979 resultados para Geologia


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O presente estudo tem como objetivo reunir os dados existentes sobre a área da futura Estação Ecológica Santa Elisa, localizada no Centro Experimental Central do Instituto Agronômico (IAC), em Campinas – SP. Assim, foram reunidos dados sobre os aspectos bióticos (fauna e flora) e abióticos (clima, geologia e geomorfologia, hidrografia e solos), resultando em uma caracterização da área como forma de subsídio para o plano de manejo. Através de saídas a campo foram levantados problemas que prejudicam a caracterização de uma estação ecológica, surgindo assim um segundo objetivo, adequar a área da futura unidade para o melhor enquadramento em tal categoria. Foram então elaborados projetos para melhorar o estado de conservação da futura unidade, sempre levando em consideração a falta de recursos. Sendo assim recomenda-se parcerias com universidades para que dessa forma se consiga implantar os projetos e realizar pesquisas de forma mais econômica. Embora o IAC tenha um histórico de pesquisas voltado apenas para a agricultura, a preocupação ambiental vem aumentando e a criação dessa unidade de conservação garante que se continue preservando os remanescentes presentes no IAC mesmo após a mudança de sua gestão.

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The crescent increasing demand of the electric power in Brazil has stimulated the implantation of Small Central Hydroelectric Power (SCHP) in several regions of the country. However, the silting up of the reservoirs is one of the main problems faced by hydroelectric power plants and SCHP. In this context, this research aimed evaluate the phenomenology and propose the enforcement of appropriate bioengineering techniques to control the intense erosive process of the hydrographical basin of the “Alto Rio Sucuriú,” that cause silting up of the reservoirs of the SCHP Costa Rica, located in the municipal district of Costa Rica (MS). In order to identify the phenomenology of the main falling in of this basin, a diagnosis of the conditions of the physical environment of the region (climate, geology, pedology, hydrology, and use of the ground) was realized. A surveying was also realized to specify the geometric feature of the falling in using the Total Station of the Ruide brand, series RTS 860R and the geodetic GPS of the Ashtech brand and the data obtained was used on the preparation of the Digital Elevation Model (DEM) of the falling in. Based on this diagnosis an official register of the falling in was done with identification of the different types of present erosion. Due to the advanced erosive stage of the falling in researched, the use of bioengineering techniques could be the best solution considering that the traditional engineering techniques make use of heavy material like concrete, iron and large machines that besides causing higher impact to the natural and esthetic aspects of the environment also require a higher investment of capital. This research establish a great cooperation to the knowledge of the erosive process and of the rehabilitation of the degraded areas with application of bioengineering techniques not only hydrographical basin of “Alto Rio Sucuriú” but also to other basins that show similar situation

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This monograph presents the data of geological mapping, structural and economic research of an area of about 230 km², in the outskirts of Jacutinga / MG, south of Minas Gerais State and adjacent areas of the northeastern state of São Paulo, in compliance with the discipline of Graduation Course of Geology at the Institute of Geosciences and Exact Sciences. It consists of Socorro-Guaxupé Nappe, developed in response to the collision of cratons Parana and Sao Francisco (630 Ma ago), with mass transit to the east, affected by the coexistence of a system pushes later, with convergence to Northwest, giving rise to the intricate area of interference of the two provinces. Locally there metasedimentary rocks of molasse basin of Proterozoic- Phanerozoic transition called Eleutério; Intrusive, equigranular and porphyroid granits, polyphase, and predominantly granodioritic migmatites Anatexia of structures with different neossomas predominantly granodioritic to granitic in Group Amparo, paragneisses arcosianos, greywacke, aluminous , calc-silicate, mica schists and migmatites of the aluminous migmatites and Itapira Anatexia of multi-phase, with neossomas predominantly granodiorite, with intercalations orthogneissic homogeneous granitic to tonalitic porphyroid composition of the Amparo. We tried to draw a geological map, semi-structural detail of the area in focus, with location of mineral occurrences economically viable operation. Furthermore, this study aims to train students in basic and applied geology, using techniques learned during the undergraduate course.

