• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 4
  • 3
  • 1
  • 1
  • Tagged with
  • 9
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Analyse cinématique et paléosismologique des terminaisons NW et SE de la faille Pampak-Sevan-Syunik (PSS), Arménie / The morphostructural and paleoseismologycal analysis of the NW and SE segments of Pambak-Sevan-Syunik fault (PSS), Armenia

Mkrtchyan, Mushegh 07 October 2016 (has links)
L’Arménie se situe dans la zone de collision entre Arabie et Eurasie et est le siège d’une déformation intracontinental active comme l’atteste les nombreux tremblements de terre historiques qui s’y sont produits. Tous ces séismes, destructeurs, attestent d’une forte activité sismique régionale, et il est par conséquent important d'évaluer l’aléa sismique associé aux structures actives qui génère cette sismicité.Le travail présenté ici, expose les résultats de l’analyse de la tectonique active au niveau des terminaisons nord-ouest et sud-est de la faille de Pambak-Sevan-Syunik (PSSF), une des failles décrochant majeure qui traverse l'Arménie du NW au SE. La quantification des déformations en termes de géométrie, cinématique, vitesse de glissement et paléosismicité, en utilisant les méthodes de datation 3He cosmogénique, OSL/IRSL et radiocarbone, révèlent des comportements différents entre les deux régions.Au niveau de la terminaison nord-ouest, dans la région d’Amassia, la faille PSSF s’incurve vers l'ouest et se subdivise en deux branches de direction WNW-ESE, et de cinématique inverse, définissant une structure en pop-up. Nous estimons une vitesse de soulèvement de 0.5 ± 0.1 mm/an et une vitesse de raccourcissement NNE-SSW de 1.4 ± 0.6 mm/an. Ces résultats suggère que l’essentiel des ~2 mm/an de mouvement dextre estimés le long de la faille de PSSF sont absorbés au niveau du pop-up d’Amassia.Au niveau de la terminaison sud-est, dans la région du volcan Tsghuk, la faille PSSF semble disparaitre. Le peu d’activité tectonique est caractérisée par des failles normales sub-méridiennes associées à une légère composante décrochant dextre. Nous déterminons une vitesse de glissement vertical de ~0,2 mm/an, une vitesse d’extension ~EW de ~0,1 mm/an associée à une composante dextre de ~0,05 mm/an. Ces résultats suggèrent que le mouvement dextre observé le long de la faille de PSSF plus au nord, a été transféré sur d'autres failles plus à l'ouest dans le Karabakh (faille Hagari ou autres structures situés encore plus au NW). / The territory of Armenia was located in the collision zone between Arabia and Eurasia, and is the seat of active intercontinental deformations, which was attested by the many historical earthquakes that have occurred in this region. All these destructive earthquakes show a strong regional seismic activity, and therefore it is important to evaluate the seismic hazard associated with active structures that generates this seismicity.This study presents the results of the analysis of the active tectonics within the northwestern and southeastern extensions of the Pambak-Sevan-Syunik fault (PSSF), a major right-lateral strike-slip fault cutting through Armenia (NW - SE). Quantifying the deformations in terms of geometry, kinematics, slip rates and earthquake activity, using cosmogenic 3He, OSL/IRSL and radiocarbon dating techniques, reveal different behaviors between the two regions.Within the northwestern extension, in the region of Amassia, the PSSF bends to the west and splits into two main WNW-ESE trending reverse faults defining a compressional pop-up structure. We estimate an uplift rate and a shortening rate of 0.5 ± 0.1 mm/y and 1.4 ± 0.6 mm/y, respectively. This suggests that most of the ~2 mm/y right lateral movement of the PSSF seems to be absorbed within the Amasia pop-structure.Within the southeastern extension, in the region of Tsghuk volcano, the PSSF shows signs of dying out at the southernmost tip of the Syunik graben. A very slow NS trending normal faulting associated with a slight right-lateral movement characterizes the tectonic activity in the region of Tsghuk volcano. We estimate vertical slip rates, EW stretching rate, and right-lateral slip rate of ~0.2 mm/y, ~0.1 mm/y and ~0.05 mm/y, respectively. These results lead to the conclusion that the right lateral movement observed further north along the PSSF is mainly transferred within other active faults further west within the Karabagh (Hagari fault or other structures further northwestwards).
2

Development of submarine canyon systems on active margins: Hikurangi Margin, New Zealand.

