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Dissertações em Geologia e Geoquímica (Mestrado) - PPGG/IG

URI Permanente para esta coleçãohttps://repositorio.ufpa.br/handle/2011/2604

O Mestrado Acadêmico pertence ao Programa de Pós-Graduação em Geologia e Geoquímica (PPGG) do Instituto de Geociências (IG) da Universidade Federal do Pará (UFPA).

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Acesso aberto (Open Access)
Acúmulo e fracionamento de fósforo nos sedimentos do estuário do rio Coreaú (Ceará) para avaliação do impacto da carcinicultura
(Universidade Federal do Pará, 2014-11-17) AQUINO, Rafael Fernando Oliveira; KAWAKAMI, Silvia Keiko; http://lattes.cnpq.br/5306256489815710; CORRÊA, José Augusto Martins; http://lattes.cnpq.br/6527800269860568
The shrimp culture (shrimp farms) is one of the activities of aquaculture widely employed in Brazilian estuaries and mangroves. The shrimps are fed with phosphate enriched compounds. Thus, the effluent produced by farms can accelerate the eutrophication process. An increase of shrimp farming has been seen in Coreaú River Estuary, state of Ceará, but data about environmental quality are scarce to allow monitoring of the region. The aim of the present research was to assess the contribution of the shrimp farms on phosphorus input to the Coreaú River Estuary. The main forms of phosphorus: bioavailable (P-Exch); bound to iron oxy-hydroxides (P-Fe), on the biogenic, autigênica carbonates and apatite (P-CFAP), on the detrital apatite (P-FAP) and organic phosphorus (P-Org) and as well as total organic carbon (%TOC) and chlorophyll-a were determined in samples of surface sediments and cores from the margins of the Coreaú River Estuary. The high concentrations of P-Total in surface sediments indicated the need for monitoring studies. The larger fraction was P-Fe, composing 30% of P-Total, approximately. These results indicate the ability of the iron oxy-hydroxides to immobilize or release phosphorus. The contribution of the farm’s effluents was evidenced by higher concentrations of P-Org in points adjacent to discharge areas. In sediment cores, the highest P-Total concentrations were found predominantly in fine sediments (silt and clay), with the P-Fe, P-CFAP and P-FAP fractions being the main contributors. The sedimentation rates and concentration increases of P-Total indicate the possible period of deforestation and starting or maximum activity of shrimp farms in the end of the 1980 and mid 1990, respectively. High phosphorus concentrations as well as %TOC and chlorophyll-a levels suggested a significant anthropogenic contribution, associated with a high potential for eutrophication.
Acesso aberto (Open Access)
Adsorção de cromato em materiais sintetizados a partir de rejeito de caulim do rio Capim
(Universidade Federal do Pará, 2008-05-13) MORAES, Milena Carvalho de; LEMOS, Vanda Porpino; http://lattes.cnpq.br/1829861620854008
Industrial and domestic waste cause serious problems for the environment. Industries treatment of kaolin have been deposited reject in large lakes of sedimentation and this has caused accidents as occurred in august/2007 and February/2008. The large volume of kaolin in the lakes sedimentation invaded lakes and rivers from Rio Capim, Para region. This fact resulted in the pollution of waters and death of fish. This problem can be minimized with the use of kaolin reject (KR) in the synthesis of new materials. In this work was used KR treated with organic acid (glycine at concentrations of 5%, 10% and 15% , being obtained the adsorbents: KR-gly-5, KRgly-10 and KL-gly-15, respectively) and mixture NaClO4:HClO4 (proportions 1:50 and 1:75, being obtained the adsorbents KR-NaClO4:HClO4-1:50 and KR- NaClO4:HClO4- 1:75, respectively) and KR as source of Si and Al in the synthesis of zeolites. The materials were characterized by chemical composition and XRD, FTIR, DTA-TG and SEM data. These materials were studied in adsorption process for CrO4 2- from aqueous solutions. The results obtained indicate that the CrO4 2- is adsorbed by kaolin reject and other materials from KR followed this order: KR-gly-10> KR-gly-5>KR-gly-15>KG> KR- NaClO4:HClO4- 1:75> zeolites.
Acesso aberto (Open Access)
Adsorção de nitrato em rejeito de caulim organofuncionalizado com uréia
(Universidade Federal do Pará, 2012-05-30) TAVARES, Laís Conceição; LEMOS, Vanda Porpino; http://lattes.cnpq.br/1829861620854008
Kaolin waste, generated in abundance by companies from Pará state, has caused to the environmental problems. In order to give input on the reuse of this waste was evaluated retention of nitrate ions on kaolin waste natural and modified with urea and studied the equilibrium of adsorption processes at solid-solution interfaces. The materials were characterized by X-ray diffraction and X-ray fluorescence (XRF and XRD, respectiely), IR spectroscopy (FTIR spectrum), scanning electron microscopy and estimated data of surface charge. Adsorption experiments of nitrate ions in the waste natural kaolin (CRJN) and modified with urea (CRJU) were performed without pH adjustment. H + concentrations were measured by direct potentiometry before and after the process of adsorption and equilibrium concentrations of nitrate were measured by ion chromatography. The results indicated: high purity kaolin waste; formation of kaolinite-urea complex confirmed by XRD reflection at 2  8,28o e d = 1.068 nm and the FTIR spectrum with the appearance of a broad band of low intensity, containing two discrete shoulder around 3500-3380 cm-1, corresponding to asymmetric and symmetric vibrations of the group-NH2 of urea-kaolinite, superimposed to the vibration of water. surface charges data, suggesting that the materials have a higher capacity to adsorb cations than anions, but depending on the concentration of H + and OH- on adsorbent, the hydroxyl surface can be protonated yielding positive charges that are reflected in the adsorption of anions, obtaining significant adsorbed nitrate, both in CRJN as CRJU (0,27-0,73 and from 0,18-0,70 3.5 mg g-1, respectively), the separation coefficient (RL) of from 0,28 to 0,828 change in free energy ΔG ° = -2,094 to + 0,445 kJ mol-1 for CRJN and ΔG° = -1,036 to + 1,32 kJ mol-1 for CRJN molecule. The data from RL indicated that the adsorption processes are less favorable in most points of the adsorption processes and based on the results of the free energy change (ΔG º) was showed low spontaneity to no spontaneity and adsorption processes are physical.
