Plate-splitting impact in the Congo Basin;
bedrock geology, plate motions and diamonds. Rev. 11/2007  

As noted by Wegener  in 1912, African and South American geological provinces and mineral belts reconstruct into systematic alignment (below). The  geologic strata are disposed and fractured about a suspected impact structure forming the Congo basin (Cuvette Centrale). Outboard rings of uplift and subsidence have the same dimensions as for the Chicxulub impact on the North American Plate. Kimberlite pipes and lamprohyre dikes with associated diamond occurrences display systematic geometry with respect to a multi-ringed impact structure, suggesting impact-fracturing to mantle depths, and perhaps the cause of kimberlite igneous activity. The crustal fracture pattern through the basin region radiates outward toward the NNW, indicating the path of crustal compression from an oblique impact. The stratigraphic relationships are compatible with a Changhsingian impact at the end of the Paleozoic. The realigned position of South America is ghost-image with the Somali Plate. The impact may haven spurred continental breakup and spreading and eventual formation of the Atlantic Ocean.

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Geographic Gondwana

Current plate motions are shown below. Red vectors are proportionately scaled to emphasize relative horizontal velocity. Overall plate motions of the African and other plates to the East move away from the South Atlantic region.

Current plate motions

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