Orientador: Marcos Aurélio Farias de Oliveira / Banca: José Paulo Peccinini Pinese / Banca: Antonio José Ranalli Nardy / Resumo: A área de ocorrência de rochas basálticas, objeto do estudo da presente dissertação, está localizada no noroeste do Estado de São Paulo, no Município de Araçatuba. Os estudos das rochas basáticas da Formação Serra Geral, da área em questão, abrangeram trabalhos de campo e de laboratório. Os trabalhos de campo compreenderam levantamentos de superfície e de subsuperfície, através da perfuração do poço profundo - PMA. As amostragens de superfície ocorreram em cavas de antigas pedreiras desativadas e em afloramentos do leito do Ribeirão Baguaçu. Em subsuperfície, foram coletadas 490 amostras de calha de rochas basálticas da Formação Serra Geral, em intervalos regulares de 2 metros, até a profundidade de 980 metros. Os estudos desenvolvidos, a partir das amostras de calha, permitiram a identificação de uma sucessão de 27 derrames, com espessuras que variam entre 10 e 84 metros, que edificaram o pacote vulcânico, atravessado pela perfuração do poço PMA. A classificação e nomenclatura, baseada em critérios químicos, revelaram, não somente, a natureza toleítica das rochas estudadas mas, também, que a maioria dessas rochas são representadas predominantemente por basaltos e andesi-basaltos. A partir das concentrações de elementos maiores, menores, dos teores de TiO2 e de elementos traços incompatíveis, bem como dos padrões de abundância de elementos terras raras, essas rochas vulcânicas foram divididas em dois grupos a saber: Paranapanema e Pitanga (Peate et al, 1992). / Abstract: The area of occurrence of basaltic rocks, object of these studies, is located in the northwest of the State of São Paulo, in the Araçatuba City. The studies of the basaltic rocks of the Serra Geral Formation, of the area in question, has enclosed laboratory and field works. The field works had understood surveys surface and of subsurface, through the borehole’s samplings, cutting through 980 m of basaltic rocks (deep well PMA). The samplings of surface had occurred on disabled stone pits of old quarries and outcrops of the of the Baguaçu’s stream’s bed . In subsurface, 490 samples of basaltic rocks of the Serra Geral Formation had been collected, in regular intervals of 2 meters, until the depth of 980 meters. The developed studies had allowed the identification of a succession of 27 basaltic flows, with thicknesses that vary between 10 and 84 meters, that had built the volcanic sequence, crossed for the drilling’s deep well PMA. The classification and nomenclature, based on chemical criteria, had revelead, not only, the tholeiitic nature of the studied rocks but, also, that the majority of these rocks is predominantly represented by basalts and andesi-basalts. From the concentrations of larger and minors elements, of tenors of TiO2 and incompatible trace elements, as well as of the standards of abundance of REE, these volcanic rocks had been divided in two groups: Paranapanema and Pitanga. / Mestre

Submitted by NUNO MANUEL MARTINHO VIEIRA null (nuno_ksudachix@hotmail.com) on 2017-07-08T09:52:07Z No. of bitstreams: 1 Dissertação Final - Nuno Vieira FINAL.pdf: 15615486 bytes, checksum: 943b208c4b937916de3dee0b7004da7a (MD5) / Approved for entry into archive by Monique Sasaki (sayumi_sasaki@hotmail.com) on 2017-07-13T19:13:50Z (GMT) No. of bitstreams: 1 vieira_nmm_me_rcla.pdf: 15615486 bytes, checksum: 943b208c4b937916de3dee0b7004da7a (MD5) / Made available in DSpace on 2017-07-13T19:13:50Z (GMT). No. of bitstreams: 1 vieira_nmm_me_rcla.pdf: 15615486 bytes, checksum: 943b208c4b937916de3dee0b7004da7a (MD5) Previous issue date: 2017-04-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / As rochas ácidas da Província Magmática do Paraná (PMP) cobrem cerca de 2,5% do volume total do vulcanismo intracontinental ocorrido durante o Cretáceo Inferior, o que levou à abertura do Atlântico Sul. As análises petrográficas e o estudo da química mineral dos principais constituintes minerais, plagioclásio, piroxênio (orto e clino) e Ti-magnetita, das rochas ácidas do tipo Palmas (ATP) e ácidas tipo Chapecó (ATC), permitiram obter dados inéditos e correlacionar, com maior rigor, os vários magmas-tipo que essas rochas geraram. Foi possível descriminar a mineralogia distinta do grupo Palmas, ao que diz respeito aos cristais de piroxênio, assim como as heterogeneidades geoquímicas deste mesmo grupo e de Chapecó. Ortopiroxênio é exclusivo das rochas ATP e