Acesso aberto (Open Access)
Adsorção de Pb por caulinita tratada com ácidos acético e cítrico
(Universidade Federal do Pará, 2005) SENA, Luciana Freitas de; LEMOS, Vanda Porpino; http://lattes.cnpq.br/1829861620854008
Acesso aberto (Open Access)
Ambiente deposicional, composição mineralógica e estudo isotópico Pb-Pb das zonas sulfetadas do Alvo São Martim, Cinturão Araguaia, sul do Pará
(Universidade Federal do Pará, 2004-07-07) LIMA, Aderson David Pires de; VILLAS, Raimundo Netuno Nobre; http://lattes.cnpq.br/1406458719432983
Acesso aberto (Open Access)
Análise da dinâmica da cobertura e uso do solo na bacia hidrográfica dos lagos Bolonha e Água Preta, Belém, Pará.
(Universidade Federal do Pará, 2024-12-20) BARROS, Jackison Mateus Lopes; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252; https://orcid.org/0000-0003-0252-808X
The increase in the urban population in the world has impacted river basins that supply water to cities, including the treatment and distribution of drinking water for domestic, industrial and commercial use. One example is the Bolonha and Água Preta Lakes Hydrographic Basin (BHLBA) in the Belém Metropolitan Region (RMB), the second largest urban agglomeration in the Brazilian Amazon, with 2.3 million inhabitants. One of the best ways to monitor the dynamics of river basins is through remote sensing techniques with orbital images, due to the quality of the spatio-temporal data. This work aims to analyze the changes in land cover and use in the last four decades in the BHLBA, through images from the Landsat satellite series from the years 1984, 1989, 1994, 1999, 2004, 2008, 2018, 2021 and 2023, using a geographic object-oriented image analysis (GEOBIA) methodology. Thus, the classes of lakes (L), urban area (AU), aquatic macrophytes (MA), arboreal vegetation (VA) and pasture (P) were evaluated. The overall accuracy of the images showed values around 90%, with the main error being allocation errors. Changes that occurred over the years were identified, such as the significant growth of macrophytes on the water surface of the Bolonha and Água Preta lakes, which decreased by approximately 3.7%. A 13.4% increase in arboreal vegetation in the BHLHA was also recorded, evidencing a forest recomposition. A 3.2% growth in urban areas around the BHLBA was also observed, which is worrying because human influence can put the health of the water supply sources of the RMB at risk. The GEOBIA methodology proved to be adequate for the study and we recommend that monitoring be continued due to the socio environmental importance of the area under study.
Acesso aberto (Open Access)
Análise da dinâmica morfo-sedimentar da praia da Marieta – Ilha do Marco-Maracanã (NE do Pará)
(Universidade Federal do Pará, 2010-04-19) GUERREIRO, Juliana de Sá; EL-ROBRINI, Maâmar; http://lattes.cnpq.br/5707365981163429
This study aims the investigation of the morphological and sedimentological variations occurred in Marieta’s Beach- Marco Island (NE of Pará) during the rainy season (March) and rainyless season (November) of 2007, seeking to identify the main factors responsible by these variations. The Marieta’s beach has 3 km long, with NW-SE direction, and is supported by the sediments of the Barreiras Group, Post-Barreiras and the recent sediments that provide much of the sediment at the mouth of the estuary Urindeua. Topographic profiles were conducted in June in the following subdivisions Beach Marieta: Sector sandy spit - profiles I and II (tgβ = 0.0015); central section - profiles III, IV (tgβ = 0.0017) and NW sector - and V profiles VI (tgβ = 0.005). We applied the following morphological beach models: Inmam & Guza (1975), Sandy Spur -        in the rainy season         in the rainyless period, Sector Central -      12 in the rainy season        during rainyless. These results show a strong reflection with some dissipation, characterized as Intermediate Bar and Longitudinal with the NW sector, which indicated a Dissipative behavior during the two periods studied, According to Wright & Short (1984) had a whole beach Dissipative behavior during the two periods studied -       in the rainy season         in the less rainy period; And following Masselink & Short (1993) showed the profiles to be modified by tides, with dissipative bars RTR = 4 in the rainy season and RTR= 3.6 in the rainyless period. The beaches are predominantly covered by very fine sand, very well selected and moderately selected, with mesocurtic and platicurtic kurtosis and negative asymmetry at the supratidal zones during the rainy season and in areas of infratidal in the rainyless season in other areas of the beach Marieta were approximately symmetrical and positive asymmetries. The Marieta’s beach has been profiled morpho-sedimentary influenced by the displacement of the Convergence Zone Inter-Tropical (ITCZ) in the rainy season (1736.6 mm) and at rainless (2.4 mm). The speed of the wind was weaker during the rainy season with an average of 6.7 nodes while in the less rainy period the average speed was 11.3 knots with preferential direction NE, and therefore, buckled with higher energy (Hb = 1 , 5 m in the rainy season in March). Coupled with an amplitude of 5.5 m tide reaching the innermost areas of the beach. In the less rainy period, the waves were smaller, compared to the rainy season, which reached 1.2 m combined with an amplitude of 4.8 m tide. Through these parameters showed that the major changes in the beach profile were associated mainly to the interaction of the effects of winds, waves and tides, showing the strong relationship between the shape and orientation of the beach and the incidence of these agents.
