; and sericite + hematite + quartz + clay minerals ± galena ± gold in the argillic alteration. In addition to evidences of alunite, the vii Sobreiro Formation may host low and high-sulfidation epithermal systems in its rocks. The Santa Rosa Formation, on the other hand, presents ahydrothermal alteration mineral assemblage composed of potash feldspar + biotite + quartz + sericite in the potassic alteration; and sericite + quartz + pyrite + sericite ± fluorite ± carbonate in the sericitic alteration. Such assemblages may host Intrusion Related Gold Systemsmineralization type into the rocks of the Santa Rosa Formation. Lithochemistry studies reveal the high potassium calc-alkaline nature for the Sobreiro Formation, with enrichment in lithophile elements such as K, Ba, Sr, Rb and low concentration of high field strength elements such as Nb and Ta. This unit shows rocks enriched in light rare earth elements in relation to heavy rare earth elements indicated by the \'(La/Yb) IND. N\' ~ 12 ratio, with absence of Eu anomalies in the less evolved and lightly negative anomalies in the most evolved rocks. Such characteristics are typical of orogenic andesites and comparative studies reveal that the Sobreiro Formation chemical characteristics are rather similar to some younger magmatic arcs, like the Aeolian Arc in the Sicily\'s region. This data corroborates with the hypothesis that the Sobreiro Formation is related to a calc-alkaline volcanism related to a subduction regime. The Santa Rosa Formation shows more heterogeneous results. Some of the analyzed samples present calc-alkaline affinity, metaluminous, with enrichment in Ba, Rb and Sr similar to the evolved rocks of the Sobreiro Formation. Such samples also present negative Nb and Ta anomalies in normalized trace elements diagrams, besides presenting light negative anomalies in normalized rare earth elements diagrams with enrichment in light rare earth elements in relation to heavy rare earth elements similar to the Sobreiro Formation. These characteristics, allied to Ba/Ta > 450 and Rb/Nb > 7 ratios, show much more similarities to the calc-alkaline rocks of the Sobreiro Formation than to the A-type rocks of the Santa Rosa Formation. The other group of samples of this unity shows a completely different behavior, being characterized by alkaline rocks, peraluminous, withenrichment in high field strength elements (mainly Nb and Ta) and strong negative anomalies for lithophile elements (mainly Ba and Sr, besides CaO, P and Ti) in normalized trace elements diagrams. In relation to rare earth elements, the Santa Rosa Formation presents much more discrete enrichment in light rare earth elements in relation to heavy rare earth elements, highlighted by the \'(La/Yb) IND.N ~ 4 ratio, with strong negative anomalies of europium. The Rb/Nb < 7 ratio indicate that these samples attend to the most of the classificatory criteria for sub-alkaline type-A rocks and, therefore must be classified as belonging to the Santa Rosa Formation. viii All things considered, the results suggest that besides grouped exclusively in the Santa Rosa Formation in the previous works, at least somepart of the rhyolites shows characteristics which presents association to the calc-alkaline volcanism of the Sobreiro Formation.

