Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-12-12T18:53:10Z No. of bitstreams: 1 MariaEmanuellaFirminoBarbosa_TESE.pdf: 17456528 bytes, checksum: 1ca17d60d4523399fe8138c2a7d13c40 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-12-13T21:30:21Z (GMT) No. of bitstreams: 1 MariaEmanuellaFirminoBarbosa_TESE.pdf: 17456528 bytes, checksum: 1ca17d60d4523399fe8138c2a7d13c40 (MD5) / Made available in DSpace on 2017-12-13T21:30:21Z (GMT). No. of bitstreams: 1 MariaEmanuellaFirminoBarbosa_TESE.pdf: 17456528 bytes, checksum: 1ca17d60d4523399fe8138c2a7d13c40 (MD5) Previous issue date: 2017-08-28 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Uma pesquisa geomorfol?gica detalhada usando Light Detection and Ranging (LIDAR) foi realizada ao longo da parte ocidental do rio Assu, estado do Rio Grande do Norte, Brasil. O estudo foi complementado por uma s?rie de sondagens com trado, indicadores de foramin?feros bent?nicos de sedimentos, bem como data??o por Optically Stimulated Luminescence (OSL) e por Radiocarbono (C14). Esses dados permitiram reconstruir a evolu??o desta ?rea desde o Pleistoceno tardio at? o presente. O ba?a rasa, que agora est? completamente preenchido formado dentro dos limites da morfologia antecedente desenvolvida desde a ?ltima interglacial. Os principais fatores for?adores respons?veis pelo reposicionamento do litoral, que correu em um ?ngulo de ca. 35% para a costa atual no Pre Holoceno e M?dio Holoceno foram: (1) atividade tect?nica ao longo da linha de falha de Afonso Bezerra, define a estrutura de horst-graben da Serra do Mel, (2) inunda??o r?pida da ba?a do paleovale raso durante a ?ltimo pulso da transgress?o do Holoceno ca. 7500 cal BP e (3) prograda??o r?pida do estu?rio do rio Assu atrav?s da acumula??o de sedimentos costeiros e sedimentos fluviais. / A detailed geomorphological survey using Light Detection and Ranging was carried out along the western part of Assu River, NE, Brazil. The study was complemented by a series of shallow boreholes, sediment benthic foraminifera indicators, as well as radiocarbon and optically stimulated luminescence dating and permitted to reconstruct the evolution of this area from the late Pleistocene until the present. The shallow embayment, which is now completely infilled formed within the limits of antecedent morphology developed since the last interglacial. The main forcing factors responsible for repositioning of the shoreline, which ran at an angle of ca. 35% to the present coast in Early/mid Holocene were: (1) tectonic activity along Afonso Bezerra a strike-slip fault line which defines the horst-graben structure of Mel dome, (2) fast inundation of the shallow paleovalley embayment during the last pulse of Holocene transgression ca. 7500 cal BP, and (3) fast progradation of the Assu estuary through accretion of coastal drift and fluvial sediments.

Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-02-22T22:19:59Z No. of bitstreams: 1 DavidLinoVasconcelos_DISSERT.pdf: 10972209 bytes, checksum: 92858ff8a60fdac09332f5f0467e6fe3 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-02-25T19:54:57Z (GMT) No. of bitstreams: 1 DavidLinoVasconcelos_DISSERT.pdf: 10972209 bytes, checksum: 92858ff8a60fdac09332f5f0467e6fe3 (MD5) / Made available in DSpace on 2016-02-25T19:54:57Z (GMT). No. of bitstreams: 1 DavidLinoVasconcelos_DISSERT.pdf: 10972209 bytes, checksum: 92858ff8a60fdac09332f5f0467e6fe3 (MD5) Previous issue date: 2014-02-26 / Na regi?o litor?nea do Cear?, entre os munic?pios de Acara? e Itapipoca, foram identificados treze s?tios contendo indicadores do n?vel relativo do mar, sendo seis destes datados por luminesc?ncia opticamente estimulada (LOE) e radiocarbono. As idades obtidas suportam que foram formadas praias progradantes na ?rea de estudo. Na parte oriental, ocorrem praias em dep?sitos de plan?cie costeira, enquanto que um sistema laguna/barreira com paleomanguezais ocorre na parte ocidental da ?rea de estudo. Em ambos os casos os dep?sitos costeiros progradam de leste para oeste. Foram identificados n?veis de mar mais alto que o atual entre: (a) 3.110-2.830 anos cal. AP; (b) 1.830 anos AP (LOE) - 1.490 anos cal. AP; (c) entre 1.240-1.060 anos cal. AP; (d) 845- 715 anos AP (LOE). Desde ent?o o n?vel do mar sofreu um abaixamento at? o n?vel atual. As varia??es do n?vel do mar s?o interpretadas como respostas a altera??es no padr?o de circula??o marinha e n?o exclu?mos poss?veis perturba??es tect?nicas na bacia da margem continental. Os indicadores do n?vel relativo do mar para litoral oeste do Cear? apresentam-se diferente das outras curvas constru?das no litoral do nordeste, sugerindo que os fatores locais citados acima contribu?ram para flutua??es do n?vel do mar. / In the coastal region of Cear?, between the municipalities of Acara? and Itapipoca, thirteen sites were identified containing indicators of relative sea level, six of these being dated by optically stimulated luminescence (OSL) and radiocarbon. Ages obtained supports that were formed prograding beaches in the study area. In the eastern portion, beaches in coastal plain deposits occur while a system lagoon/barrier paleomangrove occurs in the western portion of the study area. In both cases the coastal deposits prograde from east to west. Higher sea levels were identified between the current: (a) 3.110-2.830 cal. yr. BP; (b) 1.830 yr. BP (OSL) - 1.490 cal. yr. BP; (c) between 1.240-1.060 cal. yr. BP; (d) 845-715 yr. BP (OSL). Since then the sea level suffered by lowering the current level. Variations in sea level are interpreted as responses to changes in the pattern of marine circulation and do not exclude possible tectonic disturbances in the basin of the continental margin. The indicators of relative sea level west coast of Cear? present differently from other curves constructed in the coastal northeast, suggesting that local factors mentioned above contributed to sea level fluctuations.