Programa de Pós-Graduação em Geologia e Geoquímica - PPGG/IG
URI Permanente desta comunidadehttps://repositorio.ufpa.br/handle/2011/2603
O Programa de Pós-Graduação em Geologia e Geoquímica (PPGG) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA) surgiu em 1976 como uma necessidade de desmembramento do então já em pleno desenvolvimento Curso de Pós-Graduação em Ciências Geofísicas e Geológicas (CPGG), instalado ainda em 1973 nesta mesma Universidade. Foi o primeiro programa stricto sensu de Pós-Graduação (mestrado e doutorado) em Geociências em toda Amazônia Legal. Ao longo de sua existência, o PPGG tem pautado sua atuação na formação na qualificação de profissionais nos níveis de Mestrado e Doutorado, a base para formação de pesquisadores e profissionais de alto nível. Neste seu curto período de existência promoveu a formação de 499 mestres e 124 doutores, no total de 623 dissertações e teses.
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Item Acesso aberto (Open Access) Depósitos costeiros e microbialitos da Formação Itaituba, o Pensilvaniano da borda sul da Bacia do Amazonas, região de Placas, Pará.(Universidade Federal do Pará, 2019-12-29) OLIVEIRA, Fernando Andrade de; ROMERO, Guilherme Rafaelli; SILVA JUNIOR, José Bandeira Cavalcante da; http://lattes.cnpq.br/8615194741719443The Itaituba Formation in the Amazon Basin represents a Bhaskiriana-Moscowian carbonate succession, composed of fossiliferous limestone, fine dolomite, fine to coarsegrained sandstone, gray shales and evaporites. Outcrop-based facies and stratigraphic analysis combined with microfacies study allowed the paleoenvironmental reconstitution of the Itaituba Formation, on the southern border of the Amazon Basin, Southwestern of Pará State. The 14mthick carbonate succession with occurrence of microbialites, consists of 9 facies and microfacies, such as: a) laminated shale (F1); b) laminated sandstone (Al); c) laminated siltstone (Sl); d) massive sandstone (Mm); e) mudstone with desiccation cracks (Mg); f) wackestone bioclastic (Wb); g) packstone bioclastic (Pb), h) oncolitic floatstone (Fo) and i) boundstone. These facies are grouped into two facies association (AF): AF1, lagoon / tidal flat deposits, consisting of facies Fl, Al, Sl, Mm, Mg, Wb, related to the flat and laterally continuous buildings with predominance of facies F1, interlayed by centimeter layers of facies Wb and Pb, organized in a fining upward cycle and; and AF2, shoal / barrier island, constituted by Pb facies and Fo and Bd facies, with Pb displayed in continuous flat and lateral bodies and Fo and Bd in lensshaped bioherms. Fo facies are the oncolytic microbilites and associated with microstromatolites, described as M1 and M2a morphotypes, and Bd facies, include columnar stromatolitic forms, described as M2b and M2c morphotypes. The depositional model of the Itaituba Formation in the Placas-PA region consists of a coastal system with lagoon, shoals / barrier island and tidal flat. Microbialites developed in the coastal region in the Amazon Basin during the Bashkirian-Moscovian transition, representing a transition to more restrictive environmental conditions in relation to fauna and flora, and more conducive to the proliferation of cyanobacteria, with probably increased alkalinity in water. These cyanobacteria evidences are record, for the first time, in Carboniferous rocks of the Amazon Basin improved the knowledge related to the carbonate fabric dispersion during the implantation of the Itaituba epicontinental sea in the Western Gondwana.Item Acesso aberto (Open Access) Materiais híbridos orgânicos-inorgânicos: argilominerais, óxidos e polímeros(Universidade Federal do Pará, 2018-03-23) CAVALCANTE, Manoella da Silva; ANGÉLICA, Rômulo Simões; http://lattes.cnpq.br/7501959623721607The interaction on a nanometric scale of molecular or polymeric species with inorganic substrates constitute the basis for obtaining hybrid materials. The development of these materials represents an emerging and interdisciplinary topic between the frontiers of life sciences, materials and nanotechnology. The combination of these two materials, organic-inorganic, produces a new material with improved properties and structures essentially different from its individual components. Constituted by a continuous phase (matrix), being plastics or cellulose, and an inorganic phase, such as clay minerals or oxides. several papers have been published obtaining these materials with improved properties: traction modules, gas barrier, flame retardants, density, melt strength, electrical conductivity, etc. Capable of making industry flexible and rigid products and in the manufacture of electronic materials (wire and cable coatings manufacture of sensors / actuators), vaccine production, among others. The most clay minerals used in the synthesis of hybrid materials are the species montmorillonite, clay but others can also be used, such as illite and palygorskita. In the state of Maranhão, northeastern Brazil, there are several occurrences of clay minerals, most notably smectite, illite and palygorskite. Among these clay minerals two new occurrences have already been identified and characterized by the UFPA Group of Applied Mineralogy (GMA), such as Bentonite Formosa and Palygorskite, which are abundant in the region and do not yet have an application. In addition to a new occurrence of illite not yet characterized in the region of