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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Agora exibindo 1 - 6 de 6

Acesso aberto (Open Access)
Análises texturais de produtos derivados de LiDAR para discriminação de cangas lateríticas, Serra Sul de Carajás (PA)
(Universidade Federal do Pará, 2016-09-30) SANTOS, Jaqueline Alcântara dos; SILVA, Arnaldo de Queiroz da; http://lattes.cnpq.br/1682623730626187; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The characterization of geological features through products derived from remote sensing in humid tropical regions suffers severe restrictions due to the influence of vegetation on the radiometric measurements. This is the motivation to investigate new methodological approaches aimed at extracting remote sensing information data applied to geological mapping. This research aimed to develop a methodological approach to discriminate types of lateritic surfaces from textural parameters of the Haralick extracted shaded relief image generated Digital Model Land of high spatial resolution (1 m) derived from the last return signal (ground) of LiDAR data. The study area is located in body S11CD in Serra Sul of Carajás Mineral Province, including the city of Canãa dos Carajás (Pará State - Brazil). The body S11CD is characterized by a residual relief supported by ferruginous crust thick developed on Archean banded iron formations (Carajás Formation / Grão Pará Group) and is covered by savannah (campus rupestres) that contrast with the surroundings tropical rain forest. The lateritic crust in the study area is classified into (1) structural duricrust and (2) detrital duricrust. The difference between the types of lateritic crust was analyzed by microtopography relief metrics (Hrms), measured in the field and textural parameters of the Haralick extracted from the shaded relief image. Statistical tests of averages Hrms comparison (Student t test) showed that it is possible to identify the terrain microrugosidade kinds of lateritic duricrust present in S11CD. The object-oriented classification (GEOBIA) was used dissimilarity textural parameter of the Haralick to discriminate the types of lateritic duricrust. For this, it was used the standard deviation of the average dissimilarity threshold for separating the detrital duricrust (26.1 ↔ 33.234) and structure duricrust (20.573 ↔ 28.515). The result of this classification overlaid around 89.35% the study area, remaining ~ 11% of the image not classified, possibly as a result of noise in the LiDAR data. The validation of this classification attested that the overall accuracy of field data and the classification was 78.8%. Note also, that the structural duricrust occurs in the area as small "windows" through the detrital duricrust, which made it difficult to carry out field sampling at this site, so the errors of commission and of omission become high.
Acesso aberto (Open Access)
Aspecto tectôno-sedimentares do fanerozóico do nordeste do estado do Pará e noroeste do Maranhão, Brasil
(Universidade Federal do Pará, 1992-09-16) IGREJA, Hailton Luiz Siqueira da; FARIA JUNIOR, Luis Ercílio do Carmo; http://lattes.cnpq.br/2860327600518536
A synthesis of the tectono-sedimentary evolution of the Phanerozoic at Northeastern Pará and Northwestern Maranhão is discussed with enphasis to the Bragança-Viseu and São Luis basins. This research is based on field observations, gravity (Bouguer Anomalies), magnetic, seismic, and borehole data interpretations. Five sedimentary sequences are defined: 1) Piriá-Camiranga (Cambrian-Ordovician to Silurian), 2) Lower Itapecuru (Lower Cretaceous), 3) Upper Itapecuru (Upper Cretaceous), 4) Pirabas-Barreiras (Oligocene-Mioceneto Pliocene) and 5) Pará (Quaternarg). The regional basement is an igneous-metamorphic assemblage which outcrops in two windows. The sedimentary and structural features of the Piriá-Camiranga sequence are consistent with a tectono-sedimentary model of coastal environment with fluvio-glacial influence related to a tilted blocks system induced by strike-slip motion. This sequence represents an evolutive stage coincident to the Eo-Hercynian paroxysm (Paleozoic) which ended with the closure of the Atlantic I (first geotectonic cycle of the Gondwana). The Lower and Upper Itapecuru, as well as the Pirabas-Barreiras and Pará sequences, are related to the Equatorial Atlantic opening during the Mesozoic and Cenozoic times. They are analysed by severa), authors which reached the interpretations refered to as Models of: Fracture Zones; Anti-clockwise rotation of Africa; Intumescence and fracturing; Clockwise rotation of the South America Nate; and Wrench Tectonics. These models were experimented for the studied area. The time and environments of the sedimentary processes are related to the rift and pos-rift phases of the equatorial coastal basins, but these models were not adequate to explain the structural features. A new model is proposed to explain the origin and development of the basins taking into account a regional NE-SW extension axis and formation of the Bragança-Viseu and São Luís basins with similar polarities. The tectono-sedimentary map for the Phanerozoic of the Northeastern Pará / Northwestern Maranhão enhances the compatibility of the depositional and tectonics systems with two periods of oceanic opening of the Northern Gondwana border.