Acesso aberto (Open Access)
Análise do padrão espectro-temporal de ambientes costeiros com imagens Landsat, Ilha de Marajó/PA.
(Universidade Federal do Pará, 2010-10-06) CARDOSO, Gustavo Freitas; SOUZA JUNIOR, Carlos Moreira de; http://lattes.cnpq.br/2090802631407077; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
Knowledge of spatial and temporal distribution and monitoring of its dynamic evolution are the most important factors for the study and management of wetlands. The aim of this study was to characterize, to map, to compare the spectral response of coastal wetlands, as well as detect the changes on the eastern shore of Marajo, State of Pará, using images from TM Landsat-5 reflectance. To this end, the images were geometrically and radiometrically corrected. Were collected in the reference image (2008), at least 20 polygonal samples (5x5 pixels) for each type of land cover. The analysis of variance (ANOVA), Tukey HSD Test and an index of spectral separability of pairs of regions of interest (ROIs) were calculated. The mapping was generated from the supervised classification Spectral Angle Mapper, and validating data, outlined by the Confusion Matrix. Thus were recognized the following units: MAN - mangrove, MAD - degraded mangrove, PRD – beaches and dunes, VSI – initial secondary vegetation, VSA - advanced secondary vegetation, ACS – water with sediment, ASS - water without sediment, OCH - human occupation and CAM – marshes. The result of ANOVA showed that there are significant differences between the average reflectance in all classes and at least one pair of means, for all bands (1-5 and 7) image. The Tukey HSD test found that the smallest difference between two means of bands 1 and 2 occurs in pair VSAMAN, the band 3, VSI-MAN, the band 4, OCH-MAN, the band 5, OCH-PRD, and band 7, ASS-ACS. The function of spectral separability of pairs of ROIs highlighted a low value for the pair of classes OCH-CAM. The calculation accuracy of the mapping showed acceptable values. Was also applied the technique of spectral mixture model to determine the fractions – green vegetation, water and/or shade, soil and vegetation not photosynthetically active – in reflectance images in years from 1988, 1994, 1998, 2004, 2006 and 2008. The detection of changes over the years was done with the help of the tri-linear diagram of Thompson, used to analyze the evolution of Mangrove environments, Salt Marshes with a predominance of soils, Grassland Salt Marshes, Beaches and Dunes, Wet Sediment, Water with Sediment and Water without Sediment. The results showed that 80% of the samples from mangrove environment, maintained their spectral characteristics, ie, the environment has not changed over time, and that 15% of possible paths indicated a gradual change for the formation of mangrove until 2008. Of the total number of pixels analyzed for this environment, 93% corresponded to the actual mangrove, confirming a relative stability of this environment in the study area. Salt Marshes showed an unusual condition in the analysis of the image of the reference year (2008), with spectral response similar to the soil characteristics, this is not checked in years gone by. In recent years, there was a predominance of Grassland Salt Marshes. As for the environment Beaches and Dunes revealed a considerable increase of its surface (66.7%) in the 20-year period (1988-2008). Overall, the results suggest that the study area has undergone the process of progradation of sediments along the shoreline and stabilization in the increase of surface Mangrove since 2006. For the Salt Marshes detect the variations in the abundance values among the three fractions (Green Vegetation, Shade/Water, Non-photosynthetically Active Vegetation and Soil) generated by the spectral mixture model, mainly due to seasonal climate in the region. The method of change detection applied fostered the development of a model spectral dispersion diagram for coastal wetlands. This model should assist in future research about the monitoring of the impacts of the humid coastal environments from the increase in sea level, the location and spectral characterization, and change detection.
Acesso aberto (Open Access)
Análise faciológica das formações Poti e Piauí (carbonífero da Bacia do Parnaíba) na Região de Floriano-PI
(Universidade Federal do Pará, 2000-07-20) RIBEIRO, Cleive Maria Monteiro; GÓES, Ana Maria; http://lattes.cnpq.br/2220793632946285
Acesso aberto (Open Access)
Análise paleoambiental da Formação Pirabas no litoral do Maranhão, Brasil
(Universidade Federal do Pará, 2011-06-03) OLIVEIRA, Samantha Florinda Cecim Carvalho de; ROSSETTI, Dilce de Fátima; http://lattes.cnpq.br/0307721738107549
The Pirabas Formation is a geological unit known for its abundant fossil content, which includes a large number of invertebrate and vertebrate groups. This unit is exposed in the north and northeast coast of Brazil, in the States of Para, Maranhão and Piaui. The majority of the studies focusing the fossils of the Pirabas Formation emphasized initially, invertebrates. However, studies using ichthyoliths have been increasingly emphasized in the last years, which is due to their resistance to dissolution, transportation and deposition. Moreover, the small size favors their continuous recovery along different stratigraphic levels, allowing their use as an additional tool in paleoenvironmental interpretations. This work aimed to prospect ichthyoliths of the Pirabas Formation exposed along the coast of the State of Maranhão, as well as their identification and integration with facies analysis. This study area is part of the São Luís Basin, which is filled with a 4,000 m-thick sedimentary succession represented mainly by Cretaceous rocks, with a thin Cenozoic cover, the latter represented by the Pirabas and Barreiras Formations deposited mostly in the Miocene. The exposures studied occur along various cliffs between the towns of Alcantara and Guimarães. Miocene carbonates with ichthyoliths record in this location are occasional, occurring as thin layers up to 2 m thick, which are laterally and vertically intergraded with siliciclastic deposits. These strata occur as three stratigraphic units, with the second one documenting fossiliferous carbonates related to the Pirabas Formation. The cliffs studied include the ones in the localities of Canelateua, Mamuna Grande, Peru and Base. We analyzed 16 thin sections sampled from these localities, which resulted in description of four carbonate microfacies, and one of mudstone. The samples provided 30 ichthyoliths, which were photographed, identified and described under a scanning electron microscope. In addition to the ichthyoliths, the petrographic study recorded the presence of other fossils, including bryozoans, foraminifera, gastropods, bivalves, algae, and echinoids. The integration of paleontological data and microfacies is consistent with deposition in carbonate paleoenvironments predominantly with low energy, reducing conditions and subjected to the frequent introduction of siliciclastic grains. These characteristics, added to the low fossil frequency in most of the samples, corroborate previous interpretations that the deposition of these strata occurred in paralic, probably estuarine palaeoenvironments. However, the abundance of marine fossils in some samples, associated with the presence of ichthyological elements common in environments with normal salinity, shows periodic introduction of saline inflows. Therefore, we can conclude that the strata analyzed were deposited in association with an estuarine system, but representing more distal facies of this system, representative environments more exposed to marine influence.