Mountjoy, Joshu Joseph Byron January 2009 (has links)
The development and activity of submarine canyons on continental margins is strongly influenced by temporal and spatial changes in sediment distribution associated with orbitally-forced sea-level cyclicity. On active margins, canyons are also strongly influenced by tectonic processes such as faulting, uplift and earthquakes. Within this framework the role of mass-wasting processes, including sediment failures, bedrock landslides and sediment gravity flows, are to: 1) transport material across the slope; 2) act as intra-slope sediment sources; and 3) shape seafloor morphology. In this project the seafloor-landscape signatures of tectonic and geomorphic processes are analysed to interpret the development of submarine canyon morphology on active margins. Datasets include high-resolution bathymetry data (Simrad EM300), multichannel seismic reflection data (MCS), high-resolution 3.5 kHz seismic reflection data, sediment cores, and dated seafloor samples. High-resolution bathymetric grids are analysed using techniques developed for terrain-roughness analysis in terrestrial landscapes to objectively map and interpret features related to seafloor mass-wasting processes. The Hikurangi subduction margin of New Zealand provides world-class examples of the control of tectonic and sedimentary processes on margin development, hosting multiple examples of deeply-incised canyon systems across a range of scales. Two main study sites, in Poverty Bay and Cook Strait, provide examples of canyon formation. From these examples conceptual and representative models are developed for the spatial and temporal relationships between active tectonic structures, geology, sediment supply, slope- and shelf-incised canyons, slope gully systems, and bedrock mass failures. The Poverty Bay site occurs on the subduction-dominated northern Hikurangi Margin, where the ~3000 km² Poverty re-entrant hosts the large Poverty Canyon system, the only shelf-break-to-subduction-trough canyon on the northern margin. The geomorphic development of the re-entrant is affected by gully development on the upper slope, and multi-cubic-kilometre-scale submarine landslides. From this site the study focuses on the initiation and development of upper-slope gullies and the role of deep-seated slope failure in upper-slope evolution. The Cook Strait site occurs on the southern Hikurangi Margin in the subduction-to-strike-slip transition zone. The 1800 km² Cook Strait Canyon incises almost 50 km into the continental shelf, with a multi-branching canyon head converging to a deeply slope-incised meandering main channel fed by multiple contributing slope canyons. Other medium-sized canyons are incised into the adjacent continental slope. Fluvial sediment supply to the coast is relatively low on the southern margin, but Cook Strait is subject to large diurnal tidal currents that mobilise sediment through the main strait area. Prior to the morphostructural analysis of the Cook Strait and Poverty study sites a revision of the tectonic structure was undertaken. In Cook Strait a revision of the available fault maps was undertaken as part of a wider, related tectonic study of the central New Zealand region. In Poverty Bay very limited prior information was available, and as part of this study the structure and stratigraphy of the entire shelf and upper slope has been interpreted. On active tectonic margins submarine canyons respond to tectonics at: 1) margin-setting scales relating to their ability to become shelf incised; 2) regional scales relating to canyon-incision response to base-level perturbations; and 3) local scales relating to propagating structures affecting canyon location and geometry. Interpretation of the spatial distribution of fluid vent sites, gully development and landslide scars leads to the conclusion that seepage-driven failure is not a primary control on the widespread instances of gully formation and landslide erosion affecting structurally-generated relief across the margin. Rather, the erosion of tectonic ridges is dominated by tectonics by: slope oversteepening; weakening of the rockmass in fault-damage zones; and triggering of slope failure by earthquake-generated cyclic loading. Deep-seated mass failures affect numerous aspects of submarine landscapes and play a major role in the enlargement of canyon systems. They enable the development of slope gully systems and represent a major intra-slope sediment source. Quantitative morphometric analysis together with MCS data indicate that landslides may evolve to be active complexes where landslide debris is remobilized repeatedly, analogous to terrestrial-earthflow processes. This process has not previously been documented on submarine slopes. A model is presented for the evolution of active margin canyons that contrasts highstand and lowstand canyon activity in terms of channel incision, sedimentary processes and slope-erosion processes. During sea-level highstand intervals, canyons become decoupled from their terrestrial/coastal sediment-supply source areas, while during sea-level lowstand intervals, canyons are coupled to fluvial and littoral sediment-supply sources, and top-down (i.e. shelf-to-lower-slope) sediment transport and channel incision is active. Canyon-head areas are incision dominated during the lowstand while mid to lower canyon reaches experience both a transient increase in sediment in storage and canyon-fill degradation and incision into bedrock. Tectonics influences the canyon landscape through both uplift-controlled perturbations to canyon base-levels and earthquake-triggering of mass movement. Following sea-level rise the sediment supply to canyon heads will be switched off at a certain threshold sea level. From this point canyon heads become aggradational. Mid to lower canyon reaches continue to incise due to continuing tectonic uplift and earthquake-triggered slope instability. Knickpoints are propagated up channel and excavate canyon and sub-canyon channels from the bottom up. Thus, while top-down infilling of non-coupled canyons occurs during sea-level highstands, the lower reaches of active margin canyons continue to incise due the influence of tectonic processes.
3