Acesso aberto (Open Access)
Avaliação da exatidão cartográfica de dados SRTM e atualização da carta plani-altimétrica Salinópolis - NE do Pará
(Universidade Federal do Pará, 2009-05-22) MARTINS, Elainy do Socorro Farias; SOUZA FILHO, Pedro Walfir Martins e; http://lattes.cnpq.br/3282736820907252
The Brazilian topography information, in 1:100.000 scale, covering only 75,39 % of the country, leaving many empty mapping, especially in Amazon region. This information was derived by aerophotogrammetric methods, applied in aerials photos of the 60 to 80 decades. Because the complexity of applied methods and others technician problems, most of planialtimetric maps are outdated, which impossibility the use of them. Nowadays, the topography information is largely derived from digital elevation models, for example, imageries of Shuttle Radar Topography Mission (SRTM). In this paper, the SRTM was analyzed based on altimetric Cartography Accuracy Standard (PEC), in the update of Salinopolis map of 1982. The analysis of SRTM altimetry, on Salinópolis region, showed that it can be used in class C scale 1:50,000 and Class A scale 1:100,000. Since the SRTM images are compatible with the scale and class of Salinópolis map, was used the original version of the SRTM (90 meters spatial resolution) to update altimetry and Landsat TM-5 imagries on planimetric base, following Brazilian Institute of Geography and Statistics parameters. With the update was found several differences, mainly in relation to planimetry. The update is very important, especially in coastal regions due to the dynamics and intensity of the different natural processes and man-made active, in addition, this methodology could be the basis for the upgrade of other maps and generation of new maps without this in of information, thus resolving the issue of lack of topographical information in certain ranges. Keywords: SRTM, cartography update, topographic charts, Amazon.
Acesso aberto (Open Access)
Estratigrafia e tectônica da Faixa Paraguai Norte: implicações evolutivas neoproterozóicas no Sudeste do Cráton Amazônico
(Universidade Federal do Pará, 2016-11-11) SANTOS, Iara Maria dos; PINHEIRO, Roberto Vizeu Lima; http://lattes.cnpq.br/3251836412904734; NOGUEIRA, Afonso César Rodrigues; http://lattes.cnpq.br/8867836268820998
The Northern Paraguay Belt, located at Southeast of Amazonian Craton, was established during the final stages of Brasiliano Cycle (940-620 My.) marked by the collisions among Amazonian, San Francisco and Rio de La Plata cratons to assembly the Gondwana West Supercontinent. The Northern Paraguay Belt consists mainly of metasedimentary rocks of the Cuiabá Group (720 My.), assigned to passive margins basins in an extensional context during the break-up of Supercontinent Rodinia (1.0 Gy.). These basins were affected by tectonic inversion by Brasiliano Orogeny, causing regional metamorphism and ductile crustal level deformation. Subsequently, the orogen had been uplifted, exposed to erosion and subjected to extensional episodes, developing intracratonic basin where sedimentary rocks of the Puga Formation (635 My.), Araras Group (627 ± 32 My.), Raizama Formation (645 ± 15 My.) and Diamantino Formation (541 ± 7 Ma.) were unconformably deposited in moderately deep to shallow storm influenced plataformal environment, tidal affected transitional environment and, lacustrine deltaic environment, respectively. These rocks are classically assigned to a Foreland Basin, however, ancient suture zones usually exposes the orogen roots, and these basins are currently not well preserved. These intracratonic or plataformal basin sedimentary rocks show considerable thicknesses and outcrop in Northeast-Southwest aligned trending mountain ranges. The São Vicente Granite (518 My.) and the Tapirapuã Formation basalts (197 My.) occur as intrusive rocks in the studied area along the Northern Paraguay Belt. The geological contacts between the metasedimentary rocks of the Cuiabá Group with sedimentary rocks of Puga Formation, Araras Group and Alto Paraguay Group, is interpreted as non-conformity. The Cuiabá Group rocks (720 My.) are mainly composed by quartz, plagioclase, muscovite, biotite and phengite and correspondent to greenschist facies affecting a low grade pelitic protolith. These rocks were deformed by ductile shear zone