Evolução tectônica da Bacia de Santos com ênfase na geometria crustal: Interpretação integrada de dados de sísmica de reflexão e refração, gravimetria e magnetometria

• Autor(a) principal: Rigoti, Caesar Augusto
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/7131
• topic: Tectonic Evolution; Crustal geometry; Santos Basin; Deep seismic refraction; Rotated continental block; Core-Complex; Continental margin; Evolução tectônica; Geometria crustal; Bacia de Santos; Sísmica de refração profunda; Bloco continental rotacionados; Core-Complex; Margem continental; CNPQ::CIENCIAS EXATAS E DA TERRA::GEOCIENCIAS::GEOFISICA

Due to the recent acquisition of seismic refraction data, the Santos Basin presently has a geophysical database that allows the study of the lithosphere and the processes involved in the formation of marginal basins. Integrating the interpretation of various geophysical methods (seismic reflection, seismic refraction, gravimetric and magnetometric data) we built a tectonic model aiming to advance into the understanding of the crustal geometry and tectonic evolution of the Santos Basin. In our model the continental margin is divided into five tectonic domains: Proximal Domain, Distal Domain (subdivided into Internal Rift, External Rift and Resistant Block), Allochthonous Domain and Oceanic Domain. The tectonic domains were formed along three different tectonic phases: stretching phase, thinning phase and exhumation phase. The structure of the basin is given by a set of rotated blocks bounded by high angle faults and two Core-Complex type detachment systems. The rifting process involved focusing and lateral migration of younger structures towards the oceanic crust or future continental breakup site. The base of the salt layer evidences diachronism between tectonic phases, in the Internal Rift domain it is flat with sag type filling geometry, whereas in the External Rift domain it occurs faulted and with rift type filling geometry. During the exhumation phase a clockwise rotation of a Resistant Block creates a late V shape geometry rift over hiperextended continental crust and serpentinized upper mantle. This rotation caused the installation of a transcurrent N-S system, in relation to Africa, resulting in a breakup with sinistral strike slip component. The breakup process of the Santos Basin is classified as magma poor and of Albian age