Pre-Cruise and Site Surveys: A Synthesis of Marine Geological and Geophysical Data on the Cote D'ivoire-Ghana Transform Margin

Phanerozoic geological evolution of the Equatorial Atlantic domain

“…During the seventies, the scientific exploration was focused on the survey of fracture zones in the deep basins and dedicated to a first investigation of continental margins (Fail et al, 1970;Arens et al, 1971;Delteil et al, 1974;Emery et al, 1975). From the eighties, investigations were focused on the Cô te dÕIvoire-Ghana margin, in the central part of the African equatorial margin, and along the intersection of the Romanche fracture zone with the deep Ivorian divergent basin (review in Basile et al, 1996). These investigations culminated with four scientific drill-holes performed during Ocean Drilling Program Leg 159 along this margin .…”

Geodynamic evolution of the Côte d'Ivoire-Ghana transform margin: an overview of Leg 159 results

“…The Côte d'Ivoire-Ghana margin is probably the best known transform margin, mainly from marine geophysical cruises and scientific dives conducted prior to drilling (see review and references of previous studies in Basile et al, 1996), and from data collected during Ocean Drilling Program (ODP) Leg 159, which increased considerably our knowledge of the tectonic and sedimentary evolution of this transform margin.…”

Crustal structure and ocean–continent transition at marginal ridge: the Côte d’Ivoire–Ghana marginal ridge

“…2B). These tilted blocks are similar in trend and in size to rift-generated features detected within the adjacent deep extensional Ivorian basin (Basile et al 1996).…”

“…In the study area, north of the Coˆte d'Ivoire-Ghana marginal ridge (CIGMR), the deep Ivorian extensional basin continental basement shows a progressive westward thinning from 16 to 6 km (Pontoise et al 1994), whereas south of the CIGMR, the oceanic crust is rather thin (3-4 km) and heterogeneous (Sage 1994;Sage et al this issue). Numerous surveys have been carried out on this transform margin segment, including single-channel and multichannel seismic (MCS) reflection profiling (Mascle and Blarez 1987;Basile et al 1992;Lamarche et al this issue) and swath mapping (Mascle et al 1989;Basile et al 1996). All data support a sedimentary origin for the CIGMR, which has been shown by direct sampling and observations and recent ODP 159 drilling Bouillin et al 1994;Guiraud et al this issue;Mascle et al this issue) to consist of a thick, Early Cretaceous, siliclastic wedge deformed by extensional and wrench tectonics during rifting (Benkhelil et al this issue).…”