Tectono-stratigraphic evolution of the Mesozoic continental margins of the Central Atlantic
The geology of the continental margins of northwest Africa and northeast South America, surrounding the southern Central Atlantic have been investigated through a fully integrated, multi-disciplinary study to document the tectono-stratigraphic evolution of the Mesozoic post-rift sequence. These sedi...
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| Format: | Doctoral or Postdoctoral Thesis |
| Language: | English |
| Published: |
2020
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| Online Access: | https://research.manchester.ac.uk/en/studentTheses/8dfb2ba5-45e2-42bb-b4c9-56a7c82657aa https://pure.manchester.ac.uk/ws/files/205626747/FULL_TEXT.PDF |
| Summary: | The geology of the continental margins of northwest Africa and northeast South America, surrounding the southern Central Atlantic have been investigated through a fully integrated, multi-disciplinary study to document the tectono-stratigraphic evolution of the Mesozoic post-rift sequence. These sedimentary basins are some of the most prolific underexplored hydrocarbon provinces worldwide. Rejuvenated tectonism associated with the opening of the Equatorial Atlantic in the Aptian interrupted the relatively ‘passive’ post- rift subsidence and was a significant control on sedimentation. Across the southern Central Atlantic, this impacted the source-to-sink system through hinterland uplift (source), tectonic deformation of the basin (sink), and associated effects on sedimentary systems, routing and depositional style. A high-resolution stratigraphic framework has been constructed integrating existing data with new results from biostratigraphic and sedimentological analyses of outcrop localities on the island of Maio, Cape Verde and the re-sampling of seven key scientific boreholes and three exploration wells. Margin-scale chronostratigraphic charts have been constructed to investigate facies distribution and highlight significant regional hiati to enhance understanding of temporal stratigraphic evolution. Major unconformities are recognised extending thousands of kilometres across the Central Atlantic such as the base Albian unconformity (BAU). Local stratigraphic breaks are also identified, typically restricted to one structural domain, i.e. the Late Cretaceous regional composite unconformity (RCU) located on the distal escarpment margin offshore Senegal and The Gambia. The mechanisms generating these regional unconformities have been considered and data suggest plate- scale tectonic events are the major drivers. The middle Berriasian unconformity (MBU) recognised for the first time at DSDP Site 367 has an associated time gap of ca. 5 Myr, linked to far-field effects of North Atlantic breakup within the ... |
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