O presente trabalho procura a articulaçao das produções de cerâmicas de iluminação romanas tipo discus que estiveram em circulação no Orbis Romanorum durante o séculos II e III EC. A análise comparativa dessas produções tendo inerente a sistematização de dados físico-químicos das argilas de confecção dos objetos pode prover interessantes inferências sobre os locais de fabrico, relações de ruptura e continuidade de estilos e sistemas tecnológicos, bem como fomentar dados para o entendimento da co-constituição do espaço e identidade cultural dos grupos sociais que se utilizaram desses artefatos na paisagem / This PhD dissertation studies the production and distribution of Roman oil lamps made of clay in the Orbis Romanorum during 2nd and 3nd CE by means of thin-section analysis and comparative research, in order to identify workshops in the Levant. The results are compared with modes of production and distribution of Roman oil lamps of North African workshops, against their social and economic implications. This comparative research seeks trends of continuity, discontinuity and change of style and technology in order to foster our understanding of space and cultural identity definition amongst social groups that used clay lamps as social and mental marker

O Complexo Morro Redondo, com cerca de 250 Km2, é uma das ocorrências mais importantes de granitos de tipo-A da Província Graciosa, uma importante província póscolisional neoproterozóica (ca. 580 Ma) na região sul-sudeste do Brasil. O Complexo aflora nas proximidades de Tijucas do Sul (PR) e Garuva (SC). É formado pelos Plútons Papanduva e Quiriri, em que afloram, respectivamente, rochas graníticas das associações alcalina e aluminosa de granitos de tipo-A, respectivamente; e por rochas vulcânicas ácidas e básico-intermediárias contemporâneas. O Plúton Papanduva, objeto deste trabalho, aflora na porção norte do Complexo, estendendo-se por uma área de cerca de 100 Km2. Constitui-se essencialmente de álcalifeldspato granitos hipersolvus leucocráticos a hololeucocráticos, de granulação média a fina. De acordo com suas estrutruras, texturas e mineralogia, foram individualizadas quatro unidades distintas, denominadas informalmente de A, B, C e D. As Unidades A e B afloram junto às bordas NE e N do plúton, e nas proximidades de zonas de cisalhamento mais importantes. São caracterizadas por teores modais moderados a altos de quartzo (50-60 % modal) e por texturas deformacionais desde cataclásticas (Unidade B) até protomiloníticas (Unidade A), resultantes de eventos deformacionais tardi a pós-magmáticos. A Unidade C apresenta a maior expressão geográfica, aflorando nas zonas centrais e SW do plúton. Agrupa rochas de estrutura essencialmente maciça, com teores de quartzo mais baixos (próximos de 20% modal). A Unidade D compreende diques centimétricos a decamétricos de álcali-feldspato microgranitos interpretados como o último evento magmático. O feldspato alcalino varia de mesopertítico a pertítico, sendo relativamente mais potássico nas rochas mais deformadas das Unidades A e B. Laths de albita quase pura ocorrem em interscrescimentos com anfibólio e clinopiroxênios sódicos e alguns minerais acessórios, sugerindo coprecipitação em estágios tardi(?) ? a pós-magmáticos. As paragêneses máficas compreendem anfibólios magmáticos e clinopiroxênios tardi- a pósmagmáticos, variando desde tipos sódico-cálcicos (Fe-richterita e egirina-augita) até sódicos (arfvedsonita/riebeckita e egirina). Iniciam sua cristalização posteriormente às fases félsicas, o que caracteriza uma ?seqüência agpaítica de cristalização?. A variação composicional dos anfibólios acompanha, aproximadamente, o aumento da abundância modal de quartzo e/ou a presença de feições indicativas de deformação (cataclasitos) com os termos mais cálcicos aparecendo nas amostras com menores teores de quartzo e estruturas maciças (Unidade C). Na arfvedsonita e egirina as trajetórias evolutivas são marcadas pelo aumento de Na e Fe3+ paralelo à diminuição de Ca, Fe2+ e Ti em direção às bordas cristalinas, indicando condições progressivamente mais alcalinas e oxidantes. Riebeckita é pós-magmática, aparecendo tipicamente em amostras com indícios de alteração hidrotermal das Unidades B e D. Ilmenita ocorre ocasionalmente nas Unidades B, C e D, enquanto magnetita é rara, tipicamente pós-magmática, resultando em valores muito baixos de susceptibilidade magnética (< 1,0 x 10-3 SI). Zircão, chevkinita e astrofilita são os acessórios mais típicos nas Unidades B, C. Por outro lado, uma variedade de minerais acessórios raros, de cristalização tardi ? a pósmagmática, típicos de rochas peralcalinas, como narsarsukita, neptunita (portadores de Ti); britholita e nacareniobsita (portadores de ETR); além de zirconossilicatos de (Na, K), turkestanita e bastnäsita ocorre tipicamente em amostras mais deformadas da Unidade A. A associação aparentemente contemporânea das rochas graníticas com um vulcanismo de caráter bi-modal, a observação de cavidades miarolíticas, bolsões pegmatíticos e texturas gráficas e semi-gráficas no Plúton Papanduva indica condições crustais relativamente rasas para a colocação do magmatismo granítico. Com base nos equilíbrios minerais observados e na presença/ausência de certas fases minerais, pode-se estimar trajetórias evolutivas de T e ?O2 durante a seqüência de cristalização do Plúton Papanduva. As trajetórias são governadas, durante os estágios magmáticos, pela diminuição de T (ca. 750 ? 