Development of submarine canyon systems on active margins: Hikurangi Margin, New Zealand.

Mountjoy, Joshu Joseph Byron January 2009 (has links)
The development and activity of submarine canyons on continental margins is strongly influenced by temporal and spatial changes in sediment distribution associated with orbitally-forced sea-level cyclicity. On active margins, canyons are also strongly influenced by tectonic processes such as faulting, uplift and earthquakes. Within this framework the role of mass-wasting processes, including sediment failures, bedrock landslides and sediment gravity flows, are to: 1) transport material across the slope; 2) act as intra-slope sediment sources; and 3) shape seafloor morphology. In this project the seafloor-landscape signatures of tectonic and geomorphic processes are analysed to interpret the development of submarine canyon morphology on active margins. Datasets include high-resolution bathymetry data (Simrad EM300), multichannel seismic reflection data (MCS), high-resolution 3.5 kHz seismic reflection data, sediment cores, and dated seafloor samples. High-resolution bathymetric grids are analysed using techniques developed for terrain-roughness analysis in terrestrial landscapes to objectively map and interpret features related to seafloor mass-wasting processes. The Hikurangi subduction margin of New Zealand provides world-class examples of the control of tectonic and sedimentary processes on margin development, hosting multiple examples of deeply-incised canyon systems across a range of scales. Two main study sites, in Poverty Bay and Cook Strait, provide examples of canyon formation. From these examples conceptual and representative models are developed for the spatial and temporal relationships between active tectonic structures, geology, sediment supply, slope- and shelf-incised canyons, slope gully systems, and bedrock mass failures. The Poverty Bay site occurs on the subduction-dominated northern Hikurangi Margin, where the ~3000 km² Poverty re-entrant hosts the large Poverty Canyon system, the only shelf-break-to-subduction-trough canyon on the northern margin. The geomorphic development of the re-entrant is affected by gully development on the upper slope, and multi-cubic-kilometre-scale submarine landslides. From this site the study focuses on the initiation and development of upper-slope gullies and the role of deep-seated slope failure in upper-slope evolution. The Cook Strait site occurs on the southern Hikurangi Margin in the subduction-to-strike-slip transition zone. The 1800 km² Cook Strait Canyon incises almost 50 km into the continental shelf, with a multi-branching canyon head converging to a deeply slope-incised meandering main channel fed by multiple contributing slope canyons. Other medium-sized canyons are incised into the adjacent continental slope. Fluvial sediment supply to the coast is relatively low on the southern margin, but Cook Strait is subject to large diurnal tidal currents that mobilise sediment through the main strait area. Prior to the morphostructural analysis of the Cook Strait and Poverty study sites a revision of the tectonic structure was undertaken. In Cook Strait a revision of the available fault maps was undertaken as part of a wider, related tectonic study of the central New Zealand region. In Poverty Bay very limited prior information was available, and as part of this study the structure and stratigraphy of the entire shelf and upper slope has been interpreted. On active tectonic margins submarine canyons respond to tectonics at: 1) margin-setting scales relating to their ability to become shelf incised; 2) regional scales relating to canyon-incision response to base-level perturbations; and 3) local scales relating to propagating structures affecting canyon location and geometry. Interpretation of the spatial distribution of fluid vent sites, gully development and landslide scars leads to the conclusion that seepage-driven failure is not a primary control on the widespread instances of gully formation and landslide erosion affecting structurally-generated relief across the margin. Rather, the erosion of tectonic ridges is dominated by tectonics by: slope oversteepening; weakening of the rockmass in fault-damage zones; and triggering of slope failure by earthquake-generated cyclic loading. Deep-seated mass failures affect numerous aspects of submarine landscapes and play a major role in the enlargement of canyon systems. They enable the development of slope gully systems and represent a major intra-slope sediment source. Quantitative morphometric analysis together with MCS data indicate that landslides may evolve to be active complexes where landslide debris is remobilized repeatedly, analogous to terrestrial-earthflow processes. This process has not previously been documented on submarine slopes. A model is presented for the evolution of active margin canyons that contrasts highstand and lowstand canyon activity in terms of channel incision, sedimentary processes and slope-erosion processes. During sea-level highstand intervals, canyons become decoupled from their terrestrial/coastal sediment-supply source areas, while during sea-level lowstand intervals, canyons are coupled to fluvial and littoral sediment-supply sources, and top-down (i.e. shelf-to-lower-slope) sediment transport and channel incision is active. Canyon-head areas are incision dominated during the lowstand while mid to lower canyon reaches experience both a transient increase in sediment in storage and canyon-fill degradation and incision into bedrock. Tectonics influences the canyon landscape through both uplift-controlled perturbations to canyon base-levels and earthquake-triggering of mass movement. Following sea-level rise the sediment supply to canyon heads will be switched off at a certain threshold sea level. From this point canyon heads become aggradational. Mid to lower canyon reaches continue to incise due to continuing tectonic uplift and earthquake-triggered slope instability. Knickpoints are propagated up channel and excavate canyon and sub-canyon channels from the bottom up. Thus, while top-down infilling of non-coupled canyons occurs during sea-level highstands, the lower reaches of active margin canyons continue to incise due the influence of tectonic processes.
4

CONDICIONANTES MORFOESTRUTURAIS E SUAS IMPLICAÇÕES NOS USOS DA TERRA E ÁREAS DE PRESERVAÇÃO PERMANENTE DA BACIA HIDROGRÁFICA DO SÃO JOÃO, CARAMBEÍ-PR

