Made available in DSpace on 2015-03-13T17:08:18Z (GMT). No. of bitstreams: 1 YoeARP_ate_cap3.pdf: 4850178 bytes, checksum: 25cc3f03ddb9c3924afaca14682d8b1f (MD5) Previous issue date: 2003-03-31 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / This study focuses on the potential of several techniques used to identify depositional geometries and paleogeographical investigation on the SW border of the Potiguar Basin. Three areas were selected for an integrated geological, geophysical and geochemistry study. The main used techniques were facies analysis, remote sensing,ground penetrating radar (GPR) and gamma-ray in outcrops, as well as petrographic microscope observations and the using of scanning eletronic microscopic (SEM), and Carbon and Oxygen Isotopic study in the carbonate tufa. These methodological approaches were very efficient in the facies analysis of 2D geometries. The GPR profiles carried out in Quixer? identified important geological reflectors which allowed to the identification of depositional geometries of tufa. However, GPR profiles were not able to identify geological reflectors in the Apodi and Olho d??gua da Bica outcrops. Gammaray profiles also presented good results, which justify their use in 1D and 2D geometric analysis. Carbon and Oxygen Isotopic analyses were also used to investigate paleoenvironmental setting of tufa deposits. It is important to remark the excellent resultsof GRP using in the identification of deposition al geometries of tufa and their contact relationships with the underlying rocks. Field analysis of faults indicate a vertical sigma-1 orientation which was associated to normal faults / Com o presente trabalho foi analisado o potencial de uso de diversas t?cnicas com o objetivo de identificar geometrias deposicionais e subsidiar os estudos de reconstru??o paleogeogr?fica da borda sudoeste da Bacia Potiguar. Para tanto, foram identificadas tr?s ?reas e selecionados alguns afloramentos para estudos integrados de geologia, geof?sica e geoqu?mica. As principais t?cnicas utilizadas foram: an?lises de f?cies; sensoriamento remoto; perfis geof?sicas com GPR; levantamentos de perfis de raios gama, em afloramentos; estudos petrogr?ficos com microscopia ?tica e com o microsc?pio eletr?nico de varredura e an?lise isot?pica de carbono e oxig?nio nas tufas carbon?ticas. Esta abordagem metodol?gica se mostrou eficiente no que tange ao uso do m?todo de an?lise de f?cies para identifica??o de geometrias 2D. Os perfis de GPR realizados em Quixer? imagearam alguns importantes refletores de interesse geol?gico, permitindo identificar as geometrias deposicionais das tufas e suas rela??es de contato com as rochas abaixo. Entretanto, o GPR n?o mostrou suficiente contraste para a identifica??o de refletores de interesse geol?gico nos afloramentos Apodi e Olho d ?gua da Bica. Os perfis de raios gama tamb?m apresentaram uma boa resposta, justificando seu uso na identifica??o de geometria 1D e 2D. A an?lise isot?pica de carbono e oxig?nio, permitiu uma primeira compreens?o das condi??es paleoambientais de dep?sitos de tufas. Ressalta-se o excelente resultado obtido com o GPR na identifica??o das geometrias deposicionais das tufas e suas rela??es de contato com as rochas abaixo. A an?lise do campo de tens?o destas rochas mostrou uma dire??o vertical de maior esfor?o (sigma 1) de deforma??o, cuja origem foi associada ? a??o gravitacional

Made available in DSpace on 2015-03-13T17:08:40Z (GMT). No. of bitstreams: 1 VeronicaDA.pdf: 5709097 bytes, checksum: 4074580aee5ec2b7d354ddab1d446e43 (MD5) Previous issue date: 2006-05-19 / This work presents geophysical and geological results obtained in a dunefield located in the east coast of Rio Grande do Norte State, with the aim to recognize the aeolian body depositional geometries to a future geologic modeling of the aeolian petroliferous reservoirs. The research, which was done in blowouts region situated at Nisia Floresta Municipally, included the characterization of external geometries with GPS and internal geometry analysis by GPR. Data was integrated in GoCAD software, where it was possible the three-dimensional characterization and interpretation of the studied deposits. The interpretation of GPR profiling allowed identifying: First-order bounding surfaces that separated the aeolian deposits of the Barreiras Formation rocks; Second-order bounding surfaces, which limit dune generations and Third-order bounding surfaces, a reactivation surface. This classification was based and adapted by the Brookfield (1977) and Kocurek (1996) propose. Four radarfacies was recognized: Radarfacies 1, progradational reflectors correlated to foresets of the dunes, Radarfacies 2, plain parallels reflectors related to sand sheets, Radarfacies 3, plain parallels reflectors associated to reworking of the blowout dune crest and Radarfacies 4, mounded reflectors associated to vegetated mound of sand or objects buried in subsurface. The GPR and GPS methods was also employed to the monitoring of dunefields susceptible to human activities in Buzios Beach, where the constructions along the blowout region and the tourism are changing the natural evolution of the deposits. This fact possibly to cause negative impacts to the coastal zone. Data obtained in Dunas Park, a unit environmental conservation, was compared with information of the Buzios Beach. There is a major tendency of erosion in Buzios, specifically in blowout corridor and blowout dune / Este trabalho apresenta os resultados geol?gicos e geof?sicos obtidos em um campo de dunas situados no litoral oriental do Rio Grande do Norte e teve como objetivo definir as geometrias deposicionais dos corpos e?licos para posterior aplica??o na modelagem geol?gica de campos produtores de ?leo e g?s de origem e?lica. A pesquisa foi realizada em uma regi?o de blowouts, situada no munic?pio de N?sia Floresta - RN, onde foi poss?vel definir a superf?cie externa com o uso do GPS geod?sico e a estrutura??o interna utilizando o GPR (Ground Penetrating Radar). Estes dados foram integrados no software de modelagem geol?gica Gocad, permitindo a visualiza??o tridimensional e interpreta??o dos dep?sitos estudados. O levantamento de perfis geof?sicos permitiu a investiga??o da geometria interna dos dep?sitos, nos quais foi poss?vel reconhecer superf?cies limitantes de 1? ordem (superf?cie deposicional que separa os dep?sitos e?licos de rochas da Forma??o Barreiras), 2? ordem (superf?cie que separa diferentes pulsos de sedimenta??o e?lica) e 3? ordem (superf?cies de reativa??o). A classifica??o destas superf?cies acima descritas foi baseada e modificada das propostas de Brookfield (1977) e Kocurek (1996). Foram ainda definidas quatro radarf?cies, com base na forma e termina??o dos refletores: Radarf?cies 1, representada por refletores progradantes, os quais se relacionam aos foresets das acumula??es e?licas; Radarf?cies 2, que ? constitu?da por refletores suscept?veis ? a??o antr?pica na praia de B?zios, onde constru??es ao longo da regi?o de blowouts e a pr?tica intensiva de turismo est?o modificando o desenvolvimento natural destas acumula??es e?licas, podendo gerar impactos ambientais negativos para a zona costeira. Dados obtidos numa ?rea situada no Parque das Dunas (unidade de conserva??o ambiental) foram utilizados para compara??o com as informa??es adquiridas em B?zios. H? uma tend?ncia maior de eros?o na ?rea de B?zios, notadamente no corredor do blowout e na duna de blowout