500o C), em condições progressivamente mais oxidantes, com ?O2 variando desde valores equivalentes ao tampão WM (magnetita ? wüstita) até valores próximos àqueles definidos pelo tampão HM (hematita ? magnetita). A concentração de álcalis, voláteis, HFSE (Zr, Ti, Nb, ETR) e ocasionalmente Ca nos líquidos residuais decorrentes da evolução dos magmas peralcalinos e, em parte, devido à entrada de fluidos externos (Ca e H2O) permitiu a cristalização de minerais acessórios raros. A presença desses acessórios nas rochas tipicamente deformadas sugere que a deformação teve um papel importante na remobilização e circulação desses elementos nos estágios tardi- a pósmagmáticos. / The Morro Redondo Complex, covering an area of about 250 km2, is one of the most expressive occurrences of granites and associated bimodal volcanic rocks from the Neoproterozoic (ca. 580 Ma), post-collisional, A-type Graciosa Province in south-southeast Brazil. The Complex outcrops near Tijucas do Sul (PR) and Garuva (SC) townships, and consists of two main intrusive units: the Papanduva and Quiriri Plutons, both comprising granitic rocks from the alkaline and aluminous petrographic associations of A-type granites. The Papanduva Pluton, which is the main subject of this work, comprises the northern portion of the Morro Redondo Complex, covering an area of about 100 Km2. It is made up of leucocratic to hololeucocratic, coarse- to fine-grained hypersolvus alkali-feldspar granites. Based on their structures, textures and mineralogy, four distinct units were recognized and informally named A, B, C and D. Units A and B outcrops near the NE and N borders of the pluton, and close to major shear zones. They are characterized by high modal quartz contents (50-60 %) and deformational textures varying from cataclastic (Unit B) to protomylonitic (Unit A), as the result of late- to post-magmatic tectonic stress. Unit C, the largest in extent, occurs in the central and SW parts of the pluton. It consists of massive granitic rocks, with lower modal quartz content (ca. 20%). Unit D comprises alkali-feldspar microgranites interpreted as formed by the latest magmatic event. Alkali feldspar varies from mesoperthic to perthitic, being relatively more potassic in the deformed rocks from Units A and B. In some rocks idiomorphic laths of almost pure albite are found in intergrowths with interstitial pyroxene, amphiboles, and accessory minerals; suggesting co-precipitation in the late(?)- to post-magmatic stage. The mafic paragenesis includes magmatic amphiboles and late- to post-magmatic clinopyroxenes, varying from sodic-calcic (Fe-richterite and aegirine-augite) to sodic varieties (arfvedsonite/riebeckite and aegirine). The crystallization history of mafic minerals starts after the felsic phases, in a typical ?agpaitic crystallization sequence?. The amphibole and clinopyroxene compositional variations follow the increase in quartz modal content and/or the presence of deformational textures, with the more calcic varieties crystallizing in rocks with low modal quartz contents and massive structure (Unit C). For arfvedsonite and aegirine, the evolutional trends are marked by enrichment in Na and Fe3+ and depletion in Ca, Fe2+ and Ti towards crystal rims, suggesting progressively more oxidizing and alkaline conditions. Riebeckite is in a post-magmatic phase in hydrothermally altered rocks from Units B and D. Ilmenite appears occasionally in Units B, C and D, while magnetite is a rare phase, typically post-magmatic; thus, the magnetic susceptibility values are very low for most rocks (< 1.0 x 10-3 SI). Zircon, chevkinite and astrophyllite are the most typical accessories in Units B and C. On the other hand, a variety of late- to post-magmatic rare accessory minerals, typical of peralkaline rocks, such as narsarsukite, astrophyllite and neptunite (Ti-bearing); britholite and nacareniobsite (REE-bearing); as well as ( Na, K) zirconosilicates, turkestanite and bastnäsite, appears in the more deformed samples from Unit A. The apparently contemporary association of granitic and bi-modal volcanic rocks, the presence of miarolitic cavities, pegmatitic veins and graphic and semigraphic textures in the Papanduva Pluton indicate emplacement at a relatively high crustal level. Based on the observed mineral equilibria and the presence or absence of some mineral phases it was possible to establish evolutional trends in T-?O2 space during the crystallization sequence of rocks from Papanduva Pluton. The trajectories are governed, during the magmatic stages, by falling temperature (ca. 750 ? 500o C) in progressively more oxidizing environments, with ?O2 varying from MW (magnetite-wüstite) to HM (hematite-magnetite) buffer conditions. The concentration of alkalis, volatiles , HFSE (Zr, Ti, Nb, REE) and occasionally Ca in the residual liquids, as a consequence of peralkaline magma evolution, or, in part, due to external fluids (Ca and H2O) led to the crystallization of rare accessory mineral phases. The presence of these accessory minerals in typically deformed rocks suggests that deformational events played an important role in the remobilization and circulation of these elements in the late- to post-magmatic stages.

