Correlação entre a morfologia e a geometria interna de dunas eólicas parabólicas, com auxílio de GPR

• Ano de defesa: 2020
• Autor(a) principal: Dantas, Tarsila Barbosa
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Brasil; UFRN; PROGRAMA DE PÓS-GRADUAÇÃO EM GEODINÂMICA E GEOFÍSICA
• Palavras-chave em Português: Dunas parabólicas; GPR; Geomorfologia; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOFISICA
• Link de acesso: https://repositorio.ufrn.br/jspui/handle/123456789/28715

Parabolic dunes generally occur in coastal environments in tropical zones, and are deposits influenced by several factors besides the wind regime, such as precipitation, vegetation cover and water table. In view of their particularities, a model of the geophysical signatures of sedimentary structures of open and closed parabolic coastal dunes is presented here. Geophysical acquisition with GPR and topographic survey with UAV and geodetic GPS were carried out on dunes in Rio do Fogo and São Bento do Norte / RN, Brazil, and allowed to describe the internal structures of the following morphological features: depositional lobe, trailing arms, back ridges, dune track ridges and deflation basin. The depositional lobe has progressive foresets, as well as trailing arms. The deflation basin, in turn, has concordant and thin layers as a result of the accumulation of thicker grains and preservation of the blades. The dune track ridges and back ridges occur both in the deflation basin as arched sandy ridges, with a lack of definition in the literature when differentiating these features, especially with regard to their origins. The internal structures identified for the dune track ridges point to two signatures in this feature: at its base there is the preservation of progradant layers reliquary to the migration of the open parabolic dune, separated by a superposition surface above which trapping layers occur. The back ridge is related to the erosive event of the closed parabolic dune, which results from a wind reactivation or precedes a blowout.