especificamente do magma-tipo Caxias do Sul. Os clinopiroxênios, pigeonita e augita são comuns em todos os subtipos das ácidas, porém, esta última está ausente da associação mineralógicas das rochas do magma-tipo Santa Maria (ATP). Com o estudo detalhado da relação mineralógica entre os cristais permitiu inferir sobre a sequência de cristalização dos piroxênios e, por conseguinte das rochas tipo Palmas. As feições texturais, dados de química mineral e (raros) de geotermobarometria obtidos nas rochas ATP e ATC sugerem que os minerais presentes nestas rochas não estão em equilíbrio com o líquido que gerou a rocha hospedeira. As feições petrográficas encontradas nos cristais de piroxênio e plagioclásio, tais como, bordas corroídas, texturas corona e de embaiamento pela matriz, em “peneira” (sieve texture) entre outras, indicam o desiquilíbrio destes minerais com o líquido que gerou a matriz. Os valores de coeficiente de distribuição (Kd) desses minerais também mostram o desiquilíbrio com a rocha total e sugerem um provável equilíbrio com líquidos de composição menos evoluída, tais como rochas básicas (i.e. basaltos) e/ou rochas intermediárias (i.e. andesitos). Com todos estes dados considera-se que grande maioria dos feno e microfenocristais, principalmente de piroxênio, e subordinadamente, plagioclásio, sejam antecristais, e assim teriam sido gerados no mesmo sistema magmático mas em líquidos com graus de diferenciação e/ou evolução diferentes. / The acid rocks of the Paraná Magmatic Province (PMP) cover about 2.5% of the total volume of intracontinental volcanism that occurred during the Lower Cretaceous, which led to the opening of the South Atlantic. Petrographic analyzes and the study of mineral chemistry of the main Palmas acid type (ATP) and Chapecó acid type rocks (ATC), made it possible to obtain unpublished data and correlate, with greater rigor, the various types of magmas these rocks generated. It was possible to discriminate the mineralogy distinct from the Palmas group, as regards the pyroxene crystals, as well as the geochemical heterogeneities of this group and Chapecó group. Orthopyroxene crystals are unique to ATP rocks and specifically to the Caxias do Sul magma-type. Clinopyroxenes crystals, pigeonite and augite, are very common in all acidic subtypes, but the latter is absent from the mineralogical association of the Santa Maria magma-type rocks (from ATP). With the detailed study of the mineralogical relationship between these crystals allowed us to infer about the crystallization sequence of the pyroxenes and, consequently, of the Palmas group. The textural features, mineral chemistry data and (rare) geothermobarometry data obtained in the ATP and ATC rocks suggest that the minerals present in these rocks are not in equilibrium with the liquid that generated the host rock. The petrographic features found in pyroxene and plagioclase crystals, such as corroded edges, corona and matrix impregnation, "sieve texture", among others, indicate the disequilibrium of these minerals with the liquid that generated the matrix. The distribution coefficient (Kd’s) values of these minerals also show unbalance with total rock and suggest a probable equilibrium with less evolved composition liquids, such as basic rocks (e.g., basalts) and / or intermediate rocks (e.g., andesites). With all these data it is considered that a great majority of the phenocrysts and microphenocrysts, mainly of pyroxene, and subordinately, plagioclase, are both anticrystals, and thus they would have been generated in the same magmatic system but in liquids with different degrees of differentiation and / or evolution.

Os derrames da Formação Serra Geral fazem parte de uma grande província ígnea continental situada no sul do Brasil e em parte do Uruguai, Paraguai e Argentina, são portanto muito bem conhecidos e estudados, no entanto as pesquisas geralmente são voltadas para os minerais primários da rocha, excluindo os argilominerais que são considerados como produtos de alteração. Este trabalho é um estudo voltado para a caracterização e entendimento dos argilominerais presentes em basaltos da Formação Serra Geral na região situada entre os municípios de Frederico Westphalen, Iraí, Caiçara, Ametista do Sul e Planalto. Os derrames da região foram contabilizados e estudados através de um levantamento em perfiís de estradas, onde um dos deles foi escolhido como estudo de caso por conter grandes quantidades de argilominerais, especialmente celadonita que é o