Cette thèse de doctorat se focalise sur la fin du Précambrien, le Néoprotérozoïque, une période charnière dans lhistoire de la Terre, par létude dunités ophiolitiques datées entre 800 et 700 Ma. Les travaux présentés ici portent sur létude pétrographique, géochimique et magnétique des serpentinites de ces ophiolites. Associées à des sutures panafricaines en bordure des cratons ouest africain et amazonien, ces ophiolites sont les témoins des subductions et de la lithosphère océanique associées à la dislocation du supercontinent Rodinia. Létude de ces ophiolites permet de proposer des contextes de formation pour ces sections de lithosphère océanique. Une autre question à lorigine de ce travail était : Létude de la serpentinisation et de lhydrothermalisme associé permet-elle dapporter des contraintes sur le paléoenvironnement océanique ? Les travaux sur les serpentinites et les roches mafiques associées des unités ophiolitiques de lAraguaia belt (757 ± 49 Ma1, Brésil) constituent la première étude géochimique réalisée sur ces unités. La chimie des spinelles couplée à des travaux de modélisation géochimique, portant essentiellement sur les concentrations en REE, attestent dun protolithe hautement réfractaire, ayant enduré entre 14 et 24 % de fusion partielle. Ces travaux témoignent aussi de laffinité abyssale de ces serpentinites, confirmée par les signatures N-MORB et E-MORB des basaltes associés. Il apparait que la serpentinisation de ces unités sest probablement opérée en deux temps, en domaine océanique, puis par interaction avec des fluides dérivés des sédiments encaissants, aboutissant à de forts enrichissements en LILE, en B et en Li dans ces serpentinites. Finalement, nous proposons que ces sections de lithosphère océanique, ainsi que les métasédiments les abritant (Tocantins group), soient les reliques dune transition océan-continent (TOC) en bordure est du craton amazonien. Les études de terrain, pétrographiques et géochimiques sur les sections ophiolitiques de Khzama (762 ± 2 Ma2) et dAït Ahmane (Anti-Atlas, Maroc) ont dans un premier temps permis de confirmer le lien supposé entre ces deux ophiolites. Les spinelles des serpentinites de ces unités sont caractérisés par des Cr# très élevés et des Mg# bas témoignant dun protolithe ayant enduré des taux de fusion supérieurs à 25 %, confirmant leur affinité avec la zone de subduction anti-atlasique. Ceci est corroboré par de très faibles concentrations en éléments incompatibles comme Al, Ti, HREE et HFSE. Le contexte le plus probable concernant la genèse de ces sections de lithosphère est ainsi un même centre daccrétion arrière-arc intra-océanique, à la marge du supercontinent Rodinia. Létude comparative des serpentinites de ces ophiolites a aussi permis de mettre en évidence en évidence lintérêt des mesures magnétiques pour tracer le degré daltération des spinelles chromifères dans les serpentinites, approche pouvant être étendue à dautres types de roches. Notamment, nous montrons que la Cr-magnétite et la ferritchromite peuvent être identifiées à laide des mesures de susceptibilité magnétique en chauffe. Enfin, lassociation des méthodes magnétiques, pétrographiques et géochimiques nous permet de proposer un modèle concernant la formation des veines de magnétite massives de lunité dAït Ahmane Nord. Nous montrons que le triptyque : serpentinites et spinelles altérés et veines de magnétite centimétriques, constitue un système hydrothermal abyssal fossile, de type fumeur noir. Dans ce contexte, les compositions isotopiques en oxygène des veines de magnétite permettent de proposer une valeur du 18O des océans néoprotérozoïques profonds de -1.33 ± 0.98 (VSMOW), soit une valeur très similaire à lactuel (entre -1 et +1 VSMOW). Elle tranche aussi le débat sur lévolution du 18O des océans au cours des temps géologiques