Orientador: José Marques Júnior / Coorientador: Angélica Santos Rabelo de Souza Bahia / Banca: Adriana Aparecida Ribon / Banca: Newton La Scala Junior / Resumo: Planalto Ocidental Paulista (POP) é uma das principais áreas de cultivo de citros do país, representando cerca de 80% da produção nacional, tendo ainda grande participação na produção de açúcar e álcool. A caracterização e quantificação mineralógica dos solos desta região torna-se importante para melhor entendimento dos processos pedogênicos do solo, e uso de melhores práticas de manejo. Por meio de ferramentas como a geoestatística é possível entender a relação entre a mineralogia do solo e as formas da paisagem, indicando a variabilidade espacial dos dados e a dependência entre os atributos pedogênicos e os geomórficos da região. Assim, o presente trabalho teve como objetivos: a) caracterizar os teores e a cristalinidade da caulinita (Ct) e gibbsita (Gb), e suas relações com os diferentes compartimentos geológicos e geomorfológicos do POP; b) e avaliar o potencial de diferentes metodologias aplicadas às curvas espectrais, dada pela técnica de espectroscopia de reflectância difusa (ERD), para estimativa da razão entre Ct e Gb, e caracterizar a variabilidade espacial da razão para o POP. Foram coletadas 600 amostras de solo georreferenciadas, próximas às principais rodovias do estado de São Paulo. Para quantificação dos teores e cristalinidade da Ct e Gb foi utilizada a técnica de difratometria de raios X (DRX) e a metodologia de Rietveld. A quantificação não convencional pela técnica de ERD, foi feita por três metodologias aplicadas às curvas espectrais: contínuo removível, ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The Ouest Paulista Plateau (POP) is one of the main areas of citrus cultivation in the country, accounting for about 80% of the national production, with a large share of sugar and alcohol production. The characterization and mineralogical quantification of the soils of this region becomes important for a better understanding of the soil pedogenic processes, and the use of better management practices. Through tools such as geostatistics, it is possible to understand the relationship between soil mineralogy and landscape forms, indicating the spatial variability of the data and the dependence between the pedogenic and geomorphic attributes of the region. Thus, the present work had as objectives: a) to characterize the contents and crystallinity of kaolinite (Kt) and gibbsite (Gb), and its relations with the different geological and geomorphological compartments of POP; B) and to evaluate the potential of different methodologies applied to the spectral curves, given by the diffuse reflectance spectroscopy (DRS) technique, to estimate the ratio between Ct and Gb, and to characterize the spatial variability of the ratio for the POP. A total of 600 georeferenced soil samples were collected near the main highways in the state of São Paulo. The X-ray diffraction (XRD) technique and the Rietveld methodology were used to quantify the Ct and Gb contents and crystallinity. The unconventional quantification by the DRS technique was done by three methodologies applied to the spectral curves: removable continuous, direct ratio of the valley and minimum regression by partial squares. Data were submitted to descriptive statistics analysis, regression analysis (for comparison between the techniques) and geostatistical analysis, by simple kriging. The geological and geomorphological compartments influence the distribution of Kt and Gb con ... (Complete abstract click electronic access below) / Mestre

