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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

Assinatura estrutural e geof?sica da por??o norte (fronteira Cear?-Piau?) no lineamento transbrasiliano: reativa??o na bacia do Parna?ba

Cacama, Mois?s Samuel Jo?o Bota 25 May 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-03-31T23:12:19Z No. of bitstreams: 1 MoisesSamuelJoaoBotaCacama_DISSERT.pdf: 15699529 bytes, checksum: bf8851e1234bc09c6a2f37eb37638d6e (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-05T19:22:45Z (GMT) No. of bitstreams: 1 MoisesSamuelJoaoBotaCacama_DISSERT.pdf: 15699529 bytes, checksum: bf8851e1234bc09c6a2f37eb37638d6e (MD5) / Made available in DSpace on 2016-04-05T19:22:45Z (GMT). No. of bitstreams: 1 MoisesSamuelJoaoBotaCacama_DISSERT.pdf: 15699529 bytes, checksum: bf8851e1234bc09c6a2f37eb37638d6e (MD5) Previous issue date: 2015-05-25 / O Lineamento Transbrasiliano ? uma importante zona de cisalhamento com dire??o NE-SW, relacionada orog nese Brasiliana e que evoluiu em est?gios de alta at? baixa temperatura. No presente trabalho, investigou-se a assinatura estrutural e geof?sica da por??o norte do Lineamento Transbrasiliano (fronteira Cear?-Piau?), envolvendo a zona milon?tica brasiliana, o Graben de Jaibaras e as reativa??es que afetam as sequ?ncias sedimentares p?s-ordovicianas da Bacia do Parna?ba. Na literatura ? comum a refer?ncia ? reativa??o fanerozoica dessa estrutura, a qual teria originado diversos grabens tardi-brasilianos precedentes ? sin?clise paleozoica do Parna?ba, a exemplo do Graben de Jaibaras. As falhas que seccionam as unidades estratigr?ficas da Bacia do Parna?ba, ao longo de toda a extens?o do Lineamento Transbrasiliano, exprimem a sua reativa??o em eventos mais jovens. O mapa do campo magn?tico an?malo reduzido ao polo exibe anomalias com dire??o NE, interpretadas como a assinatura do Lineamento Transbrasiliano (e das estruturas brasilianas da Prov?ncia Borborema) na sua express?o de alta temperatura. O Graben de Jaibaras ? marcado por uma faixa an?mala retil?nea com alta susceptilidade magn?tica (interpretada como o predom?nio de rochas ferromagnesianas, provavelmente vulc?nicas), aparentemente sem continuidade expressiva no substrato da Bacia do Parna?ba. A an?lise geom?trica e cinem?tica das estruturas da ?rea enfocada, utilizando dados de sensores remotos e de campo, permitiu a caracteriza??o de quatro fases de deforma??o fr?gil a d?ctil-fr?gil Dn, D1, D2 e D3. A fase deformacional Dn, de idade ediacarana-cambriana, ocorre de modo exclusivo no Graben de Jaibaras, com desenvolvimento de estruturas de temperatura mais elevada (comparativamente aos eventos mais jovens), d?cteis-fr?geis. As fases deformacionais D1, D2 e D3 ocorrem afetando tanto o Graben de Jaibaras como as sequ?ncias paleozoicas da borda NE da Bacia do Parna?ba, com gera??o de estruturas em temperatura baixa, basicamente r?pteis/catacl?sticas. A an?lise de imagens SRTM permitiu cartografar diversos lineamentos de dire??o NE, NW e E-W na Bacia do Parna?ba, cuja correla??o com as estruturas mesosc?picas ? discutida em termos da reativa??o do Lineamento Transbrasiliano em associa??o com os est?gios de abertura do Atl?ntico e separa??o Am?rica do Sul-?frica, ou mesmo a eventos orog?nicos distais no Paleozoico. / The Transbrasiliano Lineament is a major shear zone trending NE-SW, related to the Brasiliano orogeny and evolved through high to low temperature stages. In this study, the structural and geophysical signature of the northern segment of Transbrasiliano Lineament was studied in its northern border, between Cear? and Piau? states, involving the Brasiliano mylonite zone, the Jaibaras Graben and reactivations affecting the sedimentary sequences post-ordovician of Parna?ba Basin. In the literature, is commonly the phanerozoic reactivation of this structure referred, generating several late Brasiliano grabens predating the paleozoic Parna?ba syneclises, like the Jaibaras Graben. Faults that cut the stratigraphic units of the Parna?ba Basin along the entire length of the Transbrasiliano Lineament express its reactivation during younger events. The magnetic anomaly field reduced to the pole map exhibit anomalies NE-trending, interpreted as the signature of the Transbrasiliano Lineament (and Brasiliano structures of the Borborema Province) in its high-temperature expression. The Jaibaras Graben is marked by a straight anomalous track with high magnetic susceptibility (interpreted as a prevalence of ferromagnesian rocks, probably volcanic), apparently without significant continuity in the substrate of Parna?ba Basin. The geometric and kinematic analysis of the structures in the study area, using remote sensing and field data, led to the characterization of four deformation phases brittle the ductilebrittle Dn, D1, D2 and D3. The Dn deformation phase of ediacaran-cambrian age, occurs exclusively in the Jaibaras Graben, with the development of comparatively higher temperature (as regards to younger events) ductile-brittle structures. D1, D2 and D3 deformation phases affect both the Jaibaras Graben as well as the paleozoic sequences of the northeastern edge of Parna?ba Basin, generating structures developed at lower temperatures, basically brittle/cataclastic. The SRTM image analysis allowed mapping different NE, NW and E-W trending lineaments in Parna?ba Basin, whose correlation with mesoscopic structures is discussed in terms of the reactivation of Transbrasiliano Lineament in association with the stages of general Atlantic opening and separation between South America and Africa, or even the distal orogenic events in Paleozoic.

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