Pereira, Diely Cristina 27 February 2015 (has links)
Made available in DSpace on 2017-07-21T18:15:18Z (GMT). No. of bitstreams: 1 Paginas de Diely Cristina Pereira.pdf: 17372522 bytes, checksum: ffdf795191530854b9c0b541d661ef9f (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Landscapes show standard which expose different intensity, duration and magnitude in long term physical-natural interaction and inter relational, in special in those referring to geological time. Any disturbance, internal or external, in its elements conducts to a reordering in its relations, resulting in new standard arrangements. This geological-geomorphologic natural disturbances are meaningful as they produce peculiar shapes and features, in different scale, which can add scenic value to the landscape as well as to devalue the soil fitness to agriculture. This way, the aim of this research was to analyze the landscape in São Jõao River Basin, from the linear structure in landforms and use of land. It has started by the hypotheses that linear structural feature presence acts as condition factor in the landscape in the referred basin, not only for limiting the use of land expansion but also for enlarging permanent preservation areas. The Basin is located in the Center- oriental mesoregion in Paraná, between the cities Castro e Carambeí, in the morphostructural transition between sedimentary Basin of Paraná and its basement, directly influenced by ascension movement of Ponta Grossa Arc. To reach to this objective, it was searched SRTM geomorphometric data , to map linear structural feature, which results in identification of 92 lineaments, like valleys/canyons, which average length is 1,33km, and predominant directions SE/NW, coincidently to the arc. Lineaments associate to the hydrographic system, in the special the ones from first and second order (Strahler, 1952), which valleys are embedded in steep slopes, usually bigger than 45o. Through morphometric analyses, using obtained data by Castro topographic map (SG-22-X-A-V-4), it has been detected that the Basin has irregular and elongated shape, and it houses a fluvial hydrographic system of 4 order, with low density of fluvial canals which shows lithostructural in drainage maintenance difficulty and big carving sheds. The field survey allowed to identify the predominance of litholic Neosol, intersected by rocky outcrop, which limit intense agriculture activities. Through supervised classification by LandSat 5 TM satellite image, on May 5th, 2011, it was identified as classes of land use: forest cover, forestry, fields and agricultural areas, and in lowest proportion, the urban area of Carambeí. In general, these uses have restriction in shallow soil properties. In strong slope, in permanent preservation area, all through the hydrographic system. The structural landscape in São João Basin ends a set of springs and enclosed valleys, which banks with minimum of 30m width, were defined as Permanent Preservation Areas, besides strands with superior 45o declivity. From the total area of São João River Basin, 15% is in this condition, fact that proves the initial hypothesis. / As paisagens apresentam padrões que