Arenitos do Cretáceo Superior da Bacia de Santos correspondem aos principais reservatórios clásticos de hidrocarbonetos da bacia, localizada na margem leste brasileira. Alguns desses arenitos exibem porosidades anormalmente altas, considerando suas atuais profundidades maiores que 4000 m. A preservação da porosidade nesses arenitos, assim como em diversos outros reservatórios clásticos profundos vem sendo atribuída à inibição da cimentação por crescimentos de quartzo e da dissolução por pressão exercida por franjas e cutículas de clorita autigênica. Por esse motivo, o estudo da distribuição espacial e temporal das cloritas, assim como de seus hábitos, relações paragenéticas e condições genéticas, é de grande importância. Os arenitos cretácicos de Santos são arcósios e arcósios líticos, ricos em fragmentos de rochas vulcânicas (FRV). Clorita é o constituinte diagenético mais abundante, ocorrendo principalmente como franjas e cutículas cobrindo os grãos (pore-lining), rosetas preenchendo parcialmente os poros e agregados microcristalinos substituindo grãos. A precipitação de clorita foi favorecida pela presença de cutículas eogenéticas de argila esmectítica, que foram parcialmente preservadas ao longo de contatos intergranulares apertados. Além disso, a composição primária dos arenitos exerceu um controle fundamental na autigênese das cloritas. O enriquecimento de clorita nos arenitos arcósios líticos, ricos em FRV, sugere que esses grãos são uma significativa fonte de íons de Fe e Mg para a precipitação de clorita nesses arenitos. Além dos FRV, minerais pesados instáveis, biotita e intraclastos lamosos atuaram como fonte e/ou substrato para a autigênese da clorita. Adicionalmente à composição primária, a história térmica e de soterramento, assim como o padrão de fluxo de fluidos, certamente tiveram um papel importante na distribuição da diagênese da clorita e na evolução da qualidade dos reservatórios. Prováveis fontes externas de íons devem ter envolvido as reações de transformações de argilominerais esmectíticos em lutitos associados, e a espessa seção de evaporitos Aptianos. Os diferentes hábitos das cloritas exerceram impacto distinto na qualidade dos reservatórios. Cloritas pore-lining inibiram a cimentação por quartzo, isolando as superfícies dos grãos de quartzo e reduzindo a nucleação de crescimentos secundários, contribuindo assim para a preservação da porosidade. No entanto, franjas e cutículas finas e descontínuas não foram capazes de inibir efetivamente a cimentação por quartzo, enquanto que as muito espessas reduziram severamente a permeabilidade dos reservatórios. Rosetas de clorita, por sua vez, não inibiram a cimentação de quartzo e ainda reduziram a porosidade intergranular. Estudos específicos são necessários para um melhor entendimento dos diferentes processos diagenéticos nos arenitos da Bacia de Santos, assim como de sua distribuição temporal, estratigráfica e espacial, de modo a basear o desenvolvimento de modelos que possam efetivamente contribuir para a redução dos riscos durante a exploração por esses reservatórios. / Upper Cretaceous sandstones from the Santos Basin, eastern Brazilian Margin, correspond to the main clastic hydrocarbon reservoirs of the basin. Some of these sandstones show abnormally high porosities, considering their present depths larger than 4000 m. The preservation of porosity in these sandstones, as in other deep clastic reservoirs, has been ascribed to the inhibition of quartz overgrowth cementation and pressure dissolution by rims and coatings of authigenic chlorite. Therefore, the study of the space and time distribution of the chlorites, as well as of their habits, paragenetic relations and genetic conditions, is of great importance. Santos cretaceous sandstones are arkoses and lithic arkoses, rich in volcanic rock fragments (VRF). Chlorite is the most abundant diagenetic constituent, occurring mostly as rims and coatings covering the grains (pore-lining), as rosettes partially filling the pores, and as grain-replacive microcrystalline aggregates. Chlorite precipitation was favored by the presence of eogenetic coatings of smectitic clays, which were partially preserved along tight intergranular contacts. Besides these, the primary composition of the sandstones exerted a key control in chlorite authigenesis. Chlorite enrichment in the lithic arkoses, rich in VRF, suggests that these grains are significant source of Fe and Mg ions for chlorite precipitation in these sandstones. Besides VRF, unstable heavy minerals, biotite and mud intraclasts acted as source or substrate for chlorite authigenesis. In addition to the primary composition, thermal and burial histories, as also the fluid flow patterns, certainly played an important role in chlorite diagenesis and in the evolution of reservoir quality. Probable external ionic sources must have involved the transformation of smectitic clays in associated mudrocks, and the thick section of Aptian evaporites. The diverse chlorite habits exerted distinct impact on the quality of the reservoirs. Pore-lining chlorites inhibited quartz cementation isolating quartz grains surfaces, reducing the nucleation of overgrowths, thus contributing to porosity preservation. However, thin and discontinuous rims and coatings were not able to effectively inhibit quartz cementation, while those very thick severely decreased the permeability of the reservoirs. In turn, chlorite rosettes have not inhibited quartz cementation, but have reduced intergranular porosity nonetheless. Specific studies are required for a better understanding of the diverse diagenetic processes wthin Santos Basin sandstones, as also of their time, stratigraphic and space distribution, in order to support the development of models that may effectively contribute to the reduction of risks during the exploration for these reservoirs.