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In the Serra de Jacobina, localized in the North Central portion of the state of Bahia, occours the Jacobina Group. It’s a sedimentary basin and the gold deposit is stocked on the basal portion, which consist on quartzites intercalated with oligomítico metaconglomerates of Serra do Córrego Formation. There are controversies about the origin of the gold mineralization, but the currently most accepted hypothesis corresponds to a paleoplacer deposit with subsequent ore remobilization and concentration by hydrothermal process. The sulphidation is one of the main results of hydrothermal process, which was more detail characterized, besides identifying if there was more than one sulfides phase generation and its relationship with gold mineralization. The analyzes were performed from the main reef's (metaconglomerates mineralized levels) of Mine Canavieiras: Maneira, Holandez, Liberino, Piritoso, MU and LU. Chemical analyzes semi-quantitative were developed with EDS in MEV and also petrographics analyses. The main sulfide is pyrite, followed by chalcopyrite. Six groups of pyrite were classified according with chemical composition, however they show similarities in their habit and occurrence. Were identified four types of chlorite, labeled A, B, C, D. Gold occurs in free form, associate to pyrites, to Fe-Ti-Muscovite, to chlorite type B and to microfractures with iron hydroxide. Gold presents three different compositions: pure, with Ag or associated with U-Zr. The results of chemical analysis showed that the hydrothermal process have as their main source, ultramafic rocks present in the Jacobina Basin

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This work is proposed to evaluate the potential risk of an inert landfill in the city of Rio Claro (SP), and also suggest a source for the contamination. The study was proposed because it is known that there were legal technicalities greetings to guarantee the quality of groundwater. Given the requirements of the Environmental Company of São Paulo (CETESB) were installed monitoring wells in the area; sampled to groundwater and its contamination was found. In addition, we analyzed the main characteristics of the area, the arrangement and characteristics of the waste, the local geology and the hydrogeological system, so that I could find the source of contaminants, and predict the direction of dispersion even in groundwater. At the end of the work presents conclusions, recommendations and proposals for mitigating action

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Different forms of human pressure may occur in the pipeline ranges, due to the large extensions and various configurations of land use, which can pass through the pipelines. Due to the dynamics of these pressures, it is necessary to monitor temporal changes of land use and cover the surface. Under this theme, appears as extremely important to use products and techniques of remote sensing, as they allow the identification of objects of the land surface that may compromise the security and monitoring of the pipeline, and allows the extraction of information conditions on land use at different periods of time. Based on the above, this paper aims to examine in a temporal approach, the process of urban expansion in the municipality of Duque de Caxias, located on the outskirts of the metropolitan area of the state of Rio de Janeiro, as well as settlement patterns characteristic of areas that the changes occurred in the period 1987 to 2010. We used the technique of visual analysis to perform the change detection and the technique of image classification, aimed at monitoring human pressure over a stretch of track pipeline Rio de Janeiro - Belo Horizonte, located in the state of Rio de Janeiro. The stages of work involved the characterization of the study area, urban sprawl and the existing settlement patterns, through the analysis of bibliographic data. The processing of Landsat 5 images and the application of the technique of change detection were performed in three scenes for the years 1987, 1998 and 2010, while the classification process was performed on the image RapidEye for the year 2010. Can be noted an increase in urban area of approximately 22.38% and the change of land cover from natural to built. This growth is concentrated outside to the area of direct influence of the duct, occurring in the area of indirect influence of the enterprise. Regarding the settlement patterns of growth areas, it was observed that these are predominantly

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The Linguado Field is located in the extreme southwest portion of Campos Basin. It’s associated with Structural Badejo High and can be divided in two groups of faults: one manly formed by antithetic faults, with NW-SE direction, continuous to Badejo Fault, and another identified by N-S faults. Besides these faults had affected the basement and the stratification of basin, these systems also had contributed to coquina permoporosity development, that show 80% of recoverable oil volume of the field. The carbonate marine sequence, Albian age, it was deposited under the salt. This forms structures as like as pillows and raft as a result of the halocinese. Structurally the Linguado Field coquina has monoclinal direction with east dip, it’s cut by faults with slip up to 50 meters. In addition to structural control, stratigraphy and diagenesis also were important to carbonate trap oil. The identification of recoverable oil levels in the low phase of the coquina from Lagoa Feia Group was done by well data. The seismic 2D and 3D, with the well data, was used to structural interpretation to regional scale either to reservoir scale.

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Studies of mafic-ultramafic bodies have been carried out through the years due to their great use on the interpretation of geochemical and geotectonic processes that took place in Earth's history. Amongst them, chromitites are notably recognized for being excellent indicators of their parental magma chemistry and of different geotectonic environments, as well for frequently containing associated noble metals mineralization. Thus the investigation of one of this ultramafic bodies that occurs inside the Pilar de Goiás Greenstone Belt was proposed, resulting in a detailed map of the chromitites and country rocks, as well as innumerous new data on the chemistry of chromite and associated matrix and accessory minerals. These studies were based upon geological field observations, optic and Scanning Electron Microscope (SEM), besides electron microprobe and cathodoluminescence analysis performed at the “Eugen F. Stumpfl Laboratory” of the Montanuniversität Institute of Resource Mineralogy, University of Leoben - Leoben, Austria. The chromitites are composed of 40-70% in volume of chromite (~50% on average), 14-55% of talc (~30% on average), 3-60% of chromium rich chlorite (~20% on average), traces to 4% of iron hydroxides and traces to 3% of rutile (1,5% on average). The chromite occurs as large spherical aggregates or as fine grained subhedral crystals disseminated in the matrix. This aggregates have diameters of 0.3-1.5 cm (1 cm on average) and are extremely well rounded, massive to intensively fractured, and commonly deformed to ellipsoids. When observed under the microscope, these aggregates show well rounded to slightly irregular borders, but on their interiors, these structures are represented by fine to medium grained euhedral to subhedral chromite crystals that have sharp contacts between themselves. The rock's matrix is basically made of chlorite and talc that define a metamorphic foliation (Sn), being the talc an alteration product ...

