f 100.000 km² Aerogravity survey of the Congo shows 6 basins and new structural elements

The Cuvette Basis of the Congo, Zaire, and Angola is the largest sedimentary basis in Africa. Only 4 exploration wells have been drilled into this intracratonic basis which is larger than the state of Texas. 130,000 KM² of the Congolese portion of the Cuvette Basis has been covered by a gravity survey consisting of more than 320,000 discrete gravity measurements. The aerogravity/aeromagnetic survey was flown at 2388 meters atlitude with 1 sec. sampling resulting in an average station spacing of 58 meters. Acquisition was with the patented Carson GFM System; 4-8 channel differential, phase-mode GPS positioning, and Carson modified LaCoste- Romberg Gravimeter. The data were acquired with a specially modified DeHaviland Twin-Otter Aircraft. More than 19,000 line KM of gravity and 23,000 live KM of magnetics were acquired along a 12 KM grid with some infilling. Final free air and Bouguer maps were produced with a 1 mgal contour interval. Interpretation of the magnetic data and a 3-D inversion of the aerogravity were combined with a limited amount of published seismic data to create an integrated interpretation of the Congolese Cuvette. The data provided definite identification of 6 sub-basins and key structural elements in the Cuvette, some of which have never been described previously . The 6 sub-basins or depocenters within the Congolese Cuvette are the M'Bye, Gamboma, Likouala, Impfondo, North Impfondo, and Carnot (Figure 1).