expõem diferentes intensidades, duração e magnitude nas interações e inter-relações físico-naturais, nelas estabelecidas ao logo do tempo, em especial àquelas referentes ao tempo geológico. Qualquer perturbação, interna ou externa, em seus elementos conduz a um reordenamento de suas relações, resultando em novos padrões de arranjos. As perturbações de natureza geológico-geomorfológica são significativas por produzirem formas e feições peculiares, em diferentes escalas, que podem tanto agregar valor cênico à paisagem como desvalorizar a aptidão dos solos à agricultura. Nesse sentido, o objetivo desta pesquisa foi analisar a dinâmica da paisagem na bacia hidrográfica do São João, a partir da influência das estruturas lineares nas formas de relevo e no uso da terra. Partiu-se da hipótese de que a presença de feições estruturais lineares atua como um fator condicionante na dinâmica da paisagem na referida bacia, seja por limitar a expansão dos usos do solo, seja por ampliar as áreas de preservação permanente. A bacia está situada na mesorregião Centro-oriental paranaense, entre os municípios de Castro e Carambeí, na transição morfoestrutural entre a Bacia Sedimentar do Paraná e seu embasamento, diretamente influenciada pelos movimentos ascensionais do Arco de Ponta Grossa. Para alcançar o objetivo, buscou-se a obtenção de dados geomorfométricos da SRTM, para o mapeamento das feições estruturais lineares, o que resultou na identificação de um total de 92 lineamentos, tipo vales/cânions, cujo comprimento médio é de 1,33km, e direções predominantes SE/NW, coincidente àquela do Arco. Os lineamentos associam-se a formação da rede hidrográfica, em especial aqueles de primeira e segunda ordem (Strahler, 1952), cujos vales apresentam-se encaixados entre vertentes declivosas, geralmente maior que 45º. Pela análise morfométrica, a partir dos dados obtidos pela carta topográfica de Castro (SG-22-X-A-V-4), constatou-se que a bacia tem forma alongada e irregular e abriga uma rede hidrográfica de hierarquia fluvial de 4a ordem, com baixa densidade de canais fluviais que revela a influência litoestrutural e na sua dificuldade de manutenção de drenagem e grande entalhamento de vertentes. O levantamento de campo permitiu identificar o predomínio de Neossolos litólicos, entrecortados de afloramentos rochosos, que limitam as atividades de agricultura intensiva. Mediante a classificação supervisionada da imagem do satélite LandSat 5 TM, de 05 de maio de 2011, identificou-se como classes de uso da terra:cobertura florestal, silvicultura, campos e áreas agrícolas e, em menor proporção, o perímetro urbano de Carambeí. Em geral estes usos encontram restrições nas propriedades de solos rasos, na forte declividade, nas áreas de preservação permanente, ao longo da rede hidrográfica. A paisagem estrutural na área da bacia do Rio São João encerra um conjunto de nascentes e vales encaixados, cujas margens de no mínimo 30m de largura, são enquadradas como Áreas de Preservação Permanentes, ao lado de vertentes cuja declividade seja superior a 45º.De uma área total da bacia do Rio São João, 15% dela encontra-se nesta condição, fato este que comprova a hipótese inicial.
5