trending Northeast-Southwest, with strain partitioning, described as Transpressional Structural Domain D1, which was divided into two deformation facies: (1) D1-A and (2) D1-B. (1) The D1-A features a fine continuous foliation and stretching mineral lineation, with a rake of 40º, moderately inclined to recumbent, “S” type asymmetrical flexural folds; ductile-brittle thrustfaults and late strike-slip dextral ductile-brittle shear bands; (2) The D1-B is marked by a mylonitic foliation, with its stretching mineral lineation, with a 15º rake. These deformational facies comprises a mainly transpressional sinistral flow mostly dominated by simple shear and influenced by the strain partitioning. All structures indicate tectonic vergence from Northwest toward Southeast, as a result of the collisional setting of the Brasiliano Orogeny (620 Ma.). The sedimentary rocks were deformed under brittle crustal level conditions. Consequently they show inclined to subvertical, asymmetric "Z" type drag folds indicating dextral movement, besides normal faults and cataclastic foliation. The drag folds in the sedimentary rocks indicate tectonic vergence toward both Southeast and Southwest, therefore they were not generated under directed tectonic effort. Normal faults which deform sedimentary rocks are related to later transtensional reactivation episodes of ancient structures forming drag folds and Post-Paleozoic grabens affecting both the Parecis and Parana sedimentary basins. Late quartz veins occur emplaced only in the Cuiabá Group rocks. In conclusion, the Northern Paraguay Belt rocks were affected for at least two main tectonic episodes: (1) The Brasiliano Orogeny, only represented by Cuiabá Group rocks which show metamorphism and ductile deformation; (2) and transtensional reactivation that had been responsible for the establishment of the sedimentary basins followed by brittle deformation of Puga Formation, Araras Group, Raizama and Diamantino Formation.
Acesso aberto (Open Access)
Ferramentas multidisciplinares aplicadas à cartografia geológica: o exemplo da Folha Sobral – CE (SA-24-Y-D-IV)
(Universidade Federal do Pará, 2009-10-20) SANTOS, Márcia Valadares dos; ABREU, Francisco de Assis Matos de; http://lattes.cnpq.br/9626349043103626
The northwestern region of Ceará includes land belonging to areas Médio Coreaú and Central Ceará of Borborema Province. Studies in this region, which fits Sobral Sheet (SA. YD-24-IV) scale of 1:100,000, sought to contribute to the advancement of geological knowledge of the region and this was done initially to systematize data and pre-existing geological information from an extensive body of work carried out by IG / UFPA, since the 1980s. Digital images (Landsat-5/TM and SRTM) also had been used. About the image in digital format (Landsat) were applied techniques for enhancement, filtering, processing by principal components and IHS transformation, which helped supplement the results of visual interpretation. The airborne data Project Rio Acaraú 1974 were processed using the software Montaj Oasis, and was basically in the interpolation of data (125m), micro generation and the themes processed. For magnetic data, were generated images of the anomalous magnetic field, derived from the horizontal (dx and dy) and vertical (dz), amplitude of the horizontal gradient analytic signal amplitude and slope of the analytical signal. Data airborne gama-ray spectrometry was possible to generate images of the channels of K, U, Th and CT images and ternary (RGB and CMY). The interpretation of the products of remote sensing and airborne geophysics, geological mapping associated with the scale of 1:100,000 Sheet Sobral allowed characterization of the pattern of Lito-structural region. Based on the objectives in this research and the methodology for its implementation were produced a geological map enriched with the contribution of geometric elements revealed by integrated analysis of all products considered, as well as other thematic maps. The work demonstrates the importance of using images from remote sensing and airborne integrated data digitally as important tools for geological mapping, making the maps produced richer and more reliable also providing information that may be available for fast since all products resulting from this work are in digital format.