principal foco de estudo deste trabalho. As técnicas utilizadas consistiram em análises petrográficas em microscopia ótica e microscopia eletrônica de varredura (MEV), além de difratometria raios X (DRX), espectrometria de infravermelho por transformada de Fourier (FTIR) e espectrometria Mössbauer em argilominerais e celadonitas retiradas manualmente de vesículas. As análises químicas das rochas e dos minerais foram realizadas através das técnicas de fluorescência de Raios X e microssonda eletrônica, para análise de elementos maiores, e ICP-MS para elementos traços. Foi identificada uma correlação entre o litotipo pahoehoe de derrame e a presença da celadonita que ocorre em grandes proporções, preenchendo vesículas, fraturas e rodeando geodos. As análises químicas revelaram uma variação composicional da borda da vesícula para o centro e diferenças químicas entre as celadonitas encontradas dependendo do local de coleta, mesmo ocorrendo em um mesmo derrame. A caracterização microtextural das celadonitas e esmectitas revelaram padrões de precipitação em um sistema de equilíbrio com os minerais primários da rocha, sugerindo assim uma precipitação pós-magmática. / The flows of the Serra Geral Formation are part of a continental large igneous province located at southern of Brazil and part of Uruguay, Paraguay and Argentina, are well known and studied, however researches are generally directed to the primary rock minerals, excluding the clay minerals which are considered as products of alteration. This work is a study at the characterization and understanding of the clay minerals present in basalts of the Serra Geral Formation in the region located between the cities of Frederico Westphalen, Iraí, Caiçara, Ametista do Sul and Planalto. The flows of the region were counted and studied through road profiles lifting, where one of those was chosen as a study case because the large amounts of clay minerals, mainly celadonites, which is the focus of this study. The techniques used consisted of petrographic analyzes using optical and scanning electron microscopy (SEM), powder X - ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR) and Mössbauer spectrometry in clays manually removed from vesicles. The chemical analyzes of rocks and minerals were performed using X-Ray fluorescence and electron microprobe for verification of major elements and ICP-MS for trace elements. A correlation was identified between pahoehoe litotype and the celadonite presence, which occurs filling vesicles, fractures and surrounding geodes. The chemical analyzes shows a compositional variation at the border towards the center of the vesicle and chemical differences between the celadonites depending on the place of gathering, even occurring in the same effusion. The microtexural characterization of celadonites and smectites revealed precipitation patterns in a system of equilibrium with the rock primary minerals, thus suggesting port-magmatic precipitation.

FundaÃÃo de Amparo a CiÃncia e Tecnologia de Pernambuco / A relaÃÃo entre o Arco MagmÃtico de Santa QuitÃria (AMSQ), DomÃnio Cearà Central da ProvÃncia Borborema, e as sequÃncias de rochas metassedimentares marginais ao mesmo, merece atenÃÃo quanto ao estabelecimento do arcabouÃo evolutivo paleogeogrÃfico e geotectÃnico desta ampla feiÃÃo. O presente trabalho foi realizado ao longo de 03 (trÃs) perfis transversais ao arco, de maneira a analisar por meio de dados isotÃpicos e litogeoquÃmicos a proveniÃncia das rochas metassedimentares acima mencionadas. Engloba litotipos orto e paraderivados pertencentes ao AMSQ, ao Grupo Cearà (Unidades Canindà e IndependÃncia) e ao Embasamento policÃclico. Inseridos no AMSQ, granitos neoproterozÃicos associados a fase tangencial sÃo representados na Ãrea de pesquisa por monzogranito e quartzo monzonito. Diagramas multi-elementos assinalam para as ortoderivadas uma forte anomalia negativa de P em todas as amostras, o que pode refletir o fracionamento da apatita. Anomalias negativas de Sr e Ti nos granitos podem ser atribuÃdas ao fracionamento de plagioclÃsio e de Nb nos ortognaisses pode ser indicativo de contribuiÃÃo de fontes crustais no processo magmÃtico. As amostras de proveniÃncia sedimentar incluem litologias predominantemente Ãcidas tendo como possÃveis protÃlitos folhelhos e grauvacas. Os valores de Eu/Eu* nestas rochas variam entre 0.38-0.82, semelhante ao padrÃo do PAAS (Pos-Archean AustrÃlia Share), inferindo derivaÃÃo crustal a estas. A seu turno, a razÃo (Gd/Yb)N com valores