Evolução paleogeomorfológica do Estado do Rio de Janeiro e arredores (cadernos de mapas)

Ribeiro, Luziane Santos [UNESP] 27 October 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:19Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-10-27Bitstream added on 2014-06-13T19:02:52Z : No. of bitstreams: 1 ribeiro_ls_dr_rcla.pdf: 6745290 bytes, checksum: 960fce1714eda51ceedc21a67c907211 (MD5) / Este trabalho teve como objetivo reconstruir a paleogeomorfológica do Estado do Rio de Janeiro pelo Método das Isobases Confluentes. Foram empregadas técnicas de Geoprocessamento para otimização do Método, que até então era desenvolvido manualmente. Em conseqüência disso sua aplicação, além de morosa, ficava restrita a áreas de pequena extensão. Mediante a otimização e sistematização do Método chegouse à paleosuperfície de ordem 7 para o Estado do Rio de Janeiro, a que correspondeu a eventos registrados no Cretáceo. As paleosuperfícies que se seguiram até a superfície erosiva atual mostraram a evolução tectno-estrutural pela qual o sudeste brasileiro passou, evidenciando as etapas do evento rifteamento que encaixou o rio Paraíba do Sul em sua posição atua. Verificou-se que Geoprocessamento se aplica eficientemente como ferramenta para obtenção de paleosuperfícies, as quais podem ser empregadas na reconstrução de cenários e estudo evolutivos ecogeodinâmicos / This study aimed to reconstruct the paleogeography Rio de Janeiro State by the Method of Confluent Isobases. GIS techniques were employed to automate the Method, which until then was developed manually. As a result their application was restricted to areas of small extent and it was extremely slow. Through automation and systematization of the method reached the paleosurfaces of order 7 for the State of Rio de Janeiro, which corresponded to events in the Cretaceous. From the seventh paleosurface to the current erosive surface showed step by step the developments structural and tectonic of the Brazilian southeast. The most important event was the establishment of the rift of Paraíba, wich changed all physiographic aspects in the area. It was found that GIS is an effective tool for obtaining paleosurfaces, which can be used in the reconstruction of evolutionary scenarios and in the study of dinamic of landscape
6

Evolução paleogeomorfológica do Estado do Rio de Janeiro e arredores (cadernos de mapas) /

Ribeiro, Luziane Santos. January 2010 (has links)
Volume 2 possui mapas / Orientador: Jairo Roberto Jiménez-Rueda / Banca: Juércio Tavares de Mattos / Banca: Archimedes Perez Filho / Banca: Maria da Gloria Alves / Banca: Claudio Limeira Mello / Resumo: Este trabalho teve como objetivo reconstruir a paleogeomorfológica do Estado do Rio de Janeiro pelo Método das Isobases Confluentes. Foram empregadas técnicas de Geoprocessamento para otimização do Método, que até então era desenvolvido manualmente. Em conseqüência disso sua aplicação, além de morosa, ficava restrita a áreas de pequena extensão. Mediante a otimização e sistematização do Método chegouse à paleosuperfície de ordem 7 para o Estado do Rio de Janeiro, a que correspondeu a eventos registrados no Cretáceo. As paleosuperfícies que se seguiram até a superfície erosiva atual mostraram a evolução tectno-estrutural pela qual o sudeste brasileiro passou, evidenciando as etapas do evento rifteamento que encaixou o rio Paraíba do Sul em sua posição atua. Verificou-se que Geoprocessamento se aplica eficientemente como ferramenta para obtenção de paleosuperfícies, as quais podem ser empregadas na reconstrução de cenários e estudo evolutivos ecogeodinâmicos / Abstract: This study aimed to reconstruct the paleogeography Rio de Janeiro State by the Method of Confluent Isobases. GIS techniques were employed to automate the Method, which until then was developed manually. As a result their application was restricted to areas of small extent and it was extremely slow. Through automation and systematization of the method reached the paleosurfaces of order 7 for the State of Rio de Janeiro, which corresponded to events in the Cretaceous. From the seventh paleosurface to the current erosive surface showed step by step the developments structural and tectonic of the Brazilian southeast. The most important event was the establishment of the rift of Paraíba, wich changed all physiographic aspects in the area. It was found that GIS is an effective tool for obtaining paleosurfaces, which can be used in the reconstruction of evolutionary scenarios and in the study of dinamic of landscape / Doutor
7