the municipality of Barão de Grajaú (MA). Another material with great potential for obtaining nanomaterials is the vanadium pentoxide, having intrinsic features such as alignment of the magnetic field, and redox system such as gel elasticity, enabling application in the electronics industry for the manufacture of batteries and electrochromic displays for sensors/actuators. In Brazil, vanadium pentoxide began to be produced in 2014 by Maracás S/A. Currently, its consumption is focused on the production of special steels for the manufacture of aircraft structures and the aerospace industry. At the national level the production and development of hybrid materials and platforms for use in high-tech industry is small. Thus, the development and improvement of nanomaterials is necessary using as starting material and clay minerals national occurrence oxides. Within this context, this thesis aimed to develop a study on application of three clay minerals (Mg-montmorrillonite, illite and Palygorskita) from northeastern Brazil, besides vanadium pentoxide in the processing of hybrid materials using as poly matrix (methylmethacrylate) (PMMA ) and cellulose nanofibers. For this, the methodology of this work was divided into three parts: The first one consisted of the collection or synthesis, treatment and characterization of the individual materials (clay minerals, vanadium pentoxide, methyl poly (methacrylate) and cellulose). The second was to obtain hybrid materials clay mineral-PMMA (AP) and vanadium pentoxide cellulose (VC) and the third one was mainly to evaluate the thermal and mechanical properties of the AP hybrids and the electrochromic properties of the VC films. The characterization of the samples confirmed the predominance of Mg-montmorillonite, Illita and Palygorskita. The natural clay and organophilic fraction were used to obtain 12 samples with common and elastomeric PMMA to perform the physical-chemical tests focusing mainly on flammability and traction. By means of XRD measurements it was possible to verify that there was interaction between the two organic-inorganic phases, and that in the elastomeric PMMA there was a better dispersion of the clay minerals. The tests carried out on these materials indicated that the hybrids exhibit intrinsic thermal and mechanical behavior of each material possibly related to the type of structure present in the inorganic phase, contributing to the increase or decrease of Tg, Tm, flammability and traction. Four V2O5-cellulose films were obtained and characterized. Electrochromic tests were conducted in the films that presented better performance. It was possible to verify that there was interaction between the nanofibers of vanadium pentoxide and cellulose maintaining the electrochromic property of the oxide. Potentiometric measures were found that after 30 and 100 cycles the films remained flexible and maintained their properties. In this way, this work concluded that it is possible to obtain hybrid materials with clay minerals coming from the northeastern region of Brazil and can adapt their thermal and mechanical properties according to their application. The same was observed for the VC films that presented satisfactory results and that can be used in displays and / or flexible sensors.Item Acesso aberto (Open Access) Mineralogia e geoquímica do perfil laterito bauxítico na serra Sul, Província Mineral de Carajás(Universidade Federal do Pará, 2020-11-03) RODRIGUES, Paulo Ronny Soares; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302The Amazon holds the largest reserves of bauxites in Brazil, located in Trombetas, Juruti, Paragominas and Rondon do Pará. The Carajás region, with large lateritic deposits, especially of iron, is also emerging with potential for bauxite deposits, with emphasis on those of Serra Norte. In Serras Sul, smaller occurrences were identified, which were investigated in this work. In this context, field activities were carried out with sample collection and textural, mineralogical and chemical analyzes and then a genetic discussion was presented. In four alteration profiles on a side road near the Serra Sul, after geological cartography, 23 samples were collected, which were described, photographed and prepared for mineralogical analysis (X-ray diffraction), textural (optical and scanning electron microscopy) and chemical (mass and optical emission spectrometry, with inductively coupled plasma). The bauxite laterite profile comprises from the base to the top of: 1) Kaolin Horizon (HC); 2) Mottled clay Horizon (HAM); 3) Nodular Bauxite Horizon (HBN); 4) Clayey Bauxite Horizon (HBA) and 5) Ferruginous crust Horizon (HF); and finally to the top 6) Dismantled crust ferruginous horizon (HFD. The chemical composition is essentially dominated by Al2O3, Fe2O3, SiO2 and TiO2, which compose the main minerals, kaolinite, gibbsite, hematite, goethite and anatase. The trace elements V, Cr, Cu, Ga, As, Zr, Cd, Hf, Bi and Th, whose concentrations are generally higher than those of the Upper Crust of the Earth, are more concentrated in the ferruginous horizons, related to Fe oxy-hydroxides (hematite and goethite) and also to zircon. On the other hand, the elements Co, Zn, Se, Rb, Sr, (Nb), Ag, (Sn), Cs, Ba and Pb are at lower levels than theUpper Continental Crust, and their concentrations are lower in ferruginous horizons, suggesting affinity with clay minerals.ETR at levels lower than UCC, are