entre 1.1 e 1.9 (<2.0), sendo indicativo de derivaÃÃo de rochas pÃs-arqueanas. Idades modelo TDM em rocha total com intervalo entre 1.25Ga e 2.41Ga indicam participaÃÃo de fontes mÃltiplas na formaÃÃo dos terrenos neoproterozÃicos. Valores de &#400;Nd(t) negativos e &#400;Sr(t) positivos indicam para a maioria das amostras uma marcada participaÃÃo de fontes metassedimentares e/ou meta-Ãgneas com longos perÃodos de residÃncia crustal na gÃnese destas Ãltimas. Todas as amostras sÃo de derivaÃÃo continental, cujo grau de retrabalhamento infere a estas, mistura e heterogeneidade das crostas envolvidas durante o Ciclo Brasiliano. Em termos geocronolÃgicos, idades U-Pb em zircÃo com intervalos entre 2.39 e 623.7Ma obtidas para rochas pertencentes as Unidade Canindà e IndependÃncia de 807 Ma sugerem fonte mÃltipla para a gÃnese das rochas. Tais caracterÃsticas podem ser atribuÃdas à ocorrÃncia dos diversos eventos geotectÃnicos regionais e envolvendo a participaÃÃo de terrenos arqueanos (pouca contribuiÃÃo); paleoproterozÃicos (maior contribuiÃÃo e com participaÃÃo de terrenos do tipo TTG); do perÃodo de rifteamento 1.7 â 1.8 Ga; uma participaÃÃo bem marcada do evento Brasiliano e ainda, possÃvel envolvimento de faixa transversal mesoproterozÃica. As idades U-Pb em zircÃo obtidas para as amostras GH001 (2.39Ga) e GH017 (2.15Ga) (Unidade CanindÃ) permitem sugerir que estas representam âporÃÃesâ ou âjanelasâ do embasamento, sugestiva da presenÃa de novas Ãreas paleoproterozÃicas no contexto geolÃgico da Ãrea de estudo. / The relationship between the Santa QuitÃria Magmatic Arc - AMSQ, Cearà Central Domain (northern portion of the Borborema Province), and the sequences of marginal metasedimentary rocks to the arc deserves attention on the establishement of paleogeographic and geotectonic framework evolution of this broad feature. The presente paper was realized over three (03) sections cross to the arc, in order to analyze through isotopic and lithogeochemical data the provenance of the above-mentioned metasedimentary rocks. It includes para and orthoderivative lithologies belonging to AMSQ, to Grupo Cearà (Canindà and IndependÃncia Units) and to polycyclic basement. Inserted in AMSQ, neoproterozoic granites associated with tangential phase are represented in research by monzogranite and quartz monzonite. Multi-elements diagrams signal on the orthoderivated a strong negative anomaly of P in all samples, wich may reflect the fractionation of the apatite. Negative anomalies of Sr and Ti in granites can be attributed to the fractionation of plagioclase and the Nb in orthogneisses may be the indicative of crustal sources contribution to the magmatic process. The samples of sedimentary origin include lithologies predominantly acidic having as possible protolith shales and greywacke. The Eu/Eu* values in those rocks range from 0.38 to 0.82, similar to the patterns of PAAS (Pos-Archean AustrÃlia Share), implying in crustal derivation on these. In its turn, the reason (Gd / Yb)N values between 1.1 and 1.9 (<2.0), being indicative of derivation of post-Archean rocks. Whole-rock Sm-Nd isotopic data gave TDM ages interval between 1.25Ga and 2.41Ga indicate participation from multiple sources in the formation of neoproterozoic land. Negative values of &#400;Nd(t) and positive values of &#400;Sr(t) indicate for most of the samples a marked participation of metasedimentary sources and / or meta-igneous with long periodes of crustal residence in the genesis of those. All samples are continental derivation, whose degree of reworking inferred to, mixing and heterogeneity of crusts involved during the Brasiliano Cycle. In geochronological terms, ages of U-Pb in zircon with intervals between 2.39 and 623.7Ma obtained from rocks of the Canindà e IndependÃncia Unitis with 807 Ma suggest multiple source for the genesis of the rocks. Such characteristics can be attributed to the occurrence of several regional geotectonic events and involving the participation of Archean terrains (little contribution); paleoproterozoic (greater contribution and participation of TTG land type); the rifting period 1.7 - 1.8 Ga; a marked participation of the Brasiliano event and further possible involvement of mesoproterozoic cross track. The ages of U-Pb in zircon obtained for the samples GH001 (2.39Ga) and GH017 (2.15Ga) (Canindà Unit) allow us to suggest that these represent "parts" or "windows" of the basement, suggestive of the presence of new areas paleoproterozoic in the geological context on the area of study.