Acesso aberto (Open Access)
Análise tafonômica da ostracofauna do testemunho 1AS-5-AM: contribuição para a interpretação paleoambiental dos depósitos neógenos da Formação Solimões, AM, Brasil.
(Universidade Federal do Pará, 2019-11-01) SANTOS, Katiane Silva dos; RAMOS, Maria Inês Feijó; http://lattes.cnpq.br/4546620118003936
The Solimões Formation corresponds to the miocenic sedimentation from the Solimões Basin; it is constituted, essentially by mudstone, siltstone and fine sandstone, poorly consolidated, interspersed by lignite and carbonate levels, whose deposition took place in a fluvial and fluvio-lacustrine environment. Among the invertebrates from Solimões Formation the ostracode stand out for their abundance and diversity. Initially, the studies on those microcruteacea focused mainly on taxonomy. Subsequently, contributions on the bioestigraphy field suggest Early Miocene - Late Miocene age for this unit; while geochemical and paleontological analysis point to predominantly freshwater environmental conditions, with sporadic marine influence. However, taphonomic studies with emphasis on ostracode from Solimões Formation have not yet been performed. Taphonomic analysis of fossil concentrations can provide important data on paleoenvironmental hydrodynamics, sediments geochemistry, sedimentation rates and diagenetic processes. This paper deals with the biostratinomy and fossildiagenesis of ostracodes from Solimões Formation, as well as the mineralogical composition and sedimentological aspects of lithotypes. The material analyzed comes from thecore 1AS-5-AM, drilled in the village Cachoeira, near the Itacuaí river, Amazonas State. According to lithological characteristics, types of preservation and occurrence of ostracodes it was possible to individualize three intervals along the analyzed core. The interval I (284.50-119.30 meters) corresponds to the lower portion of the core. In this, the ostracofauna is poorly preserved, occurring only few juveniles (A-2, A-3 stages) and adults, with strong dissolution process. The lithology of this interval comprises solid, dark greenish gray to black mudstone, with rich organic matter content. The Interval II (116.70-107.10 meters) presents a higher occurrence of ostracodes in excellent preservation state and several ontogenetic stages, higher occurrence of closed carapaces and low degree of dissolution (occurs partially and punctually), suggesting a rapid burial event and little influence of methanogenesis on the lower organic matter content of the samples. The lithology of these layers are the same from interval I, however the organic matter content is fewer. Interval III (106.90-41.00 meters) has a moderate preservation stage, where the highest dissolution rate is associated to oxidation of monosulfides and iron sulfides that occurs adherent to the specimens surface, which were exposed by bioturbating organisms of sediments. The predominance of juvenile ostracodes in this interval indicates high mortality in ontogeny probably due to environmental stress. The lithology of this interval is made up of light to medium solid greenish gray, locally siltitic and lignite. Bioturbations (Skolitos) were recorded only at this interval. Organic matter content varies from low to moderate. Related to the color change of the ostracodes, opaque white valves were recorded in interval I more frequently; in II predominate black, dark gray, white and in smaller quantity, amber and hyaline colored valves; while in the III predominate reddish brown specimens, followed by light gray and opaque white. The taphonomic analysis of the ostracodes allowed to verify carapaces/valves with original chemical composition preserved, however, contaminated by chemical elements from the siliciclastic sediments and thin mineral layers adhered to its surface. The following types of preservation were identified: 1) ostracode valves and carapaces covered by thin mineral layers of iron monosulfide, iron phosphate, iron and thallium sulfide; 2) preserved in iron oxides; 3) recrystallized; and 4) pyritized molds. Preservation types identified predominantly reflect conditions of early (thin mineral layers mineralization and mold formation), and late (recrystallization, oxide formation) diagenesis. Fossildiagenetic alterations correspond to mineral filling of carapaces by pyrite, dissolution, color change and recrystallization. The first is related to iron phosphate present in sediments and rapid burial events. The dissolution resulted from the oxidation of the thin mineral layers adherent in the valves and the organic matter content; while carapaces/valves with alterations to reddish brown, dark gray, black and amber reflect the deposition of thin mineral layer on the specimens surface, opaque white valves result from partial dissolution. The punctual recrystallization of few valves reflects the mineral stability of the low magnesian calcite, the main constituent of ostracod carapace. The biostratinomic alterations identified are equivalent to fragmentation, disarticulation (from death, ecdysis and transport of ostracodes), bioerosion (due to chitinolytic bacteria) and transport. In interval I juvenile allochthonous ostracodes suggest postmortem transport. In interval II the predominance of native fauna shows low energy environment. Allochthonous and autochthonous (predominant) ostracodes of interval III reflect energy variation in scenery near the coastal lake zone. Based on the types of preservation and lithological characteristics, the environment was interpreted as lacustrine, with low to moderate energy. The absence of evaporitic minerals and dispersed pyrite in sediments attest to the low salinity of the environment.
