Publicação
The seismic structure of the NW Moroccan margin, Gulf of Cadiz, from new high-quality multichannel seismic reflection data
| Resumo: | The FRAME geophysical cruise, conducted in 2018 aboard the R/V Sarmiento de Gamboa, acquired new high-quality multichannel seismic reflection data along the NW Moroccan margin. MCS data were acquired with a 6 km-long streamer towed at 19 meters water depth and a source array of 20 air guns towed at 10 meters depth. The survey was designed to provide high-quality signal and high-penetration, enabling the mapping of deep crustal structures, and achieve detailed imaging of the stratigraphy and crust structure. The NW Africa margin was selected due to the limited availability of modern data, which does not allow for detailed imaging of crustal-scale structures and contributes to the understanding of the rifting history from the Late Triassic to the Early Jurassic in the region. This work presents a seismic processing workflow applied to a 220 km-long seismic line, extending from the shallow continental shelf to the deep abyssal plain. The focus is on processing raw MCS data to generate a high-resolution seismic image, followed by an interpretation contextualized within the geographical and tectonic framework of the area. A chapter on gravity modelling is included to explain the presence of a significant negative gravity anomaly. The high-quality seismic image reveals a complex tectonic architecture from the continental shelf to the deep-water basin, where the basement is quite deep, containing salt bodies and distinct syn-rift and postrift structures. The crustal model derived from seismic and gravity data does not rule out mantle serpentinization, providing a robust framework for understanding lithospheric deformation and tectonic evolution of the passive margin. The findings demonstrate successful seismic data processing, highlighting magma-poor rifting processes and making it a valuable tool for contributing to the understanding of lithospheric dynamics. |
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| Autores principais: | Foiada, Silvia Duarte |
| Assunto: | Processamento sísmico margem noroeste de Marrocos transição continental rifting Teses de mestrado - 2025 |
| Ano: | 2025 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | The FRAME geophysical cruise, conducted in 2018 aboard the R/V Sarmiento de Gamboa, acquired new high-quality multichannel seismic reflection data along the NW Moroccan margin. MCS data were acquired with a 6 km-long streamer towed at 19 meters water depth and a source array of 20 air guns towed at 10 meters depth. The survey was designed to provide high-quality signal and high-penetration, enabling the mapping of deep crustal structures, and achieve detailed imaging of the stratigraphy and crust structure. The NW Africa margin was selected due to the limited availability of modern data, which does not allow for detailed imaging of crustal-scale structures and contributes to the understanding of the rifting history from the Late Triassic to the Early Jurassic in the region. This work presents a seismic processing workflow applied to a 220 km-long seismic line, extending from the shallow continental shelf to the deep abyssal plain. The focus is on processing raw MCS data to generate a high-resolution seismic image, followed by an interpretation contextualized within the geographical and tectonic framework of the area. A chapter on gravity modelling is included to explain the presence of a significant negative gravity anomaly. The high-quality seismic image reveals a complex tectonic architecture from the continental shelf to the deep-water basin, where the basement is quite deep, containing salt bodies and distinct syn-rift and postrift structures. The crustal model derived from seismic and gravity data does not rule out mantle serpentinization, providing a robust framework for understanding lithospheric deformation and tectonic evolution of the passive margin. The findings demonstrate successful seismic data processing, highlighting magma-poor rifting processes and making it a valuable tool for contributing to the understanding of lithospheric dynamics. |
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