Deep seismic reflection study of a passive margin, southeastern Gulf of Guinea

Crustal structure of the deepwater west Niger Delta passive margin from the interpretation of seismic reflection data

“…The seismic character of the Moho seen here in the study compares closely with that of Rosendahl et al (1991Rosendahl et al ( , 1992, Meyers et al (1996a, b) and Rosendahl and Groschel-Becker (1999), based on their studies of crustal structure in adjacent sectors of the West African continental margin.…”

Tectonic history along the South Gabon Basin: Anomalous early post-rift subsidence

“…Such a thermal anomaly would have restricted the syn-rift subsidence and, therefore, prevented the development of thick syn-rift basins. Re-interpretation of deep multi-channel seismic reflection data (Rosendahl and Groschel, 2000;Rosendahl et al, 1991) integrated with gravity modelling analysis in the South Gabon Basin support such margin geometry with shallow depth syn-rift basins associated with a relatively thin crust (Dupre´, 2003;Dupre´et al, 2001a). Further south, along the Angola Margin, the distribution together with the infill of the synrift depocentres are rather limited as inferred from the analysis of recently acquired deep reflection and refraction seismic lines (Contrucci et al, 2004;Moulin et al, 2005).…”

Neocomian to early Aptian syn-rift evolution of the normal to oblique-rifted North Gabon Margin (Interior and N'Komi Basins)

“…Both the Rio MuniSouth Cameroon Margin and the North Gabon Margin exhibit transverse-to-the-margin faults zones that continue westwards and join oceanic fracture zones (Burke, 1969;Wannesson et al, 1991;Benkhelil et al, 2002). The analysis of deep-penetrating multichannel seismic data shows the Ascension transverse fault zone forming a 200 km long transform-faulted NE-SW boundary between rifted continental crust and proto-oceanic crust (Rosendahl et al, 1991;Meyers et al, 1996;Rosendahl and GroschelBecker, 1999;Wilson et al, 2003). Comparisons of cross-sections through the normal-rifted South Gabon Margin with cross-sections from Rio Muni contrast the wider (200-300 km), gentler South Gabon topography and the steep and narrow (50-70 km) Rio Muni topography that is typical of transform margins.…”