Acesso aberto (Open Access)
Aplicação da cromatografia líquida de alta eficiência na investigação de hidrocarbonetos policíclicos aromáticos em testemunhos sedimentares
(Universidade Federal do Pará, 2013-07-31) EVANGELISTA, Camila do Carmo Pereira; KAWAKAMI, Silvia Keiko; http://lattes.cnpq.br/5306256489815710
Polycyclic aromatic hydrocarbons are organic (PAH) compounds originated from natural or anthropogenic sources and are considered priority substances by environmental agencies because of carcinogenic and mutagenic potentials. Therefore, rapid and low cost analytical methods for these compounds are of significant relevance for environmental purposes. The present study aimed the optimization of an analytical method for PAHs using High Performance Liquid chromatography with a diode array detector (HPLC-DAD) for the application to an estuarine sediment core. For the optimization and evaluation of the method, a sedimentary column measuring 46 cm length was collected at the mouth of the Igarapé Tucunduba (Belém, Pará) and sectioned in 2 cm portions. After dryness, 30 g of each portion were extracted with a mixture of dichloromethane in acetone in ultrasound bath for 40 min. the extracts obtained were centrifuged, purified on silica gel as a clean-up adaptation mainly to retained fine particles, then concentrated using vacuum evaporator and filtered through 0,2 μm nylon membrane before HPLC injection. Samples spiked with 16 PAH analytical standards and procedural blanks were processed on the same way. The parameters assessed showed: (1) good linearity, the calibration curves presented high correlation coefficients ; (2) adequate accuracy: relative standard deviations within acceptable values with 2,1% for acenaphthylene and maximum of 19,7% for fluoranthene; (3) low detection limits between 0,004 to 1,085 ng g-1 which make in situ determinations feasible; (4) adequate recovery for traces with minimum of 40,0% for acenaphthylene and maximum of 103,1% for benzo(k)fluoranthene. The total PAH concentration in the sediment core ranged between 60,77 to 783,3 ng g-1 dry sediment. The optimized method showed advantages over the traditional methods based on soxhlet extrations and clean up adsorption columns in terms of time of analysis and reduced costs with the use of smaller amounts of solvents. The limitation, however, was de coelution of some compounds, which is probably due to the low efficiency of the chromatographic column that was available at the time of the analysis. The method was applicable to estuarine complex samples, rich in silt and clay. Diagnostic ratios using parental PAHs indicated petrogenic sources at 24 - 26 cm and 28 – 30 cm depth; and pirolitics sources at 6 - 8 cm, 10 - 12 cm , and 14 - 16 cm respectively.
Acesso aberto (Open Access)
Aplicação de dados SRTM (Shuttle Radar Topography Mission) no estado do controle neotectônico da rede de drenagem e microbacias hidrográficas, na região de Urucu e Adjacências (AM)
(Universidade Federal do Pará, 2009-09-01) PINTO, Marcelo Lima; BORGES, Maurício da Silva; http://lattes.cnpq.br/1580207189205228
Geologic studies of the Neogene of the Amazon have shown significant evidence of recent tectonic processes, analysis, particularly from the structural control of the valleys and rivers. Given this context, the objective of this study referred to the research area of neotectonic Urucu and Surroundings (AM) through the structural analysis of drainage systems and topography from digital products, namely, images SRTM (Shuttle Radar Topography Mission). The understanding of the latest tectonic structure, the region of Urucu (AM), is fundamental in defining the current landscape geometry. Thus, this study was crucial for the recognition of reactivated structures (NE-SW, NNE-SSW, NW-SE) and neoformed (EW and ENE-WSW), which certainly influence the control of landscape drainage and relief during the Neogene to the present. The initial analysis of alignments of drainage and relief from SRTM images allowed the interpretation of two main sets of discontinuities. The first set includes the structures oriented EW and ENEWSW, which are associated guidelines NE-SW and NNE-SSW. The second set brings together the structures positioned to NW-SE and NNW and SSE. The first set relates to a structure with probable transcurrent movement, where NE-SW orientations represent "splays" who are willing to make up a structural sigmoidal-like duplexes directional. Structural assemblies oriented NNESSW seem to represent a second pulse within that directional movement / transpressive. The second set is represented by discontinuities NNW-SSE. These guide the geometry and impose asymmetries in the drainage network, which are compatible with the definition of "fronts" and reverse in relief. The landscape seen resembles those developed drives dip-slip "normal. A second pulse of drive geometry of normal fault oriented NW-SE limits floodplains and causes the dam's natural river system, providing displacement of fluvial channels. Latter pulse probably occurred during the Holocene. Also, based on geophysical data type field of Total Reduced IGRF (International Geomagnetic Reference Field) can be seen that there is a strong correlation between neotectonic structures and magnetic anomalies, indicating that the structures are associated with the newly formed structures EW and ENE-WSW and structures of reactivation of ancient structures are presented with directions NE-SW, NNE-SSW, NW-SE.
