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  • 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

Geomorfologia e neotect?nica no Vale do Apodi-Mossor? RN

Maia, R?bson Pinheiro 29 February 2012 (has links)
Made available in DSpace on 2015-02-24T19:48:43Z (GMT). No. of bitstreams: 1 RubsonPMaia_Tese_teste.pdf: 4164571 bytes, checksum: 21ca23dbd02850fa2009e4ee1f8b26fe (MD5) Previous issue date: 2012-02-29 / Numerous studies have indicated that the Potiguar Basin is affected by Cenozoic tectonics. The reactivation of Cretaceous fault systems affect the post-rift units, witch include Neogene and overlying Quaternary sediments. In this context, the objectives of this thesis are the followings: (1) to characterize the effects of post-rift tectonics in the morphology of Apodi Mossor?-river valley located in the central portion of the Potiguar, (2) to characterize the drainage of the Apodi Mossor? river valley and investigate the behavior of their channels across active faults, and (3) to propose a geologic-geomorphological evolutionary model for the study area. This study used a geological and geomorphological mapping of the central part of the basin, with emphasis on the Quaternary record, luminescence dating of sediments, and geoelectric profiles of the area. The results reveal by maps of structural lineaments and drainage channels of the rivers form valleys that are affected by faults and folds. In Apodi-Mossor? valley, anomalies of channel morphology are associated with the deformation of the post-rift basin. These anomalies show the reactivation of major fault systems in the Potiguar Basin in Cenozoic. On a regional scale, can be seen through the vertical electric profiles that the Cenozoic tectonics is responsible for the elevation of a macro dome NE-SE-trending 70-km long and 50km wide and up to 270 above sea level. In this sector, the vertical electric profiles data show that the contact between the Cretaceous and Neogene rise more than 100m. This Is an important feature of inversion data obtained in this work showed that the deposits that cover the macro dome (Serra do Mel) have ages of 119 ka to 43 ka. In the river valley and surrounding areas Apodi-Mossor? ages vary between 319 ka and 2.7 ka. From these data it was possible to establish the correct geochronological posiconamento paleodep?sitos of distinguishing them from the fluvial deposits of the Neogene (Barreiras Formation) / Numerosos estudos t?m indicado que a Bacia Potiguar ? afetada pela tect?nica Cenoz?ica. A reativa??o de sistemas de falhas do Cret?ceo afetam as unidades p?s-rifte que incluem o Ne?geno e o Quatern?rio. Nesse contexto, os objectivos dessa tese s?o os seguintes: (1) Caracterizar os efeitos da tect?nica p?s-rifte na morfologia do Rio Apodi-Mossor? localizado na por??o central da Bacia Potiguar, (2) Caracterizar a drenagem do vale do Rio Apodi-Mossor? e investigar o comportamento de seus canais em falhas ativas, (3) Propor um modelo geol?gico-geomorfol?gico evolutivo para a ?rea de estudo. Esse estudo utilizou-se de um mapeamento geol?gico e geomorfol?gico da parte central da Bacia Potiguar, com ?nfase nos dep?sitos sedimentares quatern?rios, na data??o de sedimentos por luminesc?ncia ?ptica estimulada e sondagens geoel?tricas verticais. Os resultados revelam atrav?s de mapas de lineamentos estruturais e canais de drenagem que os rios formam vales que s?o afetados por falhas e deforma??es tect?nicas. No vale do Rio Apodi-Mossor?, anomalias da morfologia do canal est?o associadas ? deforma??o p?s-rifte da Bacia Potiguar. Essas anomalias evidenciam a influ?ncia da reativa??o cenoz?ica de sistemas de falhas da Bacia Potiguar na morfologia do canal. Em uma escala regional, pode ser visto atrav?s da geomorfologia e dos dados das sondagens geoel?tricas que a tect?nica cenoz?ica ? respons?vel pela forma??o de fei??es de invers?o resultantes do atual campo de tens?es na Bacia Potiguar. Essa fei??o caracteriza-se por um macro domo (Serra do Mel) orientado no sentido NE-SE com 70 km de comprimento e 50 km de largura e at? 270m acima do n?vel do mar. Nesse setor, os dados obtidos nesse trabalho evidenciaram que o contato entre o Cret?ceo e o Ne?geno eleva-se mais de 100m no centro da Bacia Potiguar. Os resultados geocronol?gicos obtidos nesse trabalho mostraram que os dep?sitos que cobrem o macro domo estrutural t?m idades de 119 ka a 43 ka. No vale do Rio Apodi-Mossor? e ?reas vizinhas, as idades variam entre 319 ka e 2,7 ka. A partir desses dados, foi poss?vel estabelecer o correto posiconamento geocronol?gico dos paleodep?sitos fluvias e distingu?-los dos dep?sitos do Ne?geno (Forma??o Barreiras)
2