en attestant dune constance de celui-ci, au moins depuis le Néoprotérozoïque. / This Doctoral thesis focus on the end of the Precambrian, the Neoproterozoic, a pivotal period in the Earth history, by the study of ophiolitic units dated between 800 and 700 Ma. This work essentially deals with the petrography, geochemistry and magnetism of serpentinites from these ophiolites. They are associated with Panafrican orogenic belts along the West African and the Amazonian cratons and witnesses the subductions and the oceanic lithosphere associated to the break-up of the supercontinent Rodinia. The study of these neoproterozoic ophiolites allowed us to propose the formation settings for these sections of oceanic lithosphere. Another question behind this work is: Does the study of serpentinization and associated hydrothermalism allows one to provide constraints on the oceanic paleoenvironment? Work on the serpentinites and associated mafic rocks from the Araguaia belt ophiolitic units (757 ± 49 Ma1, Brazil) constitute the first geochemical study realized on these units. The Cr-spinel chemistry coupled with geochemical modeling, concerning essentially the REE concentrations, attest to a highly refractory protolith that endured between 14 and 24% of partial melting. This work also indicate an abyssal affinity (i.e. MOR rather than SSZ) of these serpentinites, which is confirmed by the N-MORB and E-MORB geochemical signature of the associated basalts. It appears that the serpentinization of these units probably took place in two steps, first in oceanic domain and then by interaction with fluids derived from the surrounding sediments after obduction, leading to strong LILE, B and Li enrichments in the serpentinites. Finally, we propose two potential settings concerning the origin of the sections of oceanic lithosphere presently found in the Araguaia belt: (1) an ocean-continent transition or (2) slices of a more mature lithosphere trapped into an accretionary wedge. Fieldwork, petrography and geochemical analysis on serpentinites from the Khzama (762± 2 Ma²) and Aït Ahmane ophiolitic sections (Anti-Atlas, Morocco) firstly allowed to confirm the supposed link between these two ophiolites. Cr-spinels in serpentinites from these units are characterized by very high Cr# and low Mg# testifying of a protolith having endured partial melting greater the 25%, confirming their affinity with the anti-atlasic subduction zone. This is corroborated by very low incompatible element concentrations such as Al, Ti, HREE and HFSE. Thus, the most likely setting for the genesis of these sections of lithosphere is a same intra-oceanic back-arc spreading center at the margin of the Rodinia supercontinent. The comparative study of all studied serpentinites from Neoproterozoic ophiolites in different settings also demonstrates the ability of magnetic measurements in monitoring the Cr-spinel alteration degree, a method which can be extended to other types of rocks. In particular, we show that Cr-magnetite and ferritchromite can be identified using thermomagnetic curves. Finally, the association of magnetic, petrographic and geochemical methods allows us to propose a model concerning the formation of the massive magnetite veins of the North Aït Ahmane unit. We show that the triptych consisting in: altered serpentinites, spinels and centimetric magnetite veins, results from a fossil, black smoker type, abyssal hydrothermal system. In this context, the oxygen isotopic compositions of the magnetite veins provide a 18O value of the deep Neoproterozoic oceans of -1.33 ± 0.98 (VSMOW), a value that is very similar to the current one (between -1 and +1 VSMOW). It also settles the debate on the evolution of the 18O of the oceans during geological time, attesting of its consistency, at least since the Neoproterozoic.