Acesso aberto (Open Access)
Argila de Belterra das coberturas de bauxitas da Amazônia como matéria-prima para a produção de cerâmica vermelha
(Universidade Federal do Pará, 2018-01-10) BARRETO, Igor Alexandre Rocha; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302
The Amazon region holds the largest reserves of bauxite in Brazil, whose deposits are covered by a thick bundle of clay material, known as Belterra Clay (ABT). The wide distribution, superficial occurrence, therefore accessible, and clayey ABT nature have aroused the interest of this work in evaluating its technical viability for the production of red ceramics. For the present study, ABT was selected from the large bauxite deposits of Rondon do Pará, samples of the yellow soils from Mosqueiro, illitic clay and gibbsitic clays and one sample of the clayey siltstone. This clay and other materials used as additives were characterized by X-ray Diffraction (XRD), X-Ray Fluorescence (FRX) (CT), Spectrometric Thermal Analysis (TG), Differential Scanning Calorimete (DSC), Inductively Coupled Plasma Spectrometry (ICP-MS), Coupled Plasma Optical Emission Spectrometry (ICP-OES), Scanning Electron Microscopy (SEM) Laser Particle (APL). To determine the physical and mechanical properties, were produce specimens through different mixtures with the samples of Belterra clay and percentages (20, 30 and 40%) of the yellow soil, clayey siltstone, gibbsitic clays and illitic clay. The specimens were calcined at three different temperature moments (900, 1000 and 1200 ° C). Then, linear retraction, water absorption, apparent porosity, apparent density and bending rupture tension were measured. ABT is essentially kaolinite, having quartz, goethite, anatase and gibbsite as accessory minerals. The pure and simple ABT did not present favorable technological aspects for the production of ceramic products, however the same with addition of the yellow soil and clayey silt from the same region significantly improved the technological characteristics of the ABT.
Acesso aberto (Open Access)
Arquitetura deposicional e dinâmica evolutiva de cordões litorâneos sob influência de delta, Espírito Santo (ES), Brasil
(Universidade Federal do Pará, 2020-09-30) COUTINHO, Cláudia Maria Arraes; FRANÇA, Marlon Carlos; http://lattes.cnpq.br/8225311897488790; 8225311897488790
Ridges are morphological features that frequently occur in coastal regions of prograding characteristic. These features are common along the deltaic lowland of Doce River (Espirito Santo, Brazil) however there are a lack of research works over their genesis and evolutive dynamics. The studies performed within Doce River’s region discuss its deltaic system hence its ridges are generically described though satellite images together with sedimentary and chronologic punctual data, which is inapplicable for a continuous lateral investigation of its subsurface. The GPR (Ground Penetrating Radar) application in coastal zones aiming the investigation of quaternary sedimentation has been widely explored due to the vertical subcentimetric resolution of this electromagnetic geophysical method. Therefore, to fulfill the lack of knowledge over Doce River’s deltaic lowland, the stratigraphic architecture of its complex ridges was investigated through the analysis and interpretation of GPR sections correlated to geochronologic and sedimentary unprecedented data acquired through the thematic project 2011/00995-7 sponsored by FAPESP and data available in the literature. As a result, sedimentary aspects and processes related to the ridges’ genesis and evolutive dynamics according to relative sea level variations (NRM) and climate changes.
Acesso aberto (Open Access)
Aspectos geológicos e metalogenéticos do depósito de ouro hospedado em metaconglomerados e metarenitos paleoproterozoicos Castelo de Sonhos, Província Tapajós, sudoeste do Pará
(Universidade Federal do Pará, 2015-04-06) QUEIROZ, Joana D’arc da Silva; KLEIN, Evandro Luiz; http://lattes.cnpq.br/0464969547546706
Castelo de Sonhos, located in the central-south sector of the Amazonian Craton, near the boundary between the Tapajós and Xingu-Iriri tectonic domains, is a gold deposit hosted in metaconglomerates and metasandstones of the Castelo dos Sonhos Formation (<2080 Ma U-Pb SHRIMP). Subvolcanic rocks and granitoids were identified in boreholes that drilled the deepest parts of the deposit area. Some of these rocks are intrusive into the Castelo dos Sonhos Formation, while for others rocks, the contact relationships could not be determined with confidence. In general, these rocks show calc-alkaline to alkaline affinities and their geochemical patterns indicate that they are related to volcanic arc or post-collisional tectonic settings. The subvolcanic rocks are represented by a porphyritic dacite with age of 2011 ± 6 Ma (U-Pb LA-ICP-MS).The granitoids were classified as biotite granodiorite, biotite monzogranite, muscovite monzogranite, respectively dated at 1976 ± 7 Ma, 1918 ± 9 Ma and 1978 ± 6 Ma (U-Pb SHRIMP), and an undated syenogranite. These ages represent three to four distinct magmatic events and indicate that the studied rocks are coeval to four major units from Tapajós Domain: the Cuiú-Cuiú Complex (2033-2005 Ma), the Comandante Arara Formation (2020-2012 Ma), the Creporizão Intrusive Suite (1998-1957 Ma), and the Tropas Intrusive Suite (1907-1892Ma). Despite the temporal correspondence, the geochemical data show no direct correspondence with the units cited above. Notwithstanding, the intrusion relationship between some of the studied rocks and the metasedimentary rocks of the Castelo dos Sonhos Formation establishes a temporal, spatial and possibly stratigraphic relationship between this formation and the Tapajós Domain. The intrusive contact relationship between the porphyritic dacite and metasandstones of the Castelo dos Sonhos Formation allowed us to determine at 2011 ± 6 Ma the minimum sedimentation age of this unit. The primary gold mineralization at Castelo de Sonhos deposit is stratabound and restricted to a metaconglomerate package and interlayered metasandstones. The mineralization distribution is erratic and does not seem to follow special features or structural control. In the matrix of the metaconglomerates, gold occurs as intergranular particles, occasionally associated with magnetite, and also within quartz grains (medium to coarse sand), which probably represent fragments of auriferous veins. In general, the gold particles show subrounded to rounded shapes, mild to moderately rough surfaces. The particles seldom contain inclusions, and only of magnetite. The chemical composition is homogeneous and characterized by high Au/Ag ratios. These characteristics indicate a syngenetic origin for gold within the metaconglomerates package. Therefore, the age of mineralization is limited by the time x interval of deposition of the Castelo dos Sonhos Formation (2011 ± 6 Ma to ca. 2080 Ma). On the other hand, the occurrence of gold in fracture planes of metasandstones indicates an epigenetic origin for this style of mineralization. The epigenetic mineralization is related to concurrent metamorphic, magmatic and deformational processes that affected the sedimentary sequence of the Castelo dos Sonhos Formation and caused the remobilization of gold originally hosted in metaconglomerates. It is likely that the interaction of these processes associated with infiltration of meteoric waters contributed to the generation and flow of oxidizing hydrothermal fluids, which have percolated through the metaconglomerates package and were able to solubilize some of the gold, and re-precipitate it accompanied by ferruginous films, in fracture planes of the metasandstones. As a conclusion, a modified paleoplacer model is proposed here to explain the hybrid nature (syngenetic and epigenetic) of the gold mineralization in the Castelo de Sonhos deposit.