Acesso aberto (Open Access)
Metodologia de interpretação radargeológica: exemplo da sinéclise do Parnaíba e de seu embasamento
(Universidade Federal do Pará, 1995-09-29) LIMA, Mário Ivan Cardoso de; COSTA, João Batista Sena; http://lattes.cnpq.br/0141806217745286
This thesis develops the Radargraphic Elements Sistematic method, unknown throughout the world, in the geologic interpretation with Side-Looking Radar (Radargeology), a technique of major relevante in the field of natural resources, considering that the 1990s are the Radar's decade. The Radargraphic Elements Sistematic (SER) method reveals in a sistematic form the methodological route adopted , be it trough the text, trough schematic figures, or in Side-Looking Radar (SLR), with the radargraphic elements (features), ordered in five different stages: Reading, Recognizing, Identifying, Analisys and Interpretation (stricto senso). The stage Reading seeks to understand the meaning of the image elements in the terrain, with the goal of understand their meaning ; the Recognizing stages seek to group them according to the texture and tone radargraphic, so as to obtain homogeneous radargraphic zones; Identification seeks to study the relief forms in such zones, with regard to top and pending, as well as the studying of the drainage patterns, dissection degree and erosion resistance ;and the Analysis establishes the spacial and temporal relation of the relief forms researched through linear, planar and tabular features. With such information in hand , the Interpretation stage itself is reach, in which is possible to define lithologies, rounded structures, unconformities, discontinuities, folds and their interrelations,with a view to executing the Radargeological Map.In effect, a model area was selected to serve a paradigm for the the different methodological stages. To apply the Radargraphic Elements Sistematic method, the region encompassed by Parnaíba Sineclyse and its embasement was selected, with an area of around 925 000 km2, involving mostly Maranhão e Piauí states, located in northeastern region of Brazil. Such an example seeks to emphasys the applicability of the remote sensing in sedimentar terrains and their metamorphic embasement, due to academic and economic importance involved.. To carry out this stage, 52 SLR images mosaics were utilized, scale, I: 250 000, GEMS, X band, resulting in the definition of 39 basic radargeologicals unities, with a temporal stratigraphy, and 19 regional strucutures and 30 local ones, of which more than half were unpublished. These results are expressed in an explanatory text with ilustrations, including a Radargological Map on the milionth scale , and a structural sketch on the scale of 1:2 000 000. The study reaches a favorable conclusion regarding the potentialities of SLR images in geological whose difficulties in defining the radargraphic elements (features) due mainly to extensive shadows, foreshortening , layover and paralaxe effects, will be overcome with the use of more sophisticated Radar Systems (digital mode, stereoscopy, multifrequency, differents angles of incidence,etc) , as is the case with SIR-C and RADARSAT. Finally, the study attests of the excelence of Radargraphic Elements Sistematic method considering the results achieve with the study of the Parnaíba Sineclyse and its embasement, such as : definition of radargeological units, which mantain a strict relation with the lithostratigraphic units already described in the literature; structural setting with the identification of almost 50 morphostructures of regional and local character , and a perfect correlation with aeromagnetic maps.

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Navegando Programa de Pós-Graduação em Geologia e Geoquímica - PPGG/IG por CNPq "CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOLOGIA::CARTOGRAFIA GEOLOGICA"