An?lise da din?mica deposicional das praias de Cacimbinha e do Madeiro, Tibau do Sul-RN, Brasil

Ferreira, Joyce Clara Vieira 20 February 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-01-26T20:18:14Z No. of bitstreams: 1 JoyceClaraVieiraFerreira_DISSERT.pdf: 7634206 bytes, checksum: db9fc8fc204ff7eac59168c5730912c7 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-01-29T19:25:52Z (GMT) No. of bitstreams: 1 JoyceClaraVieiraFerreira_DISSERT.pdf: 7634206 bytes, checksum: db9fc8fc204ff7eac59168c5730912c7 (MD5) / Made available in DSpace on 2016-01-29T19:25:52Z (GMT). No. of bitstreams: 1 JoyceClaraVieiraFerreira_DISSERT.pdf: 7634206 bytes, checksum: db9fc8fc204ff7eac59168c5730912c7 (MD5) Previous issue date: 2015-02-20 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / As praias de Cacimbinhas e do Madeiro est?o inseridas no litoral oriental do estado do Rio Grande do Norte, mais precisamente no munic?pio de Tibau do Sul. Diante dos indicativos de eros?o na costa deste munic?pio e dos processos costeiros atuantes nas praias, buscou-se, como objetivo geral desta pesquisa, compreender a evolu??o do ambiente deposicional de Cacimbinhas e do Madeiro, al?m de caracterizar os ambientes pret?ritos das praias por meio de an?lises sedimentol?gicas; identificar a idade dos sedimentos praiais por meio de data??o absoluta com aux?lio de t?cnicas utilizadas em estudos voltados para o per?odo Quatern?rio; e desvendar a evolu??o paleogeogr?fica das praias de Cacimbinhas e do Madeiro. Para isso, o estudo est? envolvendo pesquisa bibliogr?fica e de campo, ambas pautadas em trabalhos acad?micos, leis, conceitos e teorias concernentes ? geografia f?sica, geomorfologia do quatern?rio, geologia sedimentar e estratigrafia. Dessa forma, os procedimentos metodol?gicos foram subdivididos em tr?s etapas: Etapa pr?-campo: onde est?o sendo realizados os trabalhos de gabinete; Etapa campo: momento onde ser? realizada a aquisi??o das amostragens; e Etapa p?s-campo: onde ocorrer? a an?lise e integra??o dos dados processados adquiridos ao longo da pesquisa. Sendo assim, foram apresentados alguns resultados parciais de uma prospec??o preliminar realizada em dezembro de 2013, que teve por objetivo checar os dep?sitos sedimentares das praias e realizar uma breve caracteriza??o dos mesmos. Portanto, pode-se dizer, de maneira mais ampla, que estudos voltados para as ?reas costeiras s?o de grande import?ncia, uma vez que, em todo mundo, a maior parte dos grandes s?tios urbanos est?o assentados sob dep?sitos de idade quatern?ria e, nesse sentido, a conclus?o deste trabalho pretende contribuir para o conhecimento da din?mica sedimentar destas praias e, gest?o e planejamento desta ?rea que est? voltada, principalmente, para o turismo estrangeiro. / The Cacimbinha and Madeiro beaches are located in the eastern coast of Rio Grande do Norte state, in the municipality of Tibau do Sul. Given the indicative of erosion in the coast of this district and the coastal processes acting on the beaches, the global aim of this project is comprehend the evolution of depositional environment on the Cacimbinha beach, moreover, the project seeks to characterize deposits from the Cacimbinha and Madeiro beaches, according to the geomorphologic compartments identified on these beaches; distinguish the coastal features which possibly interact with the Cacimbinha beach; identify the potential relationship between the sediments from the coastal features and the deposits from Cacimbinha beach; understand which depositional processes that prevail at each facies deposited on the beach; and identify the probable sedimentary environments and its energy of deposition through of the materials recorded on the Cacimbinha beach. This study was based on previous bibliographic and field research, both guided by academic works, laws, concepts and theories concerning the physical geography, geomorphology of the quaternary, sedimentary geology and stratigraphy. Thus, the methodology was divided in three steps: Prefield step: office work was performed; Field step: Sampling of facies of sedimentation; PosField step: analysis and integration of data obtained during the research period. Thus, the results showed deposicional facies with distinguished energy in the relief compartments, beach and terrace. After the sedimentary analysis and its interpretation linked to the architecture of the mounted sections based on drilling, it became possible to trace the evolutionary history of this stretch of beach. Therefore, it can be stated that studies performed on coastal areas are of great importance, as long as, around the world, the most part of urban zones are seated on deposits of quaternary age and, then this work improve the knowledge regarding the sedimentary dynamics of this beach, becoming scientific support for management and planning of this area which focus on, mainly, the foreign tourism

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