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Aspectos granulométricos, mineralógicos e químicos de sedimentos de praias (Barras em Pontal) do Rio Acre e sua relação com a fertilidade
(Universidade Federal do Pará, 2004-10-30) VIANA, Érica Cristina Acácio; COSTA, Marcondes Lima da; http://lattes.cnpq.br/1639498384851302
Acesso aberto (Open Access)
Aspectos neotectônicos e ecologia da paisagem em parte da área dos municípios do NE do estado do Pará (Tucurui, Baião, Breu Branco, Goianésia, Moju e Tailândia)
(Universidade Federal do Pará, 2007-10-30) SOUZA, Francileide de Fátima Rocha; BORGES, Maurício da Silva; http://lattes.cnpq.br/1580207189205228
This work inside investigated the aspects of the landscape and geologic and geomorphological evidences of the neotectonic context in the region that understands the Tucurui Cities until Thailand (Pará). In this region the incidence of neotectonics processes was responsible for the generation of structures, sedimentary sequences, standards of draining net (Basin of the Tocantins River) and relief System. For execution of this study had been used Landsat ETM+ images for the digital processing in platform ENVI 4,0, digital Models of rise supplied by the SRTM/NASA and images of radar SAR analysis of the relief, draining and recognition of the lineaments expressives, analogical bases elaboration of cartographic bases in environment ArcGIS 9.1. The Analysis of the relief, in the investigated area, allowed to identify as genetic groups: ) Group of Degradation - Constituted of System of Mountain ranges (Mountain range of the Trucará) with flattened topos of amplitude varying between 253 and 290 meters, System of Mounts with angular topos up to 180 meters and Colinoso System with 0 amplitude varying it enters m (base level) up to 120 meters, which constitute most of the paisagística expression; b) Group of Agradação - Englobando Aluvial Plain Systems and System of Fluvial Terraces. These systems are shown with geometrias whose joints if give through the installation of discontinuities, characterizing morfoestrutural compartimentação. The integration of the data, deriving of the analysis of the relief, as well as the characterization of the anomalies of draining and the discontinuities, allowed to the recognition of "landorfms" elementary schools tectonics associates the beams of guided lineaments the E-W, NW-SE, NE-SW and N-S. The joint enters beams of neotectonics imperfections gives way to define one extensional romboedro to south of the parallel 3030"S. The romboedral structure is defined by the arrangement between beams of guided discontinuities to NW-SE, with symmetrical trend and apparent transtensive nature and guided beams of discontinuities the E-W, to the center of the area, with probable dominant component "strike-slip". This geometry is cut by to complicate structures guided to NE-SW. Three main beams of guided discontinuities the N-S affect the inquiry area, and represent "landforms" elementary schools tectonics with extensional trend. These structures had been interpreted as decurrent of the reactivation of the Cinturão Araguaia. They are organized in an anti-symmetrical structure with dominant diving for East and in the height of the meridian 49038W they seem to have strong bond with the tracing of the Tocantins River and imposes fort has controlled to the quaternary deposits. The draining net adjusts it to these standards of structural tropia readily, which answer for the presence of anomalous feições as arcs and elbows, and for the installation of standards in treliça, with strong asymmetry, some partially interpreted as treliça of imperfection. Morfogênese of the area in appraise, in that it concerns to its tectônics aspects was admitted as tied to the performance of a binary guided dextral the E-W, fruit of the dynamics established for the current phase of drift of the American South Plate for West.
Acesso aberto (Open Access)
Assinatura geoquímica de apatita de rochas sanukitoides do sudeste do cratón amazônico, Província Carajás.