Submitted by Sáboia Nágila (nagila.saboia01@gmail.com) on 2016-07-29T14:37:42Z No. of bitstreams: 1 Dissertação- Antonio Charles da Silva Oliveira.pdf: 18569379 bytes, checksum: e36fa34d61be9f4678a531c17062a3b9 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-08-26T13:24:57Z (GMT) No. of bitstreams: 1 Dissertação- Antonio Charles da Silva Oliveira.pdf: 18569379 bytes, checksum: e36fa34d61be9f4678a531c17062a3b9 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-08-26T13:27:42Z (GMT) No. of bitstreams: 1 Dissertação- Antonio Charles da Silva Oliveira.pdf: 18569379 bytes, checksum: e36fa34d61be9f4678a531c17062a3b9 (MD5) / Made available in DSpace on 2016-08-26T13:27:42Z (GMT). No. of bitstreams: 1 Dissertação- Antonio Charles da Silva Oliveira.pdf: 18569379 bytes, checksum: e36fa34d61be9f4678a531c17062a3b9 (MD5) Previous issue date: 2016-04-07 / Não informada / In the SW Amazonas State the plutonic-volcanic and sedimentary rocks were grouped in different petrotectonic associations: Juruena Basement (JBA), Juruena Supracrustal Suquence (JSSA), Post-Juruena Volcano-plutonism (PJVPA) and Post-Juruena Sedimentary Sequence (PJSSA). The JBA and JSSA (1.81–1.74 Ga), are arc magmatic-related, whereas the PJVPA (1.64–1.53 Ga) and PJSSA (1.74–1.08 Ga) define the main post-orogenetic events in this region. Magnetic data analysis show at least three patterns, named in relative chronologic, as deep linear anomalies with ENE-WSW trend (L0); linear shallow anomalies with NW-SE (L1) and NE-SW (L2) trends. The relationship of superposition suggests that L1 cross-cut L0, and both are transposed by L2 pattern. Geological-structural studies point out three structural styles, two them belongs to a NW-SE deformational belt: 1) D1 – banding folded structures from gneisses (upper amphibolite, 1.52 Ga); and 2) D2 – mylonitic foliation and schistosity structures in temperature of ~350ºC (greenschist, 1.48-1.46 Ga). The third structural style (D3) has ENE-WSW and NE-SW trends, well-defined cataclastic zones generated under temperature <350ºC (lower greenschist, 1.32 Ga). These structural styles have a correlation with main crustal reworking events of Rondônia-Juruena Provínce: a) L0 magnetic anomalies and S1 polydeformational lineaments - generated in the collisional event (1.64 Ga) responsible by Juruena magmatic arc and Tapajós-Parima continent amalgamation; b) L1 magnetic anomalies and S2 lineaments - related to the another collisional event (1.52 Ga), responsible by Tapajós-Parima and Juruena-Jamari terranes collage; c) L2 magnetic anomalies and S3 lineaments - related to Sunsás Orogenic Cycle, represented by Candeias Orogeny (1.37–1.32 Ga). / No sudeste do estado do Amazonas afloram rochas plutono-vulcânicas e sedimentares (Província Rondônia-Juruena, 1,81–1,51 Ga), agrupadas em associações petrotectônicas: Embasamento Juruena (APEJ), Sequência Supracrustais Juruena (APSSJ), Vulcano- Plutonismo Pós-Juruena (APVPJ) e Sequência Sedimentar Pós-Juruena (APSPJ). As APEJ e APSSJ marcam a geração de arcos magmáticos (1,81–1,74 Ga), enquanto as APVPJ (1,64– 1,53 Ga) e APSPJ (1,74–1,08 Ga) definem eventos pós-orogênicos. Dados aeromagnéticos identificaram o arcabouço estrutural regional definido por três padrões: L0 – anomalias profundas lineares (ENE-WSW), L1 e L2 – anomalias rasas lineares respectivamente com direções NW-SE e NE-SW. As relações de superposição mostram L1 truncando L0 e ambos são interceptados por L2. Estudo geológico-estrutural definiu três estilos estruturais, sendo dois deles com direção NW-SE: 1) D1 - bandamento gnáissico dobrado (anfibolito superior, 1,52 Ga) e 2) D2 - foliação milonítica e xistosidade geradas sob temperaturas de aproximadamente 350ºC (xisto verde, 1,48-1,46 Ga). O terceiro estilo estrutural D3 (ENEWSW a NE-SW) apresenta zonas cataclásticas geradas em temperaturas inferiores a 350ºC (baixo xisto verde, 1,32 Ga). Esses estilos deformacionais apresentam relação com os eventos de retrabalhamento da crosta Rondônia-Juruena: a) anomalias magnéticas L0 e estruturação D1 - geradas em evento colisional (1,64 Ga) relacionado à colagem do arco Juruena com a crosta Tapajós-Parima; b) anomalias magnéticas L1 e estruturação D2 - associadas a evento deformacional (1,52 Ga) atribuído a colisão entre os terrenos Tapajós- Parima e Juruena-Jamari; c) anomalias magnéticas L2 e evento deformacional D3 - correlacionadas ao Ciclo Orogênico Sunsás, representado na região pela Orogenia Candeias (1,37–1,32 Ga).

