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The Araçuaí–West Congo orogen encompasses orogenic domains located to the SE of the São Francisco Craton in Brazil, and to the SW of the Congo Craton in Africa. From the opening of the precursor basin to the last orogenic processes, the evolution of the orogen lasted from the very beginning of the Neoproterozoic up to the Cambrian–Ordovician boundary. After the spreading of the South Atlantic Ocean in Cretaceous time, the Araçuaí–West Congo orogen was split into two quite different but complementary counterparts. The Brazilian side (Araçuaí orogen) inherited two thirds of the whole orogenic edifice, including all the Neoproterozoic ophiolite slivers, the entire magmatic arc and syn-collisional to post-collisional magmatism, and the suture zone. The African counterpart (West Congo Belt), a fold–thrust belt free of Neoproterozoic ophiolite and Pan-African orogenic magmatism, inherited the thick pile of bimodal volcanic rocks of the Early Tonian rift stage, implying that the precursor basin was an asymmetrical rift with the thermal–magmatic axis located in the West Congo Belt. Both counterparts of the Araçuaí–West Congo orogen include Neoproterozoic glaciogenic deposits, allowing tentative lithostratigraphic correlations, but identification of the ice ages remains uncertain because the lack of sufficient well-constrained geochronological data.

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The stratigraphic, paleogeographic and tectonic evolution of the intracratonic Congo Basin in Central Africa has been revised on the basis of an integrated interpretation of gravity, magnetic and re£ection seismic data, together with a literature review of papers sometimes old and di⁄cult to access, map compilation and partial reexamination of outcrop and core samples stored in the Royal Museum for Central Africa (RMCA).The Congo Basin has a long and complex evolution starting in the Neoproterozoic and governed by the interplay of tectonic and climatic factors, in a variety of depositional environments.This multidisciplinary study involving 2D gravity and magnetic modeling as additional constraints for the interpretation of seismic pro¢les appears to be a powerful tool to investigate sedimentary basins where seismic data alone may be di⁄cult to interpret.The tectonic deformations detected in the Congo Basin after the 1970^1984 hydrocarbon exploration campaign in the Democratic Republic of Congo (DRC) have been attributed to crustal contraction and basement uplift at the center of the basin, following a transpressional inversion of earlier graben structures. Two -dimensional gravity and magnetic models run along key seismic lines suggest the presence of evaporite sequences in some of the deeper units of the stratigraphic succession, in the lateral continuity with those observed in the Mbandaka and Gilson exploration wells.The poorly de¢ned seismic facies that led to the previous basement uplift interpretation of the crystalline basement is shown to correspond to salt-rich formations that have been tectonically de-stabilized.These features may be related to vertical salt-tectonics connected to the near/far-¢eld e¡ects of the late Pan-African and the Permo -Triassic compressive tectonic events that a¡ected this African part of Gondwana.

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