enriched in ETRP and present strong positive and negative C and positive Eu anomaly, and suggest distribution in zircon, oxy-hydroxides of Fe and other mineral phases. and mass clearly demonstrate a complete lateritic evolution, only partially modified in its upper portion. The bauxite zone, however, does not have local potential for ore, due to the low content of usable alumina and high in reactive silica. However, its occurrence opens an opportunity for further research in view of the geological and paleoenvironmental potential of the Mineral Province of Carajás.Item Acesso aberto (Open Access) Síntese e caracterização da piroaurita a partir de resíduo de mina de cobre e sua aplicação na adsorção do corante vermelho do Congo(Universidade Federal do Pará, 2023-03-24) FERREIRA, Rafaela da Silva; RODRIGUES, Elizabeth Maria S.; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568In this study, the copper flotation tailings extracted from the Sequeirinho pit of the Sossego mine, Carajás region, Southeast of the State of Pará (Brazil), has been used as raw material for the synthesis of Pyroaurite, a potential absorbent of organic dyes. Initially, tailings characterization was performed through X-Ray Fluorescence (XRF) and X-Ray Diffraction (XRD) techniques. Next, a sample of this characterized material was leached (HCl 1:1 H2O), the obtained solution was filtered and used in the procedures of Pyroaurite synthesis. This solution was kept in the coprecipitation method at constant pH (14) with Mg/Fe molar ratio equal to 6:1, a dripping time of 4 hours, hydrothermal bath of 24 hours at high agitation rate. After, the synthesized Pyroaurite was submitted to characterization by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), X-Ray Fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), Specific Surface Area (ASE) and total pore volume (Wo) techniques. Then, the synthesized Pyroaurite was evaluated for the adsorption process of Congo Red (CR) dye, where 0.025 mg of Pyroaurite were added to 10 mL of CR samples at concentrations of 5, 10, 20, 30, 40, 50 and 80 mg·L-1, respectively. The adsorption results fitted to the Langmuir model (R2 = 0.9614), while the kinetics suggested the pseudo-second order model (R2 = 0.9977). In addition, the temperature of 40ºC showed to be the most pleasant for the adsorption of the CR dye. Finally, the thermodynamic parameters of entropy (ΔSº= 0.0886 kJ·mol-1·K-1) and enthalpy (ΔHº= 8.2999 kJ·mol-1) show that the adsorption process was found to be naturally spontaneous and endothermic.Item Acesso aberto (Open Access) Síntese e caracterização de hidróxidos duplos lamelares de Mg/Fe com esferas de carbono magnéticas(Universidade Federal do Pará, 2021-10-26) SILVA, Victor Coutinho Gonçalves; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568This research aimed to synthesize a stable magnesium/iron carbonate (Mg//Fe-CO3) lamellar double-hydroxide (LDH) compound with magnetic carbon spheres (MCS) in order to evaluate composite’s characteristics. LDHs are synthetic or natural anionic clays which structures are constituted of positively charged octahedral lamellas with intercalated di- and trivalent cations, and hydroxyls in the vertices. Water and anions are also in the inter-layered space. Spheric carbon products are known for a long time and the application of carbon nanomaterials is possible in many areas. The formation process of this material is hydrothermal, which does not result in singular products. Its results are big interconnected chains of carbon spheres (CS) attracted by Van der Waals forces. Chemical reagents of analytical purity were utilized in the synthesis. Mg/Fe-CO3 LDHs were synthetized by co-precipitation method with variable pH. And the hydrothermal method was applied to prepare the carbon spheres. The characterization of LDH, CS, MCS and LDH + MCS composite included analysis by X ray diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), infrared vibrational spectroscopy and Brunauer-Emmet-Teller method (BET) for specific surface area and pore size measurement. XRD analysis identified pyroaurite’s structure in the HDL samples and magnetite’s structure in the MCSs. The average values of pyroaurite’s unit cell, a = b parameters, interplanar distance (c) and interlamellar spacing thickness were 7,792 Å, 3,107 Å, 23,375 Å and 2,992 Å, respectively. Photomicrography was performed only in CS and MCS samples. It was possible to observe big agglomerates and chains of these materials, and the size variation between different samples and synthesis as well. Thermic decomposition of synthetic pyroaurite and the composite occurs in a similar way, which can be divided in five stages. Loss of adsorbed water and intercalated water elimination happen in the first (31-72 °C) and second (175-177 °C) stages, respectively. Then, between 284 °C and 395 °C, there is decarbonization and desidroxylation. Finally, the destruction of LDH’s structure happens at 746 – 786 °C. Intercalated anion in LDH’s structure was determined as a carbonate anion (1365 cm-2) by infrared vibrational spectroscopy. Carbonate anion and water fill the inter-layered spaces of LDH and LDH + MCS composite. Both LDH and LDH + MCS composite show infrared isotherms and type H3 hysteresis, according to IUPAC’s classification. Superficial area increased by 15-31%, while the size and volume of pores decreased by 44-49% and 26-42%, respectively.