(Universidade Federal do Pará, 2019-05-26) FONSECA, Camila Santos da; LAMARÃO, Claudio Nery; http://lattes.cnpq.br/6973820663339281
The Rio Maria Sanukitoid Suite, included in the Rio Maria Domain, southern portion of the Carajás Province, is composed of granodiorites and associated mafic and intermediary rocks. It has large exposures in the north of Redenção city, south of Rio Maria, east of Bannach and northeast of Xinguara, SE portion of the Amazonian Craton, being intrusive in greenstones of the Andorinhas Supergroup, Arco Verde Tonalite and Complex Caracol Tonalitic. Other granodioritic rocks correlated to the Rio Maria sanukitoids were described in the regions of Água Azul do Norte, Ourilândia do Norte, Serra do Inajá and Xingu region, all of them included in the Carajás Province. The Rio Maria Sanukitoids are metaluminous rocks, calcic-alkaline affinity and enriched with Mg, Cr and Ni in relation to other granodiorite rocks. They present primary epidote, zircon, allanite, titanite, apatite and magnetite as main accessory phases. U-Pb and Pb-Pb zircon dates defined crystallization ages of 2,87 Ga for these rocks. Apatite is a generally early mineral in the order of crystallization of granitoid rocks. Because of its properties, it can incorporate variable contents of REE and other trace elements, such as Na, K, Mn, F, Cl, Sr, Y, Pb, Ba, Th, U, V, and has been used as a good petrological and metallogenetic indicator of its host rock. The objective of this dissertation was the morphological and compositional study, by electron microprobe, of apatite crystals of granodioritic rocks from Rio Maria Sanukitoid Suite in Rio Maria, Ourilândia do Norte and Bannach regions, Rio Maria Domain, Carajás Province. For comparative purposes apatites of Leucogranodiorite with high Ba-Sr from Água Azul do Norte and of the Trondhjemite Mogno from Bannach region, both archaeans, have been studied. It was also compared to the apatites of the Seringa and Antônio Vicente paleoproterozoic type A granites, the first weakly oxidized and sterile, and the second, reduced and mineralized to Sn. The apatites of the Ourilândia do Norte sanukitoids have compositional zonations concentric to oscillatory more evident and complex, with well defined light-dark zones. On the other hand, the apatites of the Rio Maria and Bannach sanukitoids form more homogeneous crystals, with not evident or non-existent zones. The apatites of high Ba-Sr Leucogranodiorite and Mogno Trondhjemite are equally developed (> 150 μm), but with rare zoning restricted to the edges of some crystals. Inclusions of zircon are common only in apatites of Mogno Trondhjemite. In the Seringa granite, the apatites are comparatively smaller (<100 μm), subhedral to euhedral and with well defined zonations, while those of the Antônio Vicente granite are poorly developed (<30 μm), subrounded and free of compositional zonations. The main compositional variations among the apatite of the Rio Maria Domain, in addition to CaO, P2O5 and F, are in the highest content of LREE (La, Ce, Pr, Sm, Eu) found in the apatite of Ourilândia do Norte and Rio Maria in relation to those of Bannach, which show lower concentrations and sub-horizontal trend in the diagram (La + Ce + Pr + Sm) vs. (Gd + Yb + Y). This enrichment in REE is more evident in the diagram ΣREE + Y vs (La + Ce + Pr + Sm + Eu), where the studied apatite form an enrichment trend towards the Bannach - Rio Maria - Ourilândia do Norte sanukitoid. Based on this geochemical signature, similar and more enriched magmatic sources in LREE are suggested for the apatites of Ourilândia do Norte and Rio Maria. On the other hand, the apatites of Bannach sanukitoids presented higher and more variable concentrations of CaO, P2O5 and F and lower LREE, suggesting origin from a compositionally different and more LREE depleted magma. The apatites of the Mogno Trondhjemite and the leucogranodiorite high Ba-Sr are also more impoverished in LREE and tend to follow the apatite of the Bannach sanukitoides in the diagrams, but the apatite of the leucogranodiorites show greater enrichment in Sr. The Seringa granite has apatites more enriched in F and REE + Y when compared to the apatite of the archaean rocks, and they stand out in all the geochemical diagrams. This fact demonstrated that apatite compositions can also be used to record petrogenetic processes and to differentiate magmatic compositions that marked changes during the crustal evolution of a region, for example, distinguishing between Archaean and Paleoproterozoic granitoids, and are, therefore, useful in studies of provenance. Apatites of Antônio Vicente paleoproterozoic granite, mineralized in Sn, show high concentrations of F, Mn, Fe, Y and REE (except Eu), in comparison to other granitoids and can be used as a good metallogenetic indicator.
Acesso aberto (Open Access)
Assinatura geoquímica do ouro na Província Mineral do Tapajós, Cráton Amazônico: o exemplo dos depósitos São Jorge e São Chico
(Universidade Federal do Pará, 2025-06-19) GOMES, Iolanda Clara do Carmo; LIMA, Rafael Guimarães Corrêa; http://lattes.cnpq.br/6751523860876497; LAMARÃO, Claudio Nery; http://lattes.cnpq.br/6973820663339281; https://orcid.org/0000-0002-0672-3977
Gold has a great economic importance, and the determination of its geochemical and isotopic signatures, exploited in Brazil’s main mineral provinces, has become a valuable tool not only for mineral exploration but also for tracing its origin and circulation. The aim of this study is to characterize and compare the chemical composition of gold from two different deposits using scanning electron microscopy paired with energy-dispersive spectrometry (SEM‑EDS), to evaluate the viability in differentiating provenance on local and regional scales, and to discuss the factors controlling element distribution in native gold. São Jorge and São Chico are gold deposits located in the eastern portion of Tapajos Mineral Province, aligned along the Tocantinzinho lineament (WNW‑ESE). The gold mineralization at São Jorge deposit consists of a paragenesis formed by gold + pyrite + chalcopyrite ± sphalerite and, rarely, galena, which host two generations of gold with distinct chemical compositions. These gold phases occur either in quartz veins and/or in sulfide disseminations in strongly hydrothermally altered host rocks. In this deposit, gold is mainly hosted by pyrite, occurring in the form of inclusions with high Au contents (84.27–91.02 wt%) and filling pyrite fractures with a composition richer in Ag (7.86–15.72 wt%). The geochemical and textural differences indicate at least two distinct mineralizing events. In contrast, the São Chico deposit shows a paragenesis formed by gold + pyrite + galena + sphalerite ± chalcopyrite, in which gold occurs as electrum within polymetallic sulfide‑bearing quartz vein systems. Here, gold is mainly hosted by galena, and textural relationships between these two minerals suggest simultaneous precipitation under low‑temperature conditions. Gold in this deposit also occurs with chalcopyrite and sphalerite, as reflected in its chemical composition, which shows higher average of Cu (0.44 wt%) and Zn (0.42wt%) contents, respectively. Principal component analysis (PCA) identified Ag, Fe, and Te as the elements with the greatest potential for gold discrimination between these two deposits. Gold microparticles from the São Jorge deposit exhibits a geochemical signature with higher contents of Au (73.82–91.02 wt%), Fe (0.54–6.21 wt%), and Te (0.37–3.61 wt%), compared to gold from the São Chico deposit, which displays higher concentrations of Ag (29.82–51.42 wt%).