Les plus anciens gisements d’uranium connus sur Terre sont les gisements de type paléo-placer hôtes de conglomérats à cailloux de quartz d’âge compris entre 3,09 et 2,2 Ga. Ces gisements représentent les reliques de l’ancienne croûte continentale archéenne maintenant érodée. L’origine de leurs concentrations primaires, correspondant à des accumulations de grains détritiques d’uraninite, est toujours sujette à controverse et la nature et les processus de formation des roches sources archéennes demeurent incertains.Ce travail présente l’analyse minéralogique et géochimique détaillée des minéralisations de différents paléo-placers (Witwatersrand en Afrique du Sud, Elliot Lake au Canada et séries Jatuliennes en Russie) ainsi que de granitoïdes archéens et paléoprotérozoïques enrichis en uranium (séries granitiques calco-alcalines à potassiques du craton de Kénéma Man en Guinée, granites tardi-orogéniques du craton de Pilbara en Australie Occidentale, pegmatite peralumineuse de Tanco du Bouclier Canadien et pegmatites à uraninite du Bouclier Baltique en Finlande et Russie). L’étude comparative de ces roches uranifères échantillonnées tout autour du globe prouve à la fois i) l’existence précoce (>3,1 Ga) de granitoïdes différenciés produits par la fusion partielle d’une croûte pré-enrichie tels que des granites peralumineux ou de type S, ii) nécessairement la présence d’un mécanisme permettant de produire ce type de granites comme les zones de subduction ou de collision générées par le mouvement des plaques tectoniques, iii) l’origine magmatique des uraninites thorifères des paléo-placers, iv) la présence d’une atmosphère réductrice avant 2,2 Ga permettant la préservation des uraninites durant leur transport, v) et finalement l’augmentation de l’oxygène libre dans l’atmosphère paléo-protérozoïque à partir de 2,2 Ga provoquant la disparition des paléo-placers uranifères en faveur de l’altération et de l’oxydation des concentrations préexistantes, de la remobilisation de l’uranium et de la formation de dépôts secondaires / The oldest known uranium deposits on the Earth are the paleoplacer-type deposits hosted in quartz-pebble conglomerates from 3.09 to 2.2 Ga in age. These deposits are representative of the ancient Archean continental crust now eroded. The origin of the primary ores corresponding to accumulation of detrital uraninite is still controversy and the nature and forming processes of the Archean source rocks remain uncertain.This work provides the detail mineralogical and geochemical analysis of mineralization from different paleoplacer-type deposits (Witwatersrand in South Africa, Elliot Lake in Canada and the Jatulian series in Russia) and from Archean and Paleoproterozoic U-enriched granitoids (calco-alkaline to potassic granite series from the Kenema Man Craton in Guinea, late-orogenic granites from the Pilbara Craton in West Australia, the Tanco pegmatite from the Canadian Shield and uraninite bearing pegmatites from the Baltic Shield in Finland and Russia). The comparative study of these worldwide uraniferous rocks prove either i) the existence of highly differentiated granitoids produced by the partial melting of a pre-enriched crust as peraluminous and S-type granites in early time (>3.1 Ga), ii) obviously the presence of an effective mechanism to produce such granites as tectonic plate systems with subduction or collisional zones, iii) the magmatic origin of the thorian uraninites in paleoplacers, iv) the efficiency of a reductive atmosphere prior to 2.2 Ga permitting the preservation of uraninite during transportation, v) and finally the rise of the oxygen-free level in the paleoproterozoic atmosphere providing the disappearance of uraniferous paleoplacers in favour of weathering, oxidation of pre-existing concentrations, remobilization of uranium and formation of secondary deposits

abstract: Volcanic eruptions can be serious geologic hazards, and have the potential to effect human life, infrastructure, and climate. Therefore, an understanding of the evolution and conditions of the magmas stored beneath volcanoes prior to their eruption is crucial for the ability to monitor such systems and develop effective hazard mitigation plans. This dissertation combines classic petrologic tools such as mineral chemistry and thermometry with novel techniques such as diffusion chronometry and statistical modeling in order to better understand the processes and timing associated with volcanic eruptions. By examining zoned crystals from the fallout ash of Yellowstone’s most recent supereruption, my work shows that the rejuvenation of magma has the ability to trigger a catastrophic supereruption at Yellowstone caldera in the years (decades at most) prior to eruption. This provides one of the first studies to thoroughly identify a specific eruption trigger of a past eruption using the crystal record. Additionally, through experimental investigation, I created a novel diffusion chronometer with application to determine magmatic timescales in silicic volcanic systems (i.e., rhyolite/dacite). My results show that Mg-in-sanidine diffusion operates simultaneously by both a fast and slow diffusion path suggesting that experimentally-derived diffusion chronometers may be more complex than previously thought. When applying Mg-in-sanidine chronometry to zoned sanidine from the same supereruption at Yellowstone, the timing between rejuvenation and eruption is further resolved to as short as five months, providing a greater understanding of the timing of supereruption triggers. Additionally, I developed a new statistical model to examine the controls on a single volcano’s distribution of eruptions through time, therefore the controls on the timing between successive eruptions, or repose time. When examining six Cascade volcanoes with variable distribution patterns through time, my model shows these distributions are not result of sampling bias, rather may represent geologic processes. There is a robust negative correlation between average repose time and average magma composition (i.e., SiO2), suggesting this may be a controlling factor of long-term repose time at Cascade volcanoes. Together, my work provides a better vision for forecasting models to mitigate potential destruction. / Dissertation/Thesis / Doctoral Dissertation Geological Sciences 2020