A INFLUÊNCIA MORFOESTRUTURAL DA REDE DE DRENAGEM NA BACIA DO ALTO CURSO DO RIO PITANGUI - PARANÁ / A INFLUÊNCIA MORFOESTRUTURAL DA REDE DE DRENAGEM NA BACIA DO ALTO CURSO DO RIO PITANGUI - PARANÁ

Oliveira, Karen Aparecida de 26 March 2015 (has links)
Made available in DSpace on 2017-07-21T18:15:18Z (GMT). No. of bitstreams: 1 Karen Aparecida de Oliveira.pdf: 20558400 bytes, checksum: 828c3d06374244ce40cb5bae107104ea (MD5) Previous issue date: 2015-03-26 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Methods of morphostructural analysis, based on morphometric indices constitute important tools to assess the behavior of hydrographic systems. They are cheap and quick methods of collecting information, passable to correlate with field data. Backed up on this assertive, the aims of the research was to characterize the main morphostructural in behavior of drainage network in hydrographic basin of Alto Pitangui, Paraná. The Pitangui River tributary the of Tibagi, classified as antecedent river, transits among the igneous and metamorphic rock belonging to Cunhaporanga Granitic Complex and Itaiacoca Group, the Paranaense First Plateau, in its upper course, and Paleozoic rocks of the eastern edge of the Paraná Basin, in the Secound Plateau, the middle and lower course. The morphometry has relied on data extraction about Stream-length index (SL index), Asymmetric Factor (AF) and Drainage Basin Symmetry (DBS), longitudinal profile and transverse profile the basin. The study area has a strong structural and tectonic control which directly influences in elongated shape, NE-SW direction, of the hydrographic basin, with the main channel sometimes notched and embedded into strutural lineaments, or an extensive flood plain in assymmetric valleys and presence of terraces and oxbow lakes. Its main characteristic is represented by longitudunal misfit. The gradient index made possible the detection of 6 snippets with anomalous gradients distribued along its course. Are anomalies of second order, associated to lithological changes, or relief lineaments and channel confluences. The varation in the main channel behavior and some of its tributaries has a direct relation to the fact circular by a morphostrutural transition region, with strong influences of Ponta Grossa Arch and the Devonian Escarpment presence. The Upper course Pitangui River reflects scathing manner the importance of tectonic events and geological context to with is inserted, presenting diverse anomalies, which are indicate imbalances located along some drainages. / Os métodos de análise morfoestrutural, baseados em índices morfométricos, constituem-se em importantes ferramentas para avaliação do comportamento dos sistemas hidrográficos. São métodos baratos e rápidos na obtenção de informações quase sempre passíveis de correlação com aqueles obtidos por trabalho de campo. Apoiado nesta assertiva, o objetivo desta pesquisa foi caracterizar as principais influencias morfoestrutural no comportamento da rede de drenagem da bacia hidrográfica do Alto Pitangui, Paraná. O Rio Pitangui, afluente do Tibagi, classificado como rio antecedente, transita pelas rochas ígneas e metamórficas pertencentes ao Complexo Granítico Cunhaporanga e ao Grupo Itaiacoca, no Primeiro Planalto Paranaense, em seu alto curso, e as rochas paleozoicas da borda leste da Bacia do Paraná, no Segundo Planalto, no médio e baixo curso. A morfometria apoiou-se na extração de dados sobre o índice de Relação Declividade-Extensão (RDE), Fator de Assimetria de Bacias (FAB) e Fator de Simetria Topográfica Transversal (FSTT), perfil longitudinal e transversal da bacia. A área de estudo possui um forte controle estrutural e tectônico que influenciam diretamente na forma alongada, sentido NE-SW, da bacia hidrográfica, com o canal principal por vezes entalhado e encaixado em lineamentos estruturais, ou numa extensa planície de inundação em vales assimétricos e presença de terraços e meandros abandonados. Sua característica principal é representada pelo desajuste longitudinal. O Índice de Gradiente possibilitou a detecção de seis trechos com gradientes anômalos distribuídos ao longo de seu curso. São anomalias de 2º ordem, associadas às mudanças litológicas, aos lineamentos do relevo e ao encontro de tributários significativos. As variações no comportamento do canal principal e alguns de seus afluentes têm uma relação direta com o fato de circular por uma região de transição morfoestrutural, com forte influência do Arco de Ponta Grossa e da presença Escarpa Devoniana. O Alto Curso do Rio Pitangui reflete de forma contundente a importância dos eventos tectônicos e do contexto geológico ao qual se insere, apresentando diversas anomalias, que estão a indicar desequilíbrios localizados ao longo de algumas drenagens.
8