La formation de patines noires riches en fer et/ou manganèse sur les édifices en grès est un phénomène observé pour une grande variété d’environnements mais qui n’est pas encore totalement compris. Le château de Lunéville, situé dans l’est de la France, est un cas d’étude intéressant puisqu'il présente des patines apparues pour différentes conditions : certaines semblent s’être formées naturellement alors que d’autres se sont développées sur des pierres ayant été exposées à un incendie. Ces dernières ont connu une élévation de leur température de surface, mais ont surtout été soumises à de grandes quantités d’eau lors de l’intervention des pompiers. Ce travail de thèse vise à mieux comprendre le phénomène de formation des patines en étudiant différents faciès de grès prélevés sur le château de Lunéville et en carrière. Afin d’appréhender l’influence des paramètres intrinsèques aux grès, des faciès patinés et non patinés ont été comparés d’un point de vue pétrophysique, chimique et minéralogique en s’appuyant sur des techniques d’analyse de laboratoire (microscopies optique et électronique avec sonde d’analyse dispersive en énergie, diffraction des rayons X, spectrométrie Raman, mesures de perméabilité, porosité et capillarité, ...), et sur de grands instruments (analyses par émission de rayons X induits par des particules (PIXE) sur l’accélérateur de proton AGLAE, analyses en micro-diffraction des rayons X et micro-spectrométrie d’absorption X (XANES) au synchrotron SOLEIL). En complément de cette caractérisation des blocs de pierre, les patines formées dans différents environnements ont également été comparées afin de dégager les paramètres extrinsèques dominants. Enfin, l’aspect dynamique de la libération du manganèse par les grès a été étudié, d’une part en menant des expériences de dissolution pour plusieurs pH, d’autre part en montrant qu’il était possible de recréer une patine de manganèse en laboratoire, par imbibition d’une éprouvette de grès. Les résultats obtenus permettent de proposer un modèle de formation des patines basé sur la dissolution des phases manganésifères initialement présentes dans les grès, puis la migration des ions libérés en solution dans le milieu poreux vers la surface des pierres / The formation of iron and/or manganese black patina on sandstone buildings is a phenomenon observed for various environments but which is not fully understood yet. The palace of Lunéville, in eastern France, is an interesting example because it has patinas that have developed in different conditions : some seem to have grown naturally while others have appeared on stones which were exposed to a fire. These stones experienced an increase of their surface temperature, but most of all, they were subjected to a substantial volume of water as part of attempts to extinguish the fire. The goal of this thesis is to understand the formation of the patinas by investigating different sandstone facies collected from the palace of Lunéville and from quarry. In order to understand the influence of the sandstones intrinsic parameters, the patinated and unpatinated facies were compared from petrophysical, chemical and mineralogical point of view, using laboratory techniques (optical and electron microscopy with energy dispersive X-ray spectroscopy, X-ray diffraction, Raman spectrometry, permeability, porosity and capillarity measurements, ...) and large instruments (Particle Induced X-ray Emission (PIXE) on the AGLAE proton accelerator, X-ray micro-diffraction analysis and X-ray absorption micro spectroscopy (XANES) at the SOLEIL synchrotron). In addition to this characterization, patinas coming from different environments were also compared in order to extract the main extrinsic parameters. Finally, the dynamical aspect of the release of manganese from the sandstones was investigated by conducting dissolution experiments at various pH, and by demonstrating the possibility to recreate a Mn patina in laboratory, using sandstone imbibition techniques. The results allow to propose a model for the patina formation based on the dissolution of the Mn-phases initially present in the sandstones’ bulks, followed by the migration through the porous network towards the surface of the ions released in the solution

At the Castle Creek study area a remarkably well exposed section in the Isaac Formation, Windermere Supergroup, was measured to document potential lateral and vertical changes in facies. Here, a consistent lateral succession of facies was observed consisting of matrix-poor sandstone to clayey sandstone to bipartite bed to sandy claystone, collectively overlain by a thin-bedded turbidite and mudstone cap. These changes are interpreted to reflect particle settling in a negligibly-sheared sand-mud suspension following detachment from the margins of an avulsion jet. Vertically, similar facies stack to form packages 2-7 beds thick implying temporary stabilization of jet-margin dynamics. At a larger scale facies stack to form three stratal assemblages. SA-1: intercalated matrix-rich and matrix-poor strata and SA-2: matrix-rich strata stack vertically and laterally but then are sharply overlain everywhere by classical turbidites of SA-3, indicating a dramatic change from deposition immediately downflow of an avulsion node to conventional levee deposition.