There are many examples worldwide were fossil magmatic intrusions influence the local water and energy supply. Due to that intrusions can act as a conductor and a reservoir, but also as a barrier for fluids and gases in the ground. The decisive feature between conductor or barrier in an intrusion is its fracture network. Hence it is of paramount importance to characterize an intrusion’s fracture network and thus its permeability. However, other than through boreholes magmatic intrusions are rather inaccessible and very little is known about their influence on aquifers and reservoir rocks in the underground. It is therefore important to increase the knowledge of magmatic intrusion by investigate the intrusions that are accessible for us at ground surface. In this study, photos from a case study about the Sosa dyke have been used to map and characterizes the fractures of the Sosa dyke, which is an accessible vertical magmatic intrusion and a part of the Chachahuén volcano complex in the southwestern parts of Argentina. The photos that were used are taken with an UAV (unmanned aerial vehicle), and to analyze the photos, map the fractures and produce the results, software as Agisoft Metashape, MOVE™ and MATLAB with the toolbox FracPaQ was used. The intrusion has two distinct fracture sets, one that is perpendicular to the intrusion margins and one that stretches parallel with the intrusion. The connectivity of the fractures is low, and since the permeability of the fractures largely depends on the connectivity, it is also low. The fracture set that is perpendicular to the intrusion margin is what’s called cooling fractures, which is created as the magma in the intrusion cools. This causes the magma to contract and break, forming fractures perpendicular to the inward migrating solidification front. The fracture set that is parallel with the intrusion is caused by minerals in the magma flow being affected by friction from the intrusion margins. This causes the minerals in the magma to elongate in the direction of flow along the sides of the dyke, creating foliation, enabling fractures to propagate along. These fracture sets are poorly connected which concludes that the mapped area of the Sosa-dyke has a low permeability. / I hela världen finns det många exempel där stelnade magmatiska intrusioner påverka ett områdes vatten och energiförsörjning, på grund av att intrusioner kan agera som ledare och reservoarer men också som barriärer för vätskor och gaser in marken. Den avgörande faktorn mellan ledare och barriärer i en intrusion är dess spricknätverk. Därför är det viktigt att kartlägga och karakterisera en intrusions spricknätverk och därmed också få en uppfattning om dess permeabilitet. Magmatiska intrusioner är förutom genom borrhål ofta svåråtkomliga, det finns därför väldigt lite information om hur de påverkar akviferer och reservoarer i marken. Det är därför viktigt att öka kunskapen om magmatiska intrusioner genom att undersöka intrusionerna som är tillgängliga vid markytan. I denna studie har bilder från en fallstudie om Sosa Intrusionen använts för att kartera och karakterisera sprickor i Sosa intrusionen. Det är en vertikal magmatisk intrusion som är synlig på markytan, och en del av Chachahuén vulkan komplexet i sydvästra Argentina. Bilderna som användes är tagna med en UAV( unmanned aerial vehicle), och för att analysera bilderna, kartera sprickorna och producera resultaten, användes programmen Agisoft Metashape, MOVE™ och MATLAB med FracPaQ verktyget. Intrusionen har två distinkta sprickgrupper, en som är vinkelrät mot intrusionens kanter och en som går parallellt med kanterna. Konnektivitet mellan sprickorna är låg och eftersom permeabiliteten påverkas av konnektiviteten är den också låg. Sprickgruppen som är vinkelrätt mot intrusionskanten är så kallade kylningssprickor och bildas nät magman i intrusionen svalnar. Det leder till att magman kontraherar och spricker, och bildar sprickor som går inåt mot stelningsgränsen och därmed vinkelrätt mot intrusionskanten. Sprickgruppen som går parallellt med intrusionen bildas av att mineral i magmaströmmen påverkas av friktion från intrusionskanterna. Det gör att mineralen lägger sig och sträcks ut i samma riktning som magmaflödet, vilket när magman stelnar bildar svaghetszoner som sprickor kan fortplanta sig i. Dessa sprickgrupper har låg konnektivitet vilket gör att slutsatsen blir att det karterade området av Sosa intrusionen har låg permeabilitet.

This thesis presents a 40Ar/39Ar geochronological analyses of biotite from thin ductile shear zones in Paleoproterozoic granulite-facies gneisses from the Ellesmere-Devon crystalline terrane, Nunavut, Canada. The gneisses are part of the Paleoproterozoic Thelon tectonic zone. U-Pb dates of zircon show that the gneisses have magmatic protolith ages ranging from 2007–1958 Ma. The quartzofeldspathic gneisses in southeast Ellesmere Island display centimeter-scale E- to NE-striking sinistral and dextral mylonite zones offsetting pegmatitic dikes that are the last stage of ductile deformation of the basement rocks. Samples were taken from nearshore outcrops at Hayes Fiord, Pim Island, NE of the Leffert Glacier and NW of Cape Isabella. Biotite clusters replace orthopyroxene as the result of post-granulite facies metamorphism in the gneisses. Biotite in mylonitic and ultramylonitic fabrics is found as flattened clusters and also as individual crystals defining shear bands related to mylonitization. Eight samples were dated, including biotite from five mylonites, one deformed pegmatite, one tonalite and muscovite from a pegmatite. Major element X-ray maps demonstrate that the biotite is chemically homogenous. Backscattered electron images and electron dispersive spectroscopy via scanning electron microscopy confirm that biotite lacks intercrystalline layering with other K phases. Step-heating analysis of mica at the University of Vermont yielded Paleoproterozoic 40Ar/39Ar ages. The apparent age spectra form plateau ages in all but one mylonite sample. Biotite from a protomylonite was 2051 ± 26 Ma, older than the protolith ages obtained from U-Pb zircon geochronology, and most likely indicates excess Ar. Pegmatitic muscovite was 1977 ± 35 Ma. Biotite dates range from 1874 ± 13 Ma to 1838 ± 14 Ma for the five mylonites without excess Ar. Biotite dated from ductile shear zones signals the latest deformation in the basement, which was active as early as 1887 Ma.