Morfologinės struktūros transformacijos centriniame miesto rajone (Lietuvos pavyzdžiu) / Transformations of Urban Morphological Structure in the Central Business District (On the example of Lithuania)

Alistratovaitė, Inesa 23 February 2005 (has links)
As urban development in the 20th century has become the issue of global concern, more and more new territories have been occupied due to high intensity of the development. International conferences devoted to the regulatory issues of city development held within the current decade (such as HABITAT II held in Istanbul, 1996, ATHENS’98 – in Athens, 1998, URBAN 21 – in Berlin, 2000, and a conference in Brussels, 2001, etc) emphasized the majority of developmental aspects including the great focus on the necessity to further form urban structures with the priority of internal city development looking for more effective and more universal functional uses of the territories, restoration of the existing downtown areas and preservation of their original character. As other post-soviet countries, Lithuania has been also facing the need to reorganize various spheres including urban development. Urban territories have been dangerously expanded, especially during the soviet period, due to the increased general city building-up areas, mostly expressed by the territorial expansion rather than gradual and consistent development (by the use of internal reserves of the city). After the restoration of Lithuanian independence, privatisation, changed character of housing construction, return of land and real estate to the previous owners and increasing value of land under the free market conditions remarkably modified the nature of urban development in Lithuania, at the same time revealing the... [to full text]
9

Vývoj údolí Kladské Bělé / Valley evolution of the Kladská Bělá river

Stemberk, Jakub January 2021 (has links)
The PhD. thesis deals with the morphostructural evolution of the valley network of the Biala Lądecka river, (further refer as BL) during the Late Cenozoic. In this work, the selected methods as geomorphological research (morphostructural analysis, geomorphological mapping), structural-geological research (paleostres analysis) and geophysical survey on selected sites were used, to answer the questions of river basin development and its relationship with predicted tectonic activity within the area, as well as with anticipated or already known paleohydrographic changes. The BL basin is situated within the Rychlebské hory Mts. / Góry Złote (northern and eastern parts of the basin), Králický Sněžník (southern part) and the Krowiarki Mts. (western part) in Poland. The Marginal Sudetic fault zone, which represents one of the most important tectonic zones in the Central Europe, passes in vicinity of the study area as well as the regionally important Bělský fault, which passes directly through the BL basin. The results of the analysis indicate that the BL basin has undergone very complex development due to tectonic movements since Miocene up-to-day. Based on the results of the paleostress analysis, which was performed on the dated volcanites in Lutynia - Lądek Zdrój area, the parameters of the palaostress...

Page generated in 0.066 seconds