The animation shows the results of fitting different continental outlines with the current plate model, CR25AAKB (Africa fixed). First the coastlines (black) of central Gondwana are matched and dispersed. Coastlines are ephemeral as sea levels rise and fall by several hundred metres over geological time, so they may not be the best guide to the location of the margin of continental crust. The 2000 m isobath, added in grey, repeats the matching for an alternative indicator of the margins.

Images from satellite altimetry show clear curvilinear anomalies (purple) around large parts of the continental outlines. Generally they are offshore, but not always. The cause is probably a result of the transition in isostatic balance between thick, light continental crust onshore and thin, dense oceanic crust in the ocean deep. There may also be an added sediment load as the continental shelf leads into the transition zone. Whatever the cause, the anomalies may be interpreted unequivocally in many places and their conjugates on the re-attached continent usually have a very similar shape. Note how the re-assembled 'gravity margins' look very similar to what is observed over active rift valleys in east Africa and, for example, how the failed rift in NE Brazil may be extended SE into the successful rift between Brazil and Gabon in the reassembly.

In the third run of the animation we have added the outlines of Precambrian crust (pale pink) to the picture. These are the large areas of Gondwana where Precambrian rocks either outcrop or are thinly covered by younger rocks laid down during the Phanerozoic. Regional aeromagnetic surveys have been used widely to determine the presence or absence of Precambrian 'basement' where surface observation is uninformative. It is seen that shallow Precambrian rocks extend offshore in some areas (such as off southern Madagascar and off parts of Namibia) while in other places the tell-tale gravity margins lie well inboard of the shoreline. The plains of southern Mozambique, for example, were long argued to be continental in nature and, therefore, an obstacle to the reassembly of Gondwana that elsewhere offered a persuasive geometry. Now it is thought that the Mozambique plains are founded on magmatic material that post-dates Gondwana disruption.

Note the mosaic of reassembled Precambrian Gondwana and spaces between 'platelets' within Africa itself, some of which have undergone rifting (but not ocean growth) before, during and after Gondwana disruption. Many intra-plate rifts have been re-activated more than once and some are of immense economic importance (Macgregor and Reeves, 2025).