One of the most important volatiles in magma is water. In magma, water is incorporated in both the melt and in crystals, including hydrous and nominally anhydrous minerals (NAMs). The purpose of this study is to determine the role of magmatic water content in controlling volcano explosivity especially at Merapi volcano, Indonesia, which is one of the most active volcanoes in the world. Here I apply clinopyroxene from two types of eruption products, lava and ash, to test the magmatic water content in the Merapi 2010 eruption. Both oriented and unoriented crystals were analysed using Fourier-Transformed Infrared (FTIR) spectroscopy to establish the clinopyroxene’s crystal water content. By combining the water content of clinopyroxene and geochemical data obtained from EPMA analysis, the magmatic water content is then estimated by inserting the data into the equation of O’Leary et al. (2010) [lnD= -4.2(60.2)16.5(60.5) VI[Al3+]-1.0(60.2) [Ca2+]]. I also investigated clinopyroxene crystals that were experimentally rehydrated, including four oriented crystals from a Merapi 2010 eruption ash sample annealed at a temperature of 700°C and pressure of 1 atm. Magmatic water contents of Merapi 2010 from rehydration experiments were then compared to the Merapi 2006 magmatic water content which were treated under the same conditions. The results revealed a wide variation between samples and among crystals taken from the same sample. However, oriented samples yielded a smaller variation between minimum and maximum clinopyroxene crystal water content and, overall, ash samples yielded higher water content in clinopyroxene than lava samples. The rehydration experiment significantly amplified clinopyroxene crystal water content by 3 to 7-fold compared to the result without the rehydration procedure. Comparison of data between the 2006 and 2010 Merapi eruptions demonstrates that there was a significant difference in magmatic water contents with the 2010 eruption displaying more than twice as much magmatic water than the 2006 eruption. The result implies that magmatic water plays potentially a crucial role in controlling explosivity of Merapi eruptions. / Indonesien är det land i Världen som har den största befolkningen som lever inom 100 km av en aktiv vulkan. Merapi är en av de mest farliga vulkanerna i Indonesien, som också är en av de mest aktiva vulkanerna i Världen och ligger på ön Java runt 15-25 km från Yogyakarta med en total befolkningstäthet på 1000 personer per kvadratkilometer. Utbrott från Merapi har dödat cirka 5000 personer under de senaste 500 åren. Således är det viktigt att studera hur vulkanen beter sig och orsaken till utbrotten för att kunna vita förebyggande åtgärder för att minska antalet dödsfall eller till och med undvika dödsfall helt. Vulkanutbrott kontrolleras av många faktorer, en av faktorerna är flyktiga ämnen i magman och en av de viktigaste flyktiga ämnen är vatten. Det här projektet syftar till att ta reda på vattnets roll på explosiviteten hos utbrotten genom att undersöka eruptiva produkter från utbrotten av Merapi under 2006 och 2010 med hjälp av Fourier-Transformed Infrared (FTIR) spektroskopi. Experimentet använder normalt vattenfria mineraler (NAMs) så som klinopyroxen men vatten kan införlivas i NAMs genom att binda väte i kristallgitteret under kristalltillväxten. Tidigare studier har visat att vattenhalten i klinopyroxenkristall skulle kunna användas för att beräkna magmatisk vattenhalt och därmed jämföra den magmatiska vattenhalt mellan olika utbrott med olika explosivitet i samma vulkan, vilket kan indikera hur vattenhalten påverkar vulkanutbrotten. Magmatiskt vatteninnehåll beräknat utifrån klinopyroxenvattenhalten visade en variation mellan de undersöka proverna från samma utbrott, varför ytterligare undersökning genom rehydreringsexperiment gjordes genom annealing av proverna vid en temperatur av 700 °C och tryck vid 1 atm. Även om det var variation i magmatisk vattenhalt mellan proverna, så har utbrotten av Merapi under 2010 högre magmatiskt vatteninnehåll än utbrottet under 2006 med 3-7 gånger. Sammantaget har Merapi 2010 utbrottet högre explosivitet och högre magmatisk vattenhalt än 2006 utbrottet, vilket innebär att högre vattenhalt ger högre explosivitet. På detta sätt kontrollerade vattnet vulkanens explosivitet för Merapivulkanen.Nyckelord: Merapi vulkan, NA