Mapping of the north-eastern portion of the Bird1s River Complex revealed that two large xenoliths composed of pyroclastic rocks and sandstone of the Cave Sandstone Stage have reacted with the dolerite. All the reaction phenomena normally associated with Karroo Dolerite are encountered. These are: (a) Metasomatism during the stage of iron enrichment of the dolerite with the production of a pyroxene-plagioclase metasomatic granophyre (b) Metasomatism during the stage of alkali enrichment of the dolerite with the production of a potassium feldspar adinole C c) Assimilation 'vi th the production of contaminated doleri tes Cd) Fusion 'vi th the production of glassy rocks including buchi tes (e) The production of rheomorphic veins

Magister Scientiae - MSc / The reservoir quality (RQ) of well E-BA1 was characterized using thin sections and core samples in a petrographic study. Well E-BA1 is situated in the Bredasdorp Basin, which forms part of the Outeniqua Basin situated in the Southern Afircan offshore region. Rifting as a result of the break up of Gondwanaland formed the Outeniqua Basin. The Bredasorp Basin is characterized by half-graben structures comprised of Upper Jurassic, Lower Cretaceous and Cenozoic rift to drift strata. The current research within the thesis has indicated that well E-BA1 is one of moderate to good quality having a gas-condensate component. / South Africa

M.Tech. / Artisanal mine of sandstones especially in rural area are facing numerous challenges including the use of inadequate tools for the processing of sandstones. Since the current processing technique has limitations which consist of the use of hammer and chisels, there is a need to develop environmentally friendly and cost effective techniques for the processing of sandstones. In this project, six different sandstones samples (yellowish, blackish, reddish, greenish, greyish and whitish) from QwaQwa rural area were collected and characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM/EDS) and an optical microscope. In addition, physical properties of sandstones were also carried out including compressive strength, dielectric properties and water absorption. Furthermore sandstones samples were irradiated using multi- and single- mode microwave cavities to investigate the effect on the mineralogy of sandstones. The analysis of mineralogical change was carried out using XRD. Additionally a microwave multimode cavity was used to investigate the weight loss of sandstones after being irradiated. A microwave cavity was designed based on the characteristics of sandstones and it was simulated. A photovoltaic solar system was sized to power the microwave cutter. The experimental work was carried out on a laboratory scale. The XRD analysis revealed that quartz was the major mineral present in all sandstones which confirms that QwaQwa sandstones are quartz based sandstones. Feldspar minerals such as illite and albite were also found. Additional minerals were identified at trace level including glauconite, kaolonite, crysobalite and orthoclase. On the other hand, the XRD results of the irradiated samples using a single- and multi- mode cavity for 60 seconds revealed a strong presence of quartz which means no significant changes were observed. However, some minor overlapped peaks suspected to be muscovite (KAl2(Si3Al)O10(OH,F)2) in three samples (blackish, greyish and yellowish) were noticed. XRF study showed that the chemical elements available in the six sandstones samples are: aluminium, calcium, iron, potassium, magnesium, manganese, sodium, phosphorus, silicon and titanium.

The Saints & Sinners Quarry preserves the only known vertebrate body fossils in the Nugget Sandstone and the most diverse fauna known from the Nugget-Navajo-Aztec erg system. The fauna includes eight genera and >18,000 bone and bone fragments assignable to >76 individuals, including theropods, sphenosuchians, sphenodontians, drepanosaurs, procolophonids, and a dimorphodontid pterosaur. Cycadeoid fronds are the only plant fossils. There are two depositional environments at the site – dune and interdune, each consisting of two or more faces. The dune facies are (1) Trough Cross-Stratified Sandstone (TCS) representing dry dunes, and (2) Massive and Bioturbated Dunes (MBD) representing bioturbated, damp dunes. The interdune facies are (1) Wavy Sandstone (WSS) representing wet and damp flats with biofilms and tridactyl tracks, (2) Green Clays and Silts (GCS) representing quiet lacustrine waters, (3) Planar Laminated Sandstone (PLS) representing lacustrine dust and sand storm deposits which grade laterally into (4) Massive Bone Bed (MBB) shoreline deposits. The vertical and lateral relationships of the dune and interdune facies suggests that an interdune flat developed (WSS facies) likely by deflation of dunes down to, or near to, the water table. As the water table rose, a shallow lake developed (GCS facies) and trapped wind-blown sediment during sand storms (PLS Facies). The taxonomically diverse vertebrate fauna suggest a mass die-off occurred, likely due to drought. The carcasses and bones were buried by three distinct depositional events, each a bone bed (MBB facies) - separated by very thin clays (GCS facies). Thereafter the water table dropped resulting in several cm-scale sandstone beds with tridactyl tracks (WSS facies). Then migrating dunes buried the interdune flat. These dunes hosted burrowing invertebrates for a moderate time resulting in the destruction of nearly all primary sedimentary structures (MBD facies). Ultimately, as the area dried further, more dunes migrated over these bioturbated surfaces and the area returned to dune field conditions (TCS facies). The Saints & Sinners site indicates that a previously unrecognized, remarkably diverse vertebrate fauna thrived in wet interdunes of western North America's Late Triassic erg system. A massive-die-off, likely due to a drought, provided a wealth of carcasses and their bones. The dynamic shoreline representing the interface of dunes and standing water provided favorable conditions for rapid burial of small carcasses and the disarticulated bones of larger individuals.