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The Guaraní aquifer has relevant importance both as a source of water for several urban centres and the development of agriculture and livestock. In recharge areas the aquifer is free and, therefore, subject to contamination of effluents and tailings deposited on soils that cover it. Thus, it becomes crucial not only its protection at all levels, as the knowledge of its degree of natural vulnerability. The present work used geostatistics modeling techniques to study the natural vulnerability of the Guaraní aquifer in the city of Rio Bonito, State of São Paulo, southeastern Brazil, where the Guarani aquifer is exposed. These techniques, extensively used in evaluation studies of mineral deposits and oil tanks, can be adapted to produce a spatial classification or a regionalisation of probabilistic indices of vulnerability. By ordinary kriging method maps of vulnerability classification were obtained. To determine the vulnerability of the aquifer was employed the Aquifer Vulnerability Index (AVI), which requires knowledge of unsaturated zone thickness and permeability. The final product was a map with probabilistic index of vulnerability of the Guaraní aquifer, which presented values between 0 to 0.33 years, framing the area studied in AVI class extremely high vulnerability

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Classical statistical techniques which necessarily assume that all sampling units are random and independent were always used in the timber industry. Geostatistics considers that certain phenomena are characterized by spatial dependence: values of sampling units closer to each other tend to be more similar than values of sampling units farther away. This study aimed to characterize the spatial variability of the finishing (dyer) in the upper and lower surfaces of four edge glued panels by using geostatistical methods using geoR. Semivariograms were constructed for the analysis of spatial dependence. The spherical mathematical model was the best fit to the semivariograms generated, and was done the interpolation of the data (kriging) in samples where the distribution of dyer presents spatial dependence. In the bottom surfaces of two panels where the spatial dependence was detected geostatistical methods characterized a very large spatial variability due to the heterogeneous application of the finishing

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A tectono-stratigraphic study of bivalve coquina-reservoir of Linguado Field allowed to identify two trends of permoporosity development. The delineation of these depositional-diagenetic traps were made through structural and stratigrafic cross-sections and maps. It resulted in the identification of shelf-ramp systems (tilted to SSE), it tickens from 60 to 70 meters and ends against an antithetic fault. The main coquina is bounded by fine siliciclastic units, white clay (low Gamma Ray values) or shale (high Gamma Ray values) lithologies, influencing diagenesis of basal or top coquina limestones (cimented, non-porous). Also in the middle of coquina-reservoir the “clayer” material is also associated with cemented carbonates, with also compartimentalize the reservoir into two subzones. The coquina porosity of the subzones is taken from density-neutron logs, while induction log estimates permeabilities and fluid saturations. It’s noticed the porosity development into pairs, good one followed by a regular/poor one and vice versa. These pairs form verticals succession, pair cycles where porosity improves or decreases upwards. These two scales of pore heterogeneity impose strong layering to the reservoir, and influences fluid saturations, oil-water contacts and porosity cut-offs. In a cross-section with density and induction logs, it can be observed the porosity variation along the shelf-ramp coquina (between 3LI_0004_RJS e 3RJS_0157C_RJ), the porosity is better developed in a downdip direction in the case of the two shelf wells, and also be the three ramp wells. The southern west downdip, 3RJS_0157C_RJ well, has best porosity pairs-cycles; however, its lowest structural conditions favour water saturation. Therefore it is fundamental for reservoir fluid evaluation a cross-plot analysis of RHOB-NPHI and Induction logs