>Magister Scientiae - MSc / With the latest advancements in the Pletmos Basin it is imperative to understand and study how sandstone reservoirs are affected by clay minerals. Clay minerals are an influential component in sandstone reservoirs worldwide and thus have an impact on the reservoir quality and petrophysical properties. The present research was aimed at assessing the effects of clay minerals on the petrophysical properties of sandstone reservoirs from the Offshore Pletmos Basin. This was done by integrating geological (wireline logs and core analysis), geochemical (XRD and pore water chemistry) and petrographical (QEMSCAN and thin section petrography) analysis to highlight the effects of clay minerals on the intrinsic properties (porosity, permeability and fluid saturation) on reservoirs encountered within the two wells (Ga- Q1 and Ga – S1). The results highlight pervasive quartz cementation as well as the presence of clay minerals: Glauconite (Illite group), Kaolinite (Kaolinite group), Clinochlore (Chlorite group) as the dominant clay minerals and Calcite as the dominant cement in both well Ga – Q1 and well Ga – S1. The most abundant clay mineral in both wells is Glauconite. This clay mineral had a more profound effect on the petrophysical parameters compared to the other clay minerals. The clay minerals occur as pore–filling Kaolinite and pore–bridging Glauconite and pore–lining Clinochlore. As a result, the clay minerals affected the pore connectivity (permeability) more than the pore spaces (porosity). This is confirmed by the petrophysical analysis where both wells have extremely low permeability and good porosity values. The study concludes that the presence of Glauconite, Kaolinite, Clinochlore and Calcite in both wells (Ga-Q1 and Ga-S1) had an adverse effect on the permeability more compared to the porosity in sandstone reservoirs. Due to the high volume of clay and high clay mineral content in well Ga-Q1, the petrophysical parameters were more adversely affected compared to well Ga-S1. As a result, we see better petrophysical properties (porosity and permeability) in the sandstone reservoir from well Ga-S1 due to intense bioturbation. The reservoir quality of well Ga-S1 is much better compared to well Ga – Q1 because water saturation averages at 42% and gas saturation averages at 58%, has decent porosity averages at 12% but low permeability ranges of 0, 1 – 4mD. / 2021-09-30

We examined small-displacement faults in the Jurassic Entrada Sandstone adjacent to the Iron Wash Fault, central Utah east of the San Rafael Swell, in order to describe the nature and timing of past fluid movement and deformation in the Entrada Sandstone. Using field studies, microscopy, and X-ray diffraction analysis, we identified mineralized fractures and cementation features in association with deformation bands and fractures at the interface of the Earthy and Slick Rock Members of the Entrada Sandstone. Where the faults cross the Earthy-Slick Rock Member interface, deformation band faults in the Slick Rock Member become opening-mode fractures in the Earthy Member. These fractures are frequently mineralized with calcite, and goethite pseudomorphs after pyrite, providing evidence of at least two phases of fluid flow from the Entrada reservoir into the caprock in connection with deformation bands. We also observe mineralized fractures, poikilotopic cementation, and spherical to elongate concretions on and within deformation band fins in the Slick Rock Member. These features indicate the presence and movement of fluids parallel to and between deformation band fins. At some sites, deformation band faults and fractures cross and offset the interface; at others, they are present in both units, but deformation band faults do not cross the interface and fractures are not directly connected to any bands. Mineralized fractures are only found at breached-interface sites; evidence for fluid flow in the Slick Rock Member is only found in deformation band fins. Interface crossing and fracture formation is not related to proximity to the Iron Wash Fault. We propose that mesoscale faults can act as seal bypass systems and allow fluid leakage from reservoir rock into overlying less permeable rocks. Deformation bands act as both conduits for and barriers to flow, seen most clearly in deformation band fins where iron staining and mineralization is constrained between sets of bands within the fin. In CO2 or wastewater injection scenarios, interface deformation may prevent successful fluid trapping and cause re-emission of injected fluids.