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Geological-geotechnical problems affecting escarps as well as embankment and fill slopes of roads and motorways may generate different types of unsteadiness, which are mainly arisen from the deficient knowledge about the physical environment. This results in unsuitable engineering projects and inadequate executions, which can be worsened by an occasional inappropriate maintenance of the construction. A geologically-geotechnically characterization of escarps and slopes is crucial in order to prevent these problems. This work deals with a geological-geotechnical study of 1:10.000 scale mapping in a stretch of a local road (CHQ-40) at the Serra de Itaqueri, Charqueada town, State of São Paulo. The stretch is known by several physical problems as erosion and mass movement. The methods of study were based on an integrative analysis of the diverse elements of the physical environment by using aerial photographs - to obtain the physiographic compartmentalization of terrain units - as well as field work - to accomplish the evaluation of the units by employing sketch lists. To achieve this, we selected several techniques in order to identify and classify different types of existing problems as erosion, landslide in embankments and fill slopes, rockfall, block rolling, among others. We also included the analysis of soil horizon, thickness and composition. The geological-geotechnical mapping resulted in six units: 1- Sandstones in cuesta’s backhill; 2 – Basalts in cuesta’s front; 3- Sandstones in cuesta’s front; 4 – Talus and colluvial deposits at cuesta’s foothill; 5- Sandstones of the Piramboia Formation in hillside; and 6 – Colluvial soil in the hill top. A characterization of the geological-geotechnical units is detailed, coupled to the cartographic material. Other cartographic products elaborated for this study included 1:10.000 maps of hypsometry, slope and curvature

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The evaluation of soil permeability throughout the weathering profile is one of the most important features to be considered in environmental studies. This study, developed from field testing and analysis of data obtained by geostatistical methods, aims at mapping the permeability around the Ribeirão Claro river. The intent is to simulate an accident with toxic liquids where soil permeability is of fundamental importance. Another purpose of the research was to determine the minimum time that, in the event of an accident, a possible contaminant to reach the water table level and be routed to the nearest drain, in this case, the Ribeirao V Claro river constitutes fundamental information. The studied area of approximately 4 km² is located within the UNESP-Rio Claro campus, consisting of colluvial soil from Fm. Rio Claro superimposed on residual soil of Fm. Corumbataí. The method used to determine the permeability is the concentric cylinders performed on a sampling grid with 64 points containing spacing of 5 meters EW and 10 meters NS. In the places of permeability tests were collected samples for laboratory determination of the percentage of fines. From particle size analysis was performed and analysis statistical and geostatistical on this data. The histogram was based on the statistical studies, and the semivariograms were based on geostatistical estimation methods. Based on the comparison between the maps and the data obtained, it was determined that the percentage of fines in colluvial surface soil has little influence on permeability, which the proximity to the Ribeirao Claro river, the eastern portion, a factor that influences the distribution of permeability values

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The Namorado Oil Field represents the beginning of the oil exploration in Brazil, in the 70s, and it is still a subject of researches because the importance of this turbidite sandstone in the brazilian oil production. The Namorado’s production level was denominated “Namorado sandstone”, it is composed by turbidite sandstone deposited during the Albian-Cenomanian. In order to define the structural geometry of the main reservoir, geological and geophysical tools like RECON and Geographix (Prizm – Seisvision) softwares were used, and its application was focused on geological facies analysis, for that propose well logs, seismic interpretation and petrophysical calculations were applied. Along this work 15 vertical wells were used and the facies reservoirs were mapped of along the oil field; it is important to mentioned that the all the facies were calibrated by the correlation rock vs log profile, and 12 reservoir-levels (NA-1, NA-2, NA-3, NA-4, NA-5, NA-6, NA-7, NA-8, NA-9, NA-10, NA-11 e NA-12) were recognized and interpreted. Stratigraphic sections (NE-SW and NW-SE) were also built based on stratigraphic well correlation of each interpreted level, and seismic interpretation (pseudo-3D seismic data) on the southeastern portion of the oil field. As results it was interpreted on two- and three-dimensional maps that the deposition reservoir’s levels are hight controlled by normal faults systems. This research also shows attribute maps interpretation and its relationship with the selection of the reservoir attribute represented on it. Finally the data integration of stratigraphic, geophysical and petrophysical calculations lets us the possibility of obtain a detail geological/petrophysical 3D model of the main reservoir levels of “Namorado sandstone” inside the oil/gás field

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The work depicts the study of geological and geotechnical characteristics presents, together with an analysis of the physical environment components and evaluation of its units, along a marginal stretch at Rodovia Amparo-Morungaba (SP-360) in order to present a geological and geotechnical map, 1:25.000 scale (one of the objectives of the work). There was also a geotechnical assessment of the present geological processes and the development of corrective measures necessary to establish safe conditions for road traffic. The method for the characterization of geological and geotechnical analysis was integrated the physical components associated with photo interpretation (another objective of this work) based on Google Earth´s air images along the referred highway. In addition, field studies were made that helped in the distribution and compartmentalization of the six geological and geotechnical units and profiles of each specific alteration were also made. The finals results present the above mentioned map, a detailed description of each of the six units and a a geotechnical assessment of the present geological processes and the development of corrective measures necessary to establish safe conditions for road traffic. Also, had success at photo interpretation based